JPH0716299Y2 - Little child - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) In the present invention, one end is fitted and fixed in a hole provided in a resin case, and the other end is soldered to a metal substrate combined with the resin case. The present invention relates to a terminal structure capable of reducing or preventing solder cracks and stress caused by relative movement between a terminal and a resin case due to thermal expansion and contraction of a metal substrate during or after soldering.

(Prior Art) FIG. 5 is a cross-sectional view showing a conventional terminal and its mounting structure. Conventionally, a pillar-shaped terminal 2 is inserted into a hole 3 provided in a resin case 1 and held, The resin case 1 is combined with the metal substrate 4, and the terminal 2 is connected and fixed to the pad 5 on the metal substrate 4 with the solder 6 by cream solder or the like.

(Problems to be Solved by the Invention) According to this conventional structure, as shown in FIG. 6, due to a large difference in thermal expansion coefficient and thermal conductivity between the metal substrate 4 and the resin case 1, soldering is not possible. At this time, the metal substrate 4 moves relatively to the resin case 1 as indicated by an arrow A due to the heat of fusion (this relative movement amount is naturally in the longitudinal direction when the metal substrate has a rectangular shape. Has a problem in that a bending force is applied to the terminal 2 held by the resin case 1 and a crack 7 is generated in the solder 6. . A similar problem occurs when contracting after soldering.

The problem of cracks in the soldered part
If it is attempted to solve the problem by forming the terminal by a thin and thin plate material in which the rigidity of the terminal 2 is reduced, twisting and deformation in the plate width direction are likely to occur during assembly, and as a result, the direction and position of the soldering surface of the terminal 2 However, there is a problem in that the dimensional accuracy cannot be maintained, it is difficult to maintain the dimensional accuracy, and it is difficult to arrange the plurality of terminals in an orderly manner for soldering.

According to the present invention, when a plurality of terminals are soldered in parallel, the terminals are hardly deformed and twisted in the arrangement direction (direction perpendicular to the longitudinal direction of the metal substrate). Despite being able to maintain
The longitudinal direction of the metal substrate, that is, the direction in which the metal substrate largely moves relative to the resin case when the solder is melted, can be easily deformed, so that stress due to thermal expansion or contraction can be reduced, and the occurrence of solder cracks can be prevented. It is intended to provide a terminal of structure.

(Means for Solving the Problems) In order to achieve the above object, the terminal of the present invention is formed by bending a plate member to form a terminal in a substantially L shape composed of a leg piece and a lead piece, and In addition to providing a curved portion having a curved plate surface, in the longitudinal direction of the terminal, a slit whose both ends are closed is provided over the range in which the curved portion is included. Aiming in the longitudinal direction of the metal substrate combined with the resin case,
The lead pieces are fitted and fixed in holes provided at both ends in the longitudinal direction of the resin case, and the foot pieces are soldered to both ends in the longitudinal direction of the metal substrate.

(Operation) As described above, the terminal is formed of the plate-shaped member and the plate thickness direction of the lead piece is directed to the direction in which the metal substrate is largely deformed, that is, the longitudinal direction, which causes thermal expansion and contraction of the metal substrate. It is easy to absorb stress, and moreover, by providing the lead piece with a curved portion, and further by providing a slit in the curved portion, it is easy to deform in the plate thickness direction,
It becomes easier to absorb stress.

On the other hand, by providing the slit in the lead piece, it is difficult to twist as in the case of widening without providing the slit, and it is difficult to deform in the width direction of the lead piece, thus maintaining the dimensional accuracy, As a result, in the arrangement direction of the terminals, the distance between the terminals can be maintained accurately, and the orientation and position of the foot piece, which is the soldering surface, can be prevented from shifting.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing an embodiment of a terminal according to the present invention. The terminal 10 is formed by bending a plate-like member, and has a foot piece 11 to be soldered and is substantially perpendicular to the foot piece 11. Consisting of a lead piece 12, the lead piece 12 is provided with a curved portion 13 in which the plate surface is curved in an arc shape, the lead piece 12 to the foot piece 11 are included so as to include the curved portion 13, and both ends are provided with a closed slit 14. Become.

The sectional view of FIG. 2 and the exploded perspective view of FIG.
1 is a resin case, 4 is a metal substrate, the resin case 1 has a rectangular frame shape, and has terminal holding portions 15 and 16 at both ends in the longitudinal direction. 15, 16
Each of the plurality of terminals 10 is fixed to the resin case 1 and the metal substrate 4 with the plate thickness direction of the lead piece 12 oriented in the longitudinal direction. A boss 18 is provided in each of the inner surfaces of both side plate portions 17 of the resin case 1 in the substantially central portion in the longitudinal direction, and a hole 19 is provided in each of the approximately central portions in the longitudinal direction on both sides of the metal substrate 4, respectively. In addition to fitting with 19, the projections 20 are provided on both sides of the metal substrate 4, and the engaging portions such as the projections 20 are fitted into the grooves 21 provided in the side plate portion 17 of the resin case 1 to form a combined structure. It is adopted. In addition, a spacer may be provided between the terminal holding portions 15 and 16 and the metal substrate 4. Pads 5 are provided on the metal substrate 4 so as to correspond to the terminals 10, respectively. Illustrations of electronic components mounted on the metal substrate 4 are omitted.

The resin case 1 and the metal substrate 4 are preliminarily press-fitted and locked with the terminals 10 into the holes 3 of the terminal holding portions 15 and 16 of the resin case 1.
It is fixed by integral molding or the like, and is combined by fitting the boss 18 and the hole 19 and the projection 20 and the groove 21, and the pad 5 and the terminal 10 to which cream solder or the like has been attached in advance. Each is abutted through the solder 6, and the soldered portion is heated to be soldered.

In this case, as shown in FIG. 2, due to the large difference in thermal expansion coefficient between the metal substrate 4 and the resin case 1, the metal substrate 4
Is moved relative to the resin case 1 in the longitudinal direction of the metal substrate 4 as shown by the arrow A, the terminal 10 held in the resin case is changed from the state shown by the chain double-dashed line B to the solid line. Although the terminal 10 is bent and a bending force (stress) is applied to the terminal 10, the bending portion 13 relaxes the bending force. Further, at the time of contraction after soldering, the metal substrate 4 is attached to the resin case 1.
Moves in the direction opposite to the direction of arrow A in FIG. 2, but also in this case the bending force is relieved. Therefore, the occurrence of cracks in the solder 6 can be prevented. The slit 14 promotes the stress relieving effect. Even if the slit 14 is provided only in the lead piece 12, the stress relieving effect is improved.

Further, since the slits 14 are provided, the same twist resistance and lead pieces 12 as those of the case where the slits 14 are wide without being provided.
The deformation resistance in the width direction is maintained, and as a result, the dimensional accuracy is maintained, and in the terminal arrangement direction (direction perpendicular to the longitudinal direction of the metal substrate 4), the distance between the terminals is accurate. This can be maintained, the deviation of the orientation of the foot piece 11, which is the soldering surface, can be prevented, and a terminal arrangement with good positional accuracy can be obtained.

In the embodiment described above, the curved portion 13 is provided in the middle portion of the lead piece 12, but as shown in FIG. 4, the curved portion 13 extends from the upper portion or the middle portion of the lead piece 12 to the lower end portion of the lead piece 12.
May be provided.

(Effect of the Invention) According to the present invention, in the lead piece of the terminal made of the plate-shaped member, the relative displacement between the metal substrate and the resin case due to the thermal expansion and contraction of the metal substrate is large in the plate thickness direction Since it is arranged so as to be oriented in the longitudinal direction, the stress due to the relative displacement is easily absorbed, and further, the curved portion is provided on the lead piece, and the slit is provided in the longitudinal direction of the terminal so as to include the curved portion. The stress due to the relative displacement is more easily absorbed, and there is no risk of cracks occurring in the soldered portion.

Further, by providing the slit in the lead piece, it is difficult to twist and the deformation in the width direction of the lead piece is maintained in the same manner as in the case where the lead piece is made wide without the slit, and therefore the dimensional accuracy is maintained, As a result, with respect to the arrangement direction of the terminals, the distance between the terminals can be maintained accurately, the orientation and the position of the foot, which is the soldering surface, can be prevented from shifting, and a terminal arrangement with good positional accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the terminal according to the present invention, FIG. 2 is a sectional view showing a state in which the terminal of the embodiment is soldered to a substrate, and FIG. 3 is a terminal mounting structure of the embodiment. FIG. 4 is a perspective view showing another embodiment of the terminal according to the present invention, FIG. 5 is a sectional view showing a conventional terminal and its fixing structure, and FIG. 6 shows its problems. It is sectional drawing explaining.

Claims (1)

[Scope of utility model registration request] 1. A plate-like member is bent to form a terminal in a substantially L shape composed of a leg piece and a lead piece, and the lead piece is provided with a curved portion whose plate surface is curved, and is arranged in a longitudinal direction of the terminal. A slit formed with both ends closed over the range including the curved portion, and the plate thickness direction of the lead piece of the terminal is oriented in the longitudinal direction of the resin case and the metal substrate combined with the resin case, The terminal is characterized in that the lead pieces are fitted and fixed in holes provided at both ends of the metal substrate in the longitudinal direction, and the foot pieces are soldered to both ends of the metal substrate in the longitudinal direction.