JP4653132B2 - Thermocompression bonding method and thermocompression bonding apparatus - Google Patents

Description

  The present invention relates to a thermocompression bonding method and a thermocompression bonding apparatus for thermocompression bonding a first component and a second component, and more particularly to an outer electrode of an electronic component such as a tape carrier package on an electrode of a substrate such as a display panel. The present invention relates to a thermocompression bonding method and a thermocompression bonding apparatus suitable for use in thermocompression bonding of leads.

  A large number of electronic components are mounted on the electrodes formed at a narrow pitch on the edge of a display panel used as a display of an electronic device as a driver for driving the display panel.

  FIG. 6 is a diagram for explaining a conventional thermocompression bonding method for outer leads of electronic components.

6A is before thermocompression bonding, and FIG. 6B is after thermocompression bonding.

  The electronic component 51 is made by bonding a bare chip 53 to a film carrier 52 formed of polyimide resin or the like. On the surface of the film carrier 52, a large number of outer leads 54 are formed at narrow pitch intervals by lines made of copper or the like.

  A large number of ultrafine electrodes 58 are formed at narrow pitch intervals on the edge of the transparent plate 56 constituting the display panel. At both ends of the film carrier 52, a first mark MA for position detection and a second mark MB are provided with a gap therebetween. On the other hand, at both ends of the electrode 58 row of the transparent plate 56, corresponding to the first mark MA and the second mark MB, the first mark NA and the second mark used in pairs with the respective marks MA and MB. The mark NB is provided.

  First, in the state before the thermocompression bonding shown in FIG. 6A, the positional deviation between the first mark MA and the first mark NA, the second mark MB and the second mark using a camera (not shown). The positional deviation from the mark NB is detected.

  Next, the outer lead 54 and the electrode 58 are arranged so that the positional deviation amount between the first mark MA and the first mark NA and the positional deviation amount between the second mark MB and the second mark NB are equal. And a pressure bonding member (not shown) is pressed against the film carrier 52, and the outer lead 54 is thermocompression bonded to the electrode 58 ((b) of FIG. 6). Thus, the outer lead 54 is thermocompression bonded to the electrode 58, and the electronic component 51 is mounted on the transparent plate 56 of the display panel.

  A large number of outer leads 54 are provided on the surface of the film carrier 52 at narrow pitch intervals. For this reason, the outer lead 54 must be accurately aligned with the electrode 58 of the display panel and then thermally bonded.

  However, since the film carrier 52 is made of polyimide resin or the like, the film carrier 52 extends during thermocompression bonding. For this reason, the film carrier 52 is made short in consideration of this elongation in advance. However, due to manufacturing errors, even if thermocompression bonding is performed under the same conditions, the outer lead 54 may not be bonded to the electrode 58 at an accurate position and a defective product may be generated. Each time a defective product was generated, the thermocompression bonding conditions were reviewed. The product defect rate is expected to increase as the pitch is further reduced in the future.

  Therefore, a method has been proposed in which the state after completion of thermocompression bonding is observed, and the defect rate is suppressed by appropriately changing the conditions of subsequent thermocompression bonding based on the data obtained by this observation.

  However, the manufacturing error or the like of a film carrier that has already been subjected to thermocompression bonding is not necessarily the same as the manufacturing error or the like of a film carrier that will be subjected to thermocompression bonding. For this reason, there exists a problem that the thermocompression-bonding conditions determined based on the data obtained from the film carrier which has already completed thermocompression bonding may not be suitable for subsequent film carrier crimping.

  The present invention has been made to solve the conventional problems as described above, and its purpose is a method that can suppress the occurrence rate of defective products even when the manufacturing error of parts is not always constant. And an apparatus.

  In order to achieve the above object, in the thermocompression bonding method and the thermocompression bonding apparatus of the present invention, when the first component whose amount of elongation changes according to the thermocompression bonding condition is thermocompression bonded to the second component, The first mark and the second mark formed on the part are detected before thermocompression bonding, the distance between these marks is obtained, and the thermocompression bonding conditions are determined based on the obtained distance, and thus It is characterized by performing thermocompression bonding under the determined conditions.

  As described above in detail, according to the present invention, the distance between marks of the first component is measured before thermocompression bonding, and thermocompression bonding is performed by appropriately changing the thermocompression bonding conditions according to this distance, or By stopping the thermocompression bonding, it is possible to reduce the defective product occurrence rate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a partial perspective view of a mark distance measuring unit, FIG. 2 is a partial perspective view of a crimping unit, FIG. 3 is a flowchart for explaining a method for determining thermocompression bonding conditions, and FIG. FIG. 5 is a table showing a specific example of thermocompression bonding conditions. In addition, the same code | symbol is attached | subjected to the same element as the prior art example shown in FIG. 6, and description is abbreviate | omitted.

  In FIG. 1, a nozzle 1 vacuum-sucks a film carrier 52 of an electronic component (first component) 51 by a vacuum suction means (not shown). Then, from the lower side of the film carrier 52, the first mark MA is imaged by the camera (imaging device) 3 and the second mark MB is imaged by the camera (imaging device) 4, and the captured images by the cameras 3 and 4 are used as the basis. Then, the distance between both marks is obtained by the image processing device 5.

  FIG. 2 is a partial perspective view of the crimping portion. The crimping tool 22 of the crimping head 21 is attached to a block 24 to which a heater 23 is attached, and this block 24 is fixed to the operating shaft of the cylinder 25. By driving the servo motor 26, the crimping head 21 can be moved up and down.

  The motor control unit 11 controls the lowering speed of the crimping tool 22, and the time control unit 14 controls the crimping time. The pressure control unit 12 controls the pressure applied by the crimping tool 22. The temperature control unit 13 controls the crimping temperature of the crimping tool 22.

  These motor control unit 11, pressure control unit 12, temperature control unit 13, and time control unit 14 are centrally controlled by a control device 15.

  The control device 15 includes a storage device, and the storage device includes a manufacturing error of the film carrier 52 as shown in FIG. 5 (the difference between the distance between the first mark MA and the second mark MB and the design value). ) Is stored. The control device 15 is also connected to the image processing device 5, and based on the detection result by the image processing device 5, the electronic component 51 is thermocompression bonded to the transparent plate (second component) 56 as will be described later. The thermocompression bonding conditions for the crimping tool 22 are automatically determined.

A method for determining the thermocompression bonding condition will be described with reference to FIG.
FIG. 4 shows the magnitude relationship between “design value + X2”, “design value + X1”, “design value”, “design value−X3”, and “design value−X4”. Here, X1, X2, X3, and X4 are positive numbers, and X1 <X2, X3 <X4.
First, in step S301, the measurement result (the distance D1 (FIG. 6A) between the first mark MA and the second mark MB is “larger than the design value + X1 and smaller than the design value + X2”). It is determined whether or not.

  If it is determined as YES, the thermocompression bonding condition is changed to condition 2 (step S305). Then, a command is issued to the effect that thermocompression bonding should be performed based on condition 2 (step S310).

  As shown in FIG. 5, Condition 2 has a higher crimping temperature, a shorter crimping time, a larger crimping load, and a lowering speed of the crimping tool 22 compared to Condition 1 which is a standard crimping condition. When the pressure bonding is performed under the condition 2, the amount of elongation of the film carrier 52 caused by the pressure bonding is smaller than when the pressure bonding is performed according to the content of the condition 1.

  In step S301, YES is determined when the film carrier 52 is too long compared to the design value for pressure bonding under standard pressure bonding conditions. However, since the amount of elongation of the film carrier 52 caused by the pressure bonding is suppressed by the pressure bonding according to the condition 2, the generation of defective products can be avoided.

  If it is determined NO in step S301, it is further determined in step S302 whether or not the measurement result is “greater than design value−X4 and smaller than design value−X3”. When it determines with YES, the conditions 3 are selected as thermocompression-bonding conditions (step S308). Then, a command is issued to the effect that thermocompression bonding should be performed based on condition 3 (step S310).

  As shown in FIG. 5, Condition 3 has a lower crimping temperature, a longer crimping time, a smaller crimping load, and a lowering speed of the crimping tool 22 compared to Condition 1 which is a standard crimping condition. When the pressure bonding is performed under the condition 3, the amount of elongation of the film carrier 52 caused by the pressure bonding is larger than when the pressure bonding is performed according to the condition 1.

  In step S302, “YES” is determined when the film carrier 52 is too short as compared with the design value for pressure bonding under standard pressure bonding conditions. However, since the amount of elongation of the film carrier 52 generated by the pressure bonding is increased by performing the pressure bonding under the condition 3, the generation of defective products can be avoided.

  If NO is determined in step S302, it is further determined in step S303 whether or not the measurement result is “design value −X3 or more and design value + X1 or less”. If it is determined YES, standard condition 1 is selected as the thermocompression bonding condition (step S307). Then, a command is issued to the effect that thermocompression bonding should be performed based on condition 1 (step S310).

  The determination of YES in step S303 is a case where crimping is performed under standard crimping conditions. Therefore, a good product can be obtained by pressure bonding under the condition 1.

  If it is determined NO in step S303, the pressure bonding is stopped (step S306).

  The determination of NO in step S303 is when the film carrier 52 is too long or too short compared to the design value, which cannot be dealt with by changing the crimping conditions. Therefore, the pressure bonding must be stopped.

  In the thermocompression bonding based on each thermocompression bonding condition, the first mark MA provided on the film carrier 52 and the first mark MA provided on the transparent plate 56 shown in FIG. And the second mark MB provided on the film carrier 52 and the second mark NB provided on the transparent plate 56 (the second mark NB) (the second mark NB corresponding to the first mark MA). (Corresponding to MB) is detected using the cameras 3 and 4, respectively, and the relative alignment between the outer lead 54 and the electrode 58 is performed so that the amounts of both positional deviations are equal. This point is the same as in the prior art.

  Measure the distance between the marks on the film carrier before thermocompression bonding as described above, and change the thermocompression bonding conditions as appropriate according to this distance, or cancel the thermocompression bonding, resulting in a defective product incidence. Can be reduced.

  In the said embodiment, only the distance between marks on a film carrier is measured and the thermocompression bonding conditions are changed according to this distance. This is because the material of the transparent plate 56 is generally a glass plate or the like, and the glass plate or the like has extremely good dimensional accuracy and is not easily deformed even through a process such as circuit formation.

  However, if the material to be crimped on the film carrier is a resin that does not have good dimensional accuracy or is easily deformed even after a process such as circuit formation, not only the distance between marks on the film carrier, The distance between the marks may also be measured and the distance between the marks on the film carrier and the distance between the marks on the object to be bonded may be compared before determining the thermocompression bonding conditions.

  Specifically, as shown in FIG. 6A, the first mark MA corresponding to the first mark MA on the film carrier 52 in the electronic component 51 and the first mark MA on the transparent plate 56 by the camera 3. NA is imaged, and the camera 4 images the second mark MB on the electronic component 51 and the second mark NB corresponding to the second mark MB on the transparent plate 56.

  Next, the image processing apparatus 5 determines the distance D1 between the first mark MA and the second mark MB in the electronic component 51 and the first mark on the transparent plate 56 based on the captured images of the cameras 3 and 4. A distance D2 between NA and the second mark NB is obtained.

  Then, one of the thermocompression bonding conditions (condition 1, condition 2, condition 3) shown in FIG. 5 is automatically selected by the control device 15 based on the following comparison. However, the case where the elongation rate of the film carrier 52 is larger than the elongation rate of the transparent plate 56 will be described below as an example.

  That is, when the distance D2− (minus) distance D1 is “larger than the reference value + X1 and smaller than the reference value + X2” (X1 <X2), the condition 3 is selected as the thermocompression bonding condition. Thermocompression bonding is performed.

  When the distance D2−the distance D1 is “larger than the reference value−X4 and smaller than the reference value−X3” (X4> X3), the condition 2 is selected as the thermocompression bonding condition. Thermocompression bonding is performed.

  Further, when the distance D2−the distance D1 is “reference value −X3 or more and the reference value + X1 or less (within tolerance)”, the condition 1 is selected as the thermocompression bonding condition, and the thermocompression bonding is performed based on the condition 1. The

  By doing in this way, even if a dimensional error may occur in both the electronic component 51 and the transparent plate 56, the electronic component 1 is thermocompression bonded to the transparent plate 56 while preventing generation of defective products. Can do. Here, the reference value is a value of distance D2−distance D1 based on the design value, and X1, X2, X3, and X4 are all positive numbers.

  In the above description, the thermocompression bonding condition is selected based on the difference between the distance D1 between the marks MA and MB and the distance D2 between the marks NA and NB, but the distance D1 between the marks MA and MB and the marks NA, The thermocompression bonding conditions may be selected based on the ratio of the distance D2 between the NBs.

  That is, the ratio (D1 / D2 × 100%) R0 of the distance D1 to the distance D2 based on the design value is compared with the ratio R1 of the distance D1 to the actual distance D2, and the ratio R1 is larger than “R0 + X1 and If it is smaller than R0 + X2 (X1 <X2), condition 2 is selected.

  If the ratio R1 is “larger than R0-X4 and smaller than R0-X3” (X4> X3), the condition 3 is selected.

  Furthermore, when the ratio R1 is “R0−X3 or more and R0 + X1 or less (within tolerance)”, the condition 1 is selected.

  In the present invention, the mark formed on the first component and the second component is not limited to a mark formed for detection, but may be any mark that can be distinguished from others, such as a terminal having a characteristic in shape. Needless to say, it is good.

  In the above embodiment, the first component is the electronic component 51, the second component is the transparent plate 56, and the present invention is applied to the outer lead bonding apparatus. However, for example, the first component It is also possible to apply the present invention to a mounting apparatus or the like that mounts an IC chip on a tape-shaped component, with the second component being an IC chip.

  In the above-described embodiment, the example in which the heater 23 is provided in the crimping tool 22 has been described. However, it is not always necessary to provide the heater in the crimping tool 22, for example, instead of providing the heater 23 in the crimping tool 22. Heating means such as a heater is provided in the support means that supports the transparent plate 56 against the pressure applied by the pressure bonding tool 22 when the pressure is applied by the pressure tool 22, and instead of controlling the temperature of the pressure bonding tool 22, The amount of generated heat may be controlled.

  The thermocompression bonding condition includes at least one of the temperature, the crimping load, the crimping time, and the crimping speed of the crimping tool for thermocompression bonding the first component and the second component.

It is a fragmentary perspective view of the distance measurement part between marks. It is a fragmentary perspective view of a crimping | compression-bonding part. It is a flowchart for demonstrating the determination method of thermocompression bonding conditions. FIG. 4 is a diagram showing a magnitude relationship such as “design value + X1” shown in FIG. 3. It is a table which shows the specific example of thermocompression bonding conditions. It is a figure for demonstrating the conventional thermocompression bonding method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nozzle 3, 4 Camera 51 Electronic component 52 Film carrier 53 Bare chip 54 Outer lead 56 Transparent plate 58 Electrode MA 1st mark MB 2nd mark

Claims (2)

A thermocompression bonding method of thermocompression bonding a first component whose elongation varies according to thermocompression bonding conditions and a second component using a crimping tool,
The first mark and the second mark formed on the first part, and the first mark and the first mark corresponding to the first mark of the first part formed on the second part An imaging step of imaging a second mark corresponding to the second mark of the component;
A distance D1 between the first mark and the second mark of the first part is obtained based on the captured image obtained by the imaging process, and the first mark and the second mark of the second part are obtained. An image processing step for obtaining a distance D2 between
A ratio (D1 / D2 × 100%) R0 of the distance D1 to the distance D2 based on a design value and a ratio (D1 / D2 × 100%) R1 of the distance D1 to the distance D2 obtained in the image processing step. And determining a thermocompression bonding condition for the crimping tool based on the comparison with, and controlling the thermocompression operation by the crimping tool,
Condition 1 where the thermocompression bonding conditions are standard crimping conditions, and condition 2 where the crimping temperature is high, the crimping time is short, the crimping load is large, and the descending speed of the crimping tool is high compared to the condition 1 Compared with the above condition 1, the crimping temperature is low, the crimping time is long, the crimping load is small, and the lowering speed of the crimping tool is slow.
In the determination of the thermocompression bonding condition, when the ratio R1 is “larger than R0 + X1 and smaller than R0 + X2” (X1 <X2), the condition 2 is satisfied, and the ratio R1 is greater than “R0−X4”. When it is “larger and smaller than R0−X3” (X4> X3), the condition 3 is satisfied, and when the ratio R1 is “R0−X3 or more and R0 + X1 or less (within tolerance)”, the condition 1 (Where X1, X2, X3, and X4 are positive numbers, and X1 <X2, X3 <X4). It is a thermocompression bonding apparatus for thermocompression bonding a first component whose elongation changes depending on thermocompression bonding conditions and a second component using a crimping tool,
The first mark and the second mark formed on the first part, and the first mark and the first mark corresponding to the first mark of the first part formed on the second part An imaging device for imaging a second mark corresponding to the second mark of the component;
A distance D1 between the first mark and the second mark of the first part is obtained based on the captured image by the imaging device, and the first mark and the second mark of the second part are obtained. An image processing device for obtaining a distance D2 between
A ratio (D1 / D2 × 100%) R0 of the distance D1 to the distance D2 based on a design value and a ratio (D1 / D2 × 100%) R1 of the distance D1 to the distance D2 obtained in the image processing step. A controller for determining a thermocompression bonding condition for the crimping tool based on the comparison with the control tool, and controlling a thermocompression operation by the crimping tool,
Condition 1 where the thermocompression bonding conditions are standard crimping conditions and Condition 2 where the crimping temperature is high, the crimping time is short, the crimping load is large, and the descending speed of the crimping tool is high compared with Condition 1 Compared with the above condition 1, the crimping temperature is low, the crimping time is long, the crimping load is small, and the crimping tool descending speed is slow.
In the determination of the thermocompression bonding condition, when the ratio R1 is “larger than R0 + X1 and smaller than R0 + X2” (X1 <X2), the condition 2 is satisfied, and the ratio R1 is greater than “R0−X4”. When it is “larger and smaller than R0−X3” (X4> X3), the condition 3 is satisfied, and when the ratio R1 is “R0−X3 or more and R0 + X1 or less (within tolerance)”, the condition 1 (Where X1, X2, X3, and X4 are positive numbers, and X1 <X2, X3 <X4).

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