JPH03121756A - Tool cleaning device for inner lead bonder - Google Patents

Abstract

PURPOSE:To provide possibility of making next bonding with no await time after cleaning by keeping a grinding wheel to clean the surface of a tool at a specified temp., and thereby preventing the heat of tool from running off to the grinding wheel during cleaning. CONSTITUTION:When bonding is repeated in several tens of passes, a cylinder for cleaning of the surface of a bonding tool 7 is operated to locate a cleaning device 10 at an open window alozgside a guide rail. When a bonding tool 7 is sunk, the surface of the tool 7 is ground by a grinding wheel 15 in rotating, and foreign matters, etc., attached to the tool surface are torn off. The grinding time is approx. 10sec, but the temp. of the tool 7 will not fall during grinding because the wheel 15 has been heated by a heater 17 to a temp. equal to the tool 7, and if the cleaning cycle is finished, the next bonding is made with no await time interposed.

Description

Detailed Description of the Invention [Purpose of the Invention (Industrial Application Field) The present invention provides an inner lead bonder for bonding an electrode of a semiconductor element and an inner lead of a carrier tape. The present invention relates to a tool cleaning device for cleaning.

(Prior Art) A tool used for an inner lead bonder that bonds the electrode of a semiconductor element and the inner lead of a carrier tape in a semiconductor manufacturing process is generally made of a hard material.
It is heated to a high temperature by a cartridge heater, etc. Therefore, the tool is less likely to wear out, but rather, due to the high temperature, various foreign substances adhere to the surface during welding. Since the tool is heated to a high temperature (400 to 500° C.), foreign matter adhering to the surface tends to harden, making it difficult to transmit the heat of the tool to the inner leads and semiconductor elements.

In this way, when the inner lead bonder repeats bonding, dirt such as oxides accumulates on the tool surface. If bonding is continued without cleaning the tool surface, the heat conduction efficiency of the tool surface will deteriorate, and the bonding condition between the inner lead and the semiconductor element will deteriorate.

Therefore, in the past, for example, Japanese Patent Laid-Open No. 63-1695
As shown in Japanese Patent No. 6, a cleaning table is rotatably supported near a bonding position where inner leads are bonded, a rotary table is provided on the cleaning table, and a grindstone is provided on the upper surface of the rotary table. After the bonding is repeated, for example, several thousand times, the tool surface is bonded to the surface of the grindstone, and the tool surface is polished to remove oxides and the like attached to the tool surface.

(Problem to be Solved by the Invention) However, the tool cleaning device for the inner lead bonder configured as described above has a grindstone of 400 to 500
Cleaning is performed by pressing the tool surface of the tool held at 00° C., rotating the grindstone for about 10 seconds, and moving the tool. Therefore, there is a problem that heat from the tool escapes to the grindstone during cleaning, and it takes time for the tool to return to its original temperature (400 to 500° C.).

In addition, recently, as chips have become larger, the surface area of tools has also become larger, and the degree of surface area has become larger. For example, when cleaning a square tool surface with sides of 13 m+a for 10 seconds, the tool temperature drops from 500° C. to 470° C., and it takes about 16 seconds to return to normal. If the bonding takt time is about 4 seconds, then 4 pieces can be bonded during this time, and this loss time is very large.

This invention was made with attention to the above-mentioned circumstances, and its purpose is to provide an inner material that does not cause the temperature of the tool to drop during cleaning of the tool surface, eliminates waiting time, and allows efficient bonding. An object of the present invention is to provide a lead bonder tool cleaning device.

[Structure of the invention] (Means and effects for solving the problem) This invention has the following features:
In order to achieve the above object, a tool cleaning device for an inner lead bonder is composed of a grindstone for cleaning the tool surface, a drive mechanism for driving the grindstone, and a heat retention mechanism for keeping the grindstone at a predetermined temperature. .

Since the tool surface of the tool comes into contact with the grindstone, which is kept at a temperature approximately equal to the temperature of the tool, the heat of the tool does not escape to the grindstone, and the next bonding can be performed without waiting time after cleaning.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a cleaning device, and FIG. 3 shows an inner lead bonding device equipped with the cleaning device. 1 shown in FIG. 3 is a carrier tape, and an inner lead a is provided on the surface of the carrier tape. The carrier tape 1 is conveyed in one direction by sprockets 2.3, and a bonding portion 4 is provided between the sprockets 2.3. This bonding part 4
A guide plate 5 is provided for guiding the carrier tape 1, and a part of the guide plate 5 is provided with an opening window 6 for exposing one inner lead a on the carrier tape 1.

Above the guide plate 5 is a bonding tool 7.
is provided to be movable in the vertical direction (Z direction) and in the XY force directions, and a mounting table 8 for semiconductor elements is provided below. After the inner lead a on the carrier tape 1 is positioned to face the opening window 6 and the semiconductor element on the processing table 8 is positioned with the inner lead a, the bonding material waiting on the carrier tape 1 is The tool 7 is lowered to bond the inner lead a and the semiconductor element. That is, the bonding tool 7 is heated to 400 to 500[deg.] C., and the inner lead a and the semiconductor element are bonded together by thermocompression.

Furthermore, a guide rail 9 is provided along the running direction of the carrier tape 1 at the lower part of the guide plate 5 located near the bonding section 4 . A cleaning device 10 is mounted on the guide rail 9, and the cleaning device 10 can be moved by a cylinder 11.

To explain the cleaning device 10, as shown in FIG. 1, 12 is a motor as a drive mechanism, and a whetstone holder 14 is provided on a rotating shaft 13 of this motor 12. A disc-shaped grindstone 15 is fixed to this grindstone holder 14. Further, the whetstone holder 14 including the whetstone 15 is surrounded by a heater block 16, so that the whetstone 15 rotates inside the heater block 16.

The heater block 16 includes an electric heater 1 as a heat retention mechanism.
7 is buried, and this electric heater 17 is connected to a power source 19 via a control device 18.

Further, the heater block 16 is provided with a thermocouple 20, and a temperature detection signal from the thermocouple 20 is sent to the control device 18.
By controlling the electric heater 17, the temperature of the grinding wheel 15 is adjusted to the temperature of the bonding tool 7, e.g.
It is configured to maintain the temperature at 00 to 500°C.

Next, the operation of the inner lead bonder cleaning device configured as described above will be explained.

The electric heater 17 of the cleaning device 10 is always energized, and the heater block 16 is heated.

The temperature of the heater block 16 is detected by a thermocouple 20, and this temperature detection signal is input to the control device 18 to control the electric heater 17, so that the temperature of the grinding wheel 15 is the same as the temperature of the bonding tool 7, for example 400 to 500. It is kept at ℃.

On the other hand, the carrier tape 1 of the inner lead bonding apparatus runs one pitch at a time, and the inner lead a is positioned at a position facing the opening window 6, and the semiconductor element on the mounting table 8 is positioned with the inner lead a. Next, when the bonding tool 7 waiting on the carrier tape 1 is lowered, since the bonding tool 7 is heated to 400 to 500[deg.] C., the inner lead a and the semiconductor element are bonded by thermocompression. When one bonding process is completed, the bonding tool 7 rises, and the mounting table 8 moves laterally to retreat from the opening window 6.

Then, when the next inner lead a faces the opening window 6 as the carrier tape 1 travels, bonding is performed by repeating the same actions as described above.

After repeating this type of bonding several thousand times,
In order to clean the tool surface 7a (see FIG. 2) of the bonding tool 7, the cylinder 11 is operated to position the cleaning device 1o at the opening window 6 along the guide rail 9.

Then, when the bonding tool 7 is lowered, the tool surface 7a of the bonding tool 7 is polished by the rotating grindstone 15, and foreign matter adhering to the tool surface 7a is scraped off. This polishing time is about 10 seconds, but since the grindstone 15 is heated to the same temperature as the bonding tool 7, the temperature of the bonding tool 7 does not drop during polishing, and there is no waiting time after cleaning is completed. The next bonding can be done.

In the above embodiment, cleaning was performed by lowering the bonding tool and bringing it into contact with the upper surface of the rotating grindstone, but the bonding tool may also be moved laterally and reciprocally. Cleaning may be performed by reciprocating the grindstone at high speed without rotating it.

[Effects of the Invention] As explained above, according to the present invention, since the grindstone for cleaning the tool surface of the tool is kept at a predetermined temperature, the heat of the tool is prevented from escaping to the grindstone during cleaning. After cleaning, you can perform the next bonding without waiting. Therefore, there is no loss time as in the conventional method, and there is an effect that efficient bonding is possible.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of a cleaning device showing an embodiment of the present invention, FIG. 2 is a side view of a bonding tool, and FIG. 3 is a perspective view of a bonding device equipped with the cleaning device. 7... Tool, 7a... Tool surface, 12... Motor (drive mechanism), 15... Grinding stone, 17... Electric heater (heat retention device).

Claims (1)

[Claims] In a tool cleaning device for an inner lead bonder, which is installed in a bonder that performs bonding of inner leads with a tool provided movably in XY and Z directions, and which cleans the tool surface of the tool after performing bonding a predetermined number of times, A tool cleaning device for an inner lead bonder, comprising: a grindstone for cleaning the tool surface; a drive mechanism for driving the grindstone; and a heat retention mechanism for keeping the grindstone at a predetermined temperature.