JPH05251490A - Method of unsealing package sealed with resin - Google Patents

Abstract

PURPOSE:To enable it to cope with the downsizing of a package and the upsizing of a semiconductor chip and the surface of the semiconductor chip to be exposed completely without giving damage, in the method of unsealing a package sealed with resin which has covered the semiconductor chip the surface of which is protected with a polyimide film with molding resin. CONSTITUTION:The surface of a semiconductor chip 1 is exposed by soaking it in chemicals or applying plasma treatment thereby removing mold resin 4 and a polyimide film 2, and then the mixed liquid between hydrate hydrauzine and ethylene diamine is dipped all over the surface of the semiconductor chip 1 so as to remove the residuum on the surface of the semiconductor chip 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of opening a semiconductor device package sealed with resin.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing the structure of a resin-sealed package in which a semiconductor chip is housed. In the figure, 1 is a semiconductor chip, 2 is a polyimide film formed as a protective film on the surface of the semiconductor chip 1, 3 is a die frame on which the semiconductor chip 1 is mounted, and 4 is the semiconductor chip 1.
And the mold resin 5 that covers the periphery of the die frame 3.
Is a lead frame.

In order to expose the surface of the semiconductor chip 1 by opening such a resin-sealed package, the following method has been conventionally used. FIG. 4 is a flowchart showing a conventional method for opening a resin-sealed package. As shown in the figure, there are two methods, one is a method of directly dipping or plasma treating a sample, and the other is a method of mechanically excavating a sample and then dipping or chemical treatment. The chemical solution immersion is performed by dropping a chemical solution of acid onto the surface of the mold resin 4 on the region of the semiconductor chip 1. The plasma treatment is performed by etching the entire surface of the mold resin 4 with, for example, Freon (CF4) gas, or by etching only the mold resin 4 on the region of the semiconductor chip 1 using a mask made of aluminum tape, for example. The mechanical excavation is performed by mechanically forming a recess on the surface of the mold resin 4 on the region of the semiconductor chip 1.

By performing the above processing, the mold resin 4 on the region of the semiconductor chip 1 and the polyimide film 2 on the surface of the semiconductor chip 1 are removed to expose the surface of the semiconductor chip 1. The removal of the polyimide film 2 is performed at the same time when the mold resin 4 is removed by immersion in a chemical solution or plasma treatment. FIG. 5 is a sectional view showing the structure of a resin-sealed package opened by such a conventional method. In FIG. 5, 1 to 5 are the same as those shown in FIG. 3, and 6 is a residue of the mold resin 4 and the polyimide film 2.

[0005]

As shown in FIG. 5, the resin-sealed package unsealed by the conventional unsealing method has the mold resin 4 and the residue 6 of the polyimide film 2 in the peripheral portion on the semiconductor chip 1, as shown in FIG. There was a problem that the surface of the semiconductor chip 1 was not completely exposed. If the time of chemical solution immersion or plasma treatment is increased to remove the residue 6, the surface of the semiconductor chip 1 is damaged. For this reason, a method of opening the flat area where the mold resin 4 is removed so as to be larger than that of the semiconductor chip 1 so as to prevent the residue 6 from being opened has been conventionally performed, and will be described below with reference to FIG. In the figure, 1 to 5 are the same as those shown in FIGS. As shown in the figure, a region C where the mold resin 4 is removed is extended by a length C around the chip size of the semiconductor chip 1. The length C is constant regardless of the type of the semiconductor chip 1, but the thickness A in the lateral direction of the molding resin 4 has become shorter as the package becomes smaller and the semiconductor chip 1 becomes larger recently. For this reason, the length B (= A-C) is inevitably shortened, but the length B is required to be about 0.5 mm to 1 mm due to problems such as spilling of the chemical solution, so that the package can be made smaller and the semiconductor can be made smaller. It was not possible to cope with the increase in size of the chip 1.

The present invention has been made in order to solve the above problems, and can cope with the miniaturization of the package and the enlargement of the semiconductor chip, and the surface of the semiconductor chip can be completely completed without damaging the semiconductor chip. The present invention provides a method for opening a resin-sealed package capable of exposing a package.

[0007]

A method for opening a resin-sealed package according to the present invention is a method for opening a resin-sealed package in which the periphery of a semiconductor chip whose surface is protected by a polyimide film is covered with resin. The step of exposing the semiconductor chip surface by removing the resin and the polyimide film by subjecting the package to chemical solution immersion or plasma treatment, and then applying the immersion in a mixed solution of hydrated hydrazine and ethylenediamine to the semiconductor And a step of removing the residue on the surface of the chip.

[0008]

The method for opening the resin-sealed package according to the present invention is the same as the conventional method, in which the surface of the semiconductor chip is exposed by immersion in a chemical solution or plasma treatment, and then the residue consisting of the polyimide film and the resin on the surface of the semiconductor chip is removed. In order to remove it, it was immersed in a mixed solution of hydrated hydrazine and ethylenediamine. This mixed solution of hydrated hydrazine and ethylenediamine causes less damage to the semiconductor chip, and also has an action of dissolving and removing the polyimide, and dissolves and removes the polyimide film which is the lower layer portion of the residue. At the same time, the resin that is the upper layer portion is also dissolved and removed, and the surface of the semiconductor chip can be completely exposed without damage.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a flowchart showing a method for opening a resin-sealed package according to the present invention. Mechanical drilling, chemical immersion and plasma treatment are the same as in the conventional case.
From the time point when the unsealing is completed by the conventional method shown in (3), the residue removing liquid is further dipped to complete the unsealing. FIG. 2 is a sectional view showing the structure of a resin-sealed package that has been unsealed by the unsealing method according to the embodiment of the present invention. In the figure, 1 to 5 are the same as those described above.

The details will be described below. First, the resin-sealed package is opened by the same method as the conventional one. The mold resin 4 and the polyimide film 2 on the region of the semiconductor chip 1 are removed to expose the surface of the semiconductor chip 1, but a residue 6 is formed by the polyimide film 2 and the mold resin 4 on the periphery of the semiconductor chip 1 ( (See FIG. 5). Next, as a residue removing liquid, for example, a liquid mixture of hydrated hydrazine such as PIQ etchant (trade name of Hitachi Chemical Co., Ltd.) and ethylenediamine is dripped on the entire surface of the semiconductor chip 1 for immersion. The mixed liquid of hydrated hydrazine and ethylenediamine has an action of dissolving and removing the polyimide film 2, and the polyimide film 2 as the lower layer portion of the residue 6 is dissolved and removed, and at the same time, the mold resin of the upper layer portion is removed. 4 is also dissolved and removed. Further, the above-mentioned mixed liquid causes less damage to the semiconductor chip 1. Thus, the residue 6 is removed and the surface of the semiconductor chip 1 is completely exposed to complete the opening of the resin-sealed package (FIG. 2).

[0011]

As described above, according to the present invention, since the residue on the surface of the semiconductor chip is removed by the mixed liquid of hydrated hydrazine and ethylenediamine, the surface of the semiconductor chip is completely exposed without damage. can do. For this reason, it is not necessary to make the planar area for removing the resin larger than that of the semiconductor chip, and it is possible to cope with the miniaturization of the package and the enlargement of the semiconductor chip.

[Brief description of drawings]

FIG. 1 is a flowchart showing a method for opening a resin-sealed package according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of a resin-sealed package that has been unsealed by an unsealing method according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the structure of a resin-sealed package.

FIG. 4 is a flowchart showing a conventional method for opening a resin-sealed package.

FIG. 5 is a cross-sectional view showing the structure of a resin-sealed package that has been unsealed by a conventional unsealing method.

FIG. 6 is a cross-sectional view showing the structure of a resin-sealed package that has been unsealed by a conventional unsealing method.

[Explanation of symbols]

 1 Semiconductor Chip 2 Polyimide Film 4 Mold Resin as Resin 6 Residue

Claims (1)

[Claims] 1. A method of unsealing a resin-sealed package in which a semiconductor chip, the surface of which is protected by a polyimide film, is covered with a resin. In the method, the package is subjected to a chemical immersion or plasma treatment to remove the resin and the polyimide film. And then exposing the surface of the semiconductor chip, and then dipping in a mixed solution of hydrated hydrazine and ethylenediamine to remove the residue on the surface of the semiconductor chip, the resin encapsulation How to open the mold package.