JPH0594956U - Connection terminal member - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the reliability of electrical connection between a wiring pattern of a circuit board and a lead pin penetrating the vicinity thereof. [Structure] The wiring pattern of the circuit board 2 and the lead pin 1 are electrically connected using the connection terminal member 3. The connection terminal member 3 is made of a conductive plate material having elasticity, and has one end portion 4 fixed to the wiring pattern by soldering, the other end portion 5 in contact with the lead pin 1, and a bent portion 6 located between the both end portions. Have. The bent portion 6 has a function of absorbing stress caused by relative displacement between the lead pin 1 and the circuit board 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a shape of a connection terminal member used for electrically connecting a wiring pattern of a circuit board and a lead pin penetrating thereabout to each other.

[0002]

[Prior Art]

 2. Description of the Related Art Conventionally, in various electric devices, a structure in which a wiring pattern of a circuit board and a lead pin extending from another component are electrically connected to each other has been widely used. For example, a structure related to an acceleration sensor package in which an acceleration sensor block and a circuit board on which the driving circuit is mounted is integrally incorporated is adopted. That is, this is a case where a plurality of lead pins provided on the acceleration sensor block and the wiring pattern of the circuit board are electrically connected to each other. Generally, lead pins are inserted into the through-hole lands of the wiring pattern and fixed directly by soldering without using auxiliary connecting terminal members.

[0003]

[Problems to be solved by the device]

 Acceleration sensor packages are used in vehicles, for example, and are incorporated in vehicle control systems such as active suspension, anti-lock brake systems, and traction control. In the case of in-vehicle use, it is placed under extremely severe environmental conditions and is constantly exposed to mechanical stress such as shock and vibration, and thermal stress such as temperature change. Therefore, the conventional structure for directly soldering the lead pin and the wiring pattern is inferior in reliability, and is a problem, although high reliability is required for the electrical connection portion. When thermal stress such as temperature change is repeatedly applied, internal stress is repeatedly generated due to the difference in thermal expansion coefficient between the lead pin and the circuit board, resulting in fatigue failure of the solder joint. In addition, mechanical stress such as vibration and shock causes fatigue failure of the soldered portion.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the conventional technique, an object of the present invention is to improve reliability when electrically connecting a wiring pattern of a circuit board and a lead pin penetrating therethrough. And For this reason, a measure was taken to use a connecting terminal member having a characteristic shape as a connecting medium. The connection terminal member is made of a conductive plate material having elasticity, and has one end portion soldered and fixed to the wiring pattern, the other end portion in contact with the lead pin, and a bent portion located in the middle of the both end portions. Preferably, the one end has a substantially U-shape that can be engaged with the circuit board. Further, the other end portion has a concave portion at its tip so that the contact area with the lead pin is enlarged. The connection terminal member having such a shape is suitable for electrically connecting, for example, the lead pin provided in the acceleration sensor block and the wiring pattern of the circuit board on which the drive circuit is mounted.

[0005]

[Action]

 According to the present invention, one end that engages with the circuit board and the other end that contacts the lead pin are connected by an intermediate bent portion having elasticity or springiness. This bent portion has a cushioning function to absorb stress, and even if the positions of the circuit board and the lead pin change relative to each other due to environmental temperature change, vibration, or shock, this displacement is absorbed by this connecting terminal member. You can Therefore, there is no fear of fatigue fracture, and the reliability of electrical connection is significantly improved.

[0006]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a cross-sectional shape and a method of using the connection terminal member according to the present invention. The lead pin 1 extending from the other component penetrates an escape hole provided in the circuit board 2 on which the wiring pattern is formed. A connection terminal member 3 is interposed to electrically connect the lead pin 1 and the wiring pattern of the circuit board 2 to each other. The connection terminal member 3 is made of an elastic conductive plate material, and has one end 4 soldered and fixed to the wiring pattern of the circuit board 2, the other end 5 contacting the side of the lead pin 1, and both ends. And a bent portion 6 located in the middle. The other end portion 5 is pressed against the lead pin 1 by a spring force and fixed by solder 7. The bent portion 6 has a predetermined spring property and has a damper function or a buffer function. That is, even if the relative position of the lead pin 1 and the circuit board 2 changes due to temperature change, vibration, or shock, the amount of displacement can be sufficiently absorbed and fatigue damage of the electrical connection is not caused. The one end portion 4 preferably has a substantially U shape and encloses the thick portion of the circuit board 2. In this state, the solder 8 fixes the wiring pattern.

FIG. 2 is an external perspective view of the connection terminal member 3 shown in FIG. As shown in the drawing, a recess 9 is provided at the tip of the other end 5 to increase the contact area with the lead pin 1. With such a shape, more reliable electrical connection can be obtained. The shape of the bent portion 6 shown in the figure is an example, and the shape is not limited to this. Any shape may be used as long as it has a damper function or a buffer function. When electrical connection is made using the connecting terminal member 3 having such a shape, it suffices that the one end portion 4 having a U-shape is simply sandwiched between the thick portions of the circuit board 2 and the workability is excellent. There is.

FIG. 3 shows an example of using the connection terminal member according to the present invention. In this example, the acceleration sensor block 11 and its drive circuit 12 are integrally incorporated into a one-package type acceleration detection device. The sensor block 11 is mounted on the sensor base 13. The sensor base 13 is fixed by caulking to a post 15 provided in the case 14. A plurality of hermetically sealed lead pins 16 are inserted through the sensor base 13. The lead pin 16 is for supplying a drive signal to the sensor block 11, extracting an output signal, or grounding.

On the other hand, the drive circuit 12 is mounted on the circuit board 17. The circuit board 17 is fixedly arranged in the case 14 so as to face the sensor base 13. A wiring pattern is provided on the surface of the circuit board 17. In addition, the lead pin 16 extending from the sensor block 11 penetrates the circuit board 17. Further, a plurality of connector pins 18 are inserted in the circuit board 17. The connector pin 18 is for making an external connection to the drive circuit 12, and supplies power or takes out an output signal. The connector pin 18 is passed through the sensor base 13 via the feedthrough capacitor 19 and then inserted into the circuit board 17.

The connection terminal member 3 according to the present invention is used for electrical connection between the lead pin 16 and the circuit board 17 and electrical connection between the connector pin 18 and the circuit board 17. As shown in the figure, one end 4 of the connection terminal member 3 having a substantially U-shape is soldered onto the pattern while sandwiching the circuit board 17 on which the wiring pattern is formed. Further, the other end portion 5 has a vane property and is pressed against the side surface of the lead pin 16 or the connector pin 18 by an elastic force. In addition, solder them to these pins when the package is completed. Since the joint portion with the pin has a spring property and is bent, the displacement can be absorbed even if the positions of the sensor base 13 and the circuit board 17 are relatively changed due to temperature change or the like. Therefore, even if the acceleration detection device package is used under severe environmental conditions, fatigue failure of the connection part does not occur.

For reference, a brief description will be added to the configuration of the sensor block 11. The sensor block 11 is assembled on the sensor base 13 via the damper base 20. A support shaft 21 is planted in the center of the damper base 20. A lower fixed substrate 22 is fitted on the support shaft 21. Conductive patterns such as a capacitor electrode, a ground electrode, and a lead electrode are formed on both surfaces of the fixed substrate 22. Further, the upper fixed board 23 is also fitted to the support shaft 21 with a predetermined gap. The fixed substrate 23 also has a predetermined conductive pattern. A movable electrode piece 24 is interposed in the gap between the two substrates 22 and 23 via a spacer. The movable electrode piece 24 is displaced in the axial direction in response to external acceleration, and forms a differential capacitance between the capacitor electrodes facing the upper and lower surfaces. The laminates thus stacked are pressed and fixed to each other by a nut 27 via a washer 25 and a spring washer 26. The conductive patterns formed on both the fixed substrates 22 and 23 are electrically connected to the lead pin 16 described above through the flexible substrate 28. The sensor block 11 having such a structure is covered with a cap 29 and hermetically sealed. The inside is filled with an inert gas such as nitrogen gas.

The fixed substrates 22 and 23 forming the differential capacitance, the movable electrode pieces 24, the spacers and the like need to have a stable positional relationship with each other with respect to temperature changes. Therefore, it is desirable to make the thermal expansion coefficients of the plate members uniform. However, while the fixed substrate is made of an insulating material, the spacer and the movable electrode piece are made of a conductive material, and in general, the combination of these materials limits the choice of materials in order to match the coefficient of thermal expansion. For example, when alumina is used as the material of the fixed substrate, its linear expansion coefficient is 7.5 × 10 ⁻⁶ . On the other hand, when 42-6 alloy (Ni 42%, Cr 6%) is used as the material of the spacer and the movable electrode piece, the linear expansion coefficient is 7.3 × 10 ^−6, which are substantially equal. However, the 42-6 alloy is a magnetic substance and is not preferable under the operating environment conditions affected by the external magnetic field. In this case, a SUS-304 based material can be used for the spacer and the movable electrode piece. However, its linear expansion coefficient is about 17 × 10 ^−6, which is slightly larger than that of the fixed substrate material. Therefore, stress is generated due to temperature change. Therefore, the influence of stress can be suppressed by reducing the outer diameter of the spacer as much as possible and limiting the contact area between plate materials having different expansion coefficients.

On the other hand, the circuit board 17 on which the drive circuit 12 is mounted is covered with an electromagnetic shield 30. Further, the cover 31 is attached to the case 14 and the inside is sealed to complete the acceleration detection device package.

FIG. 4 is an equivalent circuit connection diagram of the acceleration detecting device shown in FIG. As described above, the sensor block 11 and the drive circuit 12 are electrically connected to each other by the plurality of lead pins 16. At this time, by using the connection terminal member according to the present invention, desired reliability can be obtained even under severe environment conditions. Can be maintained. The four lead pins 16 are used and form the input terminal IN1, the other input terminal IN2, the output terminal OUT, and the ground terminal GND. The capacitor electrode formed on the upper fixed substrate 23 constituting one of the capacitors C1 is connected to the input terminal IN1 via the flexible substrate, the lead pin and the connection terminal member according to the present invention. Further, the capacitor electrode formed on the lower fixed substrate 22 constituting the other capacitor C2 is also connected to the input terminal IN2. Further, the movable electrode piece 24 serving as a common intermediate electrode is connected to the output terminal OU T. In addition, the ground electrode patterns formed on the surfaces of both the fixed substrates 22 and 23 are connected to the ground terminal GND.

If the electrode area of one capacitor C1 is S1, the distance between the electrodes is d1, and the dielectric constant of the space sandwiched between them is ε, the capacitance thereof is C1 = εS1 / d1. Regarding the other capacitor C2, the capacitance is given by C2 = εS2 / d2, where S2 is the electrode area and d2 is the distance between the electrodes. Generally, the electrode areas S1 and S2 are set to be equal and are adjusted in advance so that the inter-electrode distances d1 and d2 are equal in the non-acceleration state. As a result, in the non-acceleration state, the capacitors C1 and C2 connected in series have the same capacitance. Here, when the external acceleration α is applied, the force of mα (m is the mass of the movable electrode piece) is applied to the movable electrode piece 24, and the movable electrode piece 24 is displaced by Δd. As a result, the inter-electrode distances d1 and d2 change to d1 + Δd and d2-Δd, respectively. Therefore, the capacitor capacitances C1 and C2 change differentially and appear as a capacitance change.

For example, as shown in the drawing, a rectangular wave pulse is applied to one input terminal IN1 and rectangular wave pulses having a phase difference of 180 degrees are applied to the other input terminal IN2. In the non-acceleration state, since the pair of capacitors have the same capacitance, a zero level output voltage appears at the output terminal OUT. When external acceleration is applied, the movable electrode piece 24 is displaced according to the direction and magnitude of the acceleration, and the balance of the capacitor capacitance is lost. As a result, an output voltage having a phase corresponding to the displacement direction of the movable electrode piece 24 and an amplitude corresponding to the displacement amount appears at the output terminal OUT. The drive circuit 12 can detect the direction and magnitude of acceleration by electrically processing the phase and amplitude of the output voltage.

[0017]

[Effect of the device]

 As described above, according to the present invention, the wiring pattern of the circuit board and the lead pin penetrating thereabout are electrically connected to each other by using the connection terminal member having elasticity. The connection terminal member is made of a conductive plate material having elasticity, and has one end portion soldered and fixed to the wiring pattern, the other end portion in contact with the lead pin, and a bent portion located between the both end portions. Since this bent portion has a function of absorbing stress strain generated in the electrical connection portion, it has an effect of preventing fatigue damage and improving reliability of electrical connection.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a connection terminal member according to the present invention.

FIG. 2 is an external perspective view of the connection terminal member according to the present invention.

FIG. 3 is a schematic cross-sectional view showing an example of use of the connection terminal member according to the present invention.

FIG. 4 is an electrical connection diagram of the usage example shown in FIG.

[Explanation of symbols]

 1 Lead Pin 2 Circuit Board 3 Connection Terminal Member 4 One End 5 Other End 6 Bend 7 Solder 8 Solder 9 Recess

Claims (4)

[Scope of utility model registration request] 1. A connection terminal member used for electrically connecting a wiring pattern of a circuit board and a lead pin penetrating thereabout to each other, which is made of an elastic conductive plate material and fixed to the wiring pattern by soldering. A connecting terminal member having one end, a second end that contacts the lead pin, and a bent portion located between the two ends. 2. The connection terminal member according to claim 1, wherein the one end portion has a substantially U-shape capable of sandwiching and engaging the circuit board. 3. The connection terminal member according to claim 1, wherein the other end portion has a recessed portion at the tip thereof to enlarge a contact area with the lead pin. 4. The connection terminal member according to claim 1, wherein the connection terminal member is used to electrically connect a lead pin provided in the acceleration sensor block and a wiring pattern of a circuit board on which a drive circuit thereof is mounted. .