JP2513739B2 - Box type curing furnace - Google Patents

Abstract

PURPOSE:To automatically perform the curing operations of semiconductor wafers efficiently and accurately by a method wherein a box type curing furnace 10 composed of a box type unit, a slide table, a heater block and a thermocouple is operated by the signals from an outer controller. CONSTITUTION:The overall periphery of a box type unit 11 excluding an opening part is covered with thermal insulating material 11a while inner one side is equipped with a sliding mechanism 11b. A slide table 12 connected to a driving mechanism 13 is provided with a front cover 12a and a rear cover 12b to be moved in the opening and closing directions of the opening part of the unit 11 by the slide mechanism 11b. A heater block 14 is located on the inner wall of the unit 11 while a thermocouple 16 is located inside the unit 11. This curing furnace is operated by the signals from an annexed outer controller 18. Through these procedures, the curing operations of semiconductor wafers can be automatically performed efficiently and accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] A box-type curing furnace for a curing device in a semiconductor assembly process, which is intended to reduce man-hours and defects, and covers the entire periphery except an opening with a heat insulating material, and A box-shaped unit having a slide mechanism portion on one surface inside thereof, and a front lid and a rear lid having a heat insulator that is connected to the drive mechanism portion and moves in a direction of opening and closing the opening portion of the unit by the slide mechanism portion. A box-type curing furnace comprising a slide table provided with, a heater block located on the inner wall of the unit, a thermocouple located inside the unit,
It is operated by a signal from an external control device installed at the same time.

[Industrial applications]

The present invention relates to a curing device in a semiconductor assembly process, and more particularly to a box-type curing furnace that reduces man-hours and defects.

Generally, when assembling semiconductors, there are many curing processes such as annealing after wire bonding, curing of die bonding paste, curing of imprinting ink, etc. Normally, in these processes, a magazine with several tens of semiconductor wafers to be processed is set. Curing work is carried out in a thermostatic bath or a belt furnace in units of the magazines, which is a transport unit.

However, when using a constant temperature bath, it usually takes a long time to start the work after a certain number of magazines have been gathered, and it takes time to raise and lower the temperature because the internal volume of the constant temperature bath is large. The temperature distribution in the chamber tends to be non-uniform, and when using a belt furnace, there are drawbacks such as large equipment and large electrical capacity when the curing time is long. Due to the large number of defects, there are various problems such as an increase in the number of defects when the device goes down, for example, and therefore there is a demand for the development of an efficient and highly productive curing device.

[Conventional technology]

FIG. 4 is a diagram showing an example of a curing process in a conventional constant temperature oven. (A) shows a state in which a semiconductor wafer to be processed is attached to a magazine, and (B) shows a state in which the magazine is set in the constant temperature oven. Shows.

In this case, normally, several tens of semiconductor wafers 2 to be cured are set in a magazine 1 in a shelf shape, 20 to 30 magazines 1 are further set in a constant temperature bath 3, and a door 3a is closed to perform a required curing process. For example, in the die bonding silver paste curing process, a curing operation is performed at 150 to 200 ° C. for about 2 hours.

FIG. 5 is a diagram schematically showing an example of a curing process using a conventional belt furnace.

In the figure, 4 is a belt furnace with a built-in heater 5,
Similarly to the figure, the magazine 1 in which several tens of semiconductor wafers are set is moved in the belt furnace 4 in the direction a in the figure while being placed on the conveyor belt 6.

The temperature control in this case is performed by the power of the heater 5, and the curing time is controlled by the moving speed of the conveyor belt 6 and the length of the belt furnace 4.

[Problems to be solved by the invention]

However, in the curing by the conventional method, for example, when a constant temperature bath is used, the lead time is long because it is necessary to wait until the number of semiconductor wafers to be processed becomes uniform.

Since the inner volume of the constant temperature bath is large, it is difficult to control the temperature as a whole, and for example, in the curing step of the silver paste, the adhesive strength tends to vary depending on the position in the bath.

If any trouble occurs in the constant temperature bath or work, the quantitative damage is large.

 There was a problem such as.

When a belt furnace is used, if the curing time is long, the equipment becomes large and the required electric capacity becomes large.

When tracking a specific magazine, it is difficult to determine its location during the curing process.

If any trouble occurs in the belt furnace or work, the amount of damage is large.

 There was a problem such as.

[Means for solving problems]

The above-mentioned problem is that a box-shaped unit in which the entire periphery except the opening is covered with a heat insulating material, and a slide mechanism section is provided on one inner surface thereof, and the unit is connected to the drive mechanism section by the slide mechanism section. A slide table having a front lid and a rear lid having a heat insulating material that moves in the direction of opening and closing the opening of the unit, and the slide mechanism unit that moves in the direction of opening and closing the opening of the unit connected to the air cylinder. A box-type curing furnace that is operated by a signal from an external control device that is installed side by side, including a slide table having a lid part that operates, a heater block located on the inner wall of the unit, and a thermocouple located inside the unit. Will be resolved.

[Work]

In order to cure a large number of semiconductor wafers to be processed efficiently, reliably and with high yield, it is necessary to consider shortening the lead time, facilitating temperature control, reducing the number of work in progress at the same time, and automation.

Therefore, in the present invention, the curing apparatus is configured by combining the box type curing furnace according to the present invention in which a unit having a size capable of mounting one or two magazines is provided with a function as a thermostatic chamber, thereby satisfying the above-mentioned necessary conditions. I am satisfied.

That is, since the function of the constant temperature bath is added to the unit having a size capable of accommodating one or two magazines, the time required for raising and lowering the temperature is shortened and the temperature control is facilitated because the internal volume is small. .

Since the number of semiconductor wafers accommodated in the same unit is small, the lead time until the required number is gathered is short, and the quantitative damage when a trouble occurs in the curing furnace or work can be reduced.

Since each unit is provided with an independent constant temperature bath function, lot management can be facilitated.

By controlling the curing furnace itself and the entire apparatus by computer, the work process and process control can be automatically performed.

 And so on.

〔Example〕

 Description will be given below with reference to the drawings.

FIG. 1 is a perspective view showing the configuration of a box-type curing furnace according to the present invention, FIG. 2 is a diagram showing a control circuit block, and FIG. 3 is an example of a curing device constituted by the box-type curing furnace according to the present invention. Is shown.

In FIG. 1, (A) shows the state where the magazine is not set, and (B) shows the state where the magazine is set and the curing operation is being performed.

As shown in FIG. 1A, the box-type curing furnace 10 includes a unit 11, a slide table 12, a drive mechanism section 13 including an air cylinder,
It is composed of a heater block 14 and a thermocouple 16.

That is, 11 is a box-shaped unit having an opening whose periphery is covered with a heat insulating material 11a, and a dovetail-shaped slide mechanism unit 11b is provided at the bottom thereof.

An air cylinder is connected as a drive mechanism 13 to a slide table 12 for mounting a magazine that slides smoothly with the slide mechanism 11b, and is set in advance just before or after the start of the curing work. According to the program, slide table automatically moves in the direction of b in the figure.
In addition to facilitating the setting or removal of the magazine to be placed on top of the box 12, the front lid 12a on the front side of the slide table 12 on the paper surface is in close contact with the opening of the unit 11 immediately before starting the curing work. After the furnace 10 is closed to make it into a constant temperature bath, and after the curing work is completed, the rear lid 12b on the back side of the slide table 12 closes the opening of the unit 11 to prevent the temperature inside the unit 11 from decreasing and continuing. The structure is designed to improve the efficiency of the curing work that is performed.

Further, 14 is a heater block having a cartridge heater 15 built therein, which is installed on both inner wall surfaces of the unit 11. Reference numeral 16 is a thermocouple for feeding back temperature information, and 17 is a signal line connected to an external control device 18.

FIG. 1B shows a state in which one to two magazines (two in the figure) on which several tens of semiconductor wafers to be worked are set are placed on the slide table 12 and curing work is performed. It is a thing.

As shown in the figure, the external control device 18 is preset with working conditions such as temperature and time that match the curing conditions of the semiconductor wafers to be worked set in the box-type curing furnace 10, and the curing work is automatically executed according to the program. Let

The case before the die bonding silver paste curing step will be described below. The situation before the work is as shown in FIG.

When the magazine 1 on which the work semiconductor wafer coated with the silver paste is set is placed on the slide table 12, the slide table 12 is a drive mechanism section including an air cylinder according to a program stored in the external control device 18. The operation moves to the inside of the box type curing furnace 10 by the operation of 13, and at this time, the front lid 12a provided at the front end of the slide table 12 on the front side of the drawing closes the opening of the box type curing furnace 10 to form a constant temperature bath. This is as described above.

Thereafter, the temperature control is operated according to the program stored in the external control device 18, and the curing work is performed at 150 to 200 ° C. for about 2 hours.

It has been experimentally confirmed that a more effective curing operation can be carried out by injecting air into the box-type curing furnace 10 from the outside during the curing operation to circulate the air inside the tank.

After the curing work is completed, the slide table 12 is automatically moved in the direction of b'in the figure so as to be removed from the box-type curing furnace 10, so that the magazine 1 is removed and the curing work is completed. At this time, the rear lid 12b of the slide table 12 closes the opening of the curing furnace 10 to prevent the temperature in the bath from decreasing as described above.

FIG. 2 shows an example of a control circuit block, and the figure shows a case where there is one box-type cure furnace 10.

For example, the external control device 18 is a temperature controller 19 for controlling the temperature of the heater block, a keyboard 20 for inputting various work conditions, a CRT 21 for displaying various work conditions and the temperature and time of each box-type curing furnace, and various data are printed. It is composed of a printer 22 for outputting and a microcomputer 23 for comprehensively controlling the above respective devices.

 Examples of main signal information transmitted here include (1) air cylinder control signal, (2) temperature information in box-type curing furnace, (3) heater block temperature control signal, and (4) heater block temperature control signal. Anomaly detection signals, (5) input signals for various working conditions, (6) display signals for working conditions, temperature inside the curing furnace, etc. (7) printout signals for various data.

FIG. 3 shows an example of a curing device in which ten box-type curing furnaces according to the present invention are combined. Ten box-type curing furnaces 10 are mounted on a curing device frame 24.

In the figure, for the sake of easy understanding, each curing furnace is numbered. For example, box-type curing furnaces Nos. 4, 6, and 7 show the state in which the slide table 12 is pulled out from the curing furnace, and in particular,
The curing furnaces Nos. 6 and 6 show a state in which the magazine 1 is set on the slide table 12.

Further, each of the ten curing furnaces 10 is collectively connected to an external control device 18 by a signal line 17.

In this case, the external control device 18 can control each curing furnace independently, so that
The seven box-type curing furnaces except the number can be continuously executed without interruption of the curing work.

〔The invention's effect〕

As described above, the box-type curing furnace according to the present invention can automatically and efficiently perform a semiconductor wafer curing operation.

Further, in the box-type curing furnace according to the present invention, the curing conditions can be set separately, so by configuring a curing device with a plurality of such curing furnaces, a plurality of types of curing work can be performed in parallel within the same curing device. It is also possible to do.

The productivity can be further improved by automatically setting and removing the magazine in the box-type curing furnace according to the present invention by a robot controlled by a microcomputer.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of a box-type curing furnace according to the present invention, FIG. 2 is a diagram showing a control circuit block, and FIG. 3 is an example of a curing device configured by the box-type curing furnace according to the present invention. FIG. 4 is a diagram showing an example of a curing process in a conventional constant temperature bath, and FIG. 5 is a diagram schematically showing an example of a curing process in a conventional belt furnace. In the figure, 10 is a box type curing furnace, 11 is a unit 11a is a heat insulating material, 11b is a slide mechanism part, 12 is a slide table, 12a is a front cover, 12b is a rear cover, 13 is a drive mechanism part, 14 is a heater block, Reference numeral 15 is a cartridge heater, 16 is a thermocouple, 17 is a signal line, 18 is an external control device, 19 is a temperature controller, 20 is a keyboard, 21 is a CRT, 22 is a printer, and 23 is a microcomputer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuhiro Suzuki 1 at Nishigaoka, Murata-cho, Murata-cho, Shibata-gun, Miyagi Prefecture 1 at Fujitsu Miyagi Electronics Co., Ltd.

Claims (1)

(57) [Claims] 1. A box-like unit (11) having a heat insulating material (11a) covering the entire periphery except for an opening, and a slide mechanism portion (11b) on one inner surface thereof, and a drive mechanism portion (13). ) And the slide mechanism section (11
The front lid (12a) and the rear lid (12) having a heat insulating material (11a) that moves in the direction of opening and closing the opening of the unit (11) in b).
b) equipped with a slide table (12) and a heater block (1) located on the inner wall of the unit (11).
4) and a thermocouple (16) located inside the unit (11), which is operated by a signal from an external control device (18) installed side by side, which is a box-type cure furnace.