JPH04284634A - Mounting method for chip - Google Patents

Abstract

PURPOSE:To divide a mounting operation into two parts and to shorten an indexing operation when a metal for bonding use is supplied to and melted on an island part formed on an insulating substrate and a semiconductor chip is mounted on it. CONSTITUTION:A reference position Pa, a mounting position Pb and a displacement amount Po between both are detected at a position just before a mounting position; the displacement amount Po is held as a data; after that, a metal 7 for bonding use is supplied to an island part 2. Then, while the metal 7 for bonding use is being heated and melted at a position for the mounting position, the reference position Pa is detected, the mounting position Pb on the molten metal is computed by using the reference position and the data of the reference amount, and a semiconductor chip is supplied and mounted on it.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a predetermined mounting position on an island portion formed on an insulating substrate and mounting a semiconductor chip or the like at that position.

0002

2. Description of the Related Art High frequency semiconductor chips are mounted on an insulating substrate (1) made of ceramic or the like, as shown in FIG. 3, in order to prevent interference from the outside. The insulating substrate (1) is, for example, an octagonal ceramic substrate, with an island portion (2) formed approximately in the center thereof by gold plating, and an electrode portion (3) also plated with gold arranged around the island portion (2). Next, leads (4) are led out from the corners of the octagon and connected to leads (4) of another board using tie bars (not shown) to form a lead frame. Then, as shown in FIG. 4, the semiconductor chip (6) is mounted on the island part (2) via the eutectic bonding gold (5), and then the electrode part (
3) and wire bonding.

Conventionally, when mounting the semiconductor chip (6), gold is pasted on the back surface of the chip in advance by vapor deposition or the like, and a predetermined mark is placed on top of the gold to prevent it from protruding from the island part (2). After the mounting position (the center of the island part) was recognized using a television camera or the like, the semiconductor chip (6) was supplied to that position and mounted by thermocompression bonding. However, in this case, there are difficulties in processing the wafer due to the vapor deposition technique and the instability of the gold thickness.

Therefore, conventionally, as shown in FIG. 3, a predetermined mounting position on the island part (2) is recognized using a television camera or the like at the mounting work position, and a gold tape (7) is supplied to that position. do. After supplying the semiconductor chip (6) to the mounting position thereon, the insulating substrate (1) is directly heated to melt the gold tape (7), and the semiconductor chip (6) is mounted by thermocompression bonding.

[0005]

[Problems to be Solved by the Invention] The problems to be solved are the recognition of the mounting position, the supply of the gold tape (7) and the semiconductor chip (6), and the heating and melting of the gold tape (7) at the same mounting work position. This is the point where the index drops because a series of mounts are performed. In this case, the mounting work is divided, the mounting position is recognized in advance at the position just before that, and the gold tape (7) is supplied, and the gold tape (7) is supplied at the next mounting work position.
The semiconductor chip (6) may be mounted by heating and melting the semiconductor chip (6). However, when the gold tape (7) is heated and melted, its surface reflects diffusely, making it impossible to recognize the mounting position thereon. Moreover, since the position of the island portion (2) varies from substrate to substrate, if it cannot be recognized, the mounting position of the semiconductor chip (6) will shift. Therefore, the semiconductor chip (6) may come off from the island portion (2), or each of the plurality of wires may have unequal lengths during subsequent wire bonding, resulting in nonuniform device characteristics and reduced workability. The issue arises.

[0006]

[Means for Solving the Problems] The present invention provides a method for mounting a chip as a component at a predetermined mounting position on an island portion formed on an insulating substrate and having a plurality of electrode portions arranged around the mount. A predetermined reference position, the above-mentioned mount position, and the amount of displacement between the two are detected in advance at the position just before the work, and after the amount of displacement is stored as data, a process of supplying the bonding metal to the island part and at the above-mentioned mount work position is performed. Heating the metal for joining
Detecting the reference position while melting, and calculating the mount position on the molten metal using the displacement data,
and a step of supplying and mounting a semiconductor chip at the position, and

[0007] A gold tape for eutectic bonding is supplied as a bonding metal onto the island portion and melted, and a semiconductor chip is mounted on the island portion.

[0008]

[Operation] According to the above technical means, the amount of displacement between the predetermined reference position and the above-mentioned mount position is detected in advance at the position immediately before the mounting operation, and the amount of displacement is stored as data, and the amount of displacement is stored as data at the position immediately before the mounting operation. The reference position is detected and the mounting position on the molten metal for bonding is calculated using the displacement data, and the semiconductor chip is supplied and mounted at that position.

[0009]

Embodiments An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Components that are the same as those shown in FIG. 3 are given the same reference numerals, and their explanations will be omitted. In the chip mounting method according to the present invention, as shown in FIG. 1, a predetermined reference position, for example, a reference position (P
a) and the mount position, that is, the mount position (Pb) at the center of the island portion (2), are recognized and detected by a television camera, and the amount of displacement (Po) of both is detected in advance. At the same time, the angle (θ) between the line connecting the centers of gravity of the electrode parts (3) (3) and one side of the island part (2) is detected. Then, calculate the displacement and angle data for each island (
2) After holding each, use gold tape as a joining metal (7)
is supplied to the island section (2). Next, as shown in Figure 2, the insulating substrate (1) is sent to the mounting work position, where the gold tape (7) is heated and melted while the reference position (
Pa) is recognized and detected by a television camera, and
Mount position (Pb) on the gold tape (7) related to melting with displacement amount (Po) held as data in advance
is calculated, and the angle (θ) is also calculated. Then, the position and orientation of the semiconductor chip is regulated based on the value, and the semiconductor chip is supplied onto the island section (2) and mounted by thermocompression bonding. The above mount position (Pb) is calculated for each island part (2).
This shall be done every time.

Although the electrode portion (3) is used as the reference position in the above embodiment, other special positions or reference positions may be formed. Further, the semiconductor chip may be other than a high-frequency element, and the bonding metal may be gold tape, solder, etc., and the same may be applied when the surface cannot be recognized by a television camera.

[0011]

According to the present invention, after supplying bonding metal in advance onto the island portion formed on an insulating substrate, when supplying and mounting a semiconductor chip thereon, the bonding metal supply position and the mounting Since the work is divided into two parts, the index is shortened and productivity is improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an insulating substrate immediately before a mounting work position, showing an embodiment of a mounting method according to the present invention.

FIG. 2 is a plan view of an insulating substrate in a mounting work position showing an embodiment of the mounting method according to the present invention.

FIG. 3 is a plan view of an insulating substrate in a mounting work position showing an example of a conventional mounting method.

FIG. 4 is a side view of a main part of a semiconductor chip mounted on an island section.

[Explanation of symbols]

1 Insulating substrate 2 Island part 3　Electrode part 7 Gold tape (metal for joining) Pa Reference position Pb Mount position Po Displacement amount

Claims (2)

[Claims] 1. At a position prior to assembling and placing a semiconductor chip at a predetermined position of an island portion formed on an insulating substrate and having a plurality of electrode portions arranged around the island portion, the amount of displacement between a reference position and the predetermined position is measured. At the same time, the process of supplying the bonding metal to the island part after holding the displacement data, detecting the reference position while heating the bonding metal, and detecting the position on the heated metal using the displacement data. A mounting method including the steps of calculating a predetermined position, supplying a chip thereto, and mounting the chip. 2. The mounting method according to claim 1, wherein a gold tape for eutectic bonding is supplied as a bonding metal onto the island portion and melted to mount the chip on the island portion.