JPS5925383B2 - semiconductor equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor device with a thin structure assembled on a wiring board.

Making electronic wristwatches, electronic desktop calculators, etc. thinner and more compact has become an important development element for increasing the added value of products, and therefore, the semiconductor devices and other parts that are incorporated into these types of electronic devices are becoming more and more important. Similarly, there is a strong desire for thinner and smaller devices.

Reducing product costs is also an important factor during development.
Due to these considerations, the circuit boards of electronic wristwatches and the like have changed from ceramic substrates to glass epoxy substrates, and the sealing method has changed from hermetic sealing to resin potting. In a semiconductor device using a plastic substrate such as glass epoxy, a semiconductor chip 2 is fixed on a wiring board 1 as shown in FIG. 3 in a potted structure and a desire to make it thinner as shown in FIG. There is a structure in which the resin 3 is potted after wire bonding.

However, semiconductor devices having any of the above structures have the following drawbacks. In other words, when resin potting is performed, liquid resin is potted or semi-hardened pellet resin is placed on a chip and heated to melt and harden. As shown in the figure, the product swells into a hemispherical shape due to the surface tension of the resin, increasing the thickness of the product. In addition, since the liquid resin has fluidity, it is easily affected by the horizontality of the substrate, the viscosity of the resin, and the subtle surface condition of the substrate. The purpose of thinning and downsizing cannot be achieved due to the occupying area.The present invention was made in view of the above-mentioned drawbacks of the conventional device. This arrangement suppresses the phenomenon of convex swelling due to the surface tension of the resin, and controls unstable outflow due to the fluidity of the resin using the fiber components, making it thin, small, and shaped. This provides a semiconductor device with a similar structure.

The present invention will be described in detail below with reference to Examples. In FIG. 2, a semiconductor chip 2 is fixed to a wiring board 1 in which a recess 4 is carved into which the semiconductor chip 2 can be housed, and a conductor 5 provided around the recess 4 on the wiring board surface and a conductor 5 on the chip are connected to each other. A wire 6 is used to connect the viewing pole to the viewing pole.

The recessed opening of the semiconductor chip 2 assembled on the wiring board 1 is sealed with a resin sheet 7 and isolated from the outside.
Here, the resin sheet 7 is not composed of a resin component alone, but contains a fiber material. As the fiber material, for example, a woven fabric or a non-woven fabric made of plastic fibers such as polyester or polyethylene, or inorganic fibers such as glass metal is used. The resin sheet 7 can be manufactured through the following two manufacturing processes using the force method in which the fiber material and the resin material are laminated and mixed.

That is, before supplying the recess opening 4 to the sealing process, the resin and fibers are blended in advance and laminated in a sheet form, and a woven fabric or wood fabric made of the above material is impregnated with the resin to half the resin. The cured product is cut into desired dimensions taking into account the opening of the recess and supplied to the semiconductor chip sealing process. Here, the thickness of the fiber material is approximately 0.05 to 0.20 wrm, and the thickness of the sheet 7 including the thickness of the impregnated resin is 0.05 to 0.20 wrm.
It is formed to about 1 to 1.5 m. Relatively thin 0.
The sheet 7 having a thickness of about 1 to 0.3 Tvn can be produced by a normal blibreg manufacturing method, and is applied when there is no need to specifically fill and seal the semiconductor chip storage space with resin, as shown in FIG. Ru. In addition, for sheet 7 with a thickness of 0.47 m or more, semi-hardened resin powder is placed on the fiber material, passed through gaps such as rolls to a constant thickness, heated and melted, and partially impregnated into the fiber material. It is used in devices in which the recessed space needs to be sealed with relatively multiple resin components. Resin sheet 1 torn by the above manufacturing method
The recess to which the semiconductor chip 2 has already been fixed is placed with a lid on it, and the semi-hardened resin is heated and melted in a heating furnace or the like, and then hardened and sealed. The above embodiment describes the case where a layered mixture of resin and fiber material is installed in the recess opening, but it is also possible to mix the fiber material and resin during the process of assembling the semiconductor chip and the wiring board using liquid resin. I can do it. That is, as shown in FIG.
A sealing liquid resin 7a is dropped onto the die-bonded and wire-bonded surface of the chip 2, and a fibrous material Rb cut to a desired size is placed thereon to harden the resin. The resin spreads in the fiber material and on the surface, and the affinity between the fiber material and the resin draws the fiber material to the substrate and fixes it, and the chip is sealed with a resin-impregnated sheet as in the previous embodiment. . In the cured state, the resin does not spread abnormally to the periphery, and the upper surface is finished almost flat. In both of the above embodiments, the semiconductor chip die-bonded to the wiring board may be a chip whose surface is previously undercoated with a resin such as epoxy, silicone, or polyimide to improve moisture resistance. As described above, according to the present invention, by sealing a semiconductor chip using a sealing resin sheet made of a mixture of plate-shaped fiber materials, it is possible to prevent the resin from swelling into a hemispherical shape as in conventional devices. Furthermore, since the semiconductor chip is die-bonded to the bottom of the recess formed in the wiring board, the thickness of the wiring board can be utilized, making it possible to obtain an even thinner device.

Further, once the fiber size is determined, the fibers can prevent the resin from spreading due to leakage of the resin and the fiber material, and a semiconductor device having a desired shape can be obtained.

[Brief explanation of the drawing]

1A and 1B are cross-sectional views of a conventional device, FIG. 2 is a cross-sectional view of an embodiment according to the present invention, and FIG. 3 is a cross-sectional view of another embodiment according to the present invention. DESCRIPTION OF SYMBOLS 1...Wiring board, 2...Semiconductor chip, 4...Recess, 5...Wiring conductor, 6...
... wire, 7 ... sealing resin sheet.

Claims (1)

[Claims] 1. An electrical connection is established between a wiring board in which a recess for accommodating a semiconductor chip is formed and a conductor terminal is formed on the top surface of the recess, and a conductor terminal that is die-bonded to the bottom surface of the recess of the wiring board. 1. A semiconductor device comprising: a semiconductor chip having a molded structure; and a flat resin sheet containing a fiber material and sealing an opening of the recess.