Surface equipped component

Abstract

To provide a surface equipped component which can prevent solder failures from happening when equipped by preventing bending of leads.SOLUTION: The surface equipped component of the present invention includes: an electronic component body; and a plurality of leads in a gullwing shape extending from a side surface of the electronic component body. Also, the surface equipped component has an elastic resin covering the side surface of the electronic component body to the end thereof other than the solder surface of the leads. The leads have a plate spring part in the shape of being bent over vertically between the root thereof and the solder surface, and there can be provided the surface equipped component which can prevent solder failures from happening when equipped.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a surface mount component, and more particularly to a surface mount component having a plurality of gull-wing type leads. [Background technology]

[0002] Electronic components such as LSIs and VLSIs that incorporate semiconductor integrated circuits are often mounted on the surface of a wiring board, and surface-mount electronic components require that the solder surfaces of all of their leads be on the same plane.

[0003] Patent Document 1 discloses that by placing a rod-shaped insulating frame on the upper surface of the tips of multiple leads extending from the side of an electronic component body and widening the width of the leads at both ends of the leads connected by the insulating frame, the rigidity of the entire lead is increased and bending of the leads due to impacts during transportation or when dropped can be suppressed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-321277 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the device described in Patent Document 1 increases the rigidity of the entire leads lined up on the side of the electronic component body to suppress bending of the leads, so that an impact when dropped, for example, is transmitted to the electronic component body, making it prone to breakage at the joint between the electronic component body and the leads, i.e., at the base of the leads.

[0006] The present invention has been made in consideration of the problems associated with the conventional technology, and has as its object to provide a surface mount component that can prevent not only bending of the leads but also breakage at the base of the leads, thereby preventing soldering defects during mounting. [Means for solving the problem]

[0007] As a result of extensive research into achieving the above-mentioned objective, the inventors discovered that the above-mentioned objective can be achieved by absorbing the impact when dropped, etc., with the side portion of the electronic component body on which the leads are arranged, and thus completed the present invention.

[0008] That is, the surface mount component of the present invention comprises an electronic component body and a plurality of gull-wing shaped leads extending from the side surfaces of the electronic component body. and an elastic resin is provided on the side surface of the electronic component body, the elastic resin covering the lead to its tip except for the solder surface of the lead, The lead has a leaf spring portion that is folded over in the vertical direction between its base and the solder surface. Effect of the Invention

[0009] According to the present invention, by giving the leads a spring shape and covering the leads with elastic resin, the spring shape of the leads and the elastic resin work together to absorb impact, thereby providing a surface mount component that can prevent bending of the leads and breakage at the base of the leads. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view showing an example of a surface mount component with the elastic resin removed. [Diagram 2] 1 is a perspective view showing an example of a surface mount component of the present invention; [Diagram 3] 2 is a cross-sectional view of a main portion of a lead portion of a surface mount component of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The surface mount component of the present invention will now be described in detail. Surface mount components are electronic components that are not mounted by inserting the tips of leads into holes in a wiring board, but rather by connecting the leads directly to a conductor pattern formed on the surface of a wiring board by soldering. As shown in FIG. 1, the surface mount component of the present invention comprises an electronic component body 1 and a plurality of gull-wing shaped leads 2 extending from the side of the electronic component body 1, and as shown in FIG. 2, the leads are covered with elastic resin 3.

[0012] As shown in FIG. 3, the lead 2 extends from the side of the electronic component body 1 toward the solder surface 22, and has a leaf spring portion 21 having a folded shape, as shown in the circled portion in FIG. 3, between the base where the lead is connected to the electronic component body 1 and the solder surface 22.

[0013] In the present invention, the "solder surface" refers to the surface on which soldering is performed, that is, the surface that is bonded to the wiring board.

[0014] By providing the lead with the leaf spring portion, even if an impact is applied to the lead when it is dropped, the leaf spring portion absorbs the impact, thereby preventing plastic deformation of the lead.

[0015] The leaf spring portion may be folded in an in-plane direction of the solder surface, or may be folded in an in-plane direction of the solder surface, or may be folded in both the in-plane direction and the in-plane direction.

[0016] By having a shape in which the solder surface is folded in the out-of-plane direction, the impact when a surface-mounted component is dropped while being placed on a wiring board, i.e., the external force received from the underside of the lead, can be efficiently absorbed, and plastic deformation of the lead can be prevented.

[0017] The surface mount component of the present invention has an elastic resin on the side surface of the electronic component body. As the elastic resin, an insulating resin having heat resistance capable of withstanding the heat generated during soldering can be used, and an example of such a resin is silicone rubber.

[0018] The elastic resin covers the entire lead from its base to its tip, except for the solder surface, and prevents all external forces from being applied to the lead.

[0019] That is, when the lead receives an external force from the lower solder surface side, the leaf spring portion of the lead elastically deforms and presses the elastic resin, which then elastically deforms.

[0020] Therefore, an external force applied to the lead is dispersed to the elastic resin, and the elastic resin reduces the amount of deformation of the leaf spring portion, so that the leaf spring portion can be prevented from being deformed beyond its yield point.

[0021] In addition, when an external force is applied to the lead from above, the elastic resin first elastically deforms to mitigate the external force, and then, if the external force cannot be absorbed by the deformation of the elastic resin alone, the leaf spring portion of the lead elastically deforms to attenuate the external force.

[0022] Therefore, the external force acting on the leaf spring portion is reduced, and the leaf spring portion is prevented from being deformed beyond its yield point.

[0023] It is preferable that when the leaf spring portion and the elastic resin are subjected to the same external force, the amount of deformation of the elastic resin is greater than that of the leaf spring portion.

[0024] The deformation amount of the leaf spring portion refers to the deformation amount when only the leaf spring portion of the lead is cut out, and the deformation amount of the elastic resin refers to the deformation amount of the elastic resin when the portion covering the leaf spring portion is cut out with the same width as the leaf spring portion in the direction in which the leaf spring portion is folded.

[0025] Because the elastic resin is softer and more easily deformed than the leaf spring portion, when an external force is received by the lead and transmitted to the elastic resin, for example when a surface mounted component receives an external force from below, the elastic resin can resist the external force and prevent the amount of elastic deformation of the leaf spring portion from becoming large, thereby reliably reducing the amount of deformation of the leaf spring portion.

[0026] In this way, in the surface mount component of the present invention, the leaf spring portion of the lead and the elastic resin covering the entire lead work together to attenuate external forces, preventing the external forces from being transmitted through the lead to the main body of the electronic component.

[0027] Therefore, not only can plastic deformation of the leads be prevented, but also damage to the base portions of the leads can be prevented. In addition, since there is no need to thicken the leads to increase the rigidity of the leads themselves, the leads can be made thinner, enabling surface mount components to be made smaller.

[0028] It is preferable that the tip of the solder surface of the elastic resin coincides with the tip of the lead. This makes it possible to prevent misalignment between the joint of the lead and the joint of the wiring board even if the lead is covered with the elastic resin. In addition, because the lead is covered with the elastic resin, it is also possible to prevent foreign matter from adhering to the lead.

[0029] Furthermore, since the solder surfaces of the leads are exposed from the elastic resin, this, together with the prevention of plastic deformation of the leads, makes it possible to prevent the occurrence of solder defects during mounting. [Explanation of symbols]

[0030] 1 Electronic component body (package) 2 Lead 21 Leaf spring part 22 Solder surface 3. Elastic resin

Claims

1. A surface mount component comprising an electronic component body and a plurality of gull-wing shaped leads extending from a side surface of the electronic component body, a side surface of the electronic component body having an elastic resin covering the lead to its tip except for the solder surface of the lead; A surface mount component, wherein the lead has a leaf spring portion that is folded over from its base to the solder surface.

2. 2. The surface mount component according to claim 1, wherein the leaf spring portion has a shape folded over in an out-of-plane direction of the solder surface.

3. 2. The surface mount component according to claim 1, wherein the amount of deformation of the elastic resin is greater than that of the leaf spring when the leaf spring and the elastic resin are subjected to the same external force.

4. 2. The surface mount component according to claim 1, wherein the elastic resin has an in-plane tip of the solder surface coinciding with the tip of the lead.

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