JPH10255946A - Thermo-compression bonding method for connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermo-compression bonding method for connector in which elongation control of a resin film at the time of thermo-compression bonding can be properly performed to eliminate position displacement between a terminal on a substrate and a lead on a connector to the utmost and production yield can be improved. SOLUTION: A width size of a lead line 30a on a connector 12 is set to be shorter than a width size of a terminal line 31a on a substrate 11, size difference between both sizes is optically detected before thermo-compression bonding, and at least one of parameters of a pressurizing speed, thermo-compression bonding load, and bOnding time is changed based on data showing relation between each parameter and elongation of the connector 12, so the size difference is corrected by elongation in the width direction of the connector 12 in a thermo-compression bonding process. Since relation between each parameter and elongation quantity is correctly determined based on experimental data, the size difference can be properly corrected, thereby generation of defectives caused by position displacement of the thermo-compression bonding can be reduced to improve yield.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for thermocompression bonding a connector, in which a lead array comprising a number of leads is formed on a resin film, to a substrate such as a display panel by thermocompression bonding with a thermocompression tool. is there.

[0002]

2. Description of the Related Art A substrate such as a display panel used as a display of an electronic device has a large number of terminals formed at an edge thereof, and a connector for electrically connecting to a driver is bonded to these terminals. This connector is formed by arranging a large number of very fine leads at a narrow pitch on a surface of a flexible resin film, and is generally connected to a substrate via an anisotropic conductive tape (hereinafter referred to as [ACF]). Thermocompression bonded to the surface of As such a connector, TAB
There are a film carrier (resin film) formed by a (Tape Automated Bonding) method, a resin film with leads connected to a substrate on which a driver is mounted, and the like.

[0003] Incidentally, the positions of the leads of the connector are likely to be out of order due to molding errors and expansion of the resin film during thermocompression bonding. On the other hand, terminals of a substrate such as a display panel have a large number of leads arranged at a narrow pitch, and high accuracy is required for positioning of connectors connected to these terminals. For this reason, conventionally, a method of estimating the elongation percentage of the resin film at the time of thermocompression bonding of the connector and setting dimensions so as to have an appropriate dimension after thermocompression bonding has been adopted.

[0004]

However, since the elongation at the time of thermocompression bonding is related to various factors such as thermocompression load, thermocompression bonding time and thermocompression bonding temperature, it is not always necessary to exhibit expected elongation. Not necessarily. For this reason, after the thermocompression bonding, a deviation exceeding a permissible value is exhibited and some products are discarded as defective products, which lowers the production yield.

Accordingly, the present invention provides a connector for thermocompression bonding, which can appropriately manage the extension of the resin film during thermocompression bonding, eliminate the displacement between the terminal of the board and the lead of the connector, and improve the production yield. The aim is to provide a method.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a connector in which a plurality of leads are formed on a resin film such as a film carrier, the width of which is set to be larger than the width of the leads. A method for thermocompression bonding a connector having a terminal row with thermocompression bonding with a thermocompression bonding tool, the step of optically measuring a width dimension of a lead row and a terminal row before thermocompression bonding the connector to the board; and Calculating the dimensional difference between the width dimension of the lead row and the width dimension of the terminal row from the measurement results, and based on the dimensional difference and the experimental results, the pressing speed, thermocompression load, and thermocompression time of the thermocompression bonding tool. Determining at least one of the parameters to correct the dimensional difference in the process of thermocompression bonding.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention having the above-mentioned structure has the following features. Optically detects the difference between the width of the lead row and the pressing speed, thermocompression load, and thermocompression time, and indicates the relationship between each parameter and the elongation of the connector. It is determined based on the data, and this dimensional difference is corrected by the elongation in the width direction of the connector in the thermocompression bonding process. Since the relationship between the parameters and the amount of elongation has been clarified in advance by experimental data, the dimensional difference can be appropriately corrected.

(Embodiment 1) FIGS. 1 (a) and 1 (b)
FIG. 2 is a graph showing a relationship between a thermocompression load and a thermocompression time during thermocompression bonding according to the first embodiment of the present invention; FIG. 2 is a perspective view of the thermocompression bonding apparatus of the connector; FIG. 4 is a block diagram of the system, FIG. 4 is a plan view of the connector, FIG. 5 is a graph showing a relationship between elongation of the connector and a pressing speed, and FIG. 6 is a flowchart of thermocompression bonding of the connector.

Before explaining the first embodiment, FIG. 1 shows a pattern and parameters of thermocompression bonding of a connector.
Description will be made with reference to (a) and (b). These are commonly used in Embodiments 2 and 3 to be described later. 1A and 1B show the relationship between the thermocompression load and the thermocompression time.
In (a) and (b), the horizontal axis represents the elapsed time from when the thermocompression bonding tool lands on the surface of the connector, and the vertical axis represents the load value at which the thermocompression bonding tool presses the connector.

FIG. 1A shows a first pattern of thermocompression bonding, which corresponds to the first embodiment. At the beginning of thermocompression bonding,
Since the thermocompression bonding tool is pressed against the connector at a certain speed or more, the straight line a indicating the thermocompression load value is a short time T
It rises rapidly during i and reaches the load value P. Thereafter, the load value P is held for a predetermined time t. FIG. 1B shows a second pattern of thermocompression bonding, which corresponds to the second and third embodiments described later. In the second pattern, the straight line b indicating the thermocompression bonding load value rises rapidly during a short time Ti, and reaches the load value P1. After this, a predetermined time t1
During this time, the load value P1 is held. Thereafter, the thermo-compression load value for pressing the thermo-compression tool is switched to P2, which is larger than P1, and this load value P2 is maintained for a predetermined time t2.
That is, the first pattern and the second pattern are classified according to whether the thermocompression load value P is switched in the thermocompression bonding process.

Next, parameters of thermocompression bonding will be described. First, the pressurizing speed means the gradient of the rising straight line a and the straight line b in the graphs of FIGS. 1 (a) and 1 (b). In addition, the thermocompression bonding load means a load value P1 shown in FIG. 1B, and the thermocompression bonding time means a predetermined holding time t1 shown in FIG. 1B. In this case, the above-described rise time Ti of the load value is actually considered to be ignored since it is a short time compared to t1. As will be described later, the elongation of the connector by thermocompression bonding can be controlled by appropriately determining the pressing speed, the initial load value P1 of thermocompression bonding, and the thermocompression bonding time t1 within a certain condition range. That is, the present invention is intended to correct the dimensional difference of the connector by controlling the elongation of the connector in the thermocompression bonding process using the pressing speed, the initial load value P1 of the thermocompression bonding and the thermocompression time t1 as parameters. is there.

Next, reference numerals used in the description of the first, second and third embodiments will be described. V denotes the pressing speed of the thermocompression tool, P denotes the thermocompression load of the thermocompression tool, t denotes the thermocompression time of the thermocompression tool, and E denotes the width of the connector in the thermocompression process. Means elongation in the direction. When these codes are used, if they mean a specific value, they are added with subscripts.

Hereinafter, the overall structure of the connector thermocompression bonding apparatus will be described with reference to FIGS. In FIG.
Reference numeral 1 denotes a thermocompression bonding tool, which is connected to a rod 2a of a cylinder 2. The cylinder 2 is provided on the bracket 3, and applies a thermocompression load to the connector by pushing down the thermocompression tool 1 downward. A slider 4b (FIG. 3) that slides along a vertical guide rail 4a is provided on the back of the bracket 3.
See). The guide rail 4a is mounted on the front of the box 5. A motor 6 is provided on the box 5. A vertical feed screw 7 (see FIG. 3), which is driven by a motor 6 and rotates, is housed in the box 5. A nut 8 screwed to the feed screw 7 is mounted on the back of the bracket 3. I have. Therefore, when the motor 6 rotates forward and backward, the bracket 3 and the thermocompression bonding tool 1 move up and down. The box 5 is mounted on a moving table 9 and moves to an arbitrary position in the horizontal direction.

A support 10 is provided below the thermocompression bonding tool 1, and a substrate 11 is supported on the support 10. ACF2 is provided on the terminal row (described later) at the edge of the substrate 11.
5 is stuck. Reference numeral 12 denotes a connector, which is supported by a support table 15. Support table 15
Is mounted on a movable table 18 composed of an X table 16 and a Y table 17. Therefore, the movable table 1
By driving the connector 8, the connector 12 moves horizontally to an arbitrary position and is positioned with respect to the substrate 11. A movable table 13 is provided below the end of the support base 10. The movable table 13 has two cameras 14a, 14
b is attached. When the movable table 13 is driven, the cameras 14a and 14b move horizontally in the direction in which the three connectors 12 are arranged, and are positioned below the joint between the board 11 and the connector 12.

Next, the configuration of a control system of the connector thermocompression bonding apparatus will be described with reference to FIG. In FIG. 3, reference numeral 20 denotes a motor drive unit, which controls a lowering speed, that is, a pressing speed of the thermocompression bonding tool 1. Reference numeral 21 denotes a load control unit that controls the thermocompression bonding load of the thermocompression bonding tool 1 by controlling the cylinder 2. The measurement unit 22 obtains image data from the cameras 14a and 14b, and based on the image data,
The dimensional difference between the connector 1 and the connector 12 is calculated. Storage unit 23
Stores data on parameters such as the pressing speed V, the thermocompression load P, and the thermocompression time t. The control unit 24 receives the data from the storage unit 23 and the measurement unit 22 and controls the motor drive unit 20 and the load control unit 21.

Next, referring to FIGS. 4A and 4B, the substrate 1
The joint between the connector 1 and the connector 12 will be described. 4A shows a state in which the connector 12 is roughly positioned with respect to the substrate 11, and FIG. 4B shows a state in which the connector 12 is precisely positioned with respect to the substrate 11.
In FIG. 4A, a lead row 30 a including a large number of leads 30 is formed on the surface of the connector 12. The width L of the lead row 30a is provided at both ends of the lead row 30a.
A first mark M1 and a second mark M2 for measuring 1 are provided. A terminal row 31 a including a large number of terminals 31 is formed on the edge of the substrate 11. Terminal row 3
At both ends of 1a, a third mark M3 and a fourth mark M4 for measuring the width L2 of the terminal row 31a are provided. By optically detecting the distance between the marks and calculating these differences, the dimensional difference between the width L2 of the terminal row 31a and the width L1 of the lead row 30a can be obtained.

The thermocompression bonding apparatus for a connector has the above-mentioned configuration, and its operation will be described below with reference to the flowcharts of FIGS. First, ST in FIG.
At 1, the substrate 11 is transported and supported on the support base 10. As shown in FIG. 3, an ACF 25 is attached on the substrate 11, and by driving the movable table 18, the connector 12 supported by the support table 15 is roughly aligned on the ACF 25 ( ST2). FIG.
(A) shows the state at this time.

Next, the marks M1, M2, M3 and M4 are picked up by the cameras 14a and 14b (ST3), and this image data is sent to the measuring section 22 (FIG. 3), where the width L2 of the terminal row 31a and the lead row are read. The width dimension L1 of 30a is measured (ST4), and then the dimension difference dL between L2 and L1 is calculated (ST5).

Also, based on the image data, the terminal row 31a
Of the center line A of the lead line 30a and the center line B of the lead row 30a,
The movable table 1 is moved so that these center lines A and B coincide with each other.
By driving the connector 8, the connector 12 is precisely positioned on the substrate 11 (ST6). As a result, as shown in FIG. 4B, the lead row 30a is positioned with respect to the terminal row 31a with the dimensional difference dL distributed to both sides. In the present invention, the dimensional difference dL is corrected by determining the parameters of the thermocompression bonding. In the first embodiment, this correction is performed by determining the pressing speed V.

FIG. 5 is a graph showing the relationship between the elongation E of the connector 12 and the pressing speed V, which is obtained from the results of experiments conducted by the inventor. As is clear from FIG. 5, when the descending speed after the thermocompression bonding tool 1 lands on the connector 12 is increased, that is, when the pressing speed V is increased, the elongation E of the width of the connector 12 in the crimping process decreases. . This is because when the pressing speed V is increased, the connector 12
Is suddenly pressed onto the substrate 11, and it is presumed that thermocompression bonding is completed before the resin film as the material of the connector 12 thermally expands in the horizontal direction.

Further, as shown in FIG. 5, the elongation E and the pressing speed V show a substantially linear correlation within a certain range.
Further, the elongation value E1 corresponds to the value Vmin of V on the straight line of the graph, and the elongation value E2 also corresponds to Vmax. The range between E1 and E2 is a range where this linear relationship is established with reasonable accuracy. That is, this graph can be applied only when the dL obtained by the measurement is in this range. The actual variation is within a limited range, and dL is mostly between E1 and E2. V (b) shown in FIG. 5 is a pressing speed corresponding to dL.

Returning to the flowchart of FIG. 6 again, the above-mentioned V (b) is obtained (ST7), the thermocompression bonding tool 1 descends (ST8), and lands on the surface of the connector 12. Next, thermocompression bonding is started at V (b) (ST9), whereby the connector 12 exhibits elongation equal to dL during the pressing process, and the dimensional difference dL is corrected. And the predetermined load P
Is held for a predetermined time t, the thermocompression bonding tool 1 rises (S
T10) The thermocompression bonding is completed.

As described above, in the first embodiment, the pressing speed V is determined based on the relationship between the pressing speed V obtained from the experimental data and the elongation E of the connector 12, and the dimensions of the connector 12 are determined. The difference dL is corrected by the elongation E of the connector 12 during the thermocompression bonding process.

(Embodiment 2) In Embodiment 1 described above,
According to the first pattern of thermocompression bonding, the pressing speed V is used as a parameter.
In accordance with the second pattern of thermocompression bonding that switches to two stages of P2 and P2, the dimensional difference dL is corrected using the initial thermocompression load value, that is, P1 as a parameter.

FIG. 7 is a graph showing the relationship between the elongation of the connector and the thermocompression load of the second embodiment of the present invention, FIG. 8 is a flowchart of the thermocompression of the connector, and FIG. It is a graph shown in time series.

Since the connector thermocompression bonding apparatus used in the second embodiment is the same as that in the first embodiment, the description is omitted here. In addition, in the flow shown in FIG. 8, the operation up to ST6 for calculating the dimensional difference dL and positioning the connector 12 is the same as that in the first embodiment, and therefore the description is omitted.

Hereinafter, steps after ST6 in the flow of FIG. 8 will be described. In ST7, the thermocompression bonding load P corresponding to the dimensional difference dL is obtained from the graph of FIG. As described above, the elongation E in the width direction of the connector 12 at the time of thermocompression depends on the load value P1 at the initial stage of thermocompression in a certain condition range. That is, when other conditions are constant, the elongation E decreases when the load value P1 increases, and conversely, the elongation E increases when the load value P1 decreases.

According to the experimental data of the inventor, as shown in FIG. 7, the load value P1 and the elongation E show a substantially linear correlation. In FIG. 7, the elongation value E1 corresponds to the value P1min of P1 on the straight line of the graph, and the elongation value E2 is the same as P1.
max. The range between E1 and E2 is a range where this linear relationship is established with reasonable accuracy. That is,
This graph can be applied only when the dL obtained by the measurement is in this range. Since the range of practical variation is limited, dL is mostly between E1 and E2. P1 (b) shown in FIG. 7 is a thermocompression load corresponding to dL.

Returning to the flowchart of FIG. 8 again, the thermocompression bonding tool 1 descends (ST8), and lands on the surface of the connector 12. Next, thermocompression bonding is started with the thermocompression load P1 (b) (ST9), and the thermocompression load P1 is maintained for t1. When the holding time t1 expires, the thermocompression bonding load is switched from P1 to P2 (ST10), and the thermocompression bonding load P2 is maintained during t2. When the holding time t2 elapses, the thermocompression bonding tool 1 rises (ST1).
1), thermocompression bonding is completed.

FIG. 9 shows the value of elongation E from the time when the thermocompression bonding tool 1 lands on the connector 12 and starts thermocompression bonding. This graph shows that if the thermocompression bonding load P is below a certain value, the elongation E increases in proportion to the thermocompression bonding time t, and if the thermocompression bonding load P is increased beyond a certain value, the elongation E stops. Is shown.

As described above, in the second embodiment, the thermocompression bonding load P1 and the connector 12
Thermocompression load P1 is determined based on the relationship with the elongation E of
The dimensional difference dL of the connector 12 is corrected by the elongation E of the connector 12 during the thermocompression bonding process.

(Embodiment 3) In Embodiment 2 described above,
The thermocompression bonding load P1 is used as a parameter. In the third embodiment, the dimensional difference dL is corrected using the thermocompression bonding time t1 in the initial stage of thermocompression bonding as a parameter in accordance with the second pattern of thermocompression bonding. FIG. 10 shows Embodiment 3 of the present invention.
Graph showing the relationship between the elongation of the connector and the thermocompression bonding time,
FIG. 11 is a flowchart of thermocompression bonding of the connector, and FIG.
3 is a graph showing the elongation during thermocompression bonding of the connector in chronological order.

The thermocompression bonding apparatus for a connector used in the third embodiment is the same as that in the first embodiment, and a description thereof will be omitted. Also, in FIG. 11, the steps up to ST6 are the same as in the second embodiment.

Hereinafter, the steps after ST6 in the flow of FIG. 11 will be described. In ST7, the thermocompression bonding time t1 corresponding to the dimensional difference dL is obtained from the graph of FIG. As described above, the extension E in the width direction of the connector 12 at the time of thermocompression bonding.
Depends on the thermocompression bonding time t1 at the beginning of thermocompression bonding in a certain condition range. That is, when other conditions are constant, the elongation E increases if the thermocompression bonding time t1 is increased.

According to the experimental data of the inventors, as shown in FIG. 10, the thermocompression bonding time t1 and the elongation E show a substantially linear correlation. In FIG. 10, the elongation value E1 corresponds to the value t1max of t1 on the straight line of the graph, and the elongation value E2 also corresponds to t1min. The range between E1 and E2 is a range where this linear relationship is established with reasonable accuracy.
That is, this graph can be applied only when the dL obtained by the measurement is in this range. Since the range of the actual variation is limited, d
L mostly falls between E1 and E2.
Then, t1 (b) shown in FIG. 10 is the thermocompression bonding time corresponding to dL.

Returning to the flowchart of FIG. 11 again, the thermocompression bonding tool 1 descends (ST8) and lands on the surface of the connector 12. Next, thermocompression bonding is started with the thermocompression load P1 (ST9), and the thermocompression load P1 is maintained for t1 (b). When the holding time t1 (b) times out,
The thermocompression bonding load is switched from P1 to P2 (ST1
0) and t2, this thermocompression bonding load is maintained. When the holding time t2 elapses, the thermocompression bonding tool 1 is raised (ST11), and the thermocompression bonding is completed.

FIG. 12 shows that the thermocompression bonding tool 1
The value of the elongation E from the time when it lands on the top and starts thermocompression bonding is shown. This graph shows that if the thermocompression bonding load P is below a certain value, the elongation increases in proportion to the thermocompression bonding time t1, and if the thermocompression bonding load P is increased above a certain value, the elongation E stops. ing.

As described above, in the third embodiment, the thermocompression bonding time t1 and the connector 12
The thermocompression bonding time t1 is determined based on the relationship with the elongation E of
The dimensional difference dL of the connector 12 is corrected by the elongation E of the connector 12 during the thermocompression bonding process.

The present invention is not limited to the above embodiment. For example, in order to optically detect the width of the terminal row 31a of the board 11 and the width of the lead row 30a of the connector 12, Is used, but other characteristic parts, such as the terminal 31 and the lead 30 itself, may be subjected to image recognition. Further, in each of the above embodiments, a single parameter is determined and the dimensional difference dL is corrected, but correction may be performed by combining a plurality of parameters. However, in this case, since the control becomes very complicated, it has little practical significance.

[0040]

According to the present invention, the leads of a connector made of a resin film which is thermocompression-bonded to a substrate can be accurately positioned and thermocompression-bonded. In addition, accurate positioning can be performed while adjusting the amount of extension of the connector by an extremely simple method of determining the parameters such as the pressing speed, thermocompression load, and thermocompression time of the thermocompression tool during the thermocompression bonding process. Therefore, the occurrence of defective products due to the misalignment of the thermocompression bonding can be reduced, and the production yield can be improved.

[Brief description of the drawings]

FIG. 1A is a graph showing the relationship between the thermocompression bonding load and the thermocompression bonding time during thermocompression bonding according to the first embodiment of the present invention. (B) The thermocompression bonding load during thermocompression bonding according to the first embodiment of the present invention. Graph showing the relationship between temperature and thermocompression bonding time

FIG. 2 is a perspective view of the connector thermocompression bonding apparatus according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a control system of the thermocompression bonding apparatus for the connector according to the first embodiment of the present invention.

FIG. 4A is a plan view of the connector according to the first embodiment of the present invention. FIG. 4B is a plan view of the connector according to the first embodiment of the present invention.

FIG. 5 is a graph showing the relationship between the elongation of the connector and the pressing speed according to the first embodiment of the present invention.

FIG. 6 is a flowchart of thermocompression bonding of the connector according to the first embodiment of the present invention.

FIG. 7 is a graph showing the relationship between the elongation and the thermocompression load of the connector according to the second embodiment of the present invention.

FIG. 8 is a flowchart of thermocompression bonding of the connector according to the second embodiment of the present invention.

FIG. 9 is a graph showing, in chronological order, elongation during thermocompression bonding of the connector according to the second embodiment of the present invention.

FIG. 10 is a graph showing the relationship between the elongation of the connector and the thermocompression bonding time according to the third embodiment of the present invention.

FIG. 11 is a flowchart of thermocompression bonding of the connector according to the third embodiment of the present invention.

FIG. 12 is a graph showing, in chronological order, elongation during thermocompression bonding of the connector according to the third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermocompression tool 2 Cylinder 10 Support stand 11 Substrate 12 Connector 14a Camera 14b Camera 15 Support table 18 XY table 20 Motor drive unit 21 Load control unit 22 Measurement unit 23 Storage unit 24 Control unit 30 Lead 30a Lead row 31 Terminal 31a Terminal row

Claims (1)

[Claims] A connector having a plurality of leads formed on a resin film is heat-bonded to a substrate having a terminal row whose width is set to be larger than the width of the leads by a thermocompression bonding tool. A method of thermocompression of a connector to be crimped, wherein a relationship between at least one of a pressing speed, a thermocompression load, and a thermocompression time parameter of a thermocompression tool and elongation of a connector is obtained by an experiment in advance, and this experiment result is obtained. A step of storing in a storage unit; a step of optically measuring the width of the lead row and the terminal row before the connector is thermocompression-bonded to the board; Calculating a dimensional difference, and determining the dimensional difference in the process of thermocompression bonding by determining at least one of the parameters based on the dimensional difference and the experimental results. Connector thermocompression bonding method, which comprises a positive to step.