JPH0418399A - Ic module - Google Patents

Abstract

PURPOSE:To prevent the overflow of a molding resin at the time of the sealing with said resin and to enhance the adhesive strength in the process succeeding to the sealing process by providing a linear (comb-like) pattern parallel to the edge of the shape of a molding resin seal to the wiring pattern on a printed circuit board at the position corresponding to the edge of the shape of the molding resin seal. CONSTITUTION:An IC chip 3 and a wiring pattern 6 are sealed by a molding resin 9 composed of an epoxy resin so as to cover a part on the side of the IC chip 3 of the wiring pattern 6. In this case, a wiring pattern 15 is provided in a comb-like pattern at the position corresponding to the edge part of the shape (generally a square) of the molding resin 9 almost in parallel to said edge part. This pattern is not especially limited to the comb-like shape and may be a linear pattern almost parallel to the edge part. This pattern is formed from a copper foil simultaneously with the original wiring pattern 6 and, therefore, the thickness thereof becomes same to that of the wiring pattern. That is, the shape of the wiring pattern just achieves the function of a weir (stopper) when the molding resin is injected to prevent the overflow of the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an IC module, and particularly to a wiring pattern for an IC module used in an IC card.

(Prior Art) FIGS. 2(a) and 2(b) show configuration diagrams of a conventional IC module. The figure (a) is a plan view of the side on which the IC chip is mounted, that is, the top surface, and the figure (b) is a cross-sectional view.

In recent years, IC cards have become popular as portable storage media. This IC card has an IC module equipped with an IC chip such as a memory or a microcomputer built into a card base of the size of a credit card or cash card.

As shown in Figure 2, the IC module is installed on one side (the back side in the figure) of a circuit board l made of a glass epoxy laminate, etc.
A plurality of external connection terminals 2 are provided on the other side (
An IC chip 3 is mounted on the front surface). The surface on which the IC chip 3 is mounted is provided with a counterbore portion 5 on which the IC chip 3 is mounted, and the IC chip 3 is fixed thereto. Further, on that surface, a wiring pattern 6 (generally made of copper foil or the like and plated with gold or the like) is provided around the IC chip 30 to connect with the external connection terminal (ponding pad) of the IC chip 3. It is formed. In other words, it has a structure similar to that of a printed circuit board.

Of course, the external connection terminal of the IC chip 3 and the tip of the wiring pattern 6 on the IC chip side are connected by a thin metal wire 7. The other end of the wiring pattern 6 is connected to the external connection terminal 2 via a through hole 8. The IC chip 3 and a part of the wiring pattern 6 on the IC chip 3 side are sealed with a mold resin 9 made of epoxy resin or the like, and the shape thereof is generally a square.

(Shaded area in the figure) (Problem to be solved by the invention) However, in the above-mentioned IC module, when sealing with the mold resin 9, the wiring pattern 6 on the surface of the circuit board 1 at the edge of the mold resin 9 is There was a problem in that the mold resin easily overflowed to the outside from the peripheral area (mainly at that area where there was a step).

The level difference is generally 40 to 60 μm, and the resin flows out from this gap due to the injection pressure when sealing with mold resin, resulting in a subsequent decrease in adhesive strength in the production of IC cards and the like.

Countermeasures have been considered to solve this problem, such as applying a solder resist on the wiring pattern to reduce the gap when injecting the molding resin, but this also has problems such as weak adhesive strength between the solder resist and the IC card, and partial solder resist. Using a resist increases the number of steps required for manufacturing the substrate, which is not desirable.

(Means for Solving the Problems) In order to solve the problems of NiMino, the present invention provides a wiring pattern on a circuit board at a position corresponding to the edge of the molded resin sealing shape, and a line parallel to the edge. (It has a (shi-shaped) pattern.

(Function) Since the above-mentioned pattern is provided in the wiring pattern, the pattern acts as a dam against overflowing of the resin, thereby making it possible to prevent the above-mentioned problem.

(Example) FIG. 1 shows a configuration diagram of an IC module of the present invention. (a
) is a plan view of the IC chip side (top surface), and (b) is a cross-sectional view. The same parts as in FIG. 2 for explaining the prior art are given the same symbols.

The configuration is the same as the conventional configuration except for the wiring patterns 15 and 18, so a description thereof will be omitted.

As shown in the figure, a comb-shaped pattern is provided in the wiring pattern 15 at a position corresponding to the edge of the molded resin 9 (generally rectangular) and approximately parallel to the edge. It suffices if the pattern is a linear pattern that is almost parallel to the side. (The upper and lower parts of Figure (a) are close to that.) This pattern is similar to the conventional pattern and can be made of copper foil etc. to form the original wiring pattern (see Figure 2). It is obvious that it can be formed simultaneously with step 6). Therefore, the thickness of this pattern is the same as that of the wiring pattern.

In other words, the shape of this wiring pattern serves as a layer (stopper) when molding resin is injected, and prevents the resin from overflowing.

(Effects of the Invention) As mentioned above, since the wiring pattern of the present invention is provided, there is no overflow when sealing with mold resin, which improves the adhesion strength in the subsequent process, resulting in a highly reliable product. realizable.

[Brief explanation of the drawing]

FIG. 1 shows a configuration diagram of an IC module according to the present invention, and FIG. 2 shows a configuration diagram of a conventional 16.15C module. Circuit boards, IC chips, wiring patterns, comb patterns.

Claims (1)

[Scope of Claims] An IC module mounted with an IC chip, having a wiring pattern connected to an external connection terminal of the IC chip, and in which the entire IC chip and a part of the wiring pattern are sealed with resin, An IC module characterized in that a wiring pattern around a position corresponding to an edge of the shape of the resin sealing is provided with a linear pattern substantially parallel to the edge.