US3905665A

US3905665A - Electrical contact structure and assembly method

Info

Publication number: US3905665A
Application number: US340797A
Authority: US
Inventors: James Edward Lynch; Kenneth Ronald Parmer; Robert Franklin Cobaugh
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1971-07-27
Filing date: 1973-03-13
Publication date: 1975-09-16
Anticipated expiration: 1992-09-16

Abstract

According to one aspect of the disclosure, a planar substrate receives a plurality of conductive posts therein, which posts include an offset medial portion having a laterally projecting notch portion. Certain posts are arranged with their notch portions in coplanar relationship and in latching registration with an interior sidewall portion of a housing received over the posts. Accordingly, the housing provides an insulating receptacle shroud for the posts and is latchingly retained in place without a need for attachment to the substrate. The shroud is also provided with card guides connected thereto by integral hinge portions enabling alignment of, and reducing twisting and warping of, the card guides. The card guides are additionally coupled together with rails further reducing twisting and warping of the guides. The terminals are advantageously mounted in strip form for ease in manufacture and assembly to the substrate.

Description

" United States Patent [1 1 Lynch et al.

[451 Sept. 16, 1975 ELECTRICAL CONTACT STRUCTURE AND ASSEMBLY METHOD [73] Assignee: AMP Incorporated, Harrisburg, Pa.

[22] Filed: Mar. 13, 1973 [21] Appl. No.: 340,797

Related US. Application Data [63] Continuation-impart of Ser. No. 321,076, Jan. 4, 1973, abandoned, and a continuation-in-part of Ser. No. 193,366, Oct. 28, 1971, abandoned, and a continuation of Ser. No. 224,524, Feb. 8, 1972, abandoned, said Ser. No. 321,076, is a continuation of Ser. No. 166,540, July 27, 1971, abandoned, said Ser. No. 224,504, is a continuation-in-part of Ser. No. 166,540, and Ser. No. 193,366.

[56] References Cited UNITED STATES PATENTS 3,020,510 2/1962 Kuch 339/17 L 3,365,539 1/1968 Bratschm, 339/17 R X 3,614,706 10/1971 Kukla 339/176 MP X 3,660,726 5/1972 Ammon et al. 339/17 C X 3,671,917 6/1972 Ammon et al. 339/17 L 3,685,001 8/1972 Krafthefer 339/17 L 3,693,135 9/1972 Vavrick et a1. 339/176 MP X 3,783,433 l/1974 Kurtz et al. 339/176 MP X 3,808,578 4/1974 Hansen 339/176 MP X FOREIGN PATENTS OR APPLICATIONS 1,082,958 6/1960 Germany 339/17 LM 1,079,829 8/1967 United Kingdom.. 339/176 MP 1,815,041 6/1970 Germany 317/101 Dl-I 2,030,906 12/1970 Germany 317/101 DH OTHER PUBLICATIONS Byrnes, Injectable Solderable Terminal Pins, IBM Technical Disc. Bulletin, Vol. 9, No. 4, p. 366, September 1966.

Primary ExaminerRoy D. Frazier Assistant ExaminerLawrence J. Staab Attorney, Agent, or Firm-Gerald K. Kita [57 ABSTRACT According to one aspect of the disclosure, a planar substrate receives a plurality of conductive posts therein, which posts include an offset medial portion having a laterally projecting notch portion. Certain posts are arranged with their notch portions in copla nar relationship and in latching registration with an interior sidewall portion of a housing received over the posts. Accordingly, the housing provides an insulating receptacle shroud for the posts and is latchingly retained in place without a need for attachment to the substrate. The shroud is also provided with card guides connected thereto by integral hinge portions enabling alignment of, and reducing twisting and warping of, the card guides. The card guides are additionally coupled together with rails further reducing twisting and warping of the guides. The terminals are advantageously mounted in strip form for ease in manufacture and assembly to the substrate.

7 Claims, 24 Drawing Figures Pmmwsmsm 3,905,665

SHEET I 1 INVENTOR JAMES EDwAiwYNCH Y PATENTED sEP 6 ms SHEET PATENTEB SEP 165175 SHE-U PATENTEBSEPIBEB'IS 3,905,665

INVENTOR JAMES EDWARD LYNCH BY fin SHEET PATENTEI] SEP I BIBYS 3,905,665

SHEU 1 O PATENIEBSEP 16 ms SHEET 1 1 ELECTRICAL CONTACT STRUCTURE AND ASSEMBLY METHOD CROSS REFERENCES TO RELATED APPLICATIONS This application is a continuation-in-part of application Ser. No. 321,076, filed Jan. 4, 1973 and now abandoned, which is a continuation of application Ser. No. 166,540, filed July 27, 1971 and now abandoned. This application is also a continuation-in-part of application Ser. No. 193,366, filed Oct. 28, 1971 and now abandoned. This application is also a continuation of application Ser. No. 224,504, filed Feb. 8, 1972 and now abandoned which is a continuation-in-part of application Ser. No. 166,540 and of application Ser. No. 193,366.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulation housing and card guide, and more particularly to an insulation housing and card guide for mounting on a substrate. The present invention also relates generally to the combination of a printed circuit board having mounted thereon a plurality of electrically conducting post-type contacts, enclosed by a removable electrically insulating housing latchably secured to a selected contact, and also to a multi-layer printed circuit board and a method of fabrication thereof. The present invention further relates to a method and apparatus for assembling electrically conductive posts to a substrate, and more particularly to method and apparatus for assembling conductive post-type contacts to a substrate which advantageously permits positive location and anchoring of a connector housing to the substrate and in enclosing relationship over the assembled contacts.

2. Description of the Prior Art The present invention satisfies the need for a low cost electrical insulation housing for containing a plurality of electrical terminals mounted to a substrate such as a printed circuit board. The invention further satisfies the need for inexpensive guides for a card which is to be electrically connected to and disconnected from the plurality of electrical terminals contained within the insulation housing. In addition to the objective of low cost, the card guides associated with the housing should be free of warpage and misalignment in order to receive and permit removal of a card without binding. In meeting these objectives, the insulation housing according to the present invention is not directly connected to the printed circuit board or substrate. Instead, the housing is advantageously detachably latched to the electrical terminals mounted on the substrate. The housing thereby serves as a shroud for protecting the electrical terminals and may be readily removed when desired. Each housing includes a pair of channel guides for receiving therebetween opposed margins of a card. Each channel is connected to the housing by an integral hinge or neck portion.This feature permits the rails of flex resiliently in cantilever fashion to enhance alignment thereof so that a card may be received between the channels without binding.

The card guide channels of a plurality of housings are connected to a common stiffener rail to prevent warpage and twisting of the channels.

The electrical terminals to which the insulation housing is detachably latched comprises a first conductive post portion offset from a second conductive post portion, with a shelf portion for receiving the edge of the card in registration thereagainst. Adjacent to the shelf portion, each terminal is provided with a lateral notch portion. When a plurality of the posts are mounted to the substrate, the notch portions of selected ones of the terminals are arranged in aligned generally coplanar relationship. The insulation housing is received over a plurality of the terminals and includes an inner linear projection or flange portion which latchingly registers within the aligned notch portions of the terminals. Accordingly, the housing is fixedly mounted to the substrate without a need for a direct mechanical connection therebetween. The housing is advantageously detachable from the substrate by resiliently flexing the sidewalls and disengaging the flange portion thereof from the notch portions of the terminals.

As a further feature, the shelf portion of each terminals to be advantageously supplied and handled. The a carrier strip. Thus the carriagestrip allows the terminals to bee advantageously supplied and handled. The terminals are readily connected to the substrate by individually detaching each terminal from its frangible stem.

The present invention is also directed to fabrication of an electrical panel including aboard substrate into which a plurality of electricallyconducting post-type contacts are inserted. Post portions of the contacts protrude from one side of the substrate and advantageously receive point-to-point electrical wiring. Other portions of the posts protrude from the opposite side of the substrate to form electrical contacts suitable for,

electrical registration with electrical paths of a printed circuit board or card. In most applications, an electrically insulating connector housing insulates and protects the contact portions of the posts. The housing also must be secured on the surface of the substrate. In many cases the substrate is provided with plated circuit paths in addition to the point-to-point wiring provided by the conducting posts.

Heretofore time consuming successive steps were required to fabricate such a panel. Initially the contacts were inserted individually within the connector housing. The contacts had to be individually latched in the housing to prevent removal therefrom. As a practical matter, the housing provided a plurality of individual sockets having internal latching structure for receiving and latching onto an individual-contact. The internal structure of such a connector housing was necessarily complex and was costly to design and fabricate. A great deal of time was expended to insure insertion and latching of each individual contact within a socket of the connector housing. Additional time was expended to assemble the connector housing and the retained posts to the substrate. Fasteners such as screws and the like were required to attach the connector housing to the substrate surface The posts then protrude through the apertures in the substrate to receive the point-to-point wiring.

If it was desired to electrically connect the post-type contact to plated electrical paths of the substrate. each post portion was separately hand soldered to a plated path. This procedure resulted in satisfactory electrical joining, but was time consuming.

Some attempt was made to reduce the assembly time by sliding solder rings over the posts to be soldered, and simultaneously reflowing the solder by the application of heat, inan attempt to simultaneously solder all the posts to the plated paths. Often times the reflowed solder was of insufficient mass, or did not sufficiently wick into the substrate apertures to create a strong solder joint. This required inspection and testing after soldering to insure electrical continuity of the solder joints. Those joints which did not produce electrical continuity had to be repaired by hand soldering. Also those joints which produced electrical continuity but were structurally weak and subject to breakage at a later time also had to be replaced by hand soldering. It is not uncommon in apanel as above described to have a thousand soldered posts. If only one post in a thousand has an insufficient solder joint, representing a failure rate of 0.1%, then statistically every single panel would be inoperative if fabricated according to the above described assembly procedures. Thus there has been a long existing need in the prior art for a method of reliably assembling a plurality of electrical contacts mechanically andelectrically to a substrate and suitable for use with a connector housing enclosing the contacts.

In the present invention, a plurality of electrically conducting posts individually depend from a carriage strip on precise center spacings. The posts can be si multaneously assembled into apertures of a substrate having corresponding center spacings. Each post is provided with an encircling band of solder which registers internally of a corresponding substrate aperture. Advantageously upon reflow of the solder bands, each post is reliably mechanically and electrically joined to the substrate. This assembly procedure reduces the assembly time required for insertion of individual contacts. Assembly time is further reduced by simultaneously reflowing the solder bands of all the conduct ing contacts desirably inserted into the substrate. This eliminates the need for individually treating each post, either by hand soldering, or by applying solder rings in dividually over each contact subsequent to assembly of the posts in the substrate.

Each of the contacts is attached at its terminal end to the carrier strip with no interconnection between adjacent posts. This permits individual guiding of the posts into respective substrate apertures without undue bending or deflection of the carrier strip or the individual posts. The carrier strip supports the contacts in mutual alignment and on desired center spacings in the board.

By providing the solder bands on the posts prior to insertion in the substrate, the solder bands will be located radially internally of the apertures. Each solder band is of a selected band width to provide sufficient solder mass for filling the space between the lined aperture and the post inserted therein, and for the formation of fillets encircling and adhered to a conducting post at each end of a lined aperture. In addition, the solder band is precisely located internally of the lined aperture, such that upon reflow solder will ahere along the entire length of the aperture lining. Such a joint is more reliable than a hand soldered joint or the application of solder rings to the posts after insertion.

Soldering to the posts after insertion requires wicking of molten solder into the lined substrate apertures. A joint produced by this wicking action has a relatively high probability of failure. One cause of failure results from insufficient solder mass to completely fill the space between the lined aperture and a post inserted therein, even though solder fillets are formed at each end of the aperture. The presence of the solder fillets prevents inspection for solder voids internally of each aperture. Another cause of failure results from insufficient wicking action of solder internally of an aperture. Either of these results can produce failure, which is immediately detected by testing for electrical continuity. Even if electrical continuity is initially established the joint itself is structurally weak and will later fail upon breaking of the joint when subjected to normal handling and use.

The present invention is well suited for reducing panel assembly time, since the conducting posts are uti lized to locate and anchor and enclosing connector housing to a substrate without the need for additional fasteners. According to one preferred embodiment, a connector housing is provided over the inserted contacts and is latchably joined thereto. As an alternative, the contacts may be inserted into the substrate and the connector housing simultaneously. In this embodiment, reflowing of the solder bands provided on the posts is accomplished with the connector housingin place on the substrate.

As a further feature of the invention, since the posts remain attached to their carrier strip until positively joined to the substrate by reflowing of their solder bands, they remain in desired alignment without the need for individual aligning slots in the connector housing. Accordingly, the present invention allows for the use of a connector housing with relatively simple interior structure. This further reduces panel assembly time since the posts need not be interfitted within individual slots during assembly. In addition, the costs of material and fabrication in the connector housing itself are substantially reduced due to its relatively simple interior structure.

In addition, each of the contacts according to the present invention is provided with a selected mass of solder adhered thereto in a selected band width and positively located on a selected medial portion of the contact. Each contact is further provided with structure for locating it in position on a printed circuit board, for limiting insertion thereof in a printed circuit board, as well as for positively positioning the solder band interiorly of a plating lined hole of the board into which the contact is inserted.

Each contact is additionally provided with structure to which a portion of the encircling insulation housing is removably latched.

The insulation housing includes an integral latch portion. When the housing is received over a plurality of contacts according to the present invention, the latch portion will resiliently register in latching relationship on a selected one of the contacts, advantageously securing the housing to the selected contact and thereby in fixed mounted position on the printed circuit board. To remove the housing, a tool may be used to manually pry the resilient latch portion to disengage it from the selected contact and allow removal of the housing from the enclosed plurality of contacts. I

According to a feature of the present invention, when all the desired number of contacts are mounted in corresponding plating lined apertures of the printed circuit board, all the solder bands of the posts are simultaneously heated to reduce the solder bands to a molten state and reflowed by wicking action into the clearances defined between the contacts and the apertures receiving the contacts to make positive electrical and mechanical connections of the contacts to the plating lined apertures. Such connection technique is disclosed in copending application Ser. No. 193,366, filed Oct. 28, 1971.

Another salient feature of the present invention is practiced during connection of the contacts to the printed circuit board. More specifically, the plating lined apertures of the boards are arranged in rows, each row receiving a corresponding row of contacts inserted therein. A common carrier strip remains attached to the individual ends of corresponding contacts in each row. The carrier strip retains the contact ends in desired alignment during reflow of the solder, in accordance with the disclosure of copending application Ser. No. 193,366, filed Oct. 28, 1971. The medial portions of the posts in each row are maintained in desired alignment since they are received in the corresponding plating lined apertures of the board. The free ends of the contacts of each row, namely the ends which are not connected to the carrier strip, are received in apertures of an auxiliary board or substrate. The apertures of the auxiliary board are on the same center spacings as are the plating lined apertures of the printed circuit board. Thus such free ends of the contacts of each row are maintained in desired alignment by the auxiliary board. The contacts are maintained in desired alignment by the carrier strip, the printed circuit board and the auxiliary board while the solder bands are heated are reflowed, then subsequently allowed to cool in order to form rigid solder joints positively connecting individual contacts mechanically and electrically to the plating lined holes of the printed circuit board. Upon cooling of the reflowed solder, rigid joints are obtained, allowing removal of the auxiliary boards and the common carrier strip portion from each row of posts without disturbing the desired alignment of the contacts in the printed circuit board.

According to a further feature of the present invention, the contacts provided with solder bands may be utilized to connect together a plurality of printed circuit boards in stacked relationship. Generally, a single printed circuit board has a limited surface area which accordingly limits the number of plated circuit paths which can be adhered to the surface. It is common to use both a top surface and a bottom surface of a printed circuit board for carrying printed circuit paths. It is often desirable to use a second printed circuit board additional circuit paths which would not otherwise fit on a single printed circuit board already crowded with circuit paths. It is also often desirable to provide design changes on a second printed circuit board.- Use of a second board obviates the need to discard the original printed circuit board in favor of a redesigned board. Thus, there are many instances where two printed circuit boards are favored over the use of a single board. Where two boards are desirable, it is necessary to electrically interconnect the circuit paths of the two boards. According to the present invention, a plurality of boards may be utilized in stacked relationship, with the required electrical interconnections between such boards being accomplished by a plurality of contacts according to the present invention received in plating lined apertures of the boards. To provide a positive electrical interconnection between the boards, the solder bands of the interconnecting contacts are reflowed and then cooled to form solder joints, thereby electrically and mechanically connecting the contacts to plating lines apertures of the stacked boards. To substantially reduce assembly time, it is advantageous that all the contacts be inserted in the plating lined apertures of the stacked boards, and all the solder bands of the inserted contacts be simultaneously reflowed and then cooled to form the individual solder joints. During solder reflow and cooling to form the joints, alignment of the contacts is assured by utilizing the attached carrier strip and auxiliary board alignment technique as above described.

The present invention is particularly useful for fabrieating a multi-layer printed circuit board. Generally, a multi-layer board includes a plurality of stacked planes with circuit paths being carried'in a plurality of such planes. interconnections are required between circuit paths of different planes. The location of such interconnections between planes as wellas routing of the plated paths themselves are of such design complexity that automated computer design is required. In addition, fabrication of the multi-layer board must also be accomplished by automated techniques. The present invention permits design and fabrication of a multi-layer board without the need for expensive automated computer equipment. It therefore providesa technology enabling the design and fabrication of complex electronic circuit boards without a need for investing in expensive automated equipment. The present invention accordingly enhances entry of small companies into the industry of complex electronic circuitry dominated by a relatively few large companies.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an insulating housing for a plurality of electrical terminals mounted in a substrate.

Another object of the present invention is to provide a plurality of electrical terminals in a substrate with an encircling insulation housing which is not directly connected to the substrate.

Another object of the present invention is to provide a plurality of electrical terminals mounted in a substrate with an insulation housing encircling the termi' nals and including inner projecting portions detachably latched to notch portions in selected ones of the terminals.

Another object of the present invention is to provide a plurality of electrical terminals mounted in a substrate with an insulation housing serving as a shroud for the electrical terminals.

Another object of the present invention is to provide a plurality of electrical terminals mounted in a substrate and provided thereover with an insulation housing detachably latched to the terminals, which housing is provided with a pair of card guides mounted thereto for resilient cantilever action.

Another object of the present invention is to provide a housing for a plurality of electrical terminals having a pair of aligned card guide channels connected to the housing by integral reduced neck portions allowing resilient cantilever action of the card guide channels.

Another object of the present invention is to provide a plurality of card guide channels mounted for resilient cantilever action on respective insulation housings for electrical terminals, each of which channels is detachably connected by a two-point support to a stiffening rail.

Another object of the present invention is to provide an electrical terminal including a first elongated post portion, a medial portion defining a generally planar shelf projecting laterally of the longitudinal axis of said post, a second elongated portion depending from said shelf and offset longitudinally of said post portion, and a notch portion located between the shelf portion and the second elongated portion.

Yet another object of the present invention is to provide an electrical terminal including a conductive post portion, a medial portion defining a generally planar shelf projecting laterally of the longitudinal axis of said post portion, a second elongated portion depending from said shelf and offset longitudinally of said post portion, a laterally recessed notch portion located between said shelf portion and said elongated portion, and a frangible stem connecting said shelf portion with acarrierstrip to which a plurality of like electrical terminals are connected by respective frangible stems.

.Another object of the present invention is to provide a method of assembling a substrate and a plurality of conducting post-type contacts.

Another object of the present invention is to provide a method for assembling a connector housing and a plurality of conducting post-type contacts to a substrate having electrical paths to which the posts are electrically joined.

Another object of the present invention is to provide apparatus in the form of electrically conducting posts, which are individually joined to a common carrier strip without any interconnection between individual posts,

and which are adapted for mass insertion within correspondingly spaced apertures of substrate.

Another object of the present invention is to provide a plurality of conducting contact posts individually joined to a carrier strip on precise center spacings without interconnection between individual posts, with each post provided with a band of solder mass of selected band-width, wherein each solder band is selectively located along the length of each contact and being reflowable to positively joint the posts to a substrate. plurality Another object of the present invention is to provide a method for assembling a plurality of individual conducting posts simultaneously within selected apertures of a substrate while utilizing a common carrier strip of the posts for maintaining the posts in desired alignment and center spacings until the posts are positively secured to the substrate.

Another object of the present invention is to provide apparatus in the form of an electrically insulating housing enclosing a plurality of electrically conducting posts, with the posts locating and anchoring the housing in position on a substrate, thereby eliminating the need for additional fasteners.

A further object of the present invention is to provide appartus in the form of a combination of electrically insulating housing enclosing a plurality of electrically conducting posts, the posts mechanically connecting and anchoring the housing to a substrate without the need for additional fasteners, and the posts being maintained in desired alignment and precise center spacings, initially by a common carrier strip, and subsequently by being positively secured to the substrate,

with the housing being substantially free of sockets or separating partitions between adjacent enclosed posts.

Another object of the present invention is to provide a method for fabricating a plurality of conducting posts to a common carrier strip and utilizing the carrier strip to allow simultaneous insertion and assembly of the posts in a substrate, with the carrier strip maintaining the posts in alignment and on selected center spacings until the posts are positively secured to the substrate.

Another object of the present invention is to provide a method for fabricating a plurality of conducting posts on a common carrier strip, using the carrier strip to maintain a plurality of posts in desired alignment and center spacings while the posts are inserted and secured in a substrate, and utilizing the posts to mechanically connect a connector housing to the substrate without a need for additional fasteners.

Another object of the present invention is to provide a method and apparatus for fabricating a multi-layer circuit board wherein a plurality of stacked printed circuit boards are interconnected by electrical contacts having solder bands thereon which are reflowed simultaneously to form a plurality of positive solder joints interconnecting the contacts between selected plated paths carried by the plurality of stacked printed circuit boards.

Another object of the present invention is to provide a method for fabricating a multi-layer circuit board wherein a stacked plurality of separate printed circuit boards have their circuit paths thereon selectively interconnected by corresponding electrically conductive contacts provided with solder bands thereon which are simultaneously reflowed by a flowable dielectric at elevated temperature, with both the reflowed solder and the fluid dielectric being subsequently cooled to a solid state, with the solder forming positive joints securing the boards in stacked relationship on the contacts and electrically interconnecting the contacts between circuit paths of different boards, and with the solid dielectric filling a clearance space between adjacent stacked boards to provide electrical insulation between the circuit paths of adjacent boards and to encapsulate the plurality of stacked boards into a single multi-layer board structure.

It is another object of the present invention to provide an electrically conductive post-type contact with an adhered band of solder of selected band width, together with structure for locating the contact in position on a printed circuit board and for locating the solder band in a desired position interiorly of a plating lined aperture of the printed circuit board, the contacting being further provided with structure to which an insulating connector housing may be resiliently latched thereto.

- Another object of the present invention is to provide an electrically insulating connector housing with an integral resilient latch portion for latchably securing the connector housing to at least one of a plurality of electrical contacts, which are mounted on a printed circuit board or substrate and which are enclosed by the housing.

Another object of the present invention is to provide a method of fabricating an assembly of a printed circuit board, a plurality of electrically conducting contacts and a removable electrically insulating housing with a latching portion resiliently latched to at least one of the contacts, thereby retaining the housing in desired fixed position on a printed circuit board.

Another object of the present invention is to provide a method of fabricating an assembly of a printed circuit board and a plurality of electrically conducting posttype contacts, with the contacts being maintained in desired alignment by an auxiliary board or substrate and a carrier strip to which the contacts are attached during the formation. of solder joints securing the contacts mechanically and electrically to the printed circuit board.

It is another object of the present invention to provide an insulating housing with integral latch portions on sidewalls of the housing for resilient latching to selected ones of a plurality of electrical contacts, with said latches being spaced from each other to prevent weakening of the housing.

It is another object of the present invention to pro vide an insulating housing with integral latch portions on sidewalls of the housing for resilient latching of selected ones of a plurality of electrical contacts, with said latches being spaced from each other to prevent weakening of the housing, and with said latches being spaced from the housing ends to permit trimming off an end of the housing or to permit abutting together the ends of an adjacent pair of such housings.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete appreciation of the invention any many of the attendant advantages thereof will be readilyobtained as the same becomes better understood by reference tothe following detailed description when considered inconnection with the accompanying drawings, wherein:

FIG. 1 is a fragmentary perspective of a preferred embodiment according to the present invention illustrating a plurality of electrical housings detachably latched to electrical-terminals according to the present invention, with card guide channels connected to each housing by integral, offset reduced neck portions and with the corresponding channels of the housings being connected to a stiffener rail;

FIG. 2 is a fragmentary perspective, with parts illustrated in exploded configuration, illustrating a plurality of electrical terminals according to the present invention, some of which are mounted to a substrate and additional ones of which are connected by frangible stem portions to a carrier strip;

FIG. 3 is a fragmentary elevation of an insulation housing according to the present invention illustrating a pair of card guide rails connected by integral reduced neck portions;

FIG. 4 is a side elevation of the preferred embodiment shown in FIG. 3;

FIG. 5 is a fragmentary perspective of the preferred embodiment as shown in FIG. 1 with parts broken away and with parts in exploded configuration to further illustrate the details thereof;

FIG. 6 is a fragmentary perspective of first and second rows of conducting posts individually provided with solder bands and provided on respective common carrier strips, with a substrate shown in exploded configuration and having spaced apertures into which corresponding posts are inserted;

FIG. 7 is a fragmentary perspective of the preferred embodiment shown in FIG. 6 with the first and second rows of conducting pins inserted within the correspending apertures of a substrate, and further illustrating, a plurality of jaws for simultaneously gripping and pulling a plurality of posts in order to seat them on the substrate and in corresponding apertures of the substrate;

FIG. 8 is a fragmentary enlarged elevation of the preferred embodiment as shown in FIG. 7 together with an insulating connector housing encircling the rows of conducting posts, and further illustrating, the solder bands on the posts being reflowed to positively join the posts to conducting liners of the substrate apertures and to form solder fillets at each end of the corresponding substrate apertures, with the posts mechanically connecting and anchoring the housing to the substrate without a need for additional fasteners;

FIG. 9 is a fragmentary perspective of the preferred embodiment as shown in FIG. 8 with the connector housing and the carrier strips of the first and second rows of posts in exploded configuration to illustrate that when the posts are positively joined to the substrate by reflowing the solder bands thereof the carrier strips may be removed either prior to or subsequent to the application of the connector housing over the posts;

FIG. 10 is a fragmentary perspective with parts in section and with parts broken away and illustratingan alternative embodiment according to the present invention including first and second rows of electrically conducting post-type contacts each provided with a controlled band width of solder and individually connected at a terminal end to a corresponding carrier strip together with a portion of a substrate as a connector housing initially positioned on the substrate;

FIG. 1 1 is a fragmentary perspective of the preferred embodiment as shown in FIG. 10 with parts assembled and with parts broken away and with parts in section to illustrate the details thereof; I

vFIG. 12 is a fragmentary perspective of the preferred embodiment as shown in FIG. 11 together with an alternative connector housing which is absent interior slots or partitions;

FIG. 13 is an enlarged fragmentary elevation in section of a portion of the preferred embodiment shown in FIG. 12;

FIG. 14 is a fragmentary perspective with parts in exploded configuration and with parts in section illustrating the details of the combination of a printed circuit board, a plurality of contacts mounted thereto and an insulation housing encircling the contacts and latched to at least a selected one of the contacts;

FIG. 15 is an enlarged perspective of one of the contacts of the preferred embodiment as shown in FIG 14;

FIG. 16 is an enlarged elevation with parts in section and with parts in phantom outline of the preferred embodiment as shown in FIG. 14;

FIG. I7 is a fragmentary elevation in section of a view illustrating a drilling operation during fabrication of a pair of printed circuit boards as shown in FIG. 14;

FIG. 18 is a fragmentary enlarged perspective illustrating a pair of printed circuit boards fabricated according to the techniques as shown in FIG. 17 and provided with plated electrical paths and plating lined holes receiving therein electrical contacts according to the preferred embodiments shown in FIGS. 14 and 15, thereby forming an assembly in preparation for a solder reflow operation;

FIG. 19 is a fragmentary elevation in section illustrating the assembly shown in FIG. 18 in a fluid at elevated temperature during a solder reflow operation;

FIG. 20 is an enlarged fragmentary elevation in section illustrating the assembly of FIGS. 18 and 19 subsequent to the reflow operation as shown in FIG. 19;

FIG. 21 is an enlarged elevation in section illustrating the details of the preferred embodiment as shown in FIG. 14, with the insulation housing latchably secured to at least a selected one of the contacts;

FIG. 22 is an enlarged fragmentary elevation with parts broken away and with parts in section illustrating the details of a preferred embodiment of the insulation housing according to the presesnt invention;

FIG. 23 is an enlarged fragmentary elevation with partsbroken away and with parts in section illustrating the details of the preferred embodiment as shown in FIG. 21; and

FIG. 24 is a fragmentary perspective of a preferred embodiment of the connector housing as shown in FIGS. 24 and 23, with parts broken away to illustrate the details thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With more particular reference to FIG. 1 of the drawings, there is generally indicated at l a preferred embodiment of an electrical connector and card guide according to the present invention. As shown with reference to FIGS. 1 and 2, a substrate 2, which may comprise a printed circuit board or other suitable substrate, includes a plurality of apertures 4 therein which apertures may be lined with electrically conductive plating or solder. The apertures 4 receive corresponding electrical terminals generally indicated at 6. Each terminal is fabricated from a conductive metal and is characterized by a first elongated electrically conducting post 8 having a generally tapered tip 10. The post 8 is integral with a medial portion 12 defining a generally planar shelf portion 14 extending and projecting generally laterally of the longitudinal axis of the post portion 8. Each terminal 6 is further characterized by a depending elongated electrically conducting post portion 16 generally of rectangular or square configuration and provided with a tapered tip 18. The post portion 16 is integral with and depends from the medial portion 12. The longitudinal axis of the post portion 16 is offset laterally of the longitudinal axis of the post portion 8 and is located generally perpendicular to and below the shelf portion 14. A medial portion of the post 16 is provided thereover with a band of solder 20 deposited selectively in a controlled band width. In addition, the medial portion 12 of each terminal 6 is provided with a recessed lateral notch 22 adjacent to the shelf portion 14 and located between the shelf portion 14 and the elongated post portion 16. The notch portion 22 is of a configuration having an inverted generally planar wall 22 intersectingan inclined wall 24. As further shown in FIG. 2,

each terminal 6 is initially provided with an integral elongated stem portion 26 projecting vertically from the corresponding shelf portion 14 and parallel to the post portion 8. Each stem portion 26 is integral with a side margin 28 of carrier strip 30. Each stem portion 26 is frangible generally at 32 at the intersection of the stem portion and the corresponding shelf portion 14. As shown at 34 in FIG. 2, a somewhat irregular surface remains on the shelf portion 14 of each terminal when it is separated from its corresponding stem. However, for purposes of illustration the surface 34 is greatly exaggerated and the shelf portion 14 remains substantially of planar configuration. Thus, the terminals 6 are initially in spaced relationship along the carrier strip 30 for ease in collective handling thereof. However, as shown in the FIGURE, each individual terminal may be advantageously handled, upon each terminal being frangibly separated from its corresponding stem 26 and inserted into a corresponding aperture 4 of the substrate 2. In addition, a plurality of terminals may be inserted in the corresponding substrate apertures 4, and the carrier strip subsequently separated from the inserted terminals.

As shown in FIG. 2, a plurality of terminals 6 are thereby received in corresponding apertures 4 and arranged in a plurality of rows or regular arrays 38; The terminals are fixedly mounted to the substrate 2 by refiowing the solder bands 20 thereof to form rigid mechanical and electrial bonds between the substrate and the terminals, according to standard accepted reflow soldering techniques. According to the present invention, the shelf portions 14 of selected terminals of a row are in aligned, generally coplanar, relationship for a purpose to be hereinafter described.

With more particular reference to FIGS. 1, 3 and 4, the insulation housings for the terminals arranged in the arrays 36 will be described in detail. Each housing is generally indicated at 38 and includes a generally rectangular shroud portion, defined by a pair of parallel opposed and spaced elongated sidewalls 40 and 42 and a pair of parallel spaced endwalls 44 and 46. Together the

sidewalls

40 and 42 and the endwalls 44 and 46 define therebetween a single rectangular receptacle opening extending entirely through the vertical dimension of the housing 38. The sidewall 42 is provided with an interior horizontal projection, or projecting flange of lip 42', extending the entire distance between the endwalls 44 and 46. In similar fashion, the sidewall 40 is provided with a horizontal projection, interior flange or lip 40 extending between the endwalls 44 and 46. As further shown in FIGS. 3 and 4, taken in conjunction with FIG. 5, the endwall 44 is provided with a generally vertically projecting elongated card guide channel generally indicated at 48. Three sides of the channel 48 are provided with

respective recess portions

50, 52 and 54 which communicate with one another and provide a reduced neck configuration 56 at the intersection of the channel 48 with the endwall 44. The neck portion is laterally offset from the longitudinal axis of the channel portion. The channel portion 48 is additionally provided with a longitudinal channel groove 58 extending along the longitudinal length of the channel 48 and in communication with the substantially recessed portion of a configuration determined by the recessed portions 52', and 54 which correspond to the recessed

portions

50, 52 and 54. A channel groove 58' is in parallel opposed relationship with respect to the channel groove 58, and further is in communication with a flared opening 62"provided in an end 60 of the chan nel 48. A pair of bosses 64 are provided on the end 60' which correspond to the bosses 64.

In operation, reference will be made to FIGS. 1 and 5, wherein the housing 38 is provided over selected arrays of the terminals 6. The inner flange of lip portions 40' and 42' of the

housing sidewalls

40 and 42, respectively, latchingly register within the aligned notch portions 22 of the selected terminals 6. The housing 38 is fabricated from a generally resilient plastic or other resilient electrical insulation material, thereby permitting resilient flexing of of the

sidewalls

40 and 42 and enabling the lips 40' and 42' to resiliently latch into registration within the notch portions 22. All theterminals of a selected array are received into the single opening of a corresponding housing, thereby eliminating interior webs of the housing and contributing "to the economy of the invention. Accordingly, the housing 38 is resiliently latched to the terminals 6 which in turn are fixed to the substrate 2. The housing 38 is advantageously mounted in fixed position with respect to the substrate 2 without a need for a direct mechanical attachment therebetween. Accordingly the housing may be made of low cost thin-wall resilient construction,

whereas if a direct mechanical attachment were required to the substrate 2 a corresponding rigid construction of the housing 38 would be required. That the housing is not directly attached to the substrate allows it to be readily removed merely by resiliently flexing the

sidewalls

40 and 42 away from each other to disengage the portions 40 and 42' from engagement with the notch portions 22 of the terminals 6.

As a further feature of the invention, reference is made to FIG. 1 wherein the corresponding card guide channels 48 and 48' of each housing 38 slidably receives the opposed side margins of a card 66. In practice, a card 66 is slidably inserted between the

card guide channels

48 and 48, with a plurality of electrically conducting paths 68 on the surface of the card being brought into electrical contact with correspond ing electrical terminals 6 contained within thecorresponding housing 38. The edge of the card is brought into registration on the aligned shelf portions of the corresponding terminals. It is imperative that the card 66 be freely insertable and removed from the card guide channels without binding. The reduced neck portions 56 and 56' act as resiliently deformable hinges to allow the

card guide channels

48 and 48 to flex resiliently in cantilever fashion and thereby relieve the binding stresses occasioned by insertion or removal of the card 66. Thus if a tendency toward binding of the card 66 is experienced, the card guide channels 48 andv 48 will flex individually to relieve the tendency toward binding and readily permit insertion or withdrawal of the card. In addition, the resilient cantilever action is also advantageous in that it enables alignment of the

channels

48 and 48 when the card is initially inserted therebetween. To prevent twisting of the individual card guide channels 48, the spaced bosses 64 are received in corresponding spaced apertures 70 of a rigid rail 72. Thus the bosses 64 provide a two-point support for the end of each corresponding channel 48, to prevent twisting thereof. In similar fashion, the bosses 64' are received in corresponding apertures of a rail 72' similar in configuration in the rail 72. The bosses 64 thereby provide two-point supports for corresponding ends of corresponding channels 48', thereby preventing twisting of the channels. Thus, the

channels

48 and 48 are supported each at two points to a common rail, with twisting of each individual channel thereby prevented.

Referring again to the drawings, there is shown in FIG. 6 generally at 101 a plurality of conducting posttype electrical contacts having a generally enlarged rectangular elongated medial portion 102 and a depending reduced rectangular elongated post or post portion 104 integral with and depending from the medial portion 102. Each of the posts is provided with an encircling bahd of solder 108 adhered thereto. As shown, the band is adjacent to the tapered portion 106 of the corresponding post, however'it may bedesirably located selectively along any medial portion of the post portion 104. A solder band 108 is advantageously applied to each of the posts in accordance with the teachings of application Ser. No: 153,315, filed June 15,

With reference yet to FIG. 6', the medial portion 102 of each of the contacts 101 includes a pair of spaced latching tabs 109 and depends from and is integral with a pair of leaf springs or fingers 1010. The leaf springs 1010 of each contact are reversely bent into a generally concavo-convex configuration and depend from a single stem 1012 projecting laterally ofthe longitudinal axis of an elongated carrier strip 1.014. The'carrier strip 1014 is of the ladder type with each'contact d'epending from a separate laterally projecting stern 1012. As shown in the FIGURE, the contacts are notably absent any interconnecting portions therebetween. Accordingly, the contacts are laterally unsupported and free to move relative to one another. Additionally, the contacts are free to deflect substantially with respect to the carrier strip 1014 and stems 1012 without overstressing the stock material or producing permanent bends in either the contacts or the carrier strip. In addition, the carrier strip 1014 maintains the posts inmutual alignment and locates them precisely on desired center spacings. 7

Yet with reference to FIG. 6, there is shown a portion of a substrate 1016 provided with a first row of spaced apertures 1018 on center spacings corresponding to the center spacings of the row of posts 101 depending from the common carrier strip 1014. The holes 1018 are provided with linings comprising a layer of conducting material, such as a solder or plated metal. Selected linings of selected apertures 10l8'may be electrically connected to corresponding plated electrical paths, some of which are shown at 1020,carried on the surface of the substrate 1016. Accordingly, the substrate 1016 may comprise a printed circuit board or card with plating or solder lined apertures electrically associated with circuit paths on the substrate.

Heretofore, post-type contacts were first inserted within sockets or partitions defining channels in a connector housing fabricated from an electrical insulation material. This was found to be advantageous since the connector housing retained the contacts in proper alignment and electrically insulated from one another. As a further feature, the contacts were lockingly latched in the connector housing, enabling the pins to "be forcibly inserted within respective apertures of a substrate without dislodging them from the connector housing. An exemplary locking feature is identified by

Claims

1. In a panel having a substrate provided with metal lined apertures, a plurality of contacts having medial portions mounted in said metal lined apertures and a housing mounted on said substrate and encircling said contacts, the improvement comprising: bands of solder on medial portions of said contacts joining said contacts to said metal lined apertures, sidewall portions on said housing having resilient latching means resiliently and removably latched to selected ones of said contacts, a pair of opposed elongated card guide channels projecting from said housing, integral reduced neck portions joining said channels in cantilever fashion to said housing, said neck portiOns being resiliently deformable to serve as resiliently deformable hinges between said channels and said housing, and protruding means on each of said channels for providing a two-point support at the terminal end of a corresponding channel, said protruding means extending in a direction generally parallel to the longitudinal axis of the corresponding channel.

2. The structure as recited in claim 1, wherein said protruding means includes a pair of protruding bosses mutually spaced and on the terminal end of a corresponding channel.

3. The structure as recited in claim 1, wherein, said contacts each includes an elongated first portion, a planar shelf portion extending laterally of the longitudinal axis of said first portion and engaged on said substrate, a depending elongated post portion integral with said shelf portion and providing said medial portion joined to a corresponding metal lined aperture.

4. The structure as recited in claim 3, wherein, said shelf portion of each contact includes a notch for selectively receiving said latching means in latched registration therein.

5. In a panel having a substrate provided with metal lined apertures, a plurality of contacts having medial portions mounted in said metal lined apertures and a housing mounted on said substrate and encircling said contacts, the improvement comprising: bands of solder on medial portions of said contacts joining said contacts to said metal lined apertures, sidewall portions on said housing having resilient latching means resiliently and removably latched to selected ones of said contacts, each contact medial portion having an inverted shoulder and an adjacent elongated section, said inverted shoulder having solder thereon and being engaged on said substrate against a corresponding metal lined aperture, said elongated section having said solder thereon and being internally within a corresponding metal lined aperture, means on each contact in spaced relationship from said substrate for selective latched receipt of said latching means thereon and, a clearance in a corresponding sidewall portion adjacent to said latching means to allow insertion of a tool therein to unlatch said latching means.

6. The structure as recited in claim 5, wherein, said last-mentioned means includes a second inverted shoulder.

7. The structure as recited in claim 5, wherein, said substrate includes a pair of printed circuit boards having metal lined aperture sections defining said metal lined apertures, said contact medial portions being joined internally of said aperture sections by said solder, and a solid dielectric sandwiched between said printed circuit boards.