JPH0783033B2 - Semiconductor element fixing plate sheet and method of using the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sheet having a semiconductor element fixing plate-like body in which a heat-generating power semiconductor or the like is fixed to a metal heat dissipation plate, and a method of using the same.

[Prior Art] An output element such as a hybrid IC or a power transistor may be destroyed by an abnormal load such as a load short circuit. Therefore, the protection circuit cannot be removed with a large capacity. At this time, in order to set the time of the protection circuit, it is important to design the element itself to have thermal strength. Therefore, in order to reduce the heat generally generated in the semiconductor element and the heat resistance of the portion of the electrical insulation layer where the heat conduction is poor and the heat resistance is large, a heat dissipation plate made of a copper plate or the like having good heat dissipation has a heat dissipation effect. Install the (heat sink) in the circuit.

As a method of forming a heat sink that plays such a role and a power semiconductor to which the heat sink is attached, conventionally, as shown in FIG. 2, the heat sink is manufactured through the following steps.

First, in order to divide the metal plate sheet a into a portion used as the heat sink 2 and a portion not used as the heat sink 2, rolling is performed to provide a convex band portion in the central portion.

Subsequently, the feed holes 4 are formed at regular intervals along one side or both sides of the unused portion of the metal plate sheet a. After that, unnecessary portions other than the above are removed except for the portion which becomes the continuous frame 1 having the feed hole 4, the portion which is used as the heat sink 2, and the portion which becomes the lead 5 connecting these. Then, the plate-shaped sheet a is plated.

Next, a sheet-shaped solder is applied to the portion used as the heat sink 2, and the semiconductor element 3 is mounted thereon. This state is shown in FIG. When mounting the semiconductor element 3 on the heat sink 2, a heating die having a heater is pressed and heated from below at a temperature of 300 to 320 ° C. to be stably fixed.

The heat sink 2 having the semiconductor element 3 mounted in this way
Was cut from the connection portion of the lead 5 and mounted on a circuit board to mount a power semiconductor.

[Problems to be Solved by the Invention] However, in the conventional method as shown in FIG.
If the thickness of the heat sink 2 and the leads 5 mounted is not changed, the cutting stress becomes large when the connecting portion between the heat sink 2 and the leads 5 is cut, and a large stress is generated in the mounted semiconductor element 3 to have an adverse effect. become.

For this reason, it is necessary to specially roll the metal plate-like sheet a used as the heat sink to previously form the band-shaped portion as described above, which makes the unit cost of material processing expensive.

Even when the metal plate sheet a is rolled so as to have different thicknesses as described above, when the semiconductor element 3 is mounted and the connection portion between the heat sink 2 and the lead 5 is cut, The semiconductor element 3 is stressed. Therefore, in order to minimize the stress generated in the semiconductor element 3 and prevent it from being affected by it, it is necessary to handle it with sufficient care.

Further, since the leads 5 for connecting the heat sink 2 and the frame 1 having the feed holes 4 are required, the metal plate sheet has a large number of unused portions, resulting in poor material usage efficiency.

Therefore, in order to solve the above-mentioned problems, the present invention does not use a specially rolled metal plate sheet as a material, and increases the proportion of a portion used as a heat sink. Therefore, it is an object of the present invention to provide a semiconductor element-fixed plate-like sheet which does not adversely affect the mounted semiconductor element when the heat sink is cut and a method of using the same.

[Means for Solving the Problems] That is, the semiconductor element fixing plate-shaped sheet according to the present invention is a long metal sheet having feed holes 4 provided at regular intervals along one side or both sides. From a, the heat sinks 2 for fixing the semiconductor element are punched out at regular intervals,
The punched out heat sink 2 is fitted into the punched hole b of the metal sheet a and temporarily fixed, and the semiconductor element 3 is fixed to the surface of the temporarily fixed heat sink 2.

Furthermore, the method of using the semiconductor element fixing plate-shaped sheet according to the present invention is such that a long metal sheet a having feed holes 4 provided at regular intervals along one side or both sides of the sheet is fixed at regular intervals. The heat sink 2 for fixing the semiconductor element is punched out, and the punched out heat sink 2 is the metal sheet a.
A heat sink 2 having the semiconductor element 3 fixed thereto is used by using a semiconductor element fixing plate member sheet in which the semiconductor element 3 is fixed on the surface of the heat sink 2 which is fitted into the punching hole b of FIG. Is separated from the metal sheet a to obtain a heat sink to which the semiconductor element 3 is fixed.

[Operation] According to the semiconductor element fixing plate-shaped sheet and the method of using the same according to the present invention, it is necessary to specially roll-process the metal plate-shaped sheet a used as the heat sink 2 as shown in FIG. The price of material will be cheaper.

Further, the heat sink 2 is punched out from the metal plate-like sheet a once by pressing, and is again inserted into the punching hole b of the metal plate-like sheet a used as the frame 1, and the semiconductor element 3 is further attached to the heat sink 2. As shown in FIG. 2, the lead 5 for connecting the frame 1 having the feed hole 4 and the heat sink 2 to each other is mounted and used.
Is unnecessary. Therefore, the metal sheet a
The ratio of the portion used as the heat sink 2 in the whole is increased, and the use efficiency of the material is improved. Since the portion not used as the heat sink 2 is also used as the frame 1 for carrying the heat sink 2 having the feed holes 4, it is necessary to ensure the same mount position accuracy as that of the conventional frame 1 as shown in FIG. You can

Further, since the heat sink 2 that has been press-pressed once is press-fitted into the frame 1 again and temporarily fixed, when the heat sink 2 is mounted on a circuit board, the pressure applied when the heat sink 2 is pulled out from the frame 1 is 2 to 2. The force is as low as 3 kg / cm ^2, and the semiconductor element 3 mounted on the heat sink 2 is not stressed, and the stress does not adversely affect the semiconductor element 3.

The semiconductor element-fixed plate-like sheet having the above-described operation is a metal plate-like sheet a in which the heat sink 2 is once removed from the metal plate-like sheet a by press working and the heat sink 2 is used as the frame 1. It is obtained by means of reinserting into the punching hole b, and mounting the semiconductor element 3 on the heat sink 2. Therefore, it is relatively easy to manufacture and its method of use does not require extra steps compared to using conventional carrier sheets.

[Embodiment] An embodiment of the present invention will be described according to steps with reference to the drawings.

First, as shown in FIG. 3 (a), the upper die 6 is pressed against the metal sheet a having a uniform thickness to heat sink 2
Punched out and received by the lower die 7. Then, Fig. 3 (b)
As described above, the heat sink 2 punched out and held on the lower mold 7 is press-fitted into the punching hole b of the metal plate sheet a by the lower mold 7 and fitted and temporarily fixed. As a result, a semiconductor element-fixed plate-like sheet temporarily fixed to the frame 1 composed of the unused part of the metal plate-like sheet a is obtained.

Next, as shown in FIG. 3 (c), using this semiconductor element-fixed plate-like sheet, a sheet-shaped solder 8 is placed on the heat sink 2, and the semiconductor element 3 is mounted thereon, and the sheet-shaped solder is attached. The semiconductor element 3 is stably fixed by pressing and heating 8 by the lower heating die 10 at a temperature of 300 to 320 ° C. FIG. 1 shows the plane of the semiconductor element-fixed plate-like sheet in the state where the heat sink 2 on which the semiconductor element 3 is mounted is temporarily fixed in this manner. Fig. 1 (a)
As can be seen from the above, since there is no lead portion required for the conventional conveying sheet, many heat sinks 2 can be provided per unit area of the sheet, and one side or both sides of the unused portion can be Feed holes 4 are provided at regular intervals along and are used for conveyance. Further, as shown in FIG. 1B, the heat sink 2 on which the semiconductor element 3 is mounted is already cut from the frame 1 and is temporarily fixed to the punching hole b. As in the case of being cut from the frame 1, no load is applied.

After that, as shown in FIG. 3D, the heat sink 2 on which the semiconductor element 3 is mounted is pushed up from the temporarily fixed frame 1 by using the vacuum chuck 11 and the lower mold 12 to separate the frame 1. As shown in Figure (e), the circuit electrodes on the circuit board 14
Heat sink 2 with semiconductor element 3 mounted on 15
Can be mounted to mount a power semiconductor having a metal heat sink on the circuit board 14.

[Effects of the Invention] As described above, according to the semiconductor element fixing plate-shaped sheet and the method of using the same of the present invention, the metal plate-shaped sheet a used for the heat sink 2 and the frame 1 has a thickness of It is not necessary to use different profiled materials, and the material cost can be reduced.

Further, as in the conventional example, the frame 1 having the feed hole 4
Since the part of the lead 5 for connecting the heat sink 2 and the heat sink 2 is not necessary, a large number of heat sinks 2 can be taken out per unit area of the plate-shaped sheet a, and the material usage efficiency is improved. Moreover, the frame 1 left as an unused part
Can also be used for transporting the heat sink 2 and can secure mount position accuracy equivalent to that of the conventional frame 1.

Further, since the heat sink 2 that has been press-pressed once is simply press-fitted into the frame 1 again and temporarily fixed in the punching hole b, when mounting the semiconductor element 3 and then mounting the heat sink 2 on the circuit board, As a pressing pressure when pulling out the heat sink 2 from the frame 1, a large force that affects the semiconductor element 3 is not required, which leads to reduction of product defects.

[Brief description of drawings]

FIG. 1 (a) is a plan view showing an outline of a semiconductor element-fixed plate-shaped sheet of the present invention, FIG. 1 (b) is the above-mentioned AA cross-sectional view, and FIG. FIG. 2 (b) is a plan view showing an outline of the semiconductor element fixing plate-shaped sheet of FIG.
FIGS. 3A to 3E are sectional views showing a step of forming and using a semiconductor element fixing plate sheet according to the present invention to produce a power semiconductor. 1 ... Frame, 2 ... Heat sink, 3 ... Semiconductor element, 4
... Feed hole, 13 ... Circuit board, a ... Metal plate sheet, b
... punched holes

Claims (2)

[Claims] 1. A heat sink for fixing semiconductor elements is punched out at regular intervals from a long metal sheet having feed holes provided at regular intervals along one side or both sides, and this punching is performed. A semiconductor element fixing plate-shaped sheet, wherein a heat sink is fitted into a punched hole of a metal sheet and temporarily fixed, and a semiconductor element is fixed to the surface of the temporarily fixed heat sink. 2. A heat sink for fixing semiconductor elements is punched out at regular intervals from an elongated metal sheet having feed holes provided at regular intervals along one side or both sides, and this punching is performed. The heat sink is fitted into the punched hole of the metal sheet and temporarily fixed, and the semiconductor element is fixed to the surface of the heat sink that is temporarily fixed. A method of using a semiconductor element-fixed plate-shaped sheet, characterized in that a heat sink to which a semiconductor element is fixed is obtained by re-separating the formed heat sink from the metal sheet.