DE1919567A1 - Detachable electrical connections between micro-assemblies and / or wiring boards - Google Patents

Description

Detachable electrical connections between micro-assemblies and / or Wiring Boards The invention relates to detachable electrical and mechanical at the same time and thermal connections, especially for multipolar connections between Micro-assemblies and / or wiring boards, each of which has at least one side is provided with contact surfaces whose electrical supply is perpendicular to the contact surfaces takes place in which the sides face each other with their contact surfaces in pairs and those possibly held between the contact surfaces by an insulating carrier Contact elements are arranged.

Detachable electrical connections made between contact surfaces arranged contact elements are found in high frequency technology many times Use, for example in the form of spring strips for high-frequency-tight closure of shielding housings or waveguide flange connections, as well as galvanically contacting Tuning piston for microwave lines. Such contacts have the disadvantage that they are only suitable for large-area connections.

Detachable electrical contacts are also from an assembly group known from German patent specification 1 075 691. They are used there for the connection parallel circuit boards via at least one connection board in which the contact parts preferably extend in the direction of the plane of the connecting plate.

An assembly is also known from DGM 1 891 042 in which flat contact surfaces of two parallel wiring boards in one detachable one Connection plate arranged contact elements and components are connected In DAS 1 275 170 further describes an arrangement in which a rigid connecting plate Establishes the connection between two circuit boards with S-shaped contact elements.

All the solutions described for connecting assemblies and wiring boards have the disadvantage that their contacts take up a lot of space and inductances which are disruptive for many applications at the highest frequencies Next their thermal transfer is limited to small contact points and a contact force is required to make the connections equal to multipolar designs is significant From the DAS 1 261 9-16 is finally a Process for creating integrated circuits known in which to save of connections with semiconductor bodies with their contact points directly on the conductor tracks a printed circuit can be soldered. Such printed circuits can only take up a few contact points, as the conductor tracks take up a lot of space will.

In contrast, the object on which the invention is based is Micro assemblies and / or wiring boards via a large number of simultaneously electrical, summarize mechanical and thermal connections in the smallest of spaces, which are force-free with good long-term behavior and low vibration sensitivity can be produced and removed again and, in particular, for the transmission of signals len highest frequency are suitable. The connections are supposed to be easier, cheaper and more robust sls to be known.

Based on the electrical connections of those shown in the introduction This object is achieved according to the invention in that either between the Contact surfaces of the individual pairs directly or via the contact elements of soft solder connections are provided.

In another advantageous embodiment of the invention the Metal pins, for example made of copper, are provided which carry contact surfaces in bores in a metal plate, e.g. made of Kovar, through insulating layers, for example made of glass, are electrically isolated from this grounded.

It is advantageous if the contact surfaces are rectangular to have.

In another advantageous embodiment of the invention provided that the contact surfaces carrying metal pins, for example from Kapfer, are provided that in holes in an insulating plate, for example made of ceramic, are grounded.

In a further development of the invention, areas of the metal plate can also be used be provided as mass contact surfaces.

These mass contact areas can be used together with contact areas in an advantageous manner Way result high frequency connections, for example in the form of tape or Have coaxial lines.

A solder pad should not be applied directly to the contact surfaces are, it is advantageous if a Folic, for example from Glasfascrepoxyharz is provided, which carries the solder.

It is advantageous if on the film between the pairs of Contact surfaces and ground contacts plated-through contact elements, for example made of copper.

It is also advantageous if metalized holes in the film are provided which contain soft solder plugs protruding beyond the film.

The compounds according to the invention allow the accommodation of a large number of contacts per unit area with low contact resistance and shorter electrical length The invention is described below with reference to embodiments explained in more detail.

Fig.; shows an embodiment of the detachable according to the invention Multiple connection. One half consists of a Kovarplattc 1, in which through Glass 2 insulated contact pins 3 are embedded. On the connection side is the Kevar plate 1 covered with a copper layer t. The second half of the multiple connection consists, analogous to the first, of a Kovar plate 5, insulated into it by glass 6 Kontaktstiftc 7 are embedded. Dic Kovar plate 5 carries on the connection side a copper layer 8. The electrical, mechanical and thermal connection Both halves of the multiple connection are made via solder pads 9.

The Kovar plate 1 carries on the side facing away from the connection side Ohio insulating layer that only leaves out contact pins 4. On the insulating layer Integrated circuits and cable runs are arranged that make up the integrated circuits connect with the contact pins 4 The Kovar plate 5 carries on its connection side facing away from Seitc also an insulating layer which leaves the Kontaktstiftc 7 free. Cable runs that connect the contact pins 7 are applied to the insulating layer Because the metallic base plates are on top of one another, the wiring is both hold-open plates accessible from the outside.

The wirings and integrated circuits are for clarity not shown in Fig. 1 for the sake of sake, they are not essential for the multiple connection are.

The Kovar plates 1 and 5 are produced in the following way: A Kovar plate with a copper lining is used as the starting material. With the help of well-known Etching process removes the superfluous copper and kovar areas. The remaining Copper areas 4 and 8 are used to receive the solder should be on the connection side remote side also solder connections for the Kovarplatto be provided, so one assumes a double-sided copper-clad Kovar plate. The remaining Copper areas 4 and 8, the contact pins 3, 7, for example, as a network Surround ground connection. This transfer of the earth potential ensures in particular High-frequency technically flawless contacts.

In the embodiment of FIG. 1 are the. For the sake of clarity only a few contact pins 3, 7 shown, while in a practical embodiment in a narrow grid with a grid dimension of, for example, 2.54 mm, a large one Number of contact pins is housed.

In a further embodiment of the subject matter of the invention a plurality of circuit boards 1 are connected to a circuit board 5. The Kovar boards 1, 5 can also have several wiring levels. It is also possible to have several Wiring boards and / or microassemblies in the form of a stack over several To summarize connection levels in which those arranged inside the stack Wiring plates or micro-assemblies on both sides with a Kovar plate and contact pin are provided.

The metallic plates 1, 5 are not only made of high-frequency technology Useful for reasons, but they also offer the advantage of being simpler Way of separating the releasable connection heat can be supplied Another An important advantage is to be seen in the fact that the metal plate is reversed during the Operation can serve, for example, of the integrated switching elements dissipate generated heat.

A large number of solders are available for the solder pads 9, so that the desired melting point can be selected within wide limits. It was with The following alloys are used: a) 50% Bi, 26.7% Pb, 13.3% Sn, 10% Cd (melting point 70 ° C); b) 52% Bi, 32% Pb, 16% Sb (melting point 96 ° C); c) 18% Cd, 32% Pb, 50% Sn (Melting point 145 ° C).

The compounds were kept at a temperature which is approx. 20 to 500 is above the melting point of the alloy. It has been shown that the tensile strength of the connection of a single contact with the particularly deep @f @@ high melting alloys is lower than with the high melting alloys.

In one embodiment, the cross section of the contact surface is 0.8mm x 0.5mm, while the distance between the contact surfaces is 0.3mm. The volume of a Letpe @ star 9 is a few 10-2 to 10-3 3 mm3.

There are also much smaller contact area cross-sections possible, so that a grid dimension of 0.075; 0.05 and 0.025 Z @ ll can be realized.

To make the connection, the circuit boards 1 and 5 pressed together and adjusted so that the contact pins @ 3 and 7 with their solder star 9 align with each other. The entire circuit is now placed in an oven ul; d derar mentions that the solder pads 9 of the metal pins 3, 7 flow together. After cooling down, the connections are complete. Shall merged links are released, the solder pads 9 and the circuit boards are liquefied by the supply of heat 1 and 5 apart.

The heat can, for example, also be supplied in that a temperature-controlled, soldering iron-like tool with the Kovar plates 1, 5 or the contact pins 3, 7 is brought into good thermal contact. Scll a solved The connection will merge again, will be those from the previous soldering process remaining solder drops in a melted state, for example with a in alcohol soaked cellulose cloth, wiped off. Afterward the contact surfaces of the metal pins 3 and 7 are provided with a new solder pad.

Tests have shown that even after separating and joining together eleven times no measurable change in the nature of the circuit boards 1 to 8 occurred.

The volume of the individual let cushion 9 is chosen so that spacing tolerances between the Kovar plates 1 and 5 can be compensated.

The most favorable geometric shape of the contact areas is a rectangle. If you order the rectangular cross-sections of the contact pins in the Kovar plates 1 and 5 3 and 7 perpendicular to each other, larger tolerances can be used for precise positioning of the two circuit boards 1 and 2 are allowed to each other. The couples on each other vertically standing rectangles only have to come into congruence at all and only there a fusion of the solder pads 9 will take place outside of the cover The tinned areas located in it serve as a read reserve.

Fig. 2 shows a further embodiment of the invention Multiple connection between a ceramic plate 10 with contact pins 3 and a Ceramic plate 11 with contact pins 7 which are arranged in bores. The connections the contact pins 3 and 7 via solder pads 9 are carried out in the same way as in the exemplary embodiment according to Fig. 1.

Dic cable runs and integrated circuits can be directly on the outer sides of the ceramic plates 10 and 11 are attached.

Fig. 3 shows an embodiment of the multi-pole according to the invention Connection that does not have the contact copper pins 3 and 7 of the holding plates 1 and 5 are provided with solder pads, but with a connecting foil 12 made of fiberglass epoxy resin solder plug 13 carries, which in the connection and heating of the unit between the metal pins 3 and 7.

The connecting foil 12 can be metallized to accommodate the solder plugs 13 Wear areas 14, 15, as shown in FIGS. 4a and 4b. These metallized areas 14 can be manufactured in such a way that sic according to a known optical and etching processes from an originally copper-clad on both sides Glass fiber epoxy resin film can be left out. By means of a via method known per se the walls of the bores can be provided with a metal layer 15.

Should loosened connections, in which such a connecting foil 12 was used to be fused again, a new connecting foil is placed 12 between the two contact surface grids to be connected. In this way it is guaranteed that in all cases even after several disconnection and connection cycles good electrical contact occurs.

5 shows an exemplary embodiment of a connection according to the invention two circuit boards 1 and 5, in which the circuit board 1 is shown transparent is. The circuit board 1 carries metal pins 3 of rectangular cross-section and the Circuit board 5 carries metal pins 7 of rectangular cross-section. The metal pins Both circuit boards are rotated by 900 relative to each other to allow adjustment to facilitate. Along the longer sides of the rectangle are between the rows of contact pins earth contacts 4, 8 are provided, the crossing points of which are soldered will. This enables the associated ground connection for each contact, if possible lead adjacent, so that only slight reflections occur.

Fig. 6 shows an embodiment of the invention with a coaxial transition between two circuit boards 1 and 5, where the clarity stop only a single connection is shown. Jcdc of the circuit boards contains a Metal pin 3, 7 which is surrounded by an annular wet contact 4, 8. Even here the circuit board 1 is shown transparent.

In this way, the most varied forms of connection can be found realize.

10 claims 6 figures

Claims (10)

P a t e n t a n s p r ü c h e 1. Detachable electrical and at the same time Mechanical and thermal connections, especially for multipolar connections between microassemblies and / or wiring boards, in which 3c at least one Side with contact surfaces is given away, the electrical supply line is perpendicular to the contact surfaces takes place in which the sides with their contact surfaces face to face in pairs and where, if necessary, between the contact surfaces by a insulating carrier held contact elements are disordered, d a d u r c h g c k c n n z c i c h -n e t that either between the contact surfaces of each Pairs are provided directly or via the Kontalctclemente soft solder connections. 2. Connection according to claim i, since d u r c h g e k c n n -z e i c h n c t that the contact surfaces supporting metal pins, for example made of copper, are provided, which in holes in a metal plate, for example from Kovar, electrically isolated from this by insulating layers, for example made of glass are arranged. 3. A compound according to claim 1, d a d u r c h g e k e n n -z e i c h n e t that the contact surfaces supporting metal pins, for example made of copper, are provided, which in bores of an insulating plate, for example made of ceramic, are arranged. 4. A compound according to any one of claims 1 to 3, d a d u r c h g e it is not indicated that rectangular contact surfaces are provided, and that the rectangular contact surfaces of each pair are twisted by 900 against each other. 5. A compound according to claim 3, d a d u r c h g c k e n n -z c i c h ii e t that areas of the metal plate are provided as ground contact surfaces. 6. A compound according to claim 5, d a d u r c h g c k c n n -z e i c h n c t that earth contact surfaces together with contact surfaces as high-frequency connections, for example in the form of ribbon or Kouxial lines are provided. 7. A compound according to any one of the preceding claims, d a -d u r c h g c k c n n z e i c h n e t. that as a connecting plate a film, for example made of fiberglass epoxy resin, is provided. 8. A compound according to claim 7, d a d u r c h g c k e n n -z e i c h n e t that on the foil between the pairs of contact surfaces and ground contacts Through-plated contact elements, for example made of copper, are provided. 9. Connection according to claim 8, d u r c h g c k e n n -z c i c hn e t that in the folic between the pairs of contact surfaces and ground contacts metallized bores are provided, the soft solder plugs protruding beyond the film contain. 10. A compound according to any one of the preceding claims, g e -k e n n z e i n e h n e r c h with the arrangement of the contact surfaces in a grid A grid dimension equal to or smaller than 2.54 mm.