JPS60116150A - Semiconductor device - Google Patents

Abstract

PURPOSE:To directly mount on a transparent conductive film used for a liquid crystal panel by forming a conductive material made of photosensitive polyimide resin and conductive metal oxide powder on the aluminum electrode pad of an element chip higher than the passivation film. CONSTITUTION:Tin oxide power of antimony-dope is added at the prescribed ratio to varnish made of polyimide resin and solvent, dispersed in a ball mill, and painted. This is coated on a semiconductor chip, an aluminum pad 2 is exposed with photomask, the unexposed part is developed and removed to obtain a semiconductor device. With the device as a circuit substrate it is aligned on a transparent electrode formed on a glass of a liquid crystal panel as a circuit substrate, and the device is bonded from the back surface. At this time the transparent electrode is not necessarily metallized, but heated to completely cure the resin, thereby obtaining rigid bonding and electric coupling.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semiconductor device used in various electronic devices.

2. Description of the Related Art Conventional Structures and Problems Conventionally, various methods have been devised for handling semiconductor elements in chips as a means of packaging semiconductor devices on circuit boards in the smallest size possible. One of these is the flip chip, in which protruding electrodes (bumps) are provided on the TK part of the semiconductor chip, that is, the aluminum hat, using a thin metal film and solder plating, and the semiconductor chip is mounted face down on the circuit board. It is something to do. To manufacture this flip chip, first, a metal that has good adhesion to aluminum, such as butane or chromium, is formed by vapor deposition over the entire surface of the device including the aluminum pads. Next, after depositing a good conductor such as copper on the same surface, photoresist is applied to the entire surface, only the aluminum band is removed, and tin and lead are electroplated to an appropriate thickness using the underlying metal as an electrode.

After removing the plating resist, a photoresist is applied to the tin and lead parts, and the underlying metal film is removed by etching. After peeling off this photoresist, the entire tin and lead plating layer is melted to form solder. The semiconductor element chip thus produced is placed on a circuit board and heated to be soldered to the electrodes on the circuit board, thereby establishing an electrical connection. This method requires complicated processes such as thin film formation by vapor deposition, solder formation by electroplating, resist film formation and etching by photorin, and sufficient soldering to the electrodes on the circuit board provides strength. Therefore, a large amount of solder is required, and an interval between aluminum pads of 200 to 300 microns is required. As mentioned above, flip-chip is an effective means for high-density mounting because the mounting area of the chips can be varied, but on the other hand, the manufacturing process is extremely complicated, resulting in a decrease in product yield and chip This leads to an increase in costs. On the other hand, this flip chip requires processing by the semiconductor manufacturer and is not possible by the user. Well, flip chips are mounted on a circuit board by soldering, and when mounting directly on a circuit board, such as an ITO such as a liquid crystal panel, first
', H must be metalized to enable soldering, which increases panel costs in LCD panel manufacturing.

OBJECTS OF THE INVENTION An object of the present invention is to reduce the cost of semiconductor element chips and to provide a semiconductor device that can be directly mounted on a transparent conductive film used in a circuit board, particularly a liquid crystal panel, without being metallized.

Structure of the Invention The present invention is characterized in that a conductive paint made of a photosensitive polyimide resin and a conductive metal oxide powder is formed on the aluminum electrode band portion of a semiconductor chip to be higher than the passivation film.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described. First, to describe the features of the present invention, the most significant feature is that bumps are formed using conductive resin, and by utilizing the adhesive effect of the resin, the circuit conductors of the circuit board can be electrically and mechanically processed without metallization. It is about joining. The photosensitive resin is preferably an acrylated polyimide resin, and the conductive powder is particularly effective in the present invention if it is a fine powder of tin oxide or indium oxide with a particle size of 0.1 micron or less. This is because the fine powder of tin oxide and indium oxide has a small particle size and is smaller than the original wavelength, so it has translucency and does not interfere with the photocuring of the photosensitive resin.

Generally used metal powders cannot be used in the present invention because it is difficult to make them into fine particles of 1 micron or less.

Next, an embodiment of the invention will be described with reference to the drawings.

In the figure, 1 is a silicon substrate, and on this silicon substrate 1, an aluminum pad portion 2 is formed by a method such as vapor deposition, and a passivation film 3 such as plasma nitride is further formed to constitute a semiconductor element chip. There is. Further, bumps 4 are formed on the aluminum pad portion 2 by applying a conductive paint made of photosensitive polyimide resin and conductive metal oxide powder to the passivation film 3.
Well formed and high.

A method of manufacturing a semiconductor device having such a configuration will be described below. First, 100 parts by weight of a resin component of a varnish consisting of a polyimide resin and an m agent and 40 parts by weight of antimony-doped tin oxide powder were dispersed in a D-mouth ball mill to form a paint. This was applied onto a semiconductor element chip to a thickness of 5 to 50 microns, and the aluminum pad portion 2 was exposed using a photomask.

The unexposed original portion is developed and removed to obtain a semiconductor device. After aligning this semiconductor device as a circuit board on a transparent electrode formed on the glass of a liquid crystal panel, the semiconductor device was heated at 360°C for 30 sec kyg/c1r from the back side of the semiconductor device.
Adhesion is made under the conditions of i. At this time, there is no need to metalize the ITO of the transparent electrode, and the resin is completely cured by heating, thereby providing strong adhesion and electrical connection. The height of the bump 4 is determined by the height of the bump 4 during the above crimping.
It is sufficient if the height is sufficient to apply sufficient pressure to the semiconductor element chip, and the semiconductor element chip is normally protected with a passivation film 3 made of plasma nitride or the like. Its thickness is 0.
8 to 1.0 microns, and the bump 4 according to the present invention needs to have a thickness greater than this, ideally a thickness that can absorb the unevenness of the circuit board.Specifically, as a result of experiments with various boards, the bump It has become clear that a good connection can be obtained when the thickness of No. 4 is 5 microns or more.

Further, if the thickness is greater than 5 microns, preferably in the range of 50 microns, there is a risk of short-circuiting when the pad spacing becomes, for example, about 100 microns. This is because the pattern accuracy deteriorates due to force and blur phenomena during exposure.

〔Example〕

The materials and composition of the conductive pigment were as follows, and they were mixed and dispersed in a ball mill to form a paint.

Polyimide resin (Toshiku Co., Ltd. Photonice)...
・100 parts by weight of tin oxide powder (Mitsubishi Metals Co., Ltd. T-1) ...361 parts This paint was coated with a spinner on a 4-inch wafer on which CMO8 was formed to a thickness of 10 microns. Preliminary drying was performed at ℃ for 60 minutes.

A photomask was closely exposed to this wafer, (120W
/cr; tUV lamp for 20 seconds), and the end-light area was completely developed and removed. Further, the wafer was dried at 100° C. for 60 minutes, and then cut into a predetermined chip size using a dicing saw to obtain a completed semiconductor device. After using this semiconductor device as a circuit board and aligning it with a circuit pattern formed with transparent electrodes on a glass, the semiconductor device was heated at 400°C + 30 kg from the back side.
/cnt for 30 seconds, and at the same time, air-cage connection was performed. The chip size at this time is 5n
+++++ corner, number of pads is 64, horizontal push strength is s, 9
1y, the tensile strength in the vertical direction is 2. 'It was IKg.

Circuit 'f: 1tL operation was performed and it was confirmed that the circuit operated as specified.

Effects of the Invention The present invention has a structure in which a conductive and photosensitive paint is applied to a certain thickness on a wafer to form an alumino bump (at the throat), and this semiconductor device is thermocompression bonded to a circuit board. A good adhesion and connection can be obtained. According to this method, it is possible to directly mount the device on glass such as a liquid crystal panel without metalizing it into a transparent conductive thin film. In addition, it is possible to form a semiconductor chip using a simple process, which enables a significant reduction in costs, and because it does not require special technology, it is possible to form a semiconductor chip using a simple process. Mbu Technology - User 1
The fact that it has become possible to form a composite semiconductor in the first step will contribute to the synthetic semiconductor industry.

[Brief explanation of the drawing]

The drawing is a cross-sectional view showing one embodiment 911 of the semiconductor device according to the invention. 1...Silicon substrate, 2...Aluminum/
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Claims (1)

[Claims] A semiconductor device characterized in that bumps made of a conductive paint made of photosensitive polyimide resin and conductive metal oxide powder are formed on the electrode pads of a semiconductor element chip at a height higher than a passivation film.