JPH0787200B2 - Mounting method of semiconductor chip - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a semiconductor chip on a wiring board, and more particularly to a face-down bonding method for directly connecting the connection electrode of the semiconductor chip to the connection electrode on the wiring board. It is about improvement.

2. Description of the Related Art In recent years, attention has been paid to miniaturization of electric circuits, and in particular, even in the mounting of semiconductor chips, there is a tendency toward direct mounting on a wiring board. That is, conventionally, the wire bonding method has been mainly used for the connection between the semiconductor chip and the wiring substrate, but the face-down bonding method has been reconsidered because of the efficiency of the area for connecting the semiconductor chip on the wiring substrate. There is.

In this face-down bonding method, a bump electrode called a bump is usually formed on the connection electrode of the semiconductor chip, and the bump and the conductive electrode of the wiring substrate are opposed to each other and are collectively bonded by reflow or the like. .

Next, a representative example of the bump forming process will be described with reference to FIG. Usually, the semiconductor chip 1 is formed so that the surface protection layer 3 covers the periphery of the connection electrode 2 as shown in FIG. As shown in FIG. 2B, the semiconductor chip 1 is formed by sputtering or vapor deposition with a diffusion prevention layer 5 made of Ti and Cu.
The adhesive layer 6 is formed. Then, as shown in FIG. 7C, a photoresist layer 7 is formed in advance, leaving a region where the surface protective layer 3 is not provided, and an Au plating layer 8 is formed thereon as shown in FIG. , The photoresist layer 7 is peeled off as shown in FIG.
It is formed through a heat treatment process. The bumps formed as described above are directly connected to the conductive electrodes on the wiring board by an ultrasonic heating method or the like.

Problems to be Solved by the Invention However, in the method as described above, many steps must be performed for bump formation, which is disadvantageous in terms of chip cost, and because the photoresist and etching steps are performed, the ion However, there are problems such as adverse effects on the semiconductor chip due to the above, and deterioration of reliability.

In view of the above problems, the present invention provides an inexpensive and highly reliable connection method with a short process.

Means for Solving the Problems In order to achieve this object, a method for mounting a semiconductor chip of the present invention is such that a metal filler is provided on a surface of a semiconductor chip on which connection electrodes are formed so as to cover at least the connection electrodes. After forming the mixed photosensitive thermosetting resin layer,
Other thermosetting resin layers are removed by a photolithography method while leaving the thermosetting resin layer on the connection electrode, and the semiconductor chip having the thermosetting resin layer formed only on the connection electrode is thermoset. The resin layer is placed so that it is located on the conductive electrode of the wiring board, and the connection electrode and the conductive electrode are electrically and mechanically connected via the thermosetting resin by thermocompression bonding. is there.

Function According to this structure, since the photosensitive thermosetting resin mixed with the metal filler is used, the photolithography method selectively heats only the connecting electrodes of the semiconductor chip more accurately than the screen printing method. The curable resin layer can be formed, the process for bump formation can be simplified as in the conventional case, and highly reliable connection can be achieved.

Embodiment One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a typical process diagram of the mounting method in this embodiment, and the same components as those of the conventional configuration are designated by the same reference numerals.

In FIG. 1, 4 is a photosensitive resin layer containing a metal filler, 10 is a conductive electrode, and 11 is a wiring board. The process will be described below. First, as shown in FIG. A, the photosensitive resin 4 containing a metal filler is uniformly applied to the surface of the semiconductor chip 1. Here, the metal filler is Ag, Ni,
It is composed of a single material or a mixture of conductive materials such as Cu, and has a particle size of about 2 to 10 μmφ. The photosensitive resin is a thermosetting resin having epoxy or polyimide as a basic skeleton, and the mixing ratio with the metal filler is 40 to 80 by volume.
%.

Next, for example, after prebaking at 80 ° C. for 30 minutes to increase the adhesive force between the semiconductor chip 1 and the resin layer 4, exposure and development are performed by a normal photolithography process as shown in FIG. The desired resin layer 9 is left on. Then, as shown in FIG. 7C, after the predetermined conductive electrodes 10 of the wiring board 11 and the resin layer 9 are aligned with each other, thermocompression bonding is performed to connect them.

As described above, according to the present embodiment, the wiring substrate and the semiconductor chip can be easily connected by the face-down bonding method in a short process. In terms of reliability, the high temperature and high humidity (60 ℃, 90% RH) test is 1000 hours, the high temperature storage (100 ℃) test is 1000 hours, and the heat cycle (-10
℃ ~ 100 ℃) test, 100 cycles, etc., was comparable to the normal wire bonding method.

EFFECTS OF THE INVENTION As described above, according to the present invention, by using a thermosetting resin mixed with a metal filler, by the photolithography method, a thermosetting resin layer is selectively formed only on the connection electrodes of the semiconductor chip. It can be formed, the process for forming bumps can be simplified as in the conventional case, and highly reliable connection can be achieved.

[Brief description of drawings]

FIG. 1 is a view showing main steps in an embodiment of a semiconductor chip mounting method of the present invention, and FIG. 2 is a view showing main steps in forming bumps on a conventional semiconductor chip. 1 ... Semiconductor chip, 2 ... Connection electrode, 3 ... Surface protection layer, 4,9 ... Metal filler containing resin layer, 5 ... Diffusion prevention layer, 6 ... Adhesive layer, 7 ... Photoresist layer, 8 ... Bump, 10 ... Conductive electrode, 11 ... Wiring board.

Claims (1)

[Claims] 1. A photosensitive thermosetting resin layer mixed with a metal filler is formed on a surface of a semiconductor chip on which connection electrodes are formed, so that at least the connection electrodes are covered with the photosensitive thermosetting resin layer. The other thermosetting resin layer is left by the photolithography method while leaving the thermosetting resin layer, and the semiconductor chip in which the thermosetting resin layer is formed only on the connection electrode is a wiring board having the thermosetting resin layer. The method for mounting a semiconductor chip in which the connection electrode and the conductive electrode are electrically and mechanically connected to each other through the thermosetting resin by placing the semiconductor chip on the conductive electrode and thermocompression bonding.