CA1251577A

CA1251577A - Apparatus for making scribed circuit boards and circuit board modifications

Info

Publication number: CA1251577A
Application number: CA000514115A
Authority: CA
Inventors: Brian E. Swiggett; Ronald Morino; Jonathan C. Crowell; Raymond K. Keogh
Original assignee: Kollmorgen Technologies Corp
Current assignee: Kollmorgen Technologies Corp
Priority date: 1985-07-19
Filing date: 1986-07-18
Publication date: 1989-03-21
Also published as: DE3624632A1; US4693778A; DE3624632C2; FR2598584B1; FR2598584A1; GB2180175A; EP0210520A3; AU595519B2; JPH0795622B2; AU6035186A; EP0210520B1; ATE61707T1; EP0210520A2; GB2180175B; DE3678058D1; JPS6271292A; GB8617365D0

Abstract

ABSTRACT

This invention relates to apparatus for making circuit boards and, more particularly, to apparatus for making circuit boards in which insulated conductors are applied and bonded to a nonconductive surface to form a conductive path between contact points thereon. The conductors may be wires for electrical conduction or optical fibers for conducting light between points or may be a mixture thereof.

Description

1.2~7~' This inventi.on relates to apparatus for making circuit boards and, more particularly, to apparatus for making circuit boards in which insulated Gonductors are applied and bonded to a nonconductive surface to form a conductive path between contact points thereon. The conductors may be wires for electrical conduction or optical fibers for conduc~ing light between points or may be a mixture thereof.
In U.S. Patent Nos. 3,674,602 and 3,674,914 there are shown and described apparatus for writing or scribing conductors, such as wires, on to the surface of an insulating base to form circuits between predetermined designated points on the insulated base or circuit board. In the apparatus of such patents, the surface of the base is pro~ided with a heat responsive adhesive coating which, as the wire is applied to the surface, is heated, for instance ultrasonically, to activate the adhesive. The conductor is applied or scribed into the activated adhesive on the base. The adhesive is then cooled or cured to affix the wire to the base. The ends of the conductors or wires are affixed to terminals, pads, or plated through-holes at the ends of the conductors by soldering, welding or plating the conductor end and the terminal.
The apparatus of the '602 and '914 patents have been widely used for producing circuit boards, but is not adapted to adding circuits to existing circuit boards nor to apply circuit pattern~ to ba~e which are not provided with an adhe~ive surface.
While, in the apparatus of the '602 and '914 patents it is pos~ible, as the board i9 being produced, to change the conductor pattern before the pattern is laid down, once the pattern i~ laid down and the adhesive surface of the ba~e ha~ been activated and fixed, manual wiring is thereafter required if the circuit is to be changed or additional circuits are to be added. Thua, at each point where a new circuit is to be provided, the end of a conductor wire must be stripped, the stripped wire end must be attached, such as, by aoldering, the wire must be routed and the other end stripped and soldered. This i9 time con~uming and require~ even greater time when a number of conductors are to be added. In addition to being time consuming and expenoive, the board produced has a large number of loo~e wires which are unattractive and, more important, impair u~e of automatic equipment to place and attach componenta on the base or board. The boards to which conductors have been added are not uniform, that ia, conductor length and conductor routing may vary, depending on the person doing the wiring.
In applicant's copending Canadian application Serial No.
514,114, filed July 18, 1986, there is disclosed and described a process for applying conductors, such as conductors capable of tran~mitting electrical or light energy between conductor points, to the surface of a base or circuit board having ~paced terminal points thereon which comprises adhesively bonding a conduc-tor havine an adhe~ive coating, such as of a thermosetting adhesive compo~ition, to the surface of the board, by first activating, or kh/jc ~25~5~

softening the adhesive composition with, for example, heat, applylng the conductor with the activated adhesive to the base and, as -the conductor is applied setting, hardening or curing the adhesive coating to affix or attach the conductor to the base surface. Such process has been found to be particularly suited to adding conductors to ba~es or boards having existing circuit patterns to which conductors are to be added. The process i8 also suited for the manufacture of new circuit boards.
In applicant's copending Canadian application Serial No.
514,116, filed July 18, 1986, there i9 disclosed and described a process for applying a pulsed laser beam to a heat activatable adhesive, to activate the adhesive and attach or affix a conductor to -the surface of a base. In such process, the laser beam pulse energy content is adju3ted according to surrounding conditions and pulses are applied according to the incremental displacement of equipment scribing conductors on the ~urface.
Summary of Invention The instant invention, i9 concerned with an apparatus for applying conductors to the surface of a ba~e or a circuit board between a pair of terminals or contact points in a predetermined preci3e pattern and in accordance with the process of the first of the afore listed applications with a laser beam such as described in the latter of the afore listed patent applications.
In the apparatus of the invention, conductors to be adhered to the board or base surface are coated, at leas-t on the side to be adhered, with a heat respon~ive adhesive, preferably with an adhesive which is capable of being kh/)~

~. Z~ t7 1 thermoset. The end of the conductor is tacked or affixed to

2 the base at the first of the contact points to be joined. The

3 adhesive coating on the side of the conductor to be adhesively

4 affixed to the board or base surface is then activated, such as by heat so that the coating is adhesively active. As the 6 adhesive coating is activated and softened, the conductor is 7 pressed against the board surface along the path the conductor ~ is to be applied or scribed. Such heating, pressure applying 9 or scribing o the coated conductor to the board surface is accomplished while the conductor, such as a wire, is being feed 11 from a dispensing head aligned with the path in which the 12 1 conductor is to be applied or scribed. The dispensing head and 13 l, I the board are moved relative to each other along the path in 14 ~ which the conductor is to be applied and fixed. At the second 15 'I contact point, the conductor is cut and the cut end of the 16 ¦ conductor is fixed to the second contact point. The dispensing 17 head and the board are then moved relative to each other to the 18 1 first of the next pair of contact points to be joined, the end 19 ¦ of the conductor is tacked or affixed to the board or base 20 1 surface at the first of the next pair of contact points and the 21 1 steps are repeated.
22 ~ In the apparatus of the invention, the adhesive and 23 l¦ insulation are removed from the end of the conductor where the 24 conductor is to be fixed or ~.ttached to the contact points or , terminals. This can be done at the opposite ends of the 26 1, conductor or, preferably, can be accomplished by stripping the 27 , adhesive and insulation from a section of conductor to make up 28 ~ the end o one conductor and the start of the next conductor.
29 ,' The stripped section is then severing intermediate the two sections. Thus, as one conductor is completed by affixing or lZ'il5 ~ 7 1 1 attaching the conductor end to the second contact point on the 2 board or base, the leading end of the following conductor, 3 already stripped of insulation and adhesive coating, is ready 4 to be affixed or tacked to the first contact point of the following circuit to be formed.
6 The opposite ends of the conductor may be affixed or 7 attached to the conductor points by soldering, welding or 8 ¦ otherwise affixing the end of the conductor to the conductor 9 point in interconnection therewith or, as is prefered where the contact point is a through-hole in the board or base, by staking 11 the conductor end into the hole with, for example, a staker 12 which bends or presses the wire end into the through-hole.
13 1 The board or base upon which the conductors are to be 14 ¦ scribed ~an be held fixed and the dispensing head can be moved ¦ along the path in which the conductor or wire is to be scribed 16 ¦I between contact points or, as is preferred, the dispensing head 17 il can be held fixed and the board or base can be moved along the 18 ¦j path to be scribed. In either event, as the board or base and l9 1I the dispensing head are moved relative to each other, the 20 1I conductor to be affixed or attached at its ends and scribed to 21 1I the surface of the board or base, is dispensed from the head.
22 ' As will be described in more detail later herein, the board or 73 ll base is moved along X and Y axes and, as the direction of the 24 board movement changes, the dispensing head is rotated so as to be aligned with the axis. Apparatus for guiding and feeding 26 the conductor, removing or stripping the adhesive and the 27 insulation from the conductor, at the conductor ends, 28 maintaining the re~uired tension on the conductor as it is 29 being scribed without stretching, extending or elongating the conductor and for cutting or severing the conductor are all

- 5 -. ~.2t~1t~"7 1 1 incorporated in the dispensing head.
2 In the apparatus of the invention, as will be 3 described, the adhesive coating on the conductor at the side of 4 the conductor to be scribed and affixed to the base, is heated S and activated with a laser beam, such as from a C02 laser, just

6 ¦ before the conductor is brought into contact with the board.
~ ¦ The laser beam is focused on the adhesive coated wire with 8 1 lenses and mirrors in the dispensing head. The laser beam is 9 ¦ deflected in the dispensing head with a movable mirror to a ¦ stripping chamber where, with the aid of an air blast and a 11 1 vacuum, the laser beam is used to strip the adhesive and 12 1 insul~tion from the conductor at the ends to be affixed or 13 '¦ attached at the conductor points on the board before the 14 1 conductor is dispensed.
1 The apparatus of the instant invention can be employed 16 to add a single circuit pattern to a board, a plurality of 17 , circuit patterns to a board or to add identical circuit 18 1 patterns to a plurality of boards. In the instance of adding 19 1 identical circuit patterns to a plurality of boards, the boards or bases are provided with indexing holes which are matched 21 1i with indexing pins on a base and the base and dispensing head 22 !; are pre-programmed to follow a pre-set sequence in selecting 23 1l the pairs of contact points to be joined and in applying and 24 fixing the conductors or wires to the hoard.
The dispensing head support, in the apparatus of the 26 , invention, in addition to supporting the dispensing head at one 27 'i side of the spindle axis, supports, at the other side of the 2~ axis and in alignment with the dispensing head, an indexer 29 ! having mounted thereon a pressure wheei, a tacker and a 30 ' staker. The indexer is rotatable to, in one radial position, .

1 ~ 25:~'7'7 1 position the staker and tacker at one side of the spindel axis 2 opposite to the dispensing head ard, in the other radial 3 position, to position the pressure wheel adjacent the spindel 4 axis and opposite to the dispensing head.
The invention of the instant application will be more 6 fully described and will be better understood from the

7 following description taken with the appended drawings, in which

8 Fig. 1 is a perspective view of the apparatus of the

9 instant invention;
Fig. 2 is a side elevation view, partially in section, 11 of the apparatus of Figure l;
12 1 Fig. 3 is a view similar to Fig. 2 but showing the 13 apparatus in a different position;
14 ¦ Fig. 4 is an enlarged view of a portion of the ¦ apparatus of Fig.2;
16 ! Fig. 5 is an enlarged view of a portion of the 17 ~ apparatus of Fig. 3;
18 ! Fig. 6 is a further enlarged sectional view of the 19 ! dispensing head of Figs. 4 and 5;
20 I Fig. 7 is a view taken at 7-7, Fig.6; Fig. 8 is an 21 1l enlarged view, partly in section, of the indexer;
22 I, Fig. 9 is an enlarged view, partly in section, of the ?.3 1¦ indexer showing the tacker in engaged position;
24 ' Fig. 10 is an enlarged view similar to Fig.9 but I showing the staker in engaged position;
26 !~ Fig. 11 is a view, partly in section, taken from the 27 1 top of the indexer base, Fig. 8, and showing the apparatus for 28 rotating the indexer;
29 i~ Fig. 12 is a sectional view of the indexer taken at 12-12, Fig.8;

1.2~15 77 1 Fig. 13 is a sectional view taken at 13-13, Fig.8;
2 Fig. 14 is a partial view of the apparatus of Fig. 13 3 showing a further position of the adjustment;
4 Fig. 15 is an enlarged view, taken in the direction of the arrow, Fig. 2, of the lower laser mirror;
6 Fig. 16 is a view of the lower laser mirror, taken 7 ¦ from the left, Fig. 15;
8 Fig. 17 is a view of the apparatus of Fig. 16 but 9 taken from the right, Fig. 15;
Fig. 18 is an enlarged view, partly in section, 11 showing a conductor being applied to a base or board surface in 12 accordance with the invention;
13 I Fig. 19 is an enlarged view, partly in section, 14 showing a conductor being applied with the laser beam striking the conductor to activate the adhesive just prior to contact of 16 1 the conductor with the base surface;
17 i¦ Fig. 20 is an enlarged sectional view of the staking 18 ~¦ operation; and r 19 ¦ I Figs. 21(a) to (m) are schematic views showing various 20 I steps in the operation of the apparatus of the instant 21 ¦1 inventiOn, 22 1,1 Referring to the drawings, especially Figs. 1, 2 and 73 ',¦ 3, the apparatus of the instant invention includes a tubular, 24 hollow spindel, generall~7 designated 2, supported for rotation by bearings 4, 6, in housing ~, fixed to machine base 10. Gear 26 12 is fixed to spindel 2 for rotating spindel 2 about its axis 27 l~ for purposes hereinafter described.
7.8 As best shown in Figs. 2 and 3, laser beam generator 29 I' 20 and mirror 22 are mounted on base 10 above the upper end of spindel 2, the laser beam from generator 20 being reflected by , ! I

~ 5~

l mirror 22 downward through hollow spindel 2, along the spindel 2 axis, as spindel 2 is rotated relative to base lO, as will be 3 hereinafter described: Slip-ring 26 and pneumatic manifold 28 4 are fixed to spindel 2 above gear 12 for connecting the various units, as will herinafter be described, to electric and 6 ! pneumatic power sources, respectively. Conductor supply reel 30 7 is mounted above spindel 2 for supplying conductor 32 to 8 conduit 33 in spindel 2 for purposes later described.
g Referring to Figs. 2-6, feeder head base 50 is fixed to the lower end of spindel 2 and supports, at positions 11 diametrically opposed at the opposite sides of the spindel 12 axis, conductor feed guide, generally designated 52, and 13 ! indexer, generally designated 54. Laser beam mirrors 56 and 14 58, and laser beam lens 60, Fig. 4, are optically aligned in tubular passage way 64 in feeder head base 50 for receiving 16 laser beam 65 from generator 20, reflected by mirror 22 and for 17 reflecting and transmitting the laser beam to pivotally mounted 18 mirror 62 for purposes later described.
19 j Conductor feed guide 52 is mounted, at 70, and, as 20 ~ best shown in Figs. 6 and 7, includes an upper fixed conductor 21 ,i guide 72, in fixed base 73, and a lower movable conductor guide 22 11 74, in lower movable guide head 78, fixed to the end of guide 23 1i rods 76, 77, Fig. 7, slidable in base 73 and mounted at their 24 upper ends in head 79. As best shown in Fig. 6, piston rod 75 25 ,' of air cylinder 81 mounted in fixed base 73 is attached to 26 guide head 78 for advancing and retracting lower movable 27 ,' conductor guide head 78 away from and back toward upper guide 28 housing 73 for purposes later described. Knife blade 80, Fig.
29 6, is slidably moun~ed on the end of guide housing 78 between supports 82, 84 for sliding movement therebetween by air '' _ g _ ` ~ 7~7 1 cylinder 86 attached to the end of the blade, Fig. 7, to sever 2 the conductor, as will be later described, and for return by 3 compression spring 88.
4 As best shown in Fig. 7, conductor grippers, generally designated 90, 92, having housings 94, 96, formed in gripper 6 ¦ block 99 and conductor grippers 98, 100, are mounted at the 7 ¦ opposite sid~s of conductor 32 between upper guide housing 73 8 1 and lower guide housing 78. At their outer ends, grippers 98, 9 loO are connected, respectively, to air cylinders 102, 104, for gripping engagement with the conductor and for return by 11 compression springs 106, 108. As best shown in Fig.6, gripper 12 jl block 99 is fixed to piston rod 101 of air cylinder 103 by set 13 1 screw 105 for advancing and retracting conductor grippers 98, 14 1 100, relative to head 78 for reasons more apparent later herein.
¦ Referring to Figs. 2, 3, 4 and 5, conductor 32 is fed 16 ¦I to feed guide 52 by capstan 120, driven, as hereinafter 17 explained, by a variable speed motor, conductor 32 being held 18 in driving engagement with capstan 120 by pinch roller 122 19 1 mounted for rotation on arm 124, pivoted at 126 and spring 20 ¦¦ urged toward capstan 120 to grip conductor 32 therebetween.
21 'l Conductor feed loop controller 130, with its free end in the 22 1 loop path of the conductor, for reasons later described, is 23 ¦¦ pivotally mounted at 132 for rotating cam 134 into and out of 24 the beam of photon-coupled interrupter 136 to regulate the ' speed and feed of conductor 32 by capstan 120. Conductor 3`2 is 26 fed by capstan 120 to upper and lower guides 72, 74 and is 27 I withdrawn from feed head 52 as the conductor is applied and 28 fixed to the surface of the base, as will be described. As 29 withdrawal of the conductor from feed head 52 is increased and the size of the conductor loop decreases, loop controller 130

- 10 -1 2~:157'i' 1 ll pivots counter-clockwise around pivot 132 to increase the speed 2 1~ of the variable speed capstan motor. The feed of the conductor 3 li thereby increasing the size of the conductor loop. As the 4 1 conductor loop increases in size, loop controller 130 is 1 pivoted clockwise around pivot 132 to decrease the speed of the 6 ll variable speed capstan motor. The feed of the conductor thereby 7 1l is decreased, decreasing the size of the conductor loop.
8 i ¦ As bes~ shown in Figs. 2 - 6, lower conductor guide g ¦¦ housing 78 includes a recessed opening 150 which, at its inner o !l end bisects th~e path of conductor feed and exposes conductor 32 in housing 78 to the laser beam of generator 20, reflected and 12 l guided by mirrors 22, 56, 58 and 62, when mirror 62 is so 13 , tilted, into opening 150 as shown in Fig. 4. Thus, as will be 14 '¦ more fully described later herein, with mirror 62 in one I position (Fig. 5), the adhesive coating on the conductor is 16 ¦ activated by laser beam 65 in order to apply and affix the 17 il conductor to the surface of the base and, with mirror 62 in the 18 il tilted position (Fig. 4), laser beam 65 is deflected into 19 ll opening 150 to remove or strip the adhesive and insulator ' coatings from the conductor. Recessed opening 150 is provided 21 , with a vacuum opening to apply a vaccum and remove residue as il .
22 ! I the coatings are removed or stripped and an air opening to 7.3 ;1 apply an air blast to the area to assist in the removal of 24 residue from the stripped wire and the recess.
Referring to Figs 15, 16 and 17, mounting 63 of mirror 26 62 is mounted for rotation on shafts 67, 69. As best shown in 27 Fig. 17, shaft 67 is connected by arms 110, 111 to piston rod 28 11~ of cylinder 113 activated by compressed air through port 29 114 to rotate the mirror in one direction and by spring 115 in cylinder 113 to rotate the mirror ~n the other direction. When ~.Z~1~7'7 1 rotated in the direction to reflect the laser beam against the 2 conductor to activate the adhesive coating, Figs. 3 and 5, arm 3 116 on mirror shaft 69, Fig. 16, is held against a fixed stop.
4 When rotated in the opposite direction to reflect the laser S beam into opening 150 to remove or strip the adhesive coating 6 and insulation from the conductor, arm 116 on mirror shaft 69 7 engages cam 118 driven by motor 119 to cause mirror 62 to 8 oscillate. Thus, when the laser beam is reflected into opening 9 150 to remove or strip the adhesive coating and insulation from the conductor the beam scans or sweeps a conductor length,

11 thereby removing or stripping the coating and insulation from

12 the scanned or swept length.

13 ¦¦ Referring, now, to Figs. 2, 3, 4, 5, 8, 11 and 12,

14 ¦ indexer 54 includes a base 160 mounted in fixed position on 1 feeder head base 50 and an indexing head 162 mounted on shaft 16 ~ 164 (Figs. 8 and 11) for 180 Degree rotation on indexer base 17 ¦ 160. As best shown in Figs. ~ and 11, at its upper end in fixed 18 base 160, shaft 164 is keyed to pinion 166 in engagement with 19 rack 168 connected to the piston rod of two way air cylinder 20 ¦ 169. When air cylinder 169, rack 168 and pinion 166 are in one 21 ¦I position the indexer head 162 is positioned, as will be 22 !I described, for staking and tacking the conductor. When air ?.3 ¦¦ cylinder 169 is actuated to turn rack 168 and pinion 166 in the 24 ~` opposite position, indexing head 162 is rotated 180 Degrees and 25 1I the pressure wheel is in operating position to apply, fix and 26 I scribe the conductor to the base or board surface.
27 !1 As best shown in Figs. 11 and 12 and for reasons more 28 apparent later herein, fixed indexer base 160 further includes 29 j, air cylinders 180, 182, having, respectively, pistons 184, 186 and piston rods 188, 190. Pistons 184, 186 are held upward in ~5157~ 1 1 1 cylinders 180, 182, by compression springs 192, 194 between the 2 ll respective pistons and indexer base plate 196, with piston rods 3 ! 188, 190 retracted. When the air cylinders 180 and 190 are 4 ~ actuated, as the case maybe and as will be described, spring 5 ! 192 or 194 is compressed and piston rods 188, 190 is pushed into engagement to actuate the staker, tacker or pressure 7 ' wheel, as will be described.
8 ~ Referring to Figs. 8, 9 and 10, the staker, generally 9 1 designated 200, the tacker, generally designated 202, and the 1 pressure wheel, generally designated 204, are all mounted on 11 1 indexer head 162. As best shown in Fig. 8, staker 200 has a 12 , tapered headed pin 210 slidably mounted for vertical movement in 13 , sleeve 212 and urged outwardly therein by spring 214. Sleeve 14 ~ 212 is mounted in mounting block 216 and is clamped therein by set screw 218, Figs. 13 and 14. Mounting block 216 is slidably 16 I positioned in block 220 and is adjusted therein by mating cam 17 '¦ surfaces 222, 224 adjusted by set screw 226 and held in mating 18 ¦¦ engagement by compression spring 228. Block 220, Figs. 12 and 19 il 13, is mounted by plates 230, 232 and set screws 234, 236 on 20 il the end of staker actuator rod 238 in cylindrical bore 240 in 21 ~ indexer head 162 and held retracted therein, Fig. 12, by 22 li compression spring 242 between rod head 244 and stop 246 fixed ?.3 , in opening 240.
24 Tacker 202, Figs. 8, 9 and 13, has a rod 250 having a forward end 252 which, as will be apparent form the description 26 which follows, contacts the conductor for tacking, an angular 27 portion 254 and a rearward extending portion 256 by which it is 28 pivoted, at 258. Adjacent its pivoted end, Fig. 8, rearward 29 portion 256 passes through collar 260 adjustably fixed to the end of tacker actuator rod 262 which extends upward into ' 1 57t-~

1 1 cylindrical bore 264 in indexer head 162 and is held retracted 2 therein, Fig. 8, by compression spring 266 between rod head 268 3 and stop 269 fixed in opening 264. At the opposite sides of 4 tacker rod portion 256, collar 260 is provided with pins 261 and 263 which, as actuator rod is moved up and down, as hexein 6 later described, raises and lowers the forward end 252 by 7 pivoting rod 250 on pivot 258.
8 ¦ Pressure wheel 204, Figs. 8, 9 and 13, includes wheel 9 280, suita~ly grooved to receive the coated conductor and press ¦ the conductor against the board surface, Figs. 18 and 19, 11 1 mounted by an adjustment mechanism, generally designared 282, 12 1 on rod 284 pivoted, at 286, and spring urged, by adjustable 13 , tension spring 288, into engagement with the conductor when 14 wheel 280 is engaged. Intermediate pivot 286 and the end carrying wheel 280 and adjustment mechanism 282, rod 284 is 16 connected to the end of whee' actuator rod 290 urged upward in 17 ¦ indexer 162 by compression spring 292 between actuator-rod head 18 294 and stop 296 fixed in cylindrical bore 298 of indexer 162.
19 !¦ Air cylinder 182 in indexer base 160, when indexer head 162 is 20 ,j rotated to position pressure wheel 280 in operating position, 21 , is aligned with the stop end 296 of wheel actuates rod 290 and, 22 !I when compressed air is applied to cylinder 182, pushes rod 290 ~3 ~j downward to engage wheel 280 with the board surface. When air 24 is exhausted from cylinder 182, rod 190 is lifted or retracted , by compression spring 194 and wheel 280 is lifted or retracted 26 by compression spring 292. Similarly, when indexer head 162 is 27 1I rotated on indexer base 160 to bring staker 200 and tacker 202 28 into operating position, air pressure is first applied to 29 cylinder 182 to actuated staker 200 and, while staker 200 is actuated, is applied to cylinder 180 to actuate tacker 202.

1 1.2~
. -~
. . I

1 When tacking is completed, air is exhausted from both cylinders.
2 The apparatus of the instant invention is adapted to 3 apply and affix, or scribe, one or more conductors to the 4 surface of a circuit board, each conductor being applied, or scribed along a predetermined path and between a predetermined 6 pair of conductor points~ Preferably, the table upon which the 7 board or base is to be fixed for applying the conductor or 8 conductors and the spindel, or head, are connected to and 9 controlled by a computer programmed to locate the conductor points, or terminals, to be connected on the board, the path to 11 be followed, the directions the table is to be moved and the l?. direction the spindel or head is to be oriented and the other 13 1 parameters, such as, turning the laser on and off, tipping 14 ¦ mirror 62, etc., necessary to effect proper operation and the L5 1 desired connections. Thus, as is often the case, a plurality 16 o~ boards, one after the other, are mounted on the table and 17 the conductor program is repeated. -- ¦
18 With the apparatus programmed, board 300, Fig. l, is 19 mounted on table 302 and is located thereon by location pins 304, 306, fixed to table 302 and passing upwardly through 21 1 location, or indexing holes 308, 310 in the board. By the 22 pre-program, board 300, table 302 and spindel 2 are in position ?.3 ¦ relative to conductor point or terminal A to start the 24 l application, with the feeder head facing in the required 25 ' direction for table and board travel. The laser beam is 26 ' energized, while the conductor is being applied or scribed by 27 ~ pulsing the beam in accordance with the latter of the above 28 mentioned applications. The laser is programmed to operate (1) 29 !, while the conductor is being applied or scribed and the board 30 ,, is being moved, and-(2) just before the staked conductor is to I ~51577 1 be tacked and while the adhesive and insulation are being 2 removed or striped from the conductor. When movement of the 3 board is stopped, such as for change of conductor direction, 4 change of conductors, etc., the laser is turned off and reenergized when movement of the board or laser operation is 6 resumed. During scribing operations the laser is preferably 7 pulsed according to incremental movements.
8 To commence the operation, assuming the conductor end 9 ¦ in the wire guide head is suitably stripped of adhesive and 1 insulation and is ready for application, air cylinders 102, 11 ¦ 104 of conductor grippers 90, 92 are actuated to bring grippers 12 1 98, loO into gripping engagement with the conductor and, with 13 ¦ the conductor so gripped, compressed air is introduced into air 14 1 cylinder 81 to advance conductor guide block 78 and conductor ` 32 therein toward the first of the pair of contact points or 16 ¦I terminals to be connected. With guide block 78 fully advanced, 17 ¦ air cylinders 102, 10~ still actuated and grippers 98,-100 18 1 still gripping conductor 32, compressed air is introduced into 19 ' air cylinder 103 to advance gripper block 99 and grippers 98, !¦ lOo, with conductor 32 gripped therebetween, toward conductor 21 l l guide block 78 being held advanced by the compressed air in 22 cylinder 81. Thus, the stripped end of conductor 32 is advanced 23 ,¦ outwardly through the advanced end of conductor guide block 78 24 and over the hole or first of the terminal points to be joined , or connected. Staker 202 is actuated by introducing compressed 26 1 air into air cylinder 182 and the stripped end of conductor 32 27 ' l is staked into the terminal point. With the stripped end of 28 conductor 32 staked and staker head pin 210 in the hole with 29 ~ the staked conductor end, compressed air is introduced into air cylinder 180 to bring tacker 252 down against conductor 32 next : ~ 5 1 to the staked terminal A. As tacker 252 is being brought down, 2 laser beam 65 is pulsed against the adhesive coating on 3 conductor 32 to adhesively activate the coating and the 4 conductor, adjacent the staked terminal A, is affixed to the board surface. With the leading end of the conductor staked to 6 the terminal and tacked to the board surface, staker 200 and 7 tacker 203 are lifted by releasing compressed air from 8 cylinders 180, 182, indexing head 162 is rotated 180 Degrees on 9 ¦ indexer head 160 to ~ring pressure wheel 280 into alignment ¦ with the conductor to be scribed, cylinder 182 is activated to 11 ¦ bring pressure wheel 280 down into pressure contact with the 12 1 conductor to be scribed and, 2s this is being accomplished, 13 1 laser beam 65 is energized and pulsed to activate the adhesive 14 ¦ ¦ on the conductor just ahead of the point where the conductor lS !l will be brought into pressure contact with the board surface by 16 1 pressure wheel 280. At the same time, table 302 is advance to 17 ! move board 300 relative to conductor guide block 78 along the X
18 axis, the Y axis or along a combination of the X axis and Y
19 axis, 20 1I Before the board reaches the second of the terminals 21 1 being connected and at a pre-programmed distance so that, when 22 1 is resumed, the second terminal will be reached and not passed, 73 ~ movement of the board is stopped, air cylinder 81 is activated 24 to bring conductor block 78 down toward the board surface and mirror 62 is deflected by air cylinder 113, Figs. 15-17, so 26 that arm 116 contacts cam 118 driven by motor 119. Thus, 27 ~l mirror 62 is tilted back and forth, (Fig. 21[iJ), in the 28 directions of the arrows, to sweep along a section of the 29 conductor to be stripped of adhesive coating and insulation.
With laser beam generator 20 activated and laser beam 65 ~ 7,' 1 suitably pulsed, the adhesive coating and insulation are 2 vaporized off of the conductor, the residue being removed by a 3 vacuum applied to recess 150 through port 151, Fig. 6. An air 4 jet, at the end of the removal ma~ also be employed.
When the coating and insulation have been vaporized 6 and removed, i.e. after a pre-programmed time interval, 7 compressed air in cylinder 113 is released and spring 115, Fig.
8 17, returns the mirror to its downward position. With laser 9 generator 20 again acti~ated and laser heam 65 suitably pulsed and reflected against the coating on conductor 32 ahead of 11 pressure wheel 280, movement of table 302 and board 300 is 12 l¦ resumed. When a sufficient length of the stripped conductor 13 re~uired for staking in the second terminal of the pair of 14 terminals being joined by the conductor has passed outward throught the end of guide block 78, air cylinders 102, 104 are 16 activated, engaging conductor grippers 98, lOo with conductor 17 32 therebetween and air cylinder 86 is activated, advancing 18 knife blade 80 and severing the conductor intermediate the ends 19 of the stripped section, Fig. 21(j) and the remaining end of the adhesive activated coated conductor is applied and affixed 21 1 or scribed to the board surface with the stripped conductor end 22 !1 over the second terminal hole. Movement of table 302, with ~3 1l circuit board 300 thereon and indexed thereto is stopped. Air 24 cylinder 182 is deactivated, pressure wheel 280 is lifted, . !
indexer head 162 on indexer base 160 is rotated 180 Degrees to 2~ l~ bring staker 200 into position over the terminal hole, Fig.
27 ¦~ 21(1) and staker 200 is activated, Fig. 21(m), to stake the 28 stripped end of the conductor in the terminal hole. Air 29 1l cylinder 81 is deactivated and conductor guide block 78 is 30 , retracted with the lead end of conductor 32 therein stripped ,:

~ ~.2~5~

1 il and ready for attachment to the first of the next pair of 2 l~ terminal points to be joined when the afore described operation 3 of the apparatus is repeated~
4The apparatus of the instant invention, as has already S been noted, is adapted to add one or a plurality of conductors 6 to a circuit board and to duplicate the addition to a plurality 7 of boards, each board being provided with identically located ~indexing holes 308, 310 and being position on table 302 on pins 9304, 306 and the program followed in applying the conductors to one board being duplicated on the others. In addition to 11 adding conductors to circuit boards already provided with 12 circuit patterns, the apparatus of the instant invention may be 13 1 employed to affix, apply or scribe circuit patterns to a board 14 ¦~ without existing patterns so long as such board has terminal il points with holes for staking the conductor ends.
16 ll The terms and expressions which have been employed 17 1I herein are used as terms of description and not of limitation, 18 j and there is no intention, in the use of such terms and 19 1 expressions, of excluding any equivalents of the features shown 20 j and described or portions thereof, but it is recognized that 21 .I various modifications are possible within the scope of the 2 2 ', invention claimed.
?. 3

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An apparatus for scribing a conductor to a surface of a substrate in a predetermined pattern between two points on said surface, each of said points defining a terminal point, said conductor being coated with a coating which is non-tacky and non-blocking in its coated state but activatable to be an adhesive at the time the conductor is applied to said surface and to return to a non-tacky state after said conductor is fixed to said surface, said apparatus including means for feeding said coated conductor to the first of the pair of terminal points on said surface to be connected by said conductor, means for supplying the end of said conductor to said first terminal point on said surface, tacking means comprising radiant heating means directed at a point on the conductor adjacent the terminal point to activate said adhesive coating to a tacky state and a tacker for fixing the supplied end of said conductor to said first terminal point prior to scribing a conductor path, means for moving said surface and said conductor feeding means relative to each other along a predetermined path from said first of said pair of terminal points to the second of said pair of terminal points, said radiant means activating said coating to an adhesive state as said conductor is applied to said surface, pressure means for urging said conductor with said activated adhesive coating into contact with said surface along said predetermined path, means for cutting the end of said conductor, means for applying said cut end of said conductor to said second of said terminal points and means for fixing said conductor end to said second terminal point.

2. An apparatus, as recited in claim 1, in which said radiation is heat and said radiation source is a heat source.

3. An apparatus, as recited in claim 1, in which said radiation is from a laser source and said radiation source is a laser beam.

4. An apparatus, as recited in claim 3, in which said laser beam is a CO2 laser beam.

5. An apparatus, as recited in claim 1, in which said means for feeding said conductor to said surface is a feeder head.

6. An apparatus, as recited in claim 5, in which said means for feeding said conductor includes a variable speed motor in said feeder head and means in said head for controlling the speed of said motor.

7. An apparatus, as recited in claim 5, in which said feeder head includes a conductor guide block and means for moving said conductor guide block relative to said feeder head and toward said surface for applying the end of said conductor to said first terminal point and for retracting said conductor guide block when said applied end of said conductor is fixed to said terminal point.

8. An apparatus, as recited in claim 7, in which said conductor guide block includes means for gripping said conductor to advance the end of said conductor toward said surface when said conductor guide block is advanced toward said surface and for releasing said conductor.

9. An apparatus, as recited in claim 8, in which said conductor guide block includes means for stripping said coating from a section of said conductor to expose said conductor while said conductor is held in said guide block.

10. An apparatus, as recited in claim 9, in which said coating is stripped from conductor by applying heat to said section to vaporize said coatings.

11. An apparatus, as recited in claim 10, in which a vacuum is applied as said coating is vaporized.

12. An apparatus, as recited in claim 11, in which an air blast is applied to remove residue after said coating is vaporized.

13. An apparatus, as recited in claim 1, in which said pressure means includes a wheel and means for bringing said wheel into pressure contact with said conductor after said conductor has been applied for said fixed conductor to said base.

14. An apparatus, as recited in claim 13, in which said means for bringing said wheel into pressure contact with said conductor includes an indexing head and said means for fixing the applied end of said conductor to said first terminal point is mounted on said indexing head.

15. An apparatus, as recited in claim 1, in which said first and second terminal points are metallized through holes in said substrate.

16. An apparatus, as recited in claim 15, in which said substrate is a circuit board.

17. An apparatus for scribing a conductor to a surface of a substrate in a predetermined pattern between two points on said surface, each of said points defining a terminal point, said conductor being coated with a coating which is non-tacky and non-blocking in its coated state but activatable to be an adhesive at the time the conductor is applied to said surface and to return to a non-tacky state after said conductor is fixed to said surface, said apparatus including a feeder head for feeding said coated conductor to the first of the pair of terminal points on said surface, said feeder head including a variable speed motor within the feeder head and means for controlling the speed of said motor, to be connected by said conductor, means for supplying the end of said conductor to said first terminal point to scribe a conductor path, means for moving said surface and said feeder head relative to each other along a predetermined path from said first of said pair of terminal points to the second of said pair of terminal points, means for activating said coating as said conductor is applied to said surface, pressure means for urging said conductor with said activated adhesive coating into contact with said surface along said predetermined path, means for cutting the end of said conductor, means for applying said cut end of said conductor to said second of said terminal points and means for fixing said conductor end to said second terminal point, wherein said motor speed control includes a photon-coupled interrupter, a means for controlling the output of said interrupter, a conductor loop in the path of conductor feed and a means for sensing and controlling said loop.

18. An apparatus, as recited in claim 17, in which the speed of said variable speed motor is reduced when said conductor loop is elongated and is increased as said conductor loop is decreased.

19. An apparatus for scribing a conductor to a surface of a substrate in a predetermined pattern between two points on said surface, each of said points defining a terminal point, said conductor being coated with a coating which is non-tacky and non-blocking in its coated state but activatable to be an adhesive at the time the conductor is applied to said surface and to return to a non-tacky state after said conductor is fixed to said surface said apparatus including means for feeding said coated conductor to the first of the pair of terminal points on said surface to be connected by said conductor, means for supplying the end of said conductor to said first terminal point on said surface, means for fixing the supplied end of said conductor to said first terminal point to scribe a conductor path, means for moving said surface and said conductor feeding means relative to each other along a predetermined path from said first of said pair of terminal points to the second of said pair of terminal points, means for activating said coating to an adhesive state as said conductor is applied to said surface, pressure means for urging said conductor with said activated adhesive coating into contact with said surface along said predetermined path, means for cutting the end of said conductor, means for applying said cut end of said conductor to said second of said terminal points and means for fixing said conductor end to said second terminal point in which said pressure means includes a wheel and means for bringing said pressure wheel into pressure contact with said conductor after said conductor has been applied comprising an indexing head and said means for fixing the applied end of said conductor to said first terminal point being mounted thereon, said indexing head including means for rotating said indexing head to a first position for engaging said fixing means with said conductor and into a second position for engaging said pressure wheel with said conductor.

20. An apparatus for scribing a conductor to a surface of a substrate in a predetermined pattern between two points on said surface, each of said points defining a terminal point, said conductor being coated with a coating which is non-tacky and non-blocking in its coated state but activatable to be an adhesive at the time the conductor is applied to said surface and to return to a non-tacky state after said conductor is fixed to said surface, said apparatus including means for feeding said coated conductor to the first of the pair of terminal points on said surface to be connected by said conductor, means for supplying the end of said conductor to said first terminal point on said surface, means for fixing the supplied end of said conductor to said first terminal point to scribe a conductor path, means for moving said surface and said conductor feeding means relative to each other along a predetermined path from said first of said pair of terminal points to the second of said pair of terminal points, means for activating said coating to an adhesive state as said conductor is applied to said surface pressure means for urging said conductor with said activated adhesive coating into contact with said surface along said predetermined path, means for cutting the end of said conductor, means for applying said cut end of said conductor to said second of said terminal points and means for fixing said conductor end to said second terminal point wherein said first and second terminal points are metallized through holes in said substrate, said substrate being a circuit board and wherein said fixing means includes staking means for staking the end of said conductor in said through holes.

21. An apparatus, as recited in claim 20, in which said fixing means includes staking means for staking the end of said conductor in said through holes and tacking means for tacking said conductor to said base with said activated adhesive after said end is staked.