JPH04211143A - How to bond leads to semiconductor elements - Google Patents

Abstract

PURPOSE:To bond an inner lead in position on an electrode by making position correcting information from the difference between position recognizing information after positioning of a semiconductor chip electrode to a carrier film lead and position recognizing information after bonding and by positioning on and after a next time before bonding on time basis of this position correcting information. CONSTITUTION:A position recognition of an inner lead 3a and an electrode 5 is conducted before bonding of a semiconductor chip 4 to obtain position recognizing information; then, another position recognition of the inner lead 3a and the electrode 5 is made after bonding, and their difference is calculated to serve as position correcting information. For bonding of a next semiconductor chip, positioning of an inner lead and an electrode 5 is allowed by this position correcting information, so that misregistration is necessarily corrected by an amount of misregistration before and after preceeding bonding every bonding conducted one after another.

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding method for connecting a large number of inner leads provided on a carrier film to electrodes of a semiconductor element in a tape carrier type semiconductor device. [0002]

[Prior Art] A tape carrier type (hereinafter referred to as TAB type) semiconductor device has a large number of leads formed on each frame of a tape made of polyimide film or polyester film, and a semiconductor device is attached to the tip of the lead (inner lead). The electrodes of the elements are individually bonded, the tape is cut, and then mounted on a printed circuit board, etc., which allows for miniaturization and is suitable for high-density mounting. [00031] FIG. 6 is a perspective view showing essential parts of an example of an inner lead bonding device, and FIG. 7 is an enlarged sectional view taken along line A-A in FIG. 6. In both figures, reference numeral 11 denotes a bonding head that is supported by the device main body 10 so as to be able to move up and down, and is configured to move up and down by being driven by a cam or the like, and to be able to press down by being driven by an air cylinder or the like. It has a built-in bonding tool 12. 1
3 is a position recognition device attached to the bonding head 11. 14 has a hole 15 and a guide plate fixed to the device main body 10; 16.16a is rotatably attached to the device main body 10, device holes 2 are provided at predetermined intervals, and a large number of boards 3 are formed. long length (e.g. 300m)
This is a guide roller that guides the carrier film 1 along the guide plate 14. 17 is a bonding table provided on an X-Y table (not shown) and equipped with a bonding stage 18 having a built-in heater; 4 is a semiconductor element placed on the bonding stage 18; [0004] Next, the operation of the bonding apparatus configured as described above will be explained. First, the semiconductor element 4 is transferred from a supply stage (not shown) to the bonding stage 18.
The bonding table 17 is moved in the X-Y direction to position the semiconductor element 4 at a predetermined position below the hole 15 of the guide plate 14. On the other hand, the carrier film 1 is guided by the guide plate 14 and the guide rollers 16.16a, and is fed in the direction of the arrow, and stops when the first device hole 2 reaches a predetermined position on the semiconductor element 4. Then, while checking with the position recognition device 13, the bonding table 17,
Therefore, the semiconductor element 4 is moved in the X-Y direction, and each electrode 5 of the semiconductor element 14 is inserted into the inner lead 3a that protrudes into the device hole 2 of the carrier film 1 (see FIG. 8).
The position of the bonding table 17, that is, the semiconductor element 4 is stored in a control device (not shown). [0005] Next, the rad 11 is lowered to the bonding, and the bonding tool 12 is brought into contact with each inner lead 3a and heated and pressurized to fuse and connect each electrode 5, respectively. The state at this time is shown in FIG. [0006] When the first bonding is completed, the carrier film 1 is advanced by one frame, the next device hole 2 is stopped at a predetermined position, and the semiconductor element 4 is moved in accordance with a command from the control device.
The bonding table 17 on which is placed is placed on the carrier film 1.
Position it below and perform bonding. Thereafter, bonding is sequentially performed in the same manner. [0007]

[Problems to be Solved by the Invention] In the conventional method of bonding leads to a semiconductor element as described above, each inner lead 3a is
Bonding is performed after the leads are aligned with the proper positions on the electrodes 5 of the semiconductor element 4, but after actually performing bonding, the positional relationship between each inner lead 3a and the electrode 5 of the semiconductor element 4 is determined. As you can see, bonding is not necessarily performed as aligned before bonding, and deviations occur due to mechanical accuracy of the bonding tool 12, accuracy of the position recognition device 13, etc.
As shown in FIGS. 10 and 11, the bonding is offset in the horizontal (X) or vertical (y) direction (dashed lines indicate the aligned positions before bonding), and sometimes the
In some cases, the electrode 3 is bonded off the electrode 5. [0008] This deviation is rarely constant during each bonding process, and usually varies depending on the mechanical accuracy of the bonding tool 12, the accuracy of the position recognition device 13, and the like. [0009] The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a bonding method that can bond inner leads to regular positions on electrodes of a semiconductor element.

0010

[Means for Solving the Problems] A method for bonding leads to a semiconductor element according to the present invention involves aligning the electrodes of the semiconductor element and the leads of the carrier film before bonding, and then aligning the electrodes and the leads after the alignment. Location recognition information A
bonding a lead to the electrode, and position recognition information B of the electrode and lead after bonding.
a step of detecting the difference between the position recognition information A before bonding and the position recognition information B after bonding as position correction information C; and a step of detecting the difference between the position recognition information A before bonding and the position recognition information B after bonding as position correction information C; When performing bonding, the position correction information C is used before the bonding.
and a step of correcting the alignment between the electrode and the lead based on the method. [00111 Another method of bonding leads to a semiconductor element according to the present invention is to align the electrodes of the semiconductor element and the leads of the carrier film before bonding, and to adjust the positions of the electrodes and the leads after the alignment. a step of detecting recognition information A, a step of bonding a lead to the electrode and detecting position recognition information B of the electrode and lead after bonding, and a step of detecting position recognition information A after the alignment.
Detecting the difference between the position recognition information B and the post-bonding position recognition information B as position correction information C, and using the position correction amount information with an initial value of 0, align the electrodes and leads of the semiconductor element for the first time, and from the next time onwards. A process of creating position correction amount information for the next time based on the position correction amount information C and the previous position correction information C, and sequentially updating the position correction amount information; and a step of correcting the position of the electrode and the lead based on the updated position correction amount information after detecting the position recognition information A when performing bonding between the electrode and the carrier film. be. [0012]

[Operation] In the method of the present invention, position recognition information A after alignment of the electrodes of the semiconductor element and the leads of the carrier film
The difference between the position recognition information B of the electrode and the lead after bonding is set as position correction information C, and based on the position correction information C, correction for the next alignment between the electrode of the semiconductor element and the lead of the carrier film is performed. Since this is done before bonding, when bonding a large number of semiconductor elements to a long carrier film, the positional deviations are always corrected for the positional deviations before and after the previous bonding in each successive bonding process. Therefore, positional deviations occurring between the electrodes and leads of each semiconductor element can be suppressed within a certain range. [0013] In another method of the present invention,
First, the electrodes of the semiconductor element and the leads of the carrier film are aligned before the first bonding, the position recognition information A of the electrodes and leads after the alignment is detected, and then the position recognition of the electrodes and leads after bonding is performed. Detect information B,
Thereafter, the difference between the position recognition information A after alignment and the position recognition information B after bonding is detected as position correction information C. [0014] Then, when bonding the electrode of the second semiconductor element and the lead of the carrier film, after detecting the position recognition information A, the position correction information C and the position correction amount information of the initial value are determined. The positions of the electrodes and leads are corrected based on the position correction amount information created based on the information, and then the electrodes and leads are bonded.
Position recognition information B of the electrode and lead after bonding is detected. Furthermore, as described above, the difference between the position correction information A before bonding and the position recognition information B after bonding is detected as position correction information C. [0015] When bonding the electrode of the third semiconductor element and the lead of the carrier film, after detecting the position recognition information A, the second position correction information C and the position created in the second The positions of the electrodes and leads are corrected using the position correction amount information created based on the correction amount information, and then the electrodes and the leads are bonded. [0016] In this way, when bonding the electrodes of the second and subsequent semiconductor elements and the leads of the carrier film, the information is updated one after another based on the previous position correction information C and the previously created position correction amount information. Since the position of the electrode and lead is corrected using a position correction scale created in this way, and the electrode and lead are bonded, the position correction amount information for correcting the position of the electrode and lead gradually changes from the previous value. The accuracy becomes better through learning, and the amount of positional correction between the electrode and the lead based on the positional correction amount information gradually becomes smaller, and the amount of positional correction between the electrode and the lead after bonding of the electrode and the lead of the semiconductor element is gradually reduced. The positional deviation also gradually becomes smaller. [0017]

【Example】

FIG. 1 is a flowchart showing an example of the procedure of a bonding method according to the present invention. Hereinafter, the bonding method according to the present invention will be explained according to this flowchart. [0018] (1) Assign 0 to the position correction information (data C) of the control device and save it in the storage device (step SL). [0019] (2) Moving the bonding table 17 to position the semiconductor element 4 on the bonding stage 18 under the hole 15 of the guide plate 14, and conveying the carrier film 1;
The first device hole 2a is located on the semiconductor element 4 (step S2). [00201 (3) Move the bonding table 17 in the X-Y direction according to the data C to connect each inner lead 3a of the device hole 2a.
and each electrode 5 of the semiconductor element 4 is aligned (step S3). [0021] (4) The position recognition device 13 recognizes the position of each inner lead 3a and each electrode 5 (step S4). [0022] (5) The position recognition information recognized in step S4 is set as data A and stored in the storage device (step S5). [0023] (6) The position correction information (data C) is retrieved from the storage device, and position correction is performed using the data A recognized in step S5 (step S6). [0024] (7) The bonding tool 12 is lowered, comes into contact with each inner lead 3a, and is heated and pressurized to bond each electrode 5 (step S7). [0025] (8) The position recognition device 13 recognizes the position of each inner lead 3a and each electrode 5 after bonding (step S8). [0026] (9) The position recognition information recognized in step S8 is stored as data B.
(step S9). [0027] (Data A recognized in step S5 of 1 and step S
The data B recognized in step 9 is taken out from the storage device, the difference (displacement) between the two is calculated, and the position correction information (data C) is stored in the storage device (step 510). [0028] (11) When the bonding is finished as described above (step 511), it is determined whether all the bonding of the carrier film 1 is finished or not. S12), YE
If S, bonding is completed; if NO, the process returns to step S2 and repeats the above operation. [0029] As described above, in bonding the inner leads 3a of the carrier film 1 to the electrodes 5 of the semiconductor element 4, the positions of the inner leads 3a and the electrodes 5 are recognized before bonding of the semiconductor element 4. The position recognition information (data A) is obtained, and then the position recognition of the inner lead 3a and the electrode 5 is performed again after bonding to obtain the position recognition information (data B). The positional alignment performed before bonding or the positional deviation caused by bonding is calculated, and this is used as positional correction information (data C). Then, when bonding the next semiconductor element 4, the inner leads 3a and the electrodes 5 are aligned using this position correction information (data C), so that each successive bonding is compared to the position before the previous bonding. The positional deviation is always corrected by the amount of positional deviation after bonding, and the positional deviation that occurs between the two can be suppressed within a certain range by such positional correction,
The inner lead 3a can be connected to the correct position on the electrode 5 within a certain tolerance.

FIGS. 2 and 3 are flowcharts showing an example of the procedure of another bonding method according to the present invention. The present invention will be explained below according to this flowchart. [0031] (1) Assign O to all (data A) to (data D) of the control device and save them in the storage device (step SL). [0032] (2) Moving the bonding table 17 to position the semiconductor element 4 on the bonding stage 18 under the hole 15 of the guide plate 14, and conveying the carrier film 1;
The first device hole 2a is located on the semiconductor element 4 (step S2). [0033] (3) Move the bonding table 17 in the X-Y direction to bond each inner lead 3a of the device hole 2a and the semiconductor element 4.
alignment with each electrode 5 is performed (step 33). [0034] (4) The position recognition device 13 allows each inner lead 3a to
The position of each electrode 5 is recognized (step 84). [0035] (5) The position recognition information recognized in step S4 is set as data A and stored in the storage device (step 85). [0036] (6) The position recognition information (data D) is retrieved from the storage device, and the position is corrected for the state in step S4 (step S6). [0037] (7) The bonding tool 12 is lowered, comes into contact with each inner lead 3a, and is heated and pressurized to bond each electrode 5 (step S7). (8) The position recognition device 13 recognizes the position of each inner lead 3a and each electrode 5 after bonding (step 88). [0039] (9) The position recognition information recognized in step S8 is stored as data B.
(step S9). [0040] (Data A recognized in step S5 of 1 and step S
The data B recognized in step 9 is taken out from the storage device, the difference (displacement) between the two is calculated, and the position correction information (data C) is stored in the storage device (step 510). [0041] (11) When the bonding is completed as described above (step 511), it is determined whether all the bonding of the carrier film 1 is completed or not (step 512),
If YES, bonding is completed. [0042] Generally, in order to determine whether all bonding has been completed, a carrier film 1 presence/absence sensor (not shown) is provided and a signal from this sensor is used to determine whether or not all bonding has been completed. [0043] (12) If the determination in step S12 is No, the position correction information (data C) is retrieved from the storage device (step 513), it is determined whether this is 0 or not (step 514), and if YES, the step is Since the position correction amount information (data D) used in the position correction performed in S6 was working correctly, the process moves to step S2 again without executing step S15, and repeats the above operation. . [0044] (13) If the determination in step S14 is No, it is necessary to correct the position correction amount information (data D), so the position correction amount information (data D) is retrieved from the storage device, and this and the position correction amount information (data D) are required to be corrected. The sum of the information (data C) is calculated to obtain new position correction amount information (data D), and the new position correction amount information (data D) is stored in the storage device (step 515). [0045] After that, the process moves to step S2 again and the above-described operation is repeated. [0046] Next, the specific procedure of another bonding method according to the present invention will be described based on FIGS. 4 and 5. [0047] In the figure, A is position recognition information data before bonding, B is position recognition information data after bonding, and C is position correction which is the difference between data A before bonding and data B after bonding. The information data D is created based on the position correction information C and the previous position correction amount information, and is the data of the position correction amount information that is updated one after another, that is, the data of D+C. The diagonal line indicates the bump position of the lead 3, the dashed line indicates the center of the pad which is the electrode 5 of the semiconductor element 4, and the dashed dot indicates the center of the bump of the inner lead 3. Note that for the sake of explanation, the semiconductor element 4
It is assumed that the positional deviation between the electrode 5 and the bump of the lead 3 occurs only in the vertical direction of the lead, that is, in the Y direction. [0048] First, initial values of 0 are assigned to all data A to D of the control device and stored in the storage device. [0049] Next, the electrode 5 of the first semiconductor element 4 -
Align with the board 3 before bonding. After that, position recognition information of the electrode 5 and lead 3 is detected. Data A of the position recognition information at this time is 100. and,
Since the initial value of data D is 0, alignment correction is not substantially performed before bonding, and electrode 5 and lead 3
Bonding is performed immediately. After that, data B of position recognition information of the electrode 5 and lead 3 after bonding is detected. The location recognition information data B at this time is 9
It is 1. Then, data C is data A and data B
Since the difference is 100-91, that is, 9, data D is the sum of the previous data D (in this case, the initial value is O) and data C, so it becomes 0+9, that is, 9, and data D is updated. [0050] After the bonding between the electrode 5 of the first semiconductor element 4 and the lead 3 is completed, the bonding between the electrode 5 and the lead 3 of the second semiconductor element 4 is then performed. In this case, first, the electrodes 5 and leads 3 are aligned before bonding, and then position recognition information between the electrodes 5 and leads 3 is detected. Data A at this time
becomes 100. And data D is 9. This shows that when bonding is performed with correct alignment, a positional deviation of 9 occurs. Therefore, since the position correction amount information is 9, the position is corrected by 9,
After that, bonding can be performed. When the data B after bonding is detected after that, the data B becomes 100. This indicates that it was correct to perform the position correction based on 9 of data D. Then, data C at this time becomes 0 with 100-100, data D becomes 9 with 9+0, and data D is updated to 9 again. [0051] Bonding between the electrode 5 of the third semiconductor element 4 and the lead 3 is now performed. In this case, data A becomes 100 as in the second case. Since the data D is 9, bonding is performed after performing position correction by 9. Looking at data B after bonding, it is 103, so data C is 100-103, which is -3, data D is 9-3, which is 6, and data D is updated to 6. Therefore, the electrode 5 of the fourth semiconductor element 4 -
When bonding with card 3 is performed, the bonding is performed after position correction is performed based on data D 6. [0052] Thereafter, bonding is performed between the electrodes 5 and leads 3 of up to the sixth semiconductor element 4 in FIGS. 4 and 5 using the same procedure, but the next position correction amount information is used based on the previous position correction. Since a certain data D is updated and created one after another, the numerical value of data D gradually becomes smaller.
In other words, the amount of position correction can be reduced, and the positional deviation that occurs between the electrodes of the semiconductor element and the lead after bonding them is reduced, and the inner lead 3a of the lead 3 is placed on the electrode 5 of the semiconductor element 4. This means that it can be connected in the correct position. [0053]

As is clear from the above description, in the method of the present invention, position recognition information A after alignment of the electrodes of the semiconductor element and leads of the carrier film, and position recognition information B of the electrodes and leads after bonding are obtained. The difference from When bonding a large number of semiconductor elements to a lead, the positional deviation is always corrected by the amount of positional deviation before and after the previous bonding in each bonding process. This has the effect that the positional deviation that occurs can be suppressed within a certain range, and the lead can be bonded to the correct position of the electrode within a certain tolerance range. [0054] In another method of the present invention,
In addition to the position recognition information A after alignment, the position recognition information B after bonding, and the position correction information C, position correction amount information with an initial value of 0 is used to correct the positions of the electrodes and leads of the first semiconductor element, From the next time, position correction amount information for the next time is created based on the position correction amount information C and the previous position correction information C, and the position correction amount information is sequentially updated. When bonding the electrodes of the element and the carrier film, after detecting the position recognition information A, the positions of the electrodes and leads are corrected based on the updated position correction amount information, so that from the next time onwards, The position correction amount information for the position correction of the electrode of the semiconductor element and the lead of the carrier film, which is performed one after another, gradually becomes more accurate due to the previous learning, and the position correction amount information for the electrode and lead based on the position correction amount information is gradually improved. The amount of positional correction becomes gradually smaller, and the positional deviation that occurs between the electrodes and leads of the semiconductor element after they are bonded to each other gradually decreases, so that bonding can be performed at the correct position. Therefore, there is an effect that the reliability of bonding can be improved and the yield can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a flowchart for explaining one embodiment of the present invention.

FIG. 2 is a partial flowchart for explaining another embodiment of the invention.

FIG. 3 is a remaining part of a flowchart for explaining the same embodiment of the present invention.

FIG. 4 is a partial explanatory diagram for explaining position correction in the same embodiment of the present invention.

FIG. 5 is an explanatory diagram of the remaining part for explaining position correction in the same embodiment of the present invention.

FIG. 6 is a perspective view of essential parts of an example of a bonding device.

7 is an enlarged cross-sectional view taken along line AA in FIG. 6. FIG.

FIG. 8 is a plan view showing a state in which leads are properly bonded to a semiconductor element.

9 is an enlarged view of the main part of FIG. 8. FIG.

FIG. 10 is a plan view showing a state in which leads are bonded to a semiconductor element with a positional shift caused by a conventional method for bonding leads to a semiconductor element.

FIG. 11 is a plan view showing a state in which leads are bonded to a semiconductor element with a different positional shift using a conventional method for bonding leads to a semiconductor element.

[Explanation of symbols]

1 Carrier film 2 Device hole 3 Lead 4 Semiconductor element 5 Electrode

[Figure 7]

[Figure 9]

[Figure 1]

[Figure 2]

[Figure 3]

[Figure 5]

[Figure 4]

[Figure 6]

[Figure 8]

[Figure 10]

[Figure 11]

Claims (2)

[Claims] 1. A process for forming a semiconductor device by transporting a long carrier film having a large number of device holes provided with a plurality of leads, sequentially positioning semiconductor devices in the device holes, and bonding the leads to the electrodes of the semiconductor devices. The lead bonding method includes a step of aligning the electrode and the lead before bonding, detecting position recognition information A of the electrode and the lead after the alignment, and bonding the lead to the electrode and after the bonding. a step of detecting position recognition information B of the electrodes and leads; a step of detecting a difference between the position recognition information A after alignment and the position recognition information B after bonding as position correction information C;
The present invention is characterized by comprising a step of correcting the alignment between the electrode and the lead based on the position correction information C before the next bonding between the electrode of the semiconductor element and the lead of the carrier film. A method for bonding leads to a semiconductor device. 2. A process for forming a semiconductor device by transporting a long carrier film having a large number of device holes provided with a plurality of leads, sequentially positioning semiconductor devices in the device holes, and bonding the leads to the electrodes of the semiconductor devices. The lead bonding method includes a step of aligning the electrode and the lead before bonding, detecting position recognition information A between the electrode and the lead after the alignment, and bonding the lead to the electrode, and after the bonding. a step of detecting position recognition information B of the electrodes and leads, a step of detecting a difference between the position recognition information A after the alignment and the position recognition information B after the pounding as position correction information C, and an initial value. The positions of the electrodes and leads of the first semiconductor element are corrected based on the position correction amount information of O, and from the next time, the position correction amount for the next time is calculated based on the position correction amount information and the previous position correction information C. a step of creating information and sequentially updating the position correction amount information, and updating the position recognition information A after detecting it when bonding the electrode of the semiconductor element and the carrier film from next time onwards. 1. A method for bonding a lead to a semiconductor element, comprising the step of correcting the position of the electrode and the lead based on the position correction amount information obtained.