JPH0964118A - Temperature control method of thermocompression bonding device and thermocompression bonding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect an abnormal state immediately before disconnection of a thermocouple for detecting the temperature of a thermocompression bonding head. SOLUTION: The temperature of a thermocompression bonding head 1 is controlled so as to keep it within a set temperature range of 500-550 deg.C by detecting the temperature of the thermocompression bonding head 1 generating heat in response to a supply current with a thermocouple 4 and controlling current supply by a current supply means 3 on the basis of the result of the temperature detection. When the thermocouple 4 is brought to an abnormal state immediately before disconnection, however, the detected temperature by the thermocouple 4 occasionally reaches 550 deg.C or lower such as 400 deg.C even when the temperature of the thermocompression bonding head 1 exceeds 550 deg.C and reaches 600 deg.C. Since voltage between both terminal sections 1a of the thermocompression bonding head 1 at 600 deg.C is larger than that at 550 deg.C in such a case, voltage between both terminal sections 1a of the thermocompression bonding head 1 is deteced by a voltage detecting means 5, and an alarm sound for annunciating the abnormal state from an alarm means 6 is generated on the basis of the result of the voltage detection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control method for a thermocompression bonding apparatus and a thermocompression bonding apparatus.

[0002]

2. Description of the Related Art For example, TAB (Tape Automated Bondi)
In the case of mounting a semiconductor chip in the ng) technology or when bonding the TAB substrate thus obtained to a liquid crystal display panel, a thermocompression bonding device is used. In such a thermocompression bonding device, the temperature of the thermocompression bonding head is detected by a thermocouple attached to the tip of the thermocompression bonding head that generates heat according to the supplied current, and the current to the thermocompression bonding head is detected based on the temperature detection result. By controlling the supply, the temperature of the thermocompression bonding head can be set within a set temperature range (for example, 500 to 550 ° C).
Therefore, the thermocompression bonding head itself and the heat-compression-bonded members such as semiconductor chips are prevented from burning due to overheating.

By the way, when the thermocouple is disconnected due to heat stress with the passage of time, the temperature cannot be detected. Therefore, even if the temperature of the thermocompression bonding head exceeds the upper limit temperature of the set temperature range, it can be detected. Will not be possible. Therefore, in such a case, since the resistance value of the broken thermocouple becomes infinite, an alarm sound is generated by a buzzer or the like based on this (hereinafter referred to as a disconnection detection function).

[0004]

However, when the thermocouple is in an abnormal state immediately before it is broken, the actual temperature of the thermocompression bonding head becomes higher than the upper limit temperature of 550 ° C. in the set temperature range, for example, 600 ° C. Even if the temperature detected by the thermocouple is, for example, 400 ° C. and the upper limit temperature of the set temperature range is 5
It may be lower than 50 ° C. In such a case, since the thermocouple is not disconnected, the disconnection detection function does not work, and normal temperature control based on the temperature detection result by the thermocouple is performed. As a result, the current supply to the thermocompression bonding head is continued and the temperature of the thermocompression bonding head becomes higher than 600 ° C., that is, the upper limit temperature 55 of the set temperature range.
The temperature is considerably higher than 0 ° C., and there is a problem that the thermocompression bonding head itself and the thermocompression-bonded member such as a semiconductor chip may be burned by overheating. The object of the present invention is to
It is to be able to detect that the thermocouple is in an abnormal state immediately before it is broken.

[0005]

According to a first aspect of the present invention, there is provided a temperature control method for a thermocompression bonding apparatus, which detects a temperature of a thermocompression bonding head which generates heat in accordance with an electric current supplied through a terminal portion. In the temperature control method of the thermocompression bonding apparatus, the temperature of the thermocompression bonding head is controlled to be within a set temperature range by controlling the current supply to the thermocompression bonding head based on the temperature detection result. The voltage between the terminal portions is detected, and the voltage detection signal obtained thereby is compared with a preset voltage signal that is preset corresponding to a temperature that is higher than the upper limit temperature of the preset temperature range by a predetermined temperature. An abnormal signal is generated when the voltage detection signal becomes larger than the set voltage signal. A thermocompression bonding apparatus according to a fourth aspect of the invention is a thermocompression bonding head that generates heat in accordance with a current supplied through a terminal portion, a current supply unit that supplies a current to the thermocompression bonding head, and the thermocompression bonding head. By detecting the temperature of the temperature detection means to output a temperature detection signal, by controlling the current supply to the thermocompression bonding head by the current supply means based on the temperature detection signal output from the temperature detection means, A thermocompression bonding apparatus comprising: a control unit that controls the temperature of the thermocompression bonding head to be within a set temperature range, a voltage detecting unit that detects a voltage between terminals of the thermocompression bonding head and outputs a voltage detection signal. Wherein the control means has a preset voltage signal corresponding to a voltage detection signal output from the voltage detection means and a temperature higher by a predetermined temperature than an upper limit temperature of the preset temperature range. Compares, when the voltage detection signal is greater than the set voltage signal, is obtained so as to generate an abnormality signal.

According to the present invention, since the thermocouple is in an abnormal state immediately before it is broken, the actual temperature of the thermocompression bonding head becomes higher than the upper limit temperature of the set temperature range, but the thermocouple does not work. If the detected temperature is lower than the upper limit temperature of the set temperature range, and if the temperature of the thermocompression bonding head exceeds the upper limit temperature of the set temperature range by a predetermined temperature, an abnormal signal is generated and the thermocouple is disconnected. It is possible to detect that there is an abnormal state immediately before the operation.

[0007]

1 shows a schematic structure of a thermocompression bonding apparatus according to an embodiment of the present invention. This thermocompression bonding apparatus includes a thermocompression bonding head 1 that generates heat in accordance with a supplied current by a pulse heating method. This thermocompression bonding head 1
Is a control unit 2 including a CPU (central processing unit) and the like.
The current supply means 3 which operates by receiving the current supply control signal from the terminal 1a generates heat according to the current supplied through the terminal portion 1a. The temperature of the thermocompression bonding head 1 is detected by a thermocouple (temperature detecting means) 4 attached to the side surface of the tip of the thermocompression bonding head 1.
An analog signal (temperature detection signal) corresponding to the temperature detected by the thermocouple 4 is supplied to the control means 2 and converted into a digital signal. Further, the voltage between the two terminal portions 1 a of the thermocompression bonding head 1 is detected by the voltage detecting means 5. An analog signal (voltage detection signal) corresponding to the voltage detected by the voltage detection means 5 is supplied to the control means 2 and converted into a digital signal. Further, the control means 2 is connected with an alarm means 6 for generating an alarm sound such as a buzzer.

The control means 2 will be described below.
As an example, the temperature of the thermocompression bonding head 1 is 500 to 550 ° C.
A case will be described in which control is performed so that the set temperature range is set to. In this case, the preset upper limit temperature is 550 ° C. and the lower limit temperature is 500 ° C. Therefore, the upper limit temperature 55
Set upper limit temperature signal corresponding to 0 ° C and lower limit temperature 500
The set lower limit temperature signal corresponding to ° C is stored in the storage unit of the control means 2. Further, the relationship between the temperature (° C.) and the voltage (mV) of the thermocompression bonding head 1 is as shown in FIG. Therefore, the set voltage signal corresponding to the voltage 280 mV corresponding to the temperature 600 ° C. which is higher than the upper limit temperature 550 ° C. by a predetermined temperature, for example, 50 ° C., is stored in the storage unit of the control means 2.

Next, the temperature control method of this thermocompression bonding apparatus will be described. When current is supplied to the thermocompression bonding head 1 from the current supply means 3, the thermocompression bonding head 1 generates heat according to the supplied current, and the temperature of the thermocompression bonding head 1 is detected by the thermocouple 4. An analog signal (temperature detection signal) corresponding to the temperature detected by the thermocouple 4 is supplied to the control means 2 and converted into a digital signal. Then, the control means 2
The temperature detection signal and the set upper limit temperature signal (550 ° C.) are compared. When the temperature detection signal is smaller than the set upper limit temperature signal (550 ° C.), current supply from the current supply means 3 to the thermocompression bonding head 1 is continued, and the temperature of the thermocompression bonding head 1 rises. Temperature detection signal is set upper limit temperature signal (550 ° C)
When it becomes larger than this, the current supply from the current supply means 3 to the thermocompression bonding head 1 is stopped. As a result, the temperature of the thermocompression bonding head 1 is controlled so as not to exceed the upper limit temperature of 550 ° C. When the temperature of the thermocompression bonding head 1 becomes lower than or equal to the lower limit temperature 500 ° C. due to natural cooling, the temperature detection signal at this time becomes smaller than the set lower limit temperature signal (500 ° C.). The current supply to the thermocompression bonding head 1 is restarted, and the temperature of the thermocompression bonding head 1 rises.
Thus, the temperature of the thermocompression bonding head 1 is within the set temperature range 500.
Will be maintained at ~ 550 ° C.

By the way, this thermocompression bonding apparatus has a disconnection detecting function as in the conventional case, but also has a predetermined abnormal state detecting function. Next, the predetermined abnormal state detecting function will be described. Since the thermocouple 4 is in a state immediately before the wire is broken, even if the actual temperature of the thermocompression bonding head 1 is higher than the upper limit temperature 550 ° C. of the set temperature range, for example, 600 ° C., detection by the thermocouple 4 is possible. The temperature is, for example, 400 ° C. and the upper limit temperature 55 of the set temperature range.
It is assumed that the temperature becomes lower than 0 ° C. Then, as in the conventional case, since the thermocouple 4 is not disconnected, the disconnection detection function does not work, and normal temperature control based on the temperature detection result by the thermocouple 4 is performed. As a result, the current supply from the current supply means 3 to the thermocompression bonding head 1 is continued, and the actual temperature of the thermocompression bonding head 1 becomes 600 ° C. or higher. The voltage between both terminal portions 1a of the thermocompression bonding head 1 at this time is detected by the voltage detecting means 5. An analog signal (voltage detection signal) corresponding to the voltage detected by the voltage detection means 5 is supplied to the control means 2 and converted into a digital signal. And
The control means 2 controls the voltage detection signal and the set voltage signal (280 m
V). The voltage detection signal is the set voltage signal (28
If it is smaller than 0 mV), the control means 2 ignores it. When the voltage detection signal becomes larger than the set voltage signal (280 mV), the control means 2 ignores the temperature detection signal from the thermocouple 4 and the actual temperature of the thermocompression bonding head 1 exceeds 600 ° C. Therefore, the current supply means 3 stops the current supply from the current supply means 3 to the thermocompression bonding head 1. As a result, the temperature of the thermocompression bonding head 1 is higher than the upper limit temperature of 550 ° C. by a predetermined temperature 50 ° C.
It is controlled not to exceed ℃. Further, the alarm means 6 generates an alarm sound for notifying an abnormal state.

As described above, since the thermocouple 4 is in a state immediately before breaking, the actual temperature of the thermocompression bonding head 1 is 600 ° C., which is higher than the upper limit temperature 550 ° C. of the set temperature range by a predetermined temperature 50 ° C. However, if the temperature detected by the thermocouple 4 is lower than the upper limit temperature 550 ° C. of the set temperature range, for example, 400 ° C., the temperature of the thermocompression bonding head 4 is a predetermined temperature 50 ° C. higher than the upper limit temperature 550 ° C. Only high temperature 6
When the temperature exceeds 00 ° C., an abnormal signal is generated, so that it can be detected that the thermocouple 4 is in an abnormal state immediately before the wire breaks. The voltage detecting means 5 is the thermocompression bonding head 1.
If the current is not supplied to the device, it does not operate. Therefore, it is not possible to perform the normal temperature control such that the temperature of the thermocompression bonding head 1 is within the set temperature range of 500 to 550 ° C. only by the voltage detecting means 5. Therefore, the thermocouple 4 is required to perform the normal temperature control such that the temperature of the thermocompression bonding head 1 is in the set temperature range of 500 to 550 ° C.

[0012]

As described above, according to the present invention, the actual temperature of the thermocompression bonding head becomes higher than the upper limit temperature of the set temperature range due to the abnormal state immediately before the thermocouple is broken. Nevertheless, if the temperature detected by the thermocouple is lower than the upper limit temperature of the set temperature range, if the temperature of the thermocompression bonding head exceeds the upper limit temperature of the set temperature range by a predetermined temperature, an abnormal signal will be generated. It is possible to detect that the thermocouple is in an abnormal state immediately before the thermocouple is broken.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a thermocompression bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between temperature and voltage of a thermocompression bonding head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermocompression bonding head 2 Control means 3 Current supply means 4 Thermocouple (temperature detection means) 5 Voltage detection means 6 Alarm means

Claims (6)

[Claims] 1. The temperature of a thermocompression bonding head that generates heat according to the current supplied through a terminal portion is detected, and the current supply to the thermocompression bonding head is controlled based on the temperature detection result, In a temperature control method of a thermocompression bonding apparatus for controlling the temperature of a thermocompression bonding head to fall within a set temperature range, a voltage between terminals of the thermocompression bonding head is detected, and a voltage detection signal obtained thereby and the set temperature are obtained. An abnormal signal is generated when the voltage detection signal becomes larger than the set voltage signal by comparing with a set voltage signal set in advance corresponding to a temperature higher by a predetermined temperature than the upper limit temperature of the range. A temperature control method for a thermocompression bonding apparatus, characterized in that 2. The invention according to claim 1, wherein when the abnormal signal is generated, at least one of stopping the current supply to the thermocompression bonding head and generating an alarm sound by a buzzer or the like is performed. A method for controlling a temperature of a thermocompression bonding device, comprising: 3. The method according to claim 1, wherein
The temperature control method of the thermocompression bonding apparatus, wherein the temperature of the thermocompression bonding head is detected by a thermocouple attached to the thermocompression bonding head. 4. A thermocompression bonding head that generates heat in accordance with a current supplied through a terminal portion, a current supply unit that supplies a current to the thermocompression bonding head, and a temperature detection by detecting the temperature of the thermocompression bonding head. The temperature of the thermocompression bonding head is set by controlling the temperature detection means for outputting a signal and controlling the current supply to the thermocompression bonding head by the current supply means based on the temperature detection signal output from the temperature detection means. In a thermocompression bonding apparatus including a control means for controlling the temperature range, a voltage detecting means for detecting a voltage between the terminal portions of the thermocompression bonding head and outputting a voltage detection signal is provided, and the control means is
The voltage detection signal output from the voltage detection means is compared with a preset voltage signal set in advance corresponding to a temperature higher than the upper limit temperature of the preset temperature range by a predetermined temperature, and the voltage detection signal is set to the preset value. A thermocompression bonding device, wherein an abnormal signal is generated when the voltage becomes larger than the voltage signal. 5. The invention according to claim 4, wherein at least one of stopping the current supply to the thermocompression bonding head by the current supply means and generating an alarm sound by a buzzer or the like when the abnormal signal is generated. The thermocompression bonding apparatus characterized by carrying out. 6. The invention according to claim 4, wherein
The thermocompression bonding apparatus, wherein the temperature detecting means includes a thermocouple attached to the thermocompression bonding head.