JPS60127749A - Power semiconductor device - Google Patents

Abstract

PURPOSE:To enhance the reliability by coating in advance silicone grease on a mounting surface, and using means for coating a painted surface to the time point when closely contacting and securing the using step, thereby eliminating the possibility of mixing a foreign material. CONSTITUTION:After manufacturing steps are finished, a polyethylene film 7 is coated through a silicone grease 5 on a copper base 5 up to the using step, a polyethylene film 7 is separated at the using step, and the silicone grease 6 surface is closely contacted with and secured to a cooler. Thus, when a product is associated, it can prevent a foreign material from mixing to enhance the reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a power semiconductor device that has good thermal conductivity and improved cooling effect.

[Prior art]

A conventional device of this type is shown in FIG. That is, in this figure, 1 is a power semiconductor device, for example, a transistor module, 2 is the emitter of the transistor module 1, 3 is the base of the transistor module 10, 4 is the collector of the transistor module 1, and 5 is the transistor This is a mounting surface for closely fixing the module 1 to a cooling body (not shown) K, and is made of, for example, a copper base.

Next, the operation will be explained. Transistor module 1
When the transistor is conducting current, heat is generated due to loss in the transistor. As a rule, the junction temperature of the transistor must be kept within the allowable value (the heat generated in the jack is conducted to the copper base 5, which is the mounting surface to the cooling body, and is tightly fixed to the cooling body through silicone grease, It conducts RTK heat to cool it.

Conventional power semiconductor devices have a length of 5 km as described above, so it is necessary to apply silicone grease during the usage process when closely fixing them to a cooling body. This is the process of assembling applied products using equipment, and it is a process that often involves cutting wiring lead wires.When applying silicone grease in this process, it is necessary to apply silicone grease to power semiconductors without the risk of contamination. Compared to the manufacturing process of the device, there are many foreign substances, and there are disadvantages such as foreign substances can get mixed into the tightly fixed surfaces coated with silicone grease, which can cause poor thermal conductivity.

[Summary of the invention]

The present invention has been made to eliminate the drawbacks of the conventional products as described above, and is intended to be used in manufacturing processes that have an environment in which there is little risk of contamination of the mounting surface of power semiconductor devices with foreign matter.
It is an object of the present invention to provide a highly reliable power semiconductor device that is less likely to be contaminated with foreign matter by applying silicone grease in advance and covering the coated surface at the time f when it is tightly fixed during the use process.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 2 and 3.

In these figures, 1 to 5 are the same as in Fig. 1, and 6 is a thermally conductive grease applied to the copper base 5, which is the mounting surface for the cooling body, such as silicone grease. It will be done. 1 is coated with NRS silicone grease 6 applied to the copper paste 5 (removably attached t'1k, for example, a polyethylene film which is a flexible material coating).

Next, the effect will be explained. When the transistor module is passing current, heat is generated due to losses in the transistor, and the steel base SIL is configured to conduct heat.

Therefore, in this invention, after the above manufacturing process is completed,
Until the use process, polyethylene [7] was pasted on the copper base 5 through 6 pieces of silicone grease as shown in Figure 2. ) In order to keep the jigginction temperature of the transistor within an allowable range, the polyethylene film 1 is peeled off, and the silicone grease 6 surface is closely fixed to a cooling body to conduct heat to the cooling body for cooling.

In the above embodiment, the transistor module 1 has been described, but the same effect can be achieved with other power semiconductor devices such as a SIRIS module or a GTO module.

Further, in the above embodiment, silicone grease 6 was used, but any thermally conductive grease can have the same effect.

Further, in the above embodiment, the polyethylene film 7 is used, but any film may be used as long as it covers the thermally conductive grease, and the same effect will be obtained.

〔Effect of the invention〕

As explained above, the present invention involves applying thermally conductive grease to the copper base that is the mounting surface of the power semiconductor device to the cooling body, and covering the thermally conductive grease with an appropriate film.
Since the film is peeled off and tightly fixed to the copper base Z cooling body through thermally conductive grease in a process where there is no risk of contamination of foreign matter, the product cannot be applied in a process where there is a risk of contamination of foreign matter. This also has the effect of preventing foreign matter from entering during assembly, resulting in a highly reliable power semiconductor device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional power semiconductor device, FIG. 2 is a perspective view showing a power semiconductor device IT according to an embodiment of the present invention, and FIG. 3 is a partially enlarged view of FIG. 2. In the figure, 1 is a transistor module, 5 is a copper base, and 6 is a transistor module.
7 is silicone grease, and 7 is a polyethylene film. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others)

Claims (1)

[Claims] In a power semiconductor device having a mounting surface T'LL for a stator in close contact with a cooling body via thermally conductive grease, the thermally conductive grease y! is provided on the mounting surface. - A power semiconductor device in which, after coating, the mounting surface is removably covered with a coating.