JP3417287B2 - Thermocompression bonding apparatus and thermocompression bonding method for electronic components - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component thermocompression bonding apparatus and a thermocompression bonding method for thermocompression bonding an electronic component to a substrate.

[0002]

2. Description of the Related Art As a method for bonding an electronic component to a substrate, a method by thermocompression bonding is known. In this method, an electronic component is adhered to the substrate by soldering or a resin adhesive by pressing the electronic component against the substrate while heating it using a thermocompression bonding tool. Here, in order to obtain good pressure bonding quality, it is necessary to control the heating temperature in the thermocompression bonding process according to a predetermined heating pattern. Therefore, a temperature control function is provided for detecting the temperature of the thermocompression bonding tool by a temperature detecting means such as a temperature sensor and comparing the temperature with a command temperature to control the temperature.

[0003]

By the way, a means such as a screw is usually used to fix the portion where the temperature sensor or the like is attached to the thermocompression bonding tool, and the screw portion gradually loosens with the passage of time. easy. For this reason, the temperature sensor may be displaced from the correct position and normal temperature detection may not be performed. However, in the conventional thermocompression bonding apparatus, as a method for detecting temperature control abnormality, a lower limit temperature is set and an alarm is issued when the detected temperature falls below this lower limit temperature. When not done, this method did not work well. Furthermore, in such a case, as a result that the temperature detection is not normally performed, the actual heating temperature of the thermocompression bonding tool rises above the command temperature. As described above, the conventional thermocompression bonding apparatus for electronic components has a problem that accurate temperature control may not be performed due to a defective mounting state of the temperature sensor or the like.

Therefore, it is an object of the present invention to provide a thermocompression bonding apparatus and a thermocompression bonding method for electronic parts, which can perform accurate temperature control.

[0005]

According to a first aspect of the present invention, there is provided a thermocompression bonding apparatus for an electronic component, wherein a thermocompression bonding tool for thermocompression bonding the electronic component, an elevating means for elevating the thermocompression bonding tool, and a thermocompression bonding tool are used. A heater that heats an electronic component, a temperature measuring unit that measures the temperature of the thermocompression bonding tool, a heating pattern storage unit that stores a heating pattern of the thermocompression bonding tool, and a heater that controls heating of the heater based on the heating pattern. Control means, a normal temperature adjustment range setting unit that sets a normal variation range for the heating pattern as a normal temperature adjustment range based on temperature increase data in a normal state, and an abnormal temperature rise of the thermocompression bonding tool during thermocompression bonding. Based on the normal temperature control range
An abnormal temperature control determination unit that repeatedly determines a sampling time and a notification unit that notifies the determined abnormal temperature control are provided.

According to a second aspect of the thermocompression bonding method for electronic parts,
The electronic parts are heated by a heater via a thermocompression bonding tool,
A thermocompression bonding method for an electronic component, in which an electronic component is thermocompression bonded by raising and lowering a thermocompression bonding tool to press the electronic component against a substrate, and a normal variation range for a heating pattern is set in advance based on normal temperature rise data. The normal temperature control range is set by the normal temperature control range setting unit, and it is determined whether or not the temperature rise pattern of the thermocompression bonding tool measured by the temperature measuring means is within the normal temperature control range during thermocompression bonding. repeatedly determined at the sampling time by the determination unit, was Unishi by you that effect the notification by the notification unit if it is determined to be a different room temperature control.

According to the invention described in each claim, a normal temperature control range showing a normal variation range is set in advance based on the temperature rise data at the normal time, and the temperature rise pattern at the time of thermocompression bonding is used as the normal temperature control range. By determining the presence / absence of abnormality by comparing with the adjustment range, it is possible to prevent defective temperature control caused by defective mounting of the temperature sensor.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a thermocompression bonding apparatus for electronic parts according to an embodiment of the present invention, FIG. 2 is a flow chart of the normal temperature control range setting, and FIG. 3 is a graph showing the normal temperature control range setting. FIG. 4 is a flowchart of the thermocompression bonding operation of the electronic component.

First, the structure of a thermocompression bonding apparatus for electronic components will be described with reference to FIG. In FIG. 1, a substrate 2 is placed on the positioning table 1. An electrode 2a is provided on the substrate 2, and an electronic component 3 is mounted on the electrode 2a via bumps 3a. The electronic component 3 is adsorbed and held by the thermocompression bonding tool 4 mounted on the pressure bonding head 5.
The crimping head 5 has a heater 6 built therein.
Heats the electronic component 3 via the thermocompression bonding tool 4. Further, the thermocompression bonding tool 4 is provided with a temperature sensor 7, and the temperature sensor 7 detects the temperature of the thermocompression bonding tool 4 heated by the heater 6.

The thermocompression bonding head 5 is mounted on a Z-axis table 8 as an elevating means. Z axis table has nut 1
1, equipped with a feed screw 10 and a Z-axis motor 9,
By driving the shaft motor 9, the crimping head 5 moves up and down. The power supply unit 12 supplies electric power for heating the heater 6. A
The / D converter 15 A / D-converts the temperature (a) detected by the temperature sensor 7 into a feedback temperature signal (b), which is sent to the deviation calculator 14. The PID control unit 13 includes the control unit 1
The control operation amount (d) is output to the power supply unit 12 based on the command temperature (c) commanded by the controller 7 and the deviation of the feedback signal from the temperature sensor 7 obtained by the deviation calculator 14.

Next, the control unit 17 will be described. The heating pattern storage unit 18 stores the heating pattern of the thermocompression bonding tool 4 during thermocompression bonding. The normal temperature adjustment range setting unit 19 sets a normal variation range for the heating pattern as a normal temperature adjustment range based on actual temperature increase data. The abnormal temperature control determination unit 20 determines whether or not the temperature rise of the thermocompression bonding tool during the thermocompression bonding operation is within the normal temperature control range. Notification unit 2
Reference numeral 1 denotes a buzzer, a signal light, or the like, which notifies the abnormal temperature control based on the determination result of the abnormal temperature control determination unit 20. Operation control unit 2
Reference numeral 2 controls the entire thermocompression bonding operation such as lifting and lowering of the thermocompression bonding tool 4, pressurizing operation, and heater heating control based on a heating pattern. In the present embodiment, the function of controlling the heater of the operation control unit 22 corresponds to the heater control means.

Next, the normal temperature control range set to monitor whether or not the temperature of the thermocompression bonding tool 4 is normally raised during the thermocompression bonding operation will be described. At the time of thermocompression bonding, the power supply is controlled so that the thermocompression bonding tool 4 rises in temperature according to a predetermined heating pattern, but the actual temperature does not always match the heating pattern, and exhibits a variation in a certain range.

When the temperature control function is operating normally, this variation is within a predetermined range, and when the variation exceeds the predetermined range when the temperature is raised, it means that there is some abnormality in the temperature control function. Can be determined. An example of this abnormality is defective mounting of the temperature sensor 7. In this case, the temperature of the thermocompression bonding tool 4 during the temperature rise is not correctly detected, and the temperature adjustment function does not work properly.

Next, the setting of the normal temperature control range will be described with reference to the graph of FIG. 3 along the flow of FIG.
This normal temperature control range is set for the temperature rising time from the start of heating to the designated temperature in the heating pattern. First, prior to the normal temperature adjustment setting, it is confirmed that each part of the device such as the mounting state of the temperature sensor 7 is in a normal state, and that the PID control parameters are set so as to show a response with good followability. Next, the operation control unit 22
The heating pattern is read from the heating pattern storage unit 18 by.

After that, the timer is reset and the command temperature data (c) based on the heating pattern from the operation control section 22.
Is output and the temperature control is started. (ST1), followed by temperature detection by the temperature sensor 7 (ST2). Here, it is judged whether or not the temperature is being raised (ST3), and if the temperature is being raised, the deviation D between the command temperature data and the detected temperature data is set to the normal temperature control range as shown in the graph of FIG. The data is stored in the memory data [t] of the unit 18. After that, the sampling time t1 is waited (ST5), the timer is set to t + t1 (ST6), and the process returns to ST2 again to detect the temperature.

By repeating this temperature detection, FIG.
The detected data points Td are obtained along the graph Ti showing the command temperature as shown in FIG. 3, and these detected data are stored in the above-mentioned memory. Next, from these stored data, the upper maximum deviation DU showing the maximum value of the deviation D appearing on the upper side of the graph Ti and the lower maximum deviation DL showing the maximum value of the deviation D appearing on the lower side are obtained (ST7).

Next, the upper-side maximum deviation DU and the lower-side maximum deviation DL are multiplied by the safety factor α to obtain the upper limit width UL and the lower limit width LL which define the limit of normal variation (ST8). That is, the variation range obtained in the actual normal temperature rising process (range between Tmax and Tmin shown by the chain line in FIG. 3)
To the range obtained by multiplying by the safety factor α obtained as an empirical value (TU indicated by the broken line in FIG. 3).
The range between L and TLL) is set as the normal temperature control range.

Next, the abnormal temperature control determination performed based on this normal temperature control range during thermocompression bonding will be described with reference to the flow chart of FIG. In FIG. 4, a flow showing the thermocompression bonding operation (ST11 to ST14) and a flow of abnormal temperature control determination (ST21 to ST29) are shown in parallel. These two flows are simultaneously processed by different CPUs, and the temperature control start (ST21) in the thermocompression bonding operation and the start of the abnormal temperature control determination flow are synchronized. First, the thermocompression bonding operation will be described. After the thermocompression bonding apparatus is activated to start temperature control (ST11), the Z-axis table 8 is driven and the pressure bonding head 5 is lowered (ST12). After that, thermocompression bonding is performed (ST13), and when the thermocompression bonding is completed, the next pressure bonding is waited (ST14).

Next, the flow of abnormal temperature control determination will be described. This flow starts at the same time as the temperature control start (ST11) described above, and the timer is first reset (ST2
1), the temperature of the thermocompression bonding tool 4 is detected by the temperature sensor 7 (ST22). Then, it is determined whether or not the detected temperature is within the temperature range stored as the normal temperature adjustment range (ST23). As a result, if it is within the range, the sampling time t1 is waited (ST24), and the timer is set to t + t1 (ST25). Next, it is determined whether or not the temperature is being raised (ST26), and if the temperature has already been raised, the abnormal temperature control determination is ended. If it is determined in ST26 that the temperature is still rising, the process returns to ST22 and the temperature is detected again.

If it is determined in ST23 that the detected temperature is out of the temperature range stored as the normal temperature control range, it is determined that the temperature is abnormal temperature control and an alarm is output, and the notification unit 21
Is notified (ST28). Thereafter, the pressure bonding operation is stopped (ST29), and the temperature control function is stopped. You
That is, ST22 to ST28 increase the temperature of the thermocompression bonding tool.
Abnormal temperature control judgment whether the pattern is within the normal temperature control range
Section repeatedly determines the sampling time and
If it is determined that the temperature is normal, the notification section informs that fact.
To know.

In this way, by notifying the abnormal temperature control, if there is any abnormality such as a defective mounting state of the temperature sensor 7, it is possible to quickly check the state, and if it is defective, immediately. By taking necessary measures, it is possible to prevent poor temperature control and maintain good thermocompression bonding quality.

[0022]

According to the present invention, the normal temperature control range showing the normal variation range of the temperature during the temperature increase of the thermocompression bonding tool during the thermocompression bonding operation is set based on the temperature increase data at the normal time. , The temperature rise pattern during thermocompression bonding is compared with normal temperature control half-paper, and whether there is an abnormality is repeated after a sampling time.
By making the determination, it is possible to prevent poor temperature control caused by a poor mounting state of the temperature sensor, and maintain good thermocompression bonding quality.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a thermocompression bonding apparatus for electronic components according to an embodiment of the present invention.

FIG. 2 is a flowchart for setting a normal temperature control range according to the embodiment of the present invention.

FIG. 3 is a graph showing a normal temperature control range setting according to an embodiment of the present invention.

FIG. 4 is a flow chart of thermocompression bonding operation of the electronic component according to the embodiment of the present invention.

[Explanation of symbols]

1 Positioning table 2 substrates 3 electronic components 4 Thermo-compression tool 6 heater 8 Z-axis table 18 Heating pattern storage 19 Normal temperature control range setting section 20 Abnormal temperature control determination section 21 Notification section

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-11-54904 (JP, A) JP-A-63-309385 (JP, A) JP-A-2-121345 (JP, A) JP-A-6- 13440 (JP, A) JP-A-6-314725 (JP, A) JP-A-9-64118 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/60 H05K 3 / 32 G05D 23/00

Claims (2)

(57) [Claims] 1. A thermocompression bonding tool for thermocompression bonding an electronic component, an elevating means for elevating the thermocompression bonding tool, a heater for heating the electronic component via the thermocompression bonding tool, and a temperature for measuring the temperature of the thermocompression bonding tool. A measuring unit, a heating pattern storage unit that stores a heating pattern of the thermocompression bonding tool, a heater control unit that controls heating of the heater based on the heating pattern, and a normal variation range for the heating pattern is set to a normal range. The normal temperature control range setting section that sets the normal temperature control range based on the temperature data, and the abnormal temperature rise of the thermocompression bonding tool during thermocompression bonding are sampled based on the normal temperature control range.
An apparatus for thermocompression bonding of an electronic component, comprising: an abnormal temperature control determination unit that repeatedly determines a ring time and an informing unit that reports the determined abnormal temperature control. 2. A thermocompression bonding method for an electronic component, wherein the electronic component is heated by a heater through a thermocompression bonding tool, and the thermocompression bonding tool is moved up and down to press the electronic component against a substrate, thereby thermocompression bonding the electronic component. The normal variation range for the heating pattern is set as the normal temperature control range in advance by the normal temperature control range setting unit based on the temperature rise data at the normal time, and the thermocompression bonding tool measured by the temperature measuring means at the time of thermocompression bonding. Whether or not the temperature rise pattern is within the normal temperature control range is determined by the abnormal temperature control determination unit with a sampling time.
Ri returns determined by the notification unit if it is determined that the different cold tone thermocompression bonding method of the electronic component characterized by and Turkey to that effect notification.