Electrical connector for an electronic device

Abstract

 There is provided a small electronic device to which highly reliable electrical connections can be obtained by superimposing and clamping a circuit board (50) and terminals (40,42,44,46) of an electrical connector together. The terminals ((40,42,44,46) are insert-molded in a housing (10) so that the contacts (40b,42b,44b,46b) of the terminals (40,42,44,46) are aligned with conductive pads on the board (50). The end portions of the board (50) and the contacts (40b,42b,44b,46b) are springably or elastically clamped in a superimposed state by clamping members (60,60'). The connection between the board (50) and the contacts (40b,42b,44b,46b) is maintained by metal plates (64) under spring forces thereof. Elastic bodies (64') may be used instead of the metal plates (64).

Description

[0001] The present invention relates to electrical connectors containing board mounted electronic devices.

[0002] In recent years, electronic devices containing electronic control circuits have been mounted in vehicles such as high-performance automobiles. A typical example of such an electronic device is disclosed in Japanese Patent Publication No. 4-354360. Specifically, a board on which electronic circuits are mounted is installed inside a device; the electronic circuits inside a case are connected to each other via terminals which are insert-molded into the case, and are connected to external circuits via a connector section. The terminals and board are connected to each other by wire bonding. The electronic circuits on the board are sealed by means of an insulating gel which resists humidity and dissipates heat.

[0003] Since wire bonding is used for connections between the terminals and the board in the electronic device described, the following problems arise: First, since a large number of connections cannot be formed simultaneously by wire bonding, a considerable amount of time is required to form the connections in cases where the number of connections required is large. Secondly, wire bonding generally involves the formation of connections between electrodes which are separated from each other in a substantially horizontal direction. As a result, the dimensions of the case in which the board is installed become larger than the projected area of the board. Thirdly, in order to perform wire bonding, it is necessary to use an attachment jig which corresponds to the shape of the electronic device being connected. This means that different jigs are required for electronic devices with different dimensions, so that the handling of jigs is complicated.

[0004] Furthermore, methods have also been proposed in which terminals and boards are connected to each other by soldering, as disclosed in Japanese Patent Publication No. 4-328285. However, as long as soldering is used, it is impossible to ignore the generation of cracks caused by a difference in the coefficient of thermal expansion between the housing and the board. As a result, the reliability of the connections is decreased. Furthermore, the use of high-temperature reflow soldering leads to a danger of warping or deformation of the housing.

[0005] Accordingly, the object of the present invention is to provide a small electronic device in which the board and terminals are connected to each other with high reliability.

[0006] The present invention is an electrical connector for an electronic device having a housing which can accommodate a board on which electronic circuits are mounted.

[0007] In the present invention, the terminals and board are connected to each other by being superimposed and springably or elastically clamped together.
Accordingly, a small electronic device with highly reliable connections between the terminals and the board can be obtained. Furthermore, since the connection of the terminals and the board is accomplished without the use of heat, the result is a small electronic device in which there is no warping of the housing.

[0008] Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

[0009] Figure 1 is a plan view which illustrates a first embodiment of the electronic device of the present invention.

[0010] Figure 2 is a longitudinal cross section of the electronic device shown in Figure 1.

[0011] Figure 3 is a plan view which illustrates a second embodiment of the electronic device of the present invention.

[0012] Figure 4 is a longitudinal cross section of the electronic device shown in Figure 3.

[0013] In Figure 1, electronic device 1 has an insulating housing 10 in which metal terminals 40, 42, 44, 46 (see Figure 2) made of a copper alloy or the like are accommodated, a board 50 which is accommodated in a recessed part 12 of the housing 10, clamping members 60 which clamp the board 50, contacts 40b, 42b, 44b, 46b of the terminals 40, 42, 44, 46, and a cover (not shown in the figures). The walls 14 which demarcate the recessed part 12 of the housing 10 have cut-out areas 16 at both ends of the housing 10. The clamping members 60 are inserted into these cut-out areas 16. Various electronic components (not shown in the figures) are mounted on the board 50, and specified circuit patterns (not shown in the figures) are formed thereon. These electronic components and circuit patterns make up electronic circuits.

[0014] In Figure 2, a connector section 20 which projects from the bottom surface 18 of the housing 10 is formed as an integral part of the housing 10. An engaging recess 24 is demarcated in the connector part 20 by outer walls 22. The terminals 40, 42, 44 and 46 constitute four rows which are insert-molded in the housing 10 and tines 40a, 42a, 44a and 46a project into the engaging recess 24. The contacts 40b, 42b (see Figure 1) of two rows of terminals 40, 42 extend to the right side of the recessed part 12, and are arranged in a single row as shown in Figure 1. Furthermore, the contacts 44b, 46b of the other two rows of terminals 44, 46 extend to the left side of the recessed part 12, and are similarly arranged in a single row.

[0015] The contacts 40b, 42b; 44b, 46b are thus respectively aligned with conductive pads (not shown in the figures) on the board 50 as a result of the board 50 being positioned by the walls 14 of the housing 10. As will be described below, the contacts 40b, 42b, 44b, 46b are clamped to the board 50 by the clamping members 60 so that electrical contact is maintained between the contacts 40b, 42b, 44b, 46b and the conductive pads on the board 50.

[0016] The clamping members 60 each consist of an insulating main body 62 made of plastic or the like, and a clamping spring 64, formed by bending a metal plate into a substantially U-shape, which is fastened to the main body 62 by insert molding or the like. Considering the environment, heat-resistant stainless steel plate is a preferable material for the clamping springs 64. Each of the main bodies 62 has first and second projecting parts 66 and 68 which clamp onto an insulating part 26 in the corresponding cut-out area 16 of the housing 10 (see Figure 1), and a third projecting part 70 which supports the clamping spring 64. Each clamping spring 64 is held in place by being press-fitted into a space between the third projecting part 70 and a small projecting part 72 or is insert-molded therebetween. When the clamping members 60 are attached to the housing 10, the board 50 and the contacts 40b, 42b (or 44b, 46b) are springably clamped between the corresponding clamping spring 64 and second projecting part 68. As a result of this spring clamping, electrical contact is maintained between the board 50 and the contacts 40b, 42b (or 44b, 46b). Furthermore, it is desirable that small projections 48 be formed on the contacts 40b, 42b, 44b, 46b in order to increase the contact pressure with the conductive pads (not shown in the figures) of the board 50.

[0017] An insulating filler (not shown in the figures) such as a silicon gel or the like is poured onto the surface of the board 50 so that the board 50 and the electronic components mounted on the board 50 are insulated and protected from moisture. A slight gap exists between the housing 10 and each clamping member 60. Accordingly, in cases where a filler with a high fluidity is used, these gaps may be filled with an appropriate bonding agent. The cover (not shown in the figures) engages with edges 74 formed in the clamping members 60, and covers the upper surface of the housing 10. The engagement of the clamping members 60 with the cover prevents the clamping members 60 from moving away from the housing 10. Furthermore, it would also be possible to provide other appropriate anchoring means such as mutual engagement of projections and recesses or the like between the cover and the clamping members 60.

[0018] The electrical connector housing 10 is assembled as follows:

[0019] After being punched out and formed, the terminals 40, 42, 44, 46 are set inside an insert-molding mold (not shown in the figures) for the housing 10, with the ends of the contacts 40b, 42b and the tips of the contacts 44b, 46b respectively connected by carrier strips (not shown in the figures). In this case, the terminals 40, 42 are fastened to the mold by a core pin (not shown in the figures) which forms a blind hole 28 and a core pin (not shown in the figures) which forms the engaging recess 24. Similarly, the terminals 44,46 are fastened to the mold by a core pin (not shown in the figures) which forms a blind hole 30. The carrier strips are separated from the terminals 40, 42; 44, 46 either before or after insert molding, the insert-molded housing 10 is completed.

[0020] Figures 3 and 4 are a plan view and a longitudinal cross section which illustrate a second embodiment of the electronic device of the present invention. This embodiment differs from the first embodiment as follows:
While clamping springs 64 of the clamping members 60 in the first embodiment consist of metal plates, elastic bodies 64' in the second embodiment are made of an elastomeric material such as a heat-resistant silicone rubber or the like. Each of the elastic bodies 64' has an annular part 76 which adheres tightly to the outsides of the second and third projecting parts 68, 70 of the corresponding main body 62, openings 78, 80 through which the second and third projecting parts 68, 70 are respectively passed, and a central projecting part 82 which is formed as an integral part of the annular part 76 between the two openings 78 and 80. The superimposed terminal contacts 40b, 42b (or 44b, 46b) and board 50 are clamped between the second projecting part 68 and the central projecting part 82 of the elastic body 64' which is supported by the third projecting part 70. When the clamping members 60' are attached to the housing 10, the annular parts 76 of the elastic bodies 64' contact the housing 10, and seal the gaps between the clamping members 60' and the housing 10. Accordingly, the bonding agent coating process performed prior to the pouring of the insulating filler may be omitted.

[0021] Embodiments of the present invention were described above. However, the present invention is not limited to these embodiments; various modifications or alterations may be made if necessary. For example, it would also be possible to extend the contacts 40b, 44b of the terminals to only one side of the housing, and clamp the contacts 40b, 44b and the board 50 by means of a single clamping member 60. Furthermore, the connector part 20 may open not only in a direction perpendicular to the surface of the board 50, but also in a direction parallel to the surface of the board 50. In addition, it would also be possible to clamp the board 50 and contacts 40b, 44b between the elastic bodies 64' and the housing 10 instead of clamping the board 50 and contacts 40b, 44b between the elastic bodies 64' and the second projecting parts 68 of the clamping members 60.

Claims

1. An electrical connector for connection to conductive pads of an electronic device (50) comprising:

a terminal supporting member (10) for supporting electrical terminals (40,42,44,46) having contact sections (40b,42b,44b,46b) for engagement with the conductive pads and termination sections (40a,42a,44a,46a); and

clamping means for engagement with the terminal supporting member and for applying forces maintaining the contact sections (40b,42b,44b,46b) in electrical engagement with the conductive pads of the electronic device (50).

2. An electrical connector as recited in claim 1, wherein the terminal supporting member is a housing (10).

3. An electrical connector as recited in claim 2, wherein the housing (10) comprises an electronic device receiving section (12) in which the contact sections (40b,42b,44b,46b) are disposed for engagement with the conductive ppads and a connector section (20) in which the termination section (40a,42a,44a,46a) are disposed for mating to another connector.

4. An electrical connector as recited in claim 1, wherein the clamping means comprises a clamping member (60) having an insulating main body (62) having at least first and second projecting parts (66,68) which cooperate with a projection (26) on the terminal supporting member (10), and a clamping spring (64) supported by a third projecting part (70) and disposed between the second and the third projecting parts (68,70).

5. An electrical connector as recited in claim 1, wherein the clamping means comprises a clamping member (60') having an insulating body (62) having at least two projecting parts (66,68) which cooperate with a projection (26) on the terminal supporting member (10), a third projecting part (70) extending from the insulating body (62) in substantially the same direction as the first and second projecting parts (66,68), and an elastic body (64') disposed on the second and third projecting parts (68,70).

6. An electrical connector as recited in claim 5, wherein the elastic body (64') comprises at least three legs (76,82) which are substantially parallel to each other.

7. An electrical connector as recited in claim 6, wherein the first (76) of the at least three legs (76,82) is disposed on an outer side of the third projecting part (70) of the clamping member (60), and the third (76) of the at least three legs is disposed on the second projecting part (68) of the clamping member (60) between the second and first projecting parts (66,68), whereby the first and third legs (76,82) act as a seal.

8. An electrical connector as recited in claim 6, wherein the second (82) of the at least three legs (76,82) is disposed on the third projecting part (70) of the clamping member (60) and between the second and third projecting parts (68,70) whereby the second leg (82) acts to apply connection force to the circuit board (50).

9. An electrical connector as recited in claim 5, wherein the elastic body (64') comprises:

an annular member (76) which is disposed on the outsides of the second and third projecting parts (68,70) of the insulating body (60'); and

a central projecting part (82) which is disposed between first and second projecting parts of the insulating body (60'),

whereby the central projecting part (82) cooperates with the electronic device (50) and the first projecting part of the insulating body (60') to connect the electronic device (50) to the contact sections (40b,42b,44b,46b).

10. An electrical connector which has a housing accommodating a board (50) on which electronic circuits are mounted, and terminals (40,42,44,46) which are connected to the board (50), and which has a connector part that is integrated with the housing (10), said connector being characterized in that:

the board (50) and the terminals are clamped to each other by clamping members (60') having elastic bodies (64') which exert a force on the board (50) to electrically connect it to the terminals (40,42,44,46).

11. An electrical connector for electrical connection to conductive pads of a circuit board (50) comprising a housing (10) having electrical terminals (42,44,46,48) secured therein in a row, the electrical terminals (42,44,46,48) having contact sections (40b,42b,44b,46b) arranged for electrical connection to the conductive pads when the circuit board (50) is positioned on the housing (10) a member (60) for maintaining the circuit board (50) and contact sections (40b,42b,44b,46b) together, characterized in that the member includes a force-applying member (64,64') for applying connection forces to the board member (54) and the contact sections (40b,42b,44b,46b) to maintain the contact sections in electrical engagement with the conductive pads.

Drawing