JPS61211968A - Non-solder connection method and apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for interconnecting electrical circuit elements. More particularly, the present invention relates to a new and improved solderless connector and to methods of using the same to create and maintain electrical circuits between multilayer circuit devices. The invention is particularly suitable for connecting flexible circuits having two or more layers to other flexible circuits, rigid circuits or electronic components.

Conventional methods of interconnecting electrical or electronic circuit components include using separate connector structures and/or soldering the terminals of said circuit components to conductors that carry current to or from this component. It's more than that. While interconnecting electrical components through separate connector structures is generally adequate for the intended purpose, it does involve high manufacturing costs, high purchasing costs, and labor time during installation and connection. It comes with some disadvantages, including increased labor costs. Similarly, soldering terminals requires that the substrate supporting the exposed terminals be able to withstand relatively high temperatures without adverse effects. Furthermore, since soldering connections take time, labor is required and labor costs are high. Another problem with soldered connections is that it is relatively difficult to remove soldered terminals during repair or manufacturing.

In some applications, it has been found desirable to replace the use of separate connection structures and/or soldering as the technique used to connect to flex circuits and other circuits. In such applications, the necessary electrical contact is accomplished by mechanically pressing a terminal portion of the circuit against a terminal pad of a connector, device, or another circuit. It is customary for such prior art pressure connections to be made using a stiff resilient pressure applicator, such as an elastomeric member, in which the applicator is compressed to connect the components electrically interconnected. At least one of the components is biased toward the other component and its terminal portion is brought into electrical contact. Such a solderless connection device is disclosed in U.S. Pat. No. 4,468,074.
Disclosed in the issue.

The above U.S. patent discloses that the contact portions of the first row of conductive wire elements are biased against the mating contacts of the second conductive element by a pressure applicator made of a resilient open cell plastic material to establish and maintain an electrical connection therebetween. An apparatus is disclosed.

By using such open cell elastic materials, a large number of closely spaced exposed conductors on or extending from a pair of substrates can be aligned and then reliably suppressed and integrated, and electrical connections can be made. Established by the required contact pressure applied to the substrate. The solderless connector of U.S. Pat. No. 4,468,074 connects flexible circuits to each other, connects flexible circuits to circuits on a rigid substrate, connects connections between leads extending from an integrated circuit to a flexible circuit board or to a rigid circuit board. It is used for setting circuit patterns and for other purposes.

While suitable for its intended purpose, the solderless connector of the above US patent is primarily concerned with connecting single layer flexible circuits to other circuit devices. It is recognized that flexible circuit components consisting of multiple layers of circuits are increasingly being used in the electronics industry. Unfortunately, prior art solderless connector devices are not suitable for making interconnections involving multilayer flex circuits. This is because each successive layer in a multilayer flex circuit adds stiffness and copperiness to the overall flex circuit.

As a result, the elastic force applied by the elastic pressure applicator becomes even less effective, resulting in an unreliable electrical contact.

Paper and other problems of the prior art are overcome or alleviated by the solderless connection techniques and apparatus of the present invention. In accordance with the present invention, in particular, a multilayer flex circuit device is connected to another flex circuit for establishing and maintaining electrical contact between the multilayer circuit devices.
Solderless connectors are provided for interconnecting rigid circuit boards and other electronic components.

In a first embodiment of the invention, a technique is provided that utilizes a two or more layer flex circuit with two conductor surfaces facing inward and separated by an insulating layer. Each circuit layer is then wrapped around opposing surfaces of the resilient elastomer member such that the exposed terminal portions of the plurality of flexible circuits are disposed in the same plane on one side of the elastomer element.

In a second embodiment of the invention, a technique is provided for making electrical connections between multilayer flex circuits and other electrical circuit devices having two or more layers. This embodiment utilizes a multilayer flexible circuit in which each of the terminal ends of the multilayer flexible circuit has a different length, with the bottom layer having the shortest length and the top layer having the longest length. This multilayer flexural circuit is then used in conjunction with a rigid pressure plate that also has steps formed therein, but the steps formed in the rigid pressure plate have an opposite direction to the steps formed in the flexural circuit layer. The solderless connector of this embodiment is assembled by providing a resilient elastomer element between a rigid stepped pressure plate and a stepped multilayer flexure circuit. In this connector, a rigid pressure plate brings the terminal portions of the flex circuit into electrical contact with another circuit device, and all of the stepped terminal portions of the flex circuit come into contact with the other circuit device in the same plane and under equal pressure. Alternatively, elastic pressure bistomy material may be provided between each layer of the multilayer flexure circuit.

BRIEF DESCRIPTION OF THE DRAWINGS The paper and other advantages of the present invention will be apparent and well understood to those skilled in the art from the following detailed description and drawings.

Referring now to the drawings, similar elements in the several figures are numbered similarly.

The present invention relates to a solderless connector particularly suitable for connecting flexible circuits having two or more layers to other circuit devices. In FIG. 1, a first embodiment of the solderless connector of the present invention is indicated generally at 10. Solderless connector 10 is particularly suitable for making electrical connections between two or more layers of flexible circuitry, indicated generally at 12, and another circuit device. In this case, the circuit device is a rigid circuit board 14. In this illustrated example, the solderless connector 10 utilizes a two-layer flex circuit having a first circuit layer and a second circuit layer.

The 9g1 circuit layer and the second circuit layer each include a nonconductor base or substrate 1 with a conductive circuit pattern device 18 sandwiched therebetween.
6, cover film 19, and conductive circuit pattern 22
It consists of a nonconductor base or substrate 20 and a cover film 23 sandwiched between them. Each cover film 19 and 23 acts as an insulating spacer between inwardly facing conductive circuit patterns 18 and 22 as shown in FIG. It can be seen that several circuit layers can be laminated together over most of the length of the flex circuit 12 with suitable adhesive materials. However, the two circuit layers are separated at one end of the two-layer flex circuit, as shown in FIG. Preferably, one of the separated ends (i.e. substrate 20/pattern device 2
2) is longer than the other end. In this way, the two circuit layers are arranged on opposite sides 26 and 34 of the elastomeric member 30 such that the exposed terminal layers 32 and 34 of the conductive patterns 18 and 22 are respectively disposed on the same side, ie, the lower side 28, of the resilient elastomeric member 30. It is wrapped around 28.

It will be appreciated that exposed terminal portions 32 and 34 are spaced apart to insulate them.

The two-layer flexure circuit 12 used in connection with the elastomeric member 30 as described above is suitable for use in connection with a conventional rigid clamp connector structure, such as the connector structure shown schematically in FIG. In FIG. 1, the rigid clamp connector structure consists of upper and lower rigid plates 36 and 38 having poles 40 and 42 and other suitable devices for securing the plates 36 and 38. Preferably, alignment pins, such as those shown at 43, are provided to ensure proper alignment between the flexible circuit and the rigid circuit. In this way, the exposed terminal portion 3 of the two-layer deflection circuit 12
2 and 34 are respective terminal portions 4 of the rigid circuit board 14;
4 and 46. The dual layer flex circuit 12/lastomer bud 30 structure of the present invention provides exposed terminal patterns in the same plane. This novel construction provides an even pressure that allows reliable electrical contact to be made when the respective terminal portions are mechanically pressed together through the tightening of the pressure applicator.

Although solderless connector 0 in FIG. 1 is shown for a two-layer flexural circuit, this connector 1o may further include a multi-layer flexural circuit having two or more circuit layers such as the five-layer flexural circuit shown generally at 48 in FIG. Make electrical connections even if you have a

According to a second embodiment of the invention, the five-layer multilayer flexural circuit 48 consists of successive circuit layers 50, 52, 54, 56 and 58, each circuit layer comprising a non-conductive substrate having a conductive circuit pattern 64. 62, and all of the above circuit layers are
As shown in the figure, they are laminated and integrated. According to the invention, one end of the multilayer flexural circuit includes individual circuit layers 50-58.
form a progressive step pattern. Each step is formed by progressively increasing length for each individual circuit layer 50-58. Thus, circuit layer 5o is shorter in length than circuit layer 52, which in turn is shorter than circuit layer 54, thus reaching top circuit layer 58. Therefore, each successive circuit layer 50-58
includes exposed terminal portions 86, 68, 7072 and 74. Preferably, the overlapping step or terminal portions 66-74 of the individual circuit layers 50-58 are not laminated together by adhesive to maintain flexibility in these portions. Alternatively, a flexible adhesive such as R/y1ex 20000 manufactured by Roja may be used to laminate the overlapping terminal portions.

3-6, the stepped multilayer flexure circuit 48 of FIG. 2 is used in conjunction with a rigid pressure plate or housing shown generally at 76. The rigid pressure plate 76 is connected to the deflection circuit 4 shown in FIG.
It is particularly adapted for use in conjunction with multilayer flexure circuit devices such as 8. Rigid plate 76 includes a housing 78 having a top surface 80 and a bottom surface 82 . The bottom surface 82 is the housing 7
8 includes an opening or recess 84 that provides access to the interior of the housing from the bottom surface 82 of the housing. The upper surface of the recessed portion 84 includes a series of steps 86, 88, 90.9 formed therein.
2 and 94, the depth of the concave portion 84 is small (step 86
) to dog (at step 94). Rigid pressure plate 76 also includes a pair of centering pins 96 and 98, a pair of apertures 100 and 102 for receiving bolts or other fastening devices, and a pair of angled apertures 104 and 106. Housing 8° further includes a flex circuit retaining slot 108 (see FIG. 6) and a flex circuit board receiving ramp 110 and associated retaining clamp 112 (see FIG. 61). The retaining clamp 112 is preferably a U-shaped clamp having a base with two extensions at each end. The two extensions are received in angled openings 104 and 106, respectively, and are retained within the openings with nuts (not shown).

The base of the U-shaped clamp biases the deflection circuit 48 against the rigid plate 76 as shown in Figure 17A.

Referring to FIG. 7A, this is an assembled view of the solderless connector of the present invention. In the illustration, a five-layer flex circuit, such as flex circuit 48 of FIG. 2, has stepped or terminal portions 66-74 of multi-layer circuit 48 aligned with and positioned below steps 94-86, respectively. A five-layer flex circuit is attached to the rigid connector plate 76 via insertion between a flex circuit guide ramp 110 and an associated clamp 112. It will be appreciated that the upper circuit layer 60 is loosely locked within the retention slot 108. According to one embodiment of the invention, an elastomeric resilient pressure member 116 is provided between the stepped portion of the recess 84 and the terminal portion of the multilayer flexure circuit 48. Centering pins 96 and 98 are connected to rigid circuit board 1
Eighteen conductive circuit patterns 120 are configured to engage flexural circuit 48 and another circuit arrangement, such as rigid circuit board 118, such that the eighteen conductive circuit patterns 120 are properly aligned with selected terminal portions 66-74 of multilayer flexural circuit 48. . Then the bolt (
Other fastening devices (not shown) are threaded through bolt holes 100 and 102 and corresponding holes in rigid circuit board 118 to mechanically attach housing 80 to rigid circuit board 118.

When the solderless connector 76 is mechanically engaged with the circuit board 118, the resilient pressure members 116 are placed in a compressed state to bias the respective terminal portions of the flex circuit 48 along with the respective terminal portions of the circuit pattern 120. Concave portion 8
It will be appreciated that the corresponding stepped arrangement of 4 and multilayer circuit 48 allows each terminal portion 66-74 of the flex circuit to be coplanar, maintaining equal pressure on each layer. Top 11 layers 58 of the deflection circuit 48
, the terminal portion 74 (which has the longest portion) has the shallowest depth at the step of the housing 80 (i.e., step 86).
), while the bottom layer 50, i.e., the terminal portion 66 (having the shortest portion), is located below the step of the housing 80, which is the deepest (i.e., step 94). I want my presence to be noticed.

7B, in another embodiment of the invention, a plurality of resilient pressure members 122, 124, 126
, 128 and 130 are provided between each separate layer of multilayer flexure circuit 48'.

This embodiment is preferred over the embodiment of FIG. 7A. The reason is that each terminal section is precisely matched with respect to the relative amount of elastic material required for the particular arrangement (i.e. more elastomer elastic on the underside of deeper steps than on the underside of shallower steps). (It is desirable to increase the amount of material used.)

Another advantage is that only one flexible circuit layer is pressed with a resilient pressure pad, unlike the embodiment of FIG. This ensures equal pressure. It will be appreciated that the other structural components of FIG. 7B are the same as those previously described with respect to FIG. 7A, with the addition of a prime.

Now, referring to Figures *8A and 8B which show yet another embodiment, in this embodiment a window or opening 132 is punched out from the lower circuit 711T1134. window 132
1s of adjacent layer 136 thus provides a path through this window to contact circuit board 138. These windows can be provided at desired locations. The stepped structure of rigid pressure plate 140 is preferably adjusted to provide sufficient pressure to make electrical contact.

Although the above description of FIGS. 2-7 has been made with reference to a five-layer multi-node flexible circuit and a five-step solderless connector, the stepped connector of the present invention is suitable for interconnecting multi-layer circuits. It will be appreciated that solder connectors can be utilized in any of two or more steps. The five-step structure shown is only one example.

According to the present invention, reference numeral 30 in FIG. 1, 116 in g77A
, 122, 124, 126° 128 and 1 in Figure 7B
The material defining the elastomer pad, designated 30, preferably comprises an open cell viscoelastic polymer, and in a preferred embodiment comprises polyurethane foam. Particularly good results were obtained with urethane formulations consisting of a mixed polyester/polyether system. One open cell foam material suitable for use in the practice of this invention is FC!, available from Rojas Corporation. It is D2200. This material is characterized by a compressive load deflection at 25% compression in the range of 5 to 50 psi. The elastic material used in the present invention is preferably characterized by a compression set of 5% or less. Compression set is ASTM standard D-156
Tested according to 4. This standard requires a sheet of material 2 inches square and 1 inch thick (approximately 60 ml-s/5h
eet ) is compressed 50% to 1 inch thickness, the compressed material is heated to 158 T for 22 hours, the compressed material is decompressed and the thickness is measured. ASTM D-
The compression set of the R/Flex 8770 material after 5 hours of autoclaving prior to the 1564 test is less than 10 cycles. The solderless connection of the present invention is particularly suitable for making solderless interconnections between multilayer flexible circuits and other electronic circuit devices while maintaining uniform pressure on the several terminal portions to be connected.

It is understood that the solderless connector of the present invention is suitable for interconnecting pairs of flexible circuits, interconnecting flexible circuits to rigid circuits, and interconnecting flexible circuits to integrated circuits and other electronic components. It will be.

Although the preferred embodiment has been illustrated and described, various modifications and alternative embodiments are possible without departing from the spirit and scope of the invention. Accordingly, the invention has been described by way of example and not limitation.

Please understand that this is not a written description.

[Brief explanation of drawings]

1 is a cross-sectional view of a two-layer solderless connector device of the present invention; FIG. 2 is a cross-sectional view of a five-layer multilayer flex circuit used in accordance with the present invention; FIG. 2 is a side view of a rigid pressure plate suitable for interconnecting the multilayer flexible circuit of FIG. 2 to other circuit devices according to solderless connectors; FIG. 4 is a bottom view of the rigid pressure plate of FIG. 3; FIG. 5 is a bottom view of the rigid pressure plate of FIG. A cross-sectional view taken along line 5-5 in Figure 4, and Figure 6 is a cross-sectional view taken along line 6-5 in Figure 4.
6. FIG. 7A is a cross-sectional view of another embodiment of the multilayer thermal solder connector according to the present invention. FIG. 7B is a cross-sectional view of yet another embodiment of the solderless connector of the present invention.
FIG. 8A is a bottom view of yet another embodiment of the invention; FIG. 8B is a bottom view of yet another embodiment of the invention;
The figure is a cross section taken along the line B-B of FIG. 8A. In the figure, numeral 10 is a solderless connector, 12.
48 is a multilayer flexible circuit, 16.20 is a non-conductive substrate, 18.
22 is a conductive pattern device, 19.23 is a cover film, and 30.116. 122.124, 126, 128, 130 are elastomer elements; 32, 34, 66.68°; 70.72.74 are exposed terminal portions; 43 is an alignment device; 86.88, 90;
92.94 is a step, 78 is a rigid housing, 84.
is an opening, 112 is a U-shaped clamp, 108 is a slot in the rigid housing, and 132 is a window. Patent applicant Rogers Corporation Engraving of drawings (no changes in content) FIG, I FIG, 2 F8 FIG, 8s Procedural amendment and 1) 3. The relationship between the person making the amendment and the case q*;z'i;
Tokei; Keiji name: Rossiwa-Mata・Ko I↑? Inyoung 4, agent

Claims (1)

[Scope of Claims] 1. A mechanical device is attached to an elastomer element for making electrical contact between terminal portions of a circuit device, in which at least one of the circuit devices is a multilayer flexible circuit having at least a first circuit layer and a second circuit layer. In the solderless connector that applies an external force, the first layer of the flexible circuit includes a first nonconductor substrate and a first cover film, and the substrate and the cover film sandwich a first conductor pattern device therebetween. to do and
The layer of the flexible circuit includes a second non-conducting substrate and a second cover film, the substrate and the cover film sandwiching a second conductive pattern device therebetween, and the first and second
the conductor pattern devices face inwardly from each other and are separated by the first and second cover films; the first and second layers are adhesively integrated to form a layer; The first and second pattern devices form respectively said first and second extension circuit portions, said first extension circuit portion being longer in length than said second extension portion; has a terminal portion at each end, and the elastomeric element has oppositely disposed first and second surfaces, the first extension portion comprising the entire first surface and a portion of the second surface. and the second extension portion is wrapped along a portion of the second surface so that the first and second terminal portions are electrically isolated from each other and of the elastomeric element. An improvement characterized in that the terminal portions are arranged on the second surface and are in electrical contact with another circuit device. 2. The multilayer flexible circuit includes a number of additional layers having an extended circuit portion wrapped around the elastomeric element and having a terminal portion at each end, the terminal portions of the additional layers being wrapped around the elastomer element. 2. A solderless connector according to claim 1, wherein the additional terminal portions are electrically isolated from each other and are located on the second surface of the element. 3. The solderless connector according to claim 1, which includes a device for aligning the multilayer circuit with another circuit device. 4. A solderless connector in which a mechanical device applies an external force to an elastomeric element to make an electrical contact between terminal portions of a circuit device in which at least one of the circuit devices is a multilayer flexible circuit having at least a first circuit layer and a second circuit layer. a rigid housing defining a pair of opposed first and second surfaces, the first surface having an aperture formed in the first surface;
a rigid housing, wherein the aperture includes an upper surface spaced from the first surface and defines a depth of the aperture and is adapted to receive the elastomer device and the multilayer flexure circuit; at least one step formed in the upper surface of the aperture increasing in size; and a device for applying an external force to the rigid housing to compress the elastomer device and bias respective terminal portions of the circuit device into electrical contact. connector. 5. A multilayer flexure circuit comprising at least a first layer and a second layer, the adjacent ends of the layers extending outwardly by mutually different lengths to define a stepped terminal portion, and a corresponding step of the rigid housing. the stepped terminal portion disposed below and including an exposed conductive circuit device in facing relation to a second conductive circuit device of another circuit device; . 6. The solderless connector of claim 4 including an elastomer device disposed between the at least one rigid housing step and the multilayer circuit layer. 7. The solderless connector of claim 4 including an elastomer device disposed between each adjacent layer of the terminal portion. 8. The solderless connector of claim 5, including a device for biasing the multilayer flex circuit against the rigid housing. 9. The solderless connector of claim 8, wherein said biasing device comprises a U-shaped clamp and an opening in said rigid housing device for receiving said U-shaped clamp therein. 10. The solderless connector according to claim 5, comprising a slot in the rigid housing, and at least one of the layers of the multilayer circuit is disposed in the slot. 11. A window provided in at least one of the layers, wherein a terminal portion of an adjacent layer is placed over the window, and the terminal portion of the adjacent layer passes through the window upon application of an external force. Solderless connectors described in scope 5. 12. A solderless connector in which a mechanical device applies an external force to an elastomer device to establish electrical contact between terminal portions of a circuit device in which at least one of the circuit devices is a multilayer flexible circuit having at least a first layer and a second layer. In,
defining a pair of opposed first and second surfaces, the first surface including an aperture therein, the aperture including an upper surface spaced from the first surface and defining a depth of the aperture; a rigid housing; at least one step formed on an upper surface of the aperture, the depth of the aperture varying from small to large; and at least first and second layers, with adjacent ends of the layers facing outwardly from each other. a multi-flexure circuit extending to define a stepped terminal portion and an exposed conductor circuit device disposed below a corresponding step in the rigid housing in facing relationship to a second conductor circuit device of another circuit device; A connector comprising said stepped terminal portion and a device for applying an external force to said rigid housing to compress said elastomer device and bias respective terminal portions of a circuit device into electrical contact. 13. The solderless connector of claim 12 including an elastomer device disposed between the rigid housing step and the multilayer circuit step. 14. The solderless connector of claim 12 including an elastomer device disposed between each adjacent layer of the terminal portion. 15. The solderless connector of claim 12, including a device for biasing the multilayer flex circuit with respect to the rigid housing. 16. The solderless connector of claim 15, wherein said biasing device comprises a U-shaped clamp and an opening in said rigid housing for receiving said U-shaped clamp. 17. The solderless connector of claim 12, including a slot in the rigid housing, wherein at least one of the layers of the multilayer circuit is disposed within the opening. 18, comprising a window in at least one of said layers;
13. The solderless connector of claim 12, wherein the terminal portion of the adjacent layer is disposed on the window, and the terminal portion of the adjacent layer passes through the window when an external force is applied.