JPH0878814A - Method for manufacturing semiconductor device - Google Patents

Abstract

(57) [Summary] [Object] To provide a method of manufacturing a semiconductor device capable of preventing a solder bridge from being generated between lands of a substrate. [Structure] Ink 6 containing a foaming agent between lands 2 of substrate 1
At least, a step of raising the space between the lands 2 by foaming and curing the ink 6, and a step of mounting the semiconductor 5 on the substrate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device in which an ink containing a foaming agent is printed between lands of a substrate, foamed and cured to raise the spaces between the lands to prevent the generation of solder bridges. Is.

[0002]

2. Description of the Related Art In recent years, the number of pins and pitches of semiconductors have become narrower, and as a result, the land spacing of the substrate on which the semiconductors are mounted has also become narrower.

FIG. 9 is a sectional view showing a state in which a semiconductor is mounted on a substrate in a conventional semiconductor device of this type.
In the figure, 1 is a substrate, 2 is a land arranged on the substrate 1, and 3 is an outer lead of a semiconductor (not shown), which is fixed onto the land 2 by soldering. 4 is a solder bridge generated between the adjacent lands 2.

[0004]

In the conventional semiconductor device, the solder bridge 4 is generated between the adjacent lands 2 as described above due to the narrowing of the land interval due to the narrowing of the pitch of the semiconductor. Since a situation occurs in which the outer leads 3 fixed to each other are electrically short-circuited, for example, in order to increase the dielectric strength between the lands 2, the substrate 1
Although a method of raising the solder resist (not shown) applied to the top by 10 to several tens of μm to prevent the generation of the solder bridge 4, there is a problem that the amount of rise is small and it cannot be prevented sufficiently. there were.

The present invention has been made to solve the above problems, and provides a method of manufacturing a semiconductor device capable of preventing a solder bridge from being generated between lands of a substrate. The purpose is.

[0006]

According to a first aspect of the present invention, there is provided a method of manufacturing a semiconductor device, including a step of printing an ink containing a foaming agent between lands of a substrate, and a step of landing the land by foaming and curing the ink. And at least a step of mounting a semiconductor on the substrate.

A semiconductor device manufacturing method according to a second aspect of the present invention is the method according to the first aspect, in which the semiconductor is mounted on the substrate after the ink is foamed and cured to raise the gap between the lands. Is.

The semiconductor device manufacturing method according to a third aspect of the present invention is the method according to the first or second aspect, wherein the ink is printed around the land.

[0009]

In the method for manufacturing a semiconductor device according to the first aspect of the present invention, the ink printed between the lands of the substrate is foamed and cured to raise the spaces between the lands and prevent the formation of solder bridges.

In the method for manufacturing a semiconductor device according to the second aspect of the present invention, after the ink is foamed and hardened to raise the space between the lands, the semiconductor is mounted on the substrate, so that the semiconductor is foamed and hardened. Prevents the formation of solder bridges without affecting.

Further, in the method for manufacturing a semiconductor device according to the third aspect of the present invention, the ink printed around the land of the substrate is foamed and cured to prevent the rise of the solder around the land and to prevent the formation of solder bridges.

[0012]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view showing a configuration of a semiconductor device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view showing a cross section taken along line II-II in FIG. 1, and FIG. Detailed sectional view showing the enlarged ink section,
4 to 7 are perspective views each showing one step of the method of manufacturing the semiconductor device in FIG.

In the figure, the same parts as those of the conventional one shown in FIG. 5 is a semiconductor that has a plurality of outer leads 3 and is mounted on the substrate 1,
6 is an ink which is printed around the land 2 on the substrate 1 and which contains, for example, an azo compound or a nitroso compound of a decomposition type foaming agent, or a fat of a solvent type foaming agent, a cyclic hydrocarbon, a halogenated hydrocarbon, or the like, It is formed by being foamed and cured and then raised. Reference numeral 7 is a solder for fixing the outer lead 3 of the semiconductor 5 onto the land 2.

Next, a method of manufacturing the semiconductor device having the above structure will be described with reference to FIGS. First, the ink 6 containing the foaming agent as described above is printed around the lands 2 arranged on the substrate 1 as shown in FIG. 4 as shown in FIG. Next, when the ink 6 is foamed and cured, it is raised and formed as shown in FIG. The amount of swelling can be adjusted by the content of the foaming agent and the printing density of the ink,
It is possible to make it several 1000 μm. Then, finally, the semiconductor device is completed by mounting the semiconductor 5 on the substrate 1.

As described above, according to the first embodiment, the ink 6 containing the foaming agent is printed around the land 2, and the ink 6 is raised by foaming and curing, so that the raised portion is formed. Plays a role of a breakwater, so that the solder 7 for fixing the outer lead 3 of the semiconductor 5 to the land 2 is not connected, that is, the solder bridge is not generated. In addition, since the amount of build-up can be significantly increased as compared with the case of the conventional solder resist, the effect of preventing the solder bridge is further improved.

In addition, the land 6 is formed by foaming and curing the ink 6.
Since the semiconductor 5 is mounted after the periphery of the semiconductor 5 is raised, the generation of solder bridges can be prevented without affecting the semiconductor 5 by heat or the like during foaming or curing.

Example 2. In the first embodiment described above, the case where the ink 6 is printed around the lands 2 has been described. However, as shown in FIG. 8, the ink 8 may be printed only between the lands 2 so as to be foamed and cured. Good, it is possible to prevent the generation of solder bridges between the lands 2 by printing in the minimum necessary range.

Example 3. In the first embodiment, the case where the semiconductor 5 is mounted after the ink 6 is foamed and cured to raise the periphery of the land 2 and then the semiconductor 5 is mounted is the opposite. After that, the ink 6 may be foamed and hardened to raise the periphery of the land 2, and the same effects as those of the above-described respective embodiments can be exhibited unless the influence at the time of foaming and hardening becomes a serious problem.

[0019]

As described above, according to claim 1 of the present invention, the step of printing the ink containing the foaming agent between the lands of the substrate, and the step of raising the land by foaming and curing the ink. Since at least the step of mounting the semiconductor on the substrate is included, it is possible to provide a method for manufacturing a semiconductor device capable of preventing the occurrence of solder bridges between lands of the substrate.

According to a second aspect of the present invention, in the first aspect, the semiconductor is mounted on the substrate after the ink is foamed and cured to raise the space between the lands. It is possible to provide a method for manufacturing a semiconductor device capable of preventing the generation of solder bridges between lands of a substrate without giving an influence of heat or the like upon curing to the semiconductor.

According to the third aspect of the present invention, since the ink is printed around the lands in the first or second aspect, it is possible to prevent a solder bridge from being generated between the lands of the substrate. It is possible to provide a method of manufacturing a semiconductor device capable of achieving the above.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a section taken along line II-II in FIG.

FIG. 3 is a detailed cross-sectional view showing an enlarged ink portion which is foamed, cured and raised as shown in FIG.

FIG. 4 is a perspective view showing a step of the method of manufacturing the semiconductor device in FIG.

5 is a perspective view showing a step subsequent to the step shown in FIG. 4 of the method for manufacturing the semiconductor device in FIG.

6 is a perspective view showing a step subsequent to the step shown in FIG. 5 of the method for manufacturing the semiconductor device in FIG.

7 is a perspective view showing a step subsequent to the step shown in FIG. 6 of the method for manufacturing the semiconductor device in FIG.

FIG. 8 is a plan view showing a configuration of a semiconductor device according to a second embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a state in which a semiconductor is mounted on a substrate in a conventional semiconductor device.

[Explanation of symbols]

1 substrate, 2 lands, 3 outer leads, 4 solder bridges, 5 semiconductors, 6 inks, 7 solders.

Claims (3)

[Claims] 1. At least a step of printing an ink containing a foaming agent between lands of a substrate, a step of raising the gap between the lands by foaming and curing the ink, and a step of mounting a semiconductor on the substrate. A method of manufacturing a semiconductor device, comprising: 2. The method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor is mounted on the substrate after the ink is foamed and cured to raise the gap between the lands. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the ink is printed around the land.