JPH10149862A - Connecting structure for circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shrink the connecting area of a circuit board and further miniaturize an electronic device. SOLUTION: This circuit board 3 has electronic circuits on both the surface and back face. Many land sections 13 for connecting connector pins 10 are provided on the circuit board 3 horizontally in a line. The connector pins 10 are inserted into the pin holes 11 of a terminal housing 4, and each tip section is constituted of a base section 14 serving as a connecting terminal to the outside and a connecting lead section 15 extended on the circuit board 3 on the right of the housing 4. The connecting lead section 15 is provided with a vertical shape section 15a made of a material having a strong spring property (elasticity) and bent nearly perpendicularly to the longitudinal direction of the base section 14 and a curved shape section 15b curved nearly spirally at the tip. The curved shape section 15b of each connector pin 10 is kept in contact with the land section 13 on the circuit board 3 for electric connection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure between an external terminal and a circuit board used in, for example, a vehicle-mounted electronic device.

[0002]

2. Description of the Related Art As a conventional technique of this kind, a technique shown in FIG. 8 has been proposed. FIG. 8A shows a connection structure generally called a “wire bonding method”. In this structure, for example, a circuit board 2 made of a thick-film ceramic substrate is used.
1 are provided with a large number of land portions 22, and an external terminal 2 is provided.
The connection with No. 3 was performed by mounting wire bonding 24. Further, in this method, a method has been adopted in which a dedicated lead is mounted on the circuit board 21 and its tip is connected to the external terminal 23 by soldering or welding.

FIG. 8B shows a connection structure generally called an “edge clip method”. In such a structure, a holding portion 33 provided at one end of a connection lead 32 is used to connect the circuit board 31 to the connection lead 32. The connection lead 32 was connected. In this case, one end of the connection lead 32 was connected to the circuit board 31 by soldering, and the other end was connected to a connector (not shown) for connection to an external device.

[0004]

FIG. 8A and FIG.
In the technique (b), the lengths required for connection between the circuit board and the external terminals are La and Lb, respectively.
Normally, La> Lb, and the latter can reduce the area required for connection. However, in recent in-vehicle electronic devices and the like, it is desired to accommodate more electronic components in a limited space. As a result, there is a demand for a technology capable of reducing the size of the entire electronic device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to promote a reduction in a connection area of a circuit board and to further downsize an electronic device. It is an object of the present invention to provide a connection structure for a circuit board that can be used.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, connection electrodes are provided on both sides of a circuit board, and a housing member for supporting the circuit board is provided. A connection lead connected to the connection electrode is applied to the housing member while applying a contact pressure due to elasticity in a direction substantially perpendicular to the front side and the back side of the circuit board.

In such a case, since the connection lead is connected to the connection electrode in a state in which contact pressure due to elasticity is applied in a direction substantially orthogonal to the circuit board, the circuit board and the external device are electrically connected via the connection lead. Connection is possible. By providing the connection electrodes on both sides of the circuit board, the connection area of the circuit board can be reduced to about half if the number of electrodes is the same as in the conventional case where the connection electrodes are provided only on one side. At this time, since the connection between the circuit board and the connection lead is made using the contact pressure of the connection lead, the structure does not become complicated. As a result, the object of the present invention to promote the reduction of the connection area of the circuit board and to further reduce the size of the electronic device can be achieved.

As a more specific structure of the above-mentioned invention, in the invention described in claim 2, connection leads connected to the front surface side and the back surface side of the circuit board are provided at symmetrical positions. In this case, even if there is a possibility that the circuit board may be warped due to the contact pressure due to the elasticity received from the connection lead, the trouble can be prevented beforehand.

According to the third aspect of the present invention, the connection lead is formed by bending a material having elasticity in advance. In this case, the contact pressure of the connection lead can be more reliably obtained, and the electrical connection between the circuit board and the connection lead can be properly performed.

In order to more efficiently reduce the connection area between the connection leads and the circuit board, it is preferable to arrange the connection leads in a plurality of stages on one side of the circuit board. desirable. In such a case, in the housing member extending in the direction orthogonal to the circuit board, the connection lead outlets may be provided in a plurality of stages. Incidentally, it is preferable that the outlets of the plurality of connection leads provided in the housing member are provided so as to be alternately provided in, for example, different step portions in the vertical direction.

According to the fifth aspect of the invention, the plurality of connection leads provided on one side of the circuit board are formed with electrode contact portions having the same shape. in this case,
The balance of the contact pressure acting on the circuit board is improved, and the circuit board is prevented from being warped or deformed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. The present embodiment relates to the connection between the circuit board of the on-vehicle electronic device and the external connector terminal, and in particular, the connection between the external connector terminal and a board not suitable for drilling, such as a ceramic substrate, is substantially orthogonal to the circuit board. This is performed using connection leads that apply contact pressure in the direction.

As shown in FIG. 3, an electronic device 1 according to the present embodiment is roughly divided into a resin molded base portion 2, a main body portion 5 in which a circuit board 3 and a terminal housing 4 are integrated, and a rectangular flat plate. And a plate portion 6 in the shape of a circle. That is, in the present configuration, the main body 5 is accommodated in the concave portion 2 a formed in the base portion 2, and in this state, the case portion 2 is covered with the plate portion 6 so that the electronic device can be connected to the external terminal. 1 is configured.

The circuit board 3 has a square plate shape (more specifically,
The circuit board 3 is made of a rectangular ceramic substrate having a rectangular shape.
Various electronic components 7 as electronic circuit components are mounted thereon. Specifically, a capacitor, an IC circuit, an oscillator, and the like are mounted on the circuit board 3 as the electronic components 7, and these electronic components 7 form an electronic circuit. Although not shown, in the present embodiment, an electronic circuit is also formed on the back surface of the circuit board 3 in the same manner as the upper surface (front surface) in the figure. Incidentally, the circuit board 3 is integrated with the terminal housing 4 by being guided by a board fixing groove 8 formed in the terminal housing 4.

A pair of left and right connector portions 9 are formed on the terminal housing 4 forming a housing member by resin molding.
The connector portion 9 has a large number of connector pins 10 as connection leads protruding therefrom. Here, as shown in FIG. 4 (a front view of the connector section 9), the connector section 9 is provided with pin holes 11 in two stages vertically symmetrically with respect to a center line L which divides the connector portion into two in the vertical direction. The connector pins 10 are individually inserted into the pin holes 11. Further, the upper and lower pin holes 11 with respect to the center line L are respectively
They are provided alternately in the vertical direction. Here, the connector pin 10 is, for example, a locking mechanism (not shown) such as a key groove.
Thus, the rotation is suppressed.

FIGS. 1A and 1B are a longitudinal sectional view and a front view showing a connection structure between a circuit board 3 and a terminal housing 4. FIG. In the figure, an electronic component 7 is a circuit board 3
It is fixed by a solder material 12 at a predetermined land portion formed thereon. Also, at the left end of the drawing of the circuit board 3,
A large number of lands 13 for connecting the connector pins 10 are provided in a row. Incidentally, in the configuration of the present embodiment, at the connection portion between the connector pin 10 and the circuit board 3, solder plating or solder paste is provided on both.

The connector pins 10 are largely inserted into the pin holes 11 of the terminal housing 4, and the ends of the connector pins 10 extend on the circuit board 3 to the right of the terminal housing 4 and the base 14 serving as a connection terminal with the outside. And a connection lead 15. The cross section of the base 14 is formed in a cylindrical shape or a C shape. The connection lead portion 15 has a band shape as a whole, and is formed of phosphor bronze (copper alloy) having a strong spring property (elasticity). The connection lead portion 15 has a vertical portion 15a bent substantially at right angles to the longitudinal direction of the base portion 14, and a curved portion 15b bent substantially spirally at the tip thereof. These parts have spring properties as a result of bending. At this time, in the state of FIG. 1, the curved portion 15 b of the connector pin 10 is in contact with the land 13 on the circuit board 3 to make an electrical connection.

Here, the circuit board 3 is disposed at a position coinciding with the longitudinal center line L of the terminal housing 4, so that the inner connector pins 10 (inner pins) close to the center line L have the vertical shape portions. 15a is bent outwardly, that is, upwardly above the center line L in FIG. 1 and downwardly below the center line L in FIG. In contrast,
Outer connector pin 10 far from center line L (outer pin)
The vertical shape portion 15a is formed to be bent inward, that is, in a downward direction above the center line L in FIG. 1 and upward in a direction below the center line L in FIG. However, the curved portions 15b of the connector pins 10 have the same shape.

In short, in such a connection structure between the circuit board 3 and the connector pins 10, it is necessary to increase the contact pressure of the connection lead 15 of the connector pins 10 to the circuit board 3 without increasing the size of the terminal housing 4. There is. In this case, the curved portion 1 of the connector pin 10
It is desirable to make the stroke amount (bending amount) of 5b as large as possible. Therefore, in the present embodiment, as described above, the vertical shape portion 15a that is bent in the opposite direction by the inner pin and the outer pin is provided.

That is, as shown in FIG. 6, when the inner pin is not provided with the vertical portion, the stroke between the pin and the circuit board 3 cannot be made large, and the contact pressure cannot be increased. Specifically, in the configuration shown in FIG. 1, the maximum distance between the curved portion 15b of the connector pin 10 and the circuit board 3 is c1, c2, whereas in the configuration shown in FIG. Is the maximum distance d1, d2 (<c
1, c2). From the above, in the configuration of FIG.
Since the dimensions of c1 and c2 are increased, the pressing force of the connector pins 10 on the circuit board 3 increases.

In FIG. 1, the vertical pitch of the connector pins 10 is represented by a, b1, and b2. Actually, a = 4 mm, and here, the circuit board 3 having a thickness of 1 mm is provided.
The remaining dimension after inserting is about 3 mm. In the present embodiment, even when there is such a dimensional limitation, it is possible to increase the contact pressure on the contact portion.

Further, in this embodiment, on each side of the circuit board 3, the connector pins 10 (inner pins) located inside and the connector pins 10 (outer pins) located outside.
Since the shape of the curved portion 15b is the same, variations in the contact pressure acting on the inner pin and the outer pin are suppressed.

In the electronic device 1 configured as described above, at the time of its manufacture, the connector pin 10 described above is first pressed into the pin hole 11 of the terminal housing 4 as shown in FIG. At this time, before assembling the circuit board 3 to the terminal housing 4, the clearance between the curved portions 15b of the connector pins 10 facing each other has the dimension D1 near the center line L as shown in FIG. . In the present embodiment, the dimension D1 is configured to be substantially “0”.

After that, when the circuit board 3 is assembled to the terminal housing 4, the curved portion 15b of the connector pin 10 bends and deforms by the thickness of the circuit board 3, and at the same time, the curved portion 15b of the connector pin 10 is deformed.
The (connecting lead portion 15) contacts the land portion 13 of the circuit board 3 while pressing the land portion 13 by its elasticity. This state is the state shown in FIG. At the time of such assembling, it is preferable to apply solder plating to the curved portion 15b (contact portion with the circuit board 3) in advance, and to print solder paste on the circuit board 3 side. In this case, even when the circuit board 3 warps as shown in FIG. 7 during the actual assembly, the electrical connection is properly performed. At this time, the amount of warpage of the circuit board 3 is represented by t as its own thickness.
It is desirable to use one having a maximum of t / 2 or less.

According to the embodiment described above, the following effects can be obtained. (A) In the present embodiment, land portions 13 (connection electrodes) are provided on both surfaces of the circuit board 3 and a terminal housing 4 for supporting the circuit board 3 is provided, and the contact is made by elasticity in a direction substantially orthogonal to the circuit board 3. Land 13 while applying pressure
The connector pin 10 connected to the housing 4 is disposed on the housing 4. In such a case, by providing the connection electrodes on both surfaces of the circuit board 3, the connection area of the circuit board 3 can be greatly reduced as compared with the conventional case where connection electrodes are provided only on one side. More specifically, according to the prototype of the inventor of the present invention having the same number of electrodes on the circuit board 3 and provided with connector pins (connection leads) at the same pitch, in the present embodiment, as shown in FIG. The dimension of the connection portion is L1, and the relationship of L1 <Lb <La is established when compared with the dimensions La and Lb of the conventional structure shown in FIGS. 8A and 8B. That is, the dimension required for the connection portion is smaller than that of the conventional structure.

In the present embodiment, the connection between the circuit board 3 and the connector pins 10 is made using the contact pressure of the connector pins 10, so that the structure is not complicated. As a result, the connection area of the circuit board 3 can be reduced, and the size of the electronic device 1 can be further reduced.

(B) Since the connector pins 10 (connection leads) connected to the front side and the back side of the circuit board 3 are provided at symmetrical positions, the circuit board 3 warps due to the contact pressure received from the connector pins 10. Even if there is a possibility that the problem described above may occur, the problem can be prevented before it occurs.

(C) Connection lead 1 of connector pin 10
5 was formed by bending a material having elasticity in advance. In this case, the contact pressure of the connector pin 10 can be obtained more reliably,
Electrical connection between the circuit board 3 and the connector pins 10 can be properly performed.

(D) In the present embodiment, the connector pins 10 are arranged in a plurality of stages on one side of the circuit board 3 and the plurality of pin holes 11 provided in the terminal housing 4 are alternately arranged in the upper and lower stages. It was provided to be. Therefore, according to this configuration, the connector pins 10
And the circuit board 3 can be more efficiently reduced in connection area.

(E) A plurality of connector pins 10 provided on one side of the circuit board 3 are formed with curved portions 15b (electrode contact portions) having the same shape. In this case, the balance of the contact pressure acting on the circuit board 3 is improved, and the circuit board 3 can be prevented from being warped or deformed.

(F) Further, in the electronic component 1 having the above configuration, the connection structure of the circuit board 3 can be simplified, so that the working efficiency at the time of manufacturing is improved and the manufacturing cost can be reduced.

The present invention can be realized in the following form in addition to the above embodiment. (1) In the above embodiment, the two members are integrated by press-fitting the connector pin 10 into the pin hole 11 of the terminal housing 4, but this may be changed. For example, the connector pins 10 may be integrally molded when the terminal housing 4 is molded with resin.

(2) In the above embodiment, in the terminal housing 4 corresponding to each of the front and back surfaces of the circuit board 3,
Although the connector pins (connection leads) 10 are arranged in two stages, the configuration may be changed. For example, in the terminal housing 4 corresponding to the front and back surfaces of the circuit board 3,
The connector pins may be arranged one by one, or three or more connector pins may be arranged.

(3) The shape of the distal end of the connector pin 10 on the side of the base 14 may be arbitrary. For example, if the cross section is polygonal,
It may be a bar. (4) The shape of the connection lead portion 15 (vertical shape portion 15a, curved shape portion 15b) of the connector pin 10 is not limited to that shown in the drawing, and may be, for example, a triangular shape such that the top portion contacts the land portion 13. Or other polygonal shapes. Further, a configuration without the vertical shape portion 15a may be adopted. The point is that the circuit board 3 can be arbitrarily changed as long as the circuit board 3 is connected to the land 13 (connection electrode) while applying elastic contact pressure in a direction substantially orthogonal to the front side and the back side.

(5) In the above-described embodiment, the connection portion between the connector pin 10 and the circuit board 3 has a configuration in which solder plating and solder paste are applied to both, but this is changed and a special surface treatment is performed. It is also possible to use a circuit board 3 made of a material that allows both to be connected without being necessary.

(6) In the above embodiment, the thick film ceramic substrate is used as the circuit substrate, but other substrates may be used.
For example, it may be a printed circuit board on which a conductor pattern is simply printed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view and a front view showing a connection structure between a circuit board and a terminal housing in an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the shapes of a terminal housing and a connector pin.

FIG. 3 is an exploded perspective view showing the entire configuration of the electronic device.

FIG. 4 is a front view showing a connector portion of the terminal housing.

FIG. 5 is a diagram showing clearances between upper and lower connector pins before the circuit board is assembled.

FIG. 6 is a sectional view showing a connection structure having a connector pin without a vertical shape portion.

FIG. 7 is a sectional view showing a warped state of the circuit board.

FIG. 8 is an explanatory view showing a connection structure of a conventional circuit board.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic device, 3 ... Circuit board, 4 ... Terminal housing as housing member, 10 ... Connector pin as connection lead, 11 ... Pin hole, 13 ... Land part as connection electrode, 15 ... Connection lead part, 15b ... A curved shape part that forms an electrode contact part.

Claims (5)

[Claims] A circuit board is provided with connection electrodes on both sides thereof, a housing member for supporting the circuit board is provided, and the connection is performed while applying elastic contact pressure in a direction substantially perpendicular to the front and back sides of the circuit board. A connection structure for a circuit board, wherein connection leads connected to electrodes are arranged on the housing member. 2. The circuit board connection structure according to claim 1, wherein the connection leads connected to the front side and the back side of the circuit board are provided at symmetrical positions. 3. The circuit board connection structure according to claim 1, wherein the connection lead is formed by bending a material having elasticity in advance. 4. The circuit board connection structure according to claim 1, wherein the connection leads provided on the housing member are arranged in a plurality of stages on one side of the circuit board. 5. The circuit board connection structure according to claim 4, wherein the plurality of connection leads provided on one side of the circuit board have electrode contact portions having the same shape as each other.