JPH062702U - Semiconductor element mounting clip - Google Patents

Abstract

(57) [Summary] [Purpose] A switching transistor 30 with a cap 40 made of silicone rubber on the semiconductor element mounting clip 10.
When the heat sink 20 and the front side surface 21 of the heat sink 20 are sandwiched and attached from the outside, the silicon rubber cap 40 is prevented from being easily scratched or torn. [Structure] Even in the semiconductor element mounting clip 10, an edge 121 of the clip that comes into contact with the silicon rubber cap 40 has a smooth shape.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a semiconductor element mounting clip which sandwiches a semiconductor element covered with a heat conductive cap or the like and one surface of a heat sink from the outside so as to adhere them to each other.

[0002]

[Prior art]

 A heat sink may be used to efficiently dissipate the heat generated from a semiconductor element. However, if the heat conductivity between the semiconductor element and the heat sink is poor, the heat sink's original heat dissipation effect cannot be obtained, so the semiconductor element should be covered with a silicon rubber cap with high heat conductivity. Using a component called a mounting clip, the semiconductor element and one surface of the heat sink are brought into close contact with each other.

As shown in FIG. 4, a conventional semiconductor element mounting clip is a component formed by molding stainless steel or the like into a substantially U-shaped cross section, and a semiconductor element covered with a silicon rubber cap and one surface of a heat sink are outside. It can be attached by sandwiching it from the inside. A silicone rubber tube may be used instead of the silicone rubber cap.

[0004]

[Problems to be solved by the device]

 However, in the case of the above-mentioned semiconductor element mounting clip, the elastic force of the clip itself may be set to the extent necessary for sufficient adhesion between the semiconductor element and the heat sink, so the mounting work should not be done carefully. This has the drawback that the silicone rubber cap may be scratched or torn by the edge of the clip (indicated by α in Figure 4).

Since the location where the silicone rubber cap is damaged or torn is on the side opposite to the heat sink, it does not pose a serious problem in terms of heat, but it causes various problems in terms of electrical characteristics. May occur. For example, when the silicone rubber cap also acts as an insulator, it usually causes a short because the heat sink is grounded. Even when the semiconductor element is molded with resin or the like, the withstand voltage and creepage distance between the semiconductor element and the heat sink cannot be sufficiently secured, which may cause a problem in this respect. In particular, in the case of a switching regulator, when the switching transistor as a semiconductor element belongs to the primary side system, while the heat sink belongs to the secondary side system, if the silicon rubber cap is scratched or torn, the prescribed creepage distance etc. In some cases, the standard cannot be met, and in this case, it is essential to inspect the silicon rubber caps strictly.

[0006] Therefore, when the silicon rubber cap is damaged or torn, it must be replaced with a new one, and the manufacturing cost becomes high because it requires manual work.

The present invention was created in view of the above background. The purpose of the present invention is that a silicon rubber cap or the like can be easily scratched or torn during mounting work. It is to provide a semiconductor device mounting clip which is not provided.

[0008]

[Means for Solving the Problems]

 The semiconductor device mounting clip according to the present invention is characterized in that the edge of the clip that comes into contact with the heat conductive cap or the heat conductive tube is formed into a smooth shape.

[0009]

[Action]

 When mounting the semiconductor element mounting clip by sandwiching the semiconductor element covered with the heat conductive cap or the heat conductive tube and the one surface of the heat sink from the outside, the edge of the clip contacts the heat conductive cap, etc. , This edge has a smooth shape, so it will not damage or tear the heat conductive cap.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 is a perspective view showing a situation in which a semiconductor element mounting clip is attached, FIG. 2 is a perspective view showing a state in which a semiconductor element mounting clip is attached, and FIG. 3 is a perspective view of a semiconductor element mounting clip.

The semiconductor element mounting clip described here by way of example is used to bring the switching transistor mounted on the substrate of the AC / DC switching regulator into close contact with the heat sink. The structure of the semiconductor element mounting clip will be described later, and its usage will be described first with reference to FIGS. 1 and 2. However, the circuit board and other components of the switching regulator are omitted in FIGS.

In the figure, 10 is a semiconductor element mounting clip also called a transistor mounting clip, 20 is a heat sink made by bending a metal plate, 30 is a switching transistor as a semiconductor element, and 40 is a silicon rubber as a heat conductive cap. It is a cap made.

The switching transistor 30 is a component belonging to the primary side system of the AC / DC switching regulator. On the other hand, the heat sink 20 is a component belonging to the secondary system and is electrically connected to the ground line of the secondary system.

As shown in FIG. 1, the switching transistor 30 is covered with a silicon rubber cap 40 cut into a predetermined length. Although the switching transistor 30 is arranged adjacent to the front side surface 21 which is one surface of the heat sink 20, the semiconductor transistor mounting clip 10 is used to cover the switching transistor 30 covered with the heat conductive cap 40 and the front side surface 21 of the heat sink 20 ( (Corresponding to the metal plate in the claim) is sandwiched from the outside to bring them into close contact with each other. That is, when the semiconductor element mounting clip 10 is sandwiched and mounted as shown in FIG. 2, the heat generated from the switching transistor 30 is efficiently transmitted to the heat sink 20 through the silicon rubber cap 40, and the heat dissipation effect of the heat sink 20 is originally obtained. Will be obtained.

In this embodiment, as shown in FIG. 1, a hole 211 is provided on the front side surface 21 of the heat sink 20 to prevent the semiconductor element mounting clip 10 from easily falling off, and the heat sink 20 A notch 212 is provided at the end of the front side surface 21 of the semiconductor device 20 to prevent the semiconductor element mounting clip 10 from being easily displaced.

Next, the structure of the semiconductor element mounting clip 10 will be described with reference to FIG. The semi-conductor element mounting clip 10 is an elastic component made of stainless steel or the like and formed into a substantially U-shaped cross section. Although this is an integral part, for convenience of explanation, it is assumed that it is composed of an L angle portion 11 and an R portion 12.

In the semiconductor element mounting clip 10, the R portion 12 is a portion of the clip that comes into contact with the silicon rubber cap 40 (the L angle portion 11 also partially comes into contact with the silicon rubber cap 40. , I shall not think about this). Both sides of the R portion 12 are bent to the upper side in the figure, whereby the edge 121 of the clip has a smooth shape. That is, no sharp portion is left on the edge 121 of the clip since the semiconductor element mounting clip 10 was molded.

It should be noted that after the semiconductor element mounting clip is molded, a process for smoothing the edge shape of the clip may be performed.

On the other hand, most of the L angle portion 11 is a portion that contacts the front side surface 21 of the heat sink 20. The L-angle portion 11 is formed with a protrusion 111 that engages with a hole 211 provided in the heat sink 20.

Therefore, when the semiconductor element mounting clip 10 is mounted by sandwiching the switching transistor 30 covered with the silicon rubber cap 40 and the front side surface 21 of the heat sink 20 from the outside, the clip edge 121 is made of silicon rubber. Although it will come in contact with the cap 40, the silicone rubber cap 40 is not easily scratched or torn by the smoothened shape of the edge 121 of the clip.

In other words, the silicon rubber cap 40 is not easily scratched or torn even if the operation of mounting the semiconductor element mounting clip 10 is not performed carefully, and no troublesome replacement work is required. The cost can be reduced.

In particular, in the case of a switching regulator, if the silicon rubber cap 40 is scratched or torn, it may not be possible to meet the standards for withstand voltage and creepage distance between the switching transistor 30 and the heat sink 20. In this case, a great merit can be expected in the sense that it is not necessary to strictly inspect the silicon rubber cap 40.

If it is not necessary to give importance to the above-mentioned standards, a silicone rubber tube can be used instead of the silicone rubber cap 40.

Further, once the semiconductor element mounting clip 10 is mounted, it does not easily come off or come off. This is because when the semiconductor element mounting clip 10 is attached, the protrusion 111 on the semiconductor element mounting clip 10 side engages with the hole 211 on the heat sink 20 side, and part of the L angle portion 11 of the semiconductor element mounting clip 10 heats up. This is because it goes into the notch 212 on the sink 20 side. Therefore, there is also an advantage that the reliability of the switching regulator can be improved.

The semiconductor device clip according to the present invention is not limited to the above-described embodiment, and can be applied to any type of heat sink, and its basic shape can be changed according to the type and size of the semiconductor device. Can change. The same is true if a heat conductive tube is used instead of the heat conductive cap.

[0026]

[Effect of device]

 As described above, in the case of the semiconductor device mounting clip according to the present invention, the edge of the clip that comes into contact with the heat conductive cap or the heat conductive tube has a smooth shape. Even if it is not performed, the thermal conductive cap, etc. will not be scratched or torn. Therefore, unlike the case of the conventional example, there is an advantage that the manufacturing cost can be reduced because the troublesome work of replacing the heat conductive cap and the like with a new one is not required.

[Brief description of drawings]

FIG. 1 is a view for explaining an embodiment of the present invention and is a perspective view showing a state in which a semiconductor element mounting clip is mounted.

FIG. 2 is a perspective view showing a state in which a semiconductor element mounting clip is attached.

FIG. 3 is a perspective view of a semiconductor element mounting clip.

FIG. 4 is a diagram for explaining a conventional semiconductor element mounting clip, which is a diagram corresponding to FIG. 3;

[Explanation of symbols]

 10 Semiconductor element mounting clip 111 Protrusion 121 Edge of clip 20 Heat sink 21 Front side surface 211 Hole 30 Switching transistor 40 Silicon rubber cap

Claims (3)

[Scope of utility model registration request] 1. A semiconductor element mounting clip which is an elastic body having a substantially U-shaped cross section, and which sandwiches a semiconductor element covered with a heat conductive cap or a heat conductive tube and one surface of a heat sink from the outside to bring them into close contact with each other, A semiconductor device mounting clip, characterized in that the edge of the clip that comes into contact with the heat conductive cap or the heat conductive tube is formed into a smooth shape. 2. The mounting of the semiconductor element according to claim 1, wherein the portion of the clip that comes into contact with the one surface of the heat sink is provided with a protrusion that is engaged with a hole formed in the one surface of the heat sink. clip. 3. A switching transistor as a semiconductor element and a metal plate as a heat sink are mounted adjacent to each other on a substrate of a switching regulator, and while the switching transistor belongs to a primary side system, the metal plate is The semiconductor element according to claim 1 or 2, which is used for sandwiching the switching transistor, which is covered with a silicon rubber cap as a heat conductive cap, and the metal plate from the outside when they belong to the secondary system, to bring them into close contact with each other. Mounting clip.