JP3202543B2 - Die bonding method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die bonding method for mounting each semiconductor element on a lead frame while classifying each semiconductor element on the basis of characteristic information on a wafer basis in which characteristics of semiconductor elements formed on a semiconductor wafer are classified. Related to the device.

[0002]

2. Description of the Related Art Conventionally, die bonding of a semiconductor chip (hereinafter, referred to as a chip) to a lead frame has been performed as follows. First, a semiconductor wafer (hereinafter, referred to as a wafer) is held by a wafer ring and provided with a barcode on which information such as a lot number and a wafer number is written. Then, a characteristic inspection is performed for each chip formed on the wafer, and a characteristic classification of each chip and a defect mark is given to a chip other than a non-defective product, or a pass / fail result is stored on a lot basis in a storage medium such as a floppy disk. (Hereinafter, described as FD) or a host computer (hereinafter, described as H / C).

[0003] Thereafter, the chips are divided into individual chips in a dicing process, are assembled in a ring cassette in a unit of a lot while being held by a wafer ring, and supplied to a die bonder.

[0004] In the next die bonder step, for each chip of the wafer supplied to the die bonder, a defect mark is recognized based on the quality result of the characteristic inspection, or information is read out from the FD by collating with a bar code, and each individual chip is read. Only non-defective chips of the wafer are selected and taken out, and die bonding is performed on the lead frame via a silver paste. Note that the die-bonded chip to the lead frame is then subjected to wire bonding, molding, plating,
The semiconductor device is completed as a result of going through each post-process of the trim form, a test evaluation process, a mark, a pack, and the like.

[0005] However, especially in the memory field where it is necessary to classify characteristics such as operating voltage, power consumption and speed,
In order to classify such characteristics, it is necessary to select characteristics in a test evaluation process after assembling. However,
In test evaluation equipment in the test evaluation process, which is considerably expensive compared to the equipment in other assembly processes, the test evaluation time for characteristic selection is proportional to the memory capacity. There has been a problem that the cost only increases and the investment efficiency drops remarkably.

[0006] In addition, since screening is performed in a test evaluation process immediately before product completion, which is close to the final process of product assembly,
Even if a semiconductor device is a product having a characteristic that is highly required in the market, a semiconductor device having a characteristic different from this is also manufactured at the same time. For this reason, the production period required to complete a semiconductor device having high market needs has been prolonged, and the production efficiency has been low due to an increase in the inventory of unrequired products having different characteristics. .

In order to solve these problems and the like, characteristics are classified in advance in a process prior to the die bonding process, and not only non-defective information on a wafer basis but also individual characteristic information (hereinafter, wafer map). A production method of selecting chips having necessary characteristics based on the product and dividing and producing the chips can be considered.
At present, two methods, a die bonding method and a transfer method, have been proposed.

Hereinafter, these two methods will be described with reference to FIGS. 6 and 7. FIG. FIG. 6 is a schematic configuration diagram for explaining a die bonding method, and FIG. 7 is a schematic configuration diagram for explaining a transfer method.

First, the first method, the “die bonding method”, will be described with reference to FIG. The die bonder 1 used in this method has a wafer map function. With this function, only the chips 2 having desired characteristics are selected, picked up, and die-bonded to the lead frame 3.

That is, the wafer map data created in the previous process corresponds to the symbols A, B, and C written on the chips 2 of the wafer 5 held on the wafer ring 4 in FIG. The die bonder 1 is stored in the FD 6 in which chip characteristics and position information (array information) are stored, or the upper H / C 7.
And is compared with the barcode 8 of the wafer ring 4 to obtain arrangement information of only the chips 2 having necessary characteristics.

The chips 2a and 2a can be efficiently used without recognizing the chip 2 having other unnecessary characteristics and the defective chip 2.
b and 2c are picked up and die-bonded to the corresponding lead frames 3a, 3b and 3c for each of the characteristics A, B and C. Then, chips 2a, 2 having the same characteristic category
lead frame 3 in which b and 2c are die-bonded
a, 3b, and 3c are stored magazines 9 for each of the characteristics A, B, and C.
a, 9b and 9c. Thereafter, when it is necessary to assemble the semiconductor device having the desired characteristics, the lead frame 3 is taken out from the storage magazine 9 having the desired characteristics and assembled.

Such a conventional die bonding method is the simplest method of simply adding a wafer map function to the die bonder 1, and further includes the following two methods.

In the first method, the characteristic A
→ Characteristic B → Each chip 2a, 2b, 2c of characteristic C is sequentially taken out.
, For example, only the chip 2a having the characteristic A or the chip 2 having the characteristic B
Only b is taken out at a time.

For example, in the case where the characteristic classification is only two classifications of characteristic A and characteristic B, in the first method, the first wafer ring 4 is taken out from a ring cassette (not shown), and first, only the chip 2a of characteristic A Are picked up and sequentially die-bonded to the lead frame 3a and stored in the storage magazine 9a.
In a, a fractional frame (or fractional chip) less than the predetermined number of mounted chips may occur.

However, in order to separate the products, the fraction frame is stored in the storage magazine 9a, and then replaced with a new storage magazine 9b for the chip 2b having the characteristic B. The number of magazines in the replaced storage magazine 9b is also determined. 1
It was necessary to reset to the stage.

Subsequently, the chips 2b having the characteristic B remaining in the first wafer ring 4 are sequentially die-bonded. When the die bonding of all the chips 2 in the first wafer ring 4 is completed, the first The wafer ring 4 is stored in a ring cassette. Then, a new second wafer ring 4 is taken out and die-bonded again from the chip 2a having the characteristic A.

In this case, similarly, after the last fractional frame of the lead frame 3b to which the chip 2b of the characteristic B is die-bonded is stored in the storage magazine 9b, it is again stored in the storage magazine 9a of the chip 2a of the characteristic A. It was necessary to replace the magazine and adjust the number of magazines to the previous number of magazines.

As described above, when the characteristics are sequentially classified in wafer units, fraction frames are generated by the number of characteristic classifications per wafer. That is, for example, in the case of n-classification of 24 wafers 5 of 24 ring cassettes, a maximum of (24 × n) fractional frames are generated, and the exchange of the storage magazine 9 and the operation of adjusting the number of magazine stages are required for the same number of times. Therefore, there was a major obstacle in terms of material loss and equipment operation rate.

In the second method, for all the wafer rings 4 stored in the ring cassette, first, only the chips 2a having the characteristic A are taken out, and after all the chips 2a having the characteristic A have been taken out, the storage magazine 9a is moved to the next magazine. Storage magazine 9
b, and the die 2b of the chip 2b having the characteristic B for the wafer ring 4 is again bonded. However, in this case, it is necessary to repeat the operation of taking out and storing the wafer ring 4 from the ring cassette by the number of characteristic classifications (n times), which has the following problem.

(1) If the chip 2 is large, such as a memory, the number of chips per wafer 5 is small,
The proportion of the operation of taking out and storing the wafer ring 4 occupying in the die bonding time increases, and by performing such a classification, the operation rate of the apparatus is significantly reduced. For example, in the case of a memory of a large chip, the characteristics are roughly estimated to be about 20 in three classes.
% Or more. (2) There is a dicing tape expanding operation to obtain a chip interval required for picking up when the wafer ring 4 is supplied and taken out. Due to the repetition of the expansion operation, the chip interval changes, and there are defects such as chipping and cracking due to interference between the cut surfaces of the chips 2 and the quality and reliability are reduced.

Next, the second method, "transfer method", will be described with reference to FIG. This transfer method is a method in which the chips 2 are classified and transferred according to the same characteristics in advance before the chips 2 are die-bonded to the lead frame 3.

First, in the same manner as in the above-described die bonding method, all the characteristics A, B, and C of the wafer ring 4 stored in the ring cassette are compared with the wafer map stored in the FD 6 by the transfer device 10. The chips 2a, 2b, 2c are assigned to the corresponding wafer rings 11a,
Transfer to 11b and 11c. Thereafter, when it is necessary to assemble the semiconductor device having the desired characteristics, the wafer ring 11 having the desired characteristic category is taken out of the wafer rings 11a, 11b, and 11c, and the chip 2 is picked up by using the die bonder 12, and is illustrated. Die bonding to a lead frame not to be performed.

However, the die bonder 12 is not subject to any restrictions in the die bonding by the above transfer method, but has the following problems.

That is, (1) one step of transferring the chips 2a, 2b, 2c from the wafer ring 4 of the ring cassette to the wafer rings 11a, 11b, 11c for each characteristic category before die bonding by the die bonder 12. Therefore, equipment and auxiliary processes for this, as well as new tools and materials, are required. For example, it is needless to say that the wafer ring 11 for transferring the jigs and tools and the tape attaching machine (not shown) and the like in the auxiliary process increase the space for holding and installing them. Also,
(2) As the number of steps increases, the number of times of handling (pickup) of the chips 2a, 2b, 2c increases, which may damage the chips 2a, 2b, 2c, leaving a quality problem. Further, (3) the chips 2a, 2b, 2
c is premised on storage in a state of being adhered to the tapes of the wafer rings 11a, 11b and 11c, and there is a limit to the number of storage days in terms of storage space and aging.

[0025]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and has as its object to easily classify semiconductor chips into individual characteristics while ensuring high quality. Die bonding that enables efficient production of semiconductor devices with desired characteristics without increasing unnecessary inventory, etc., and also improves the operation rate of expensive equipment such as test evaluation equipment and improves productivity efficiency. It is an object of the present invention to provide a method and an apparatus therefor.

[0026]

According to the present invention, there is provided a die bonding method and apparatus for picking up, from a diced semiconductor wafer, semiconductor chips classified into a plurality of characteristic sections according to semiconductor element characteristics for each of the characteristic sections. In the die bonding method in which the lead frame on which the semiconductor chip is mounted is housed in a dedicated magazine for each characteristic category after die bonding to the lead frame, the semiconductor chips classified from the semiconductor wafer are picked up for each characteristic category and the characteristic classification is performed. In the process of die bonding to each lead frame, a fractional semiconductor chip generated when a semiconductor chip of the same characteristic category of one semiconductor wafer is mounted on a lead frame is temporarily placed for each characteristic category, and a new semiconductor Mounting semiconductor chips of the same characteristic category on the wafer on the lead frame In this case, the method is characterized in that a fractional number of semiconductor chips temporarily placed on the previous semiconductor wafer are mounted on a lead frame, and the semiconductor chips classified into characteristics are located at a pickup position. Wafer holding means for holding a semiconductor wafer, chip transfer means for picking up and transferring semiconductor chips located at a pickup position, temporary placement means for supporting the semiconductor chips transferred by the chip transfer means at a temporary placement position,
A frame transporting unit for die-bonding the semiconductor chip supported at the temporary placing position to a predetermined portion of the lead frame corresponding to the characteristic division of the semiconductor chip at the die bonding position, and sending out the lead frame sent out from the frame transporting unit; A frame storing means for storing in a dedicated magazine for each characteristic category of the semiconductor chip,
The temporary placement means is characterized in that it is configured to hold a fractional number of semiconductor chips generated when a semiconductor chip having the same characteristic section of the semiconductor wafer is mounted on a lead frame for each characteristic section, The temporary placing means includes a rotating body provided between the pickup position and the die bonding position, and holds the plurality of semiconductor chips by suction on an outer surface of the rotating body in a rotating direction. Further, the temporary placement means is configured to be capable of holding at least [(the number of classifications of characteristic categories) × (the number of semiconductor chips mounted on the lead frame−1)] semiconductor chips. It is.

[0027]

According to the die bonding method and the apparatus configured as described above, in the process of picking up semiconductor chips classified by the die bonding method for each characteristic category and die-bonding them to a lead frame, a single semiconductor wafer is used. The semiconductor chips of the same characteristic section generated when mounting the lead frame are temporarily placed temporarily for each characteristic section, and when the semiconductor chips of a new semiconductor wafer are mounted on the lead frame, they are temporarily stored in the previous semiconductor wafer. The semiconductor chip of the fraction placed is mounted on a lead frame, and the semiconductor chip of the newly generated fraction is temporarily placed temporarily for each characteristic classification. From the pickup position to the temporary storage position of the temporary storage device by the chip transfer device, and And the temporary placement means removes a fraction of the semiconductor chips generated when the lead frame is mounted on the same semiconductor wafer. Since it is designed to be retained for each characteristic section, by temporarily placing the remaining fractional semiconductor chips that cannot be mounted on the lead frame of the semiconductor wafer for each characteristic section, the lead frame where some semiconductor chips are not mounted Fractional semiconductor chips generated for each semiconductor wafer can be efficiently die-bonded without making the semiconductor wafer and performing the semiconductor wafer replacement operation only once.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view showing a schematic configuration of a die bonding apparatus, FIG. 2 is a perspective view of a main part, FIG. 3 is a perspective view of a wafer ring, and FIG. 4 is a perspective view of a ring cassette. 5 is a side view of a lead frame to which a semiconductor chip is die-bonded.

1 to 5, reference numeral 21 denotes a semiconductor wafer (hereinafter, referred to as a wafer) on which a plurality of semiconductor elements are formed, and reference numeral 22 denotes a wafer ring for holding the wafer 21 having a dicing tape 23 adhered to the back surface. The wafer 21 held by the wafer ring 22 is provided with a bar code 24 on which information such as a manufacturing lot number and a wafer number is written. The wafer 21 is a semiconductor chip formed of individual semiconductor elements in a dicing process. (Hereinafter, referred to as a chip). Reference numeral 26 denotes a ring cassette in which wafers 21 are stored in lot units, for example, up to 2 units.
Approximately four wafers are held and accommodated by the wafer ring 22.

On the other hand, reference numeral 27 denotes a die bonding apparatus, which includes a frame loader 28, a frame feeder 29, a frame transfer section 31 including a frame unloader 30, a wafer loader 32, a ring transfer rail 33, and a bar code provided on the ring transfer rail 33. A wafer transfer unit 36 having a reader 34, a wafer ring holder 35, and a chip temporary placement unit 37;
It has a bonding head 39 and a dispense head 40.

The frame loader 28 sequentially feeds and separates the lead frames 41 stacked and stocked one by one by a loading arm 42 and feeds them out.
It is transported to a position and sent out to the frame feeder 29.

The frame feeder 29 is adapted to move the lead frame 41 one by one along a guide 44 by a feed mechanism (not shown), and to move the lead frame 41 from a dispense head 40 having an XY table to a lead frame 41 at a dispense position 45. Plural formed islands 46
The chip 25 is transferred to the island 46 of the lead frame 41 at the die bonding position 48 by the bonding head 39 having an XY table, and is die-bonded. P is a trajectory of the chip 25 transferred from the chip temporary placement section 37 to the lead frame 41 by the bonding head 39. Then, the lead frame 41 in which the chips 25 are die-bonded to all the islands 46 is sent out to the frame unloader 30.

The frame unloader 30 includes magazines 49 corresponding to the number of characteristics of the chips 25, for example, characteristics A and B.
The dedicated magazines 49a and 49b are stored for the two classifications. The dedicated magazines 49a and 49b are stored in the dedicated magazines 49 so that the chips 25 having predetermined characteristics transferred from the frame feeder 29 can be stored in the die-bonded lead frame 41.
The positions of a and 49b are independently driven in the vertical direction, and move in the direction of arrow Q. FIG. 1 shows a state where the lead frame 41a to which the semiconductor chip 25a having the characteristic A is die-bonded is housed in a dedicated magazine 49a.

Further, the wafer transfer section 36 transfers the wafer 21 from the ring cassette 26 set in the wafer loader 32.
Is sequentially sent out to the wafer ring holder 35 via the ring transfer rail 33. Information such as a production lot number and a wafer number of the wafer 21 sent to the wafer ring holder 35 is read by a bar code reader 34 attached to the ring transport rail 33, and is output to a control unit (not shown) and stored. The wafer ring holder 35 has an XY-θ table (not shown), and is configured so that the rotation direction can be adjusted together with the XY directions so that the wafer 21 is at a predetermined position.

The frame feeder 29 of the frame transfer section 31 and the wafer ring holder 35 of the wafer transfer section 36 are provided.
Between them, a pickup section 38 and a temporary chip placement section 37 are provided. The pickup section 38 is provided with a pickup head 52 at the tip of a pickup arm 51, and the wafer 2 held by the wafer ring holder 35 is provided.
The chips 25 are picked up one by one by the pickup head 52 at the pickup position 53 from above, and the pickup arm 51 is rotated as shown by the arrow R and transferred to the chip temporary placement section 37. Reference numeral 54 denotes a recognition camera fixed immediately above the pickup position 53, and S denotes a trajectory of the chip 25 transferred by the pickup unit 38.

The chip temporary placement section 37 includes a pulse motor 55
, A polygonal column-shaped rotating body 5 having a short length in the direction of the rotating shaft that rotates intermittently in the direction of arrow T via the drive belt 56.
7 and a large number of suction plates 58
Is provided. A suction port 59 communicating with a suction source (not shown) is opened in the suction plate 58.
8, the chips 25 transferred to the suction plate 58 located at the temporary placement position 60 are sucked and held one by one while rotating the rotating body 57, so that a large number of chips 25 can be stocked in the rotating body 57. . Before the chip 25 is transferred by the bonding head 39, the position and the rotation direction of the chip 25 are corrected by a gauging mechanism (not shown) provided alongside the temporary placement position 60.

The die bonding by the die bonding apparatus configured as described above is performed as follows. First, the wafer 21 is held by a wafer ring 22 and a bar code 24 is provided. The individual chips 25 formed on the wafer 21 are subjected to a characteristic inspection to determine whether they are good or bad and the characteristics A and B. The classification, the good or bad result, the position information (array information) of each of the chips 25a and 25b, the manufacturing lot The number and the wafer number are stored in lot units in a storage medium such as a floppy disk (hereinafter referred to as FD) or a host computer (hereinafter referred to as H / C).

After that, the chips are divided into individual chips 25a and 25b by dicing, are assembled in a ring cassette 26 in lot units while being held by the wafer ring 22, are set on the wafer loader 32, and the following steps are sequentially performed. Is done.

First, in the wafer removal step, the wafer 2 is loaded from the ring cassette 26 set in the wafer loader 32.
The first wafer ring 22 holding 1 is taken out onto the ring transfer rail 33 by a mechanism not shown.

In the subsequent bar code reading step, information such as the production lot number and wafer number of the wafer 21 is read by the bar code reader 34 for the wafer ring 22 taken out on the ring transport rail 33 and stored in the control unit. , The wafer ring 22 is the wafer ring holder 3
It is sent to 5.

Subsequently, in a wafer setting / expansion step, the dicing tape 23 is expanded by a mechanism (not shown) with respect to the wafer ring 22 fed and inserted into the wafer ring holder 35, whereby the chips divided individually by dicing are formed. A predetermined chip interval is secured between each other.

Next, in the wafer alignment step, the wafer 2
A recognition camera 54 immediately above the pickup position 53 so that the plurality of chips 25a and 25b on the camera 1 are at predetermined positions and directions.
, And the actual distance and the rotation amount of the chips 25 whose mutual distance is secured by expansion are corrected while moving the XY-θ table. Then, before dicing, a characteristic inspection is performed in advance to determine the quality and the characteristics A and B, and based on the characteristic classification and arrangement information of the map data stored in the FD or H / C, for example, the necessary characteristic A Only the chip arrangement information of the chip 25a is taken out, the chip 25a to be picked up first is selected, and its position is recognized.

In the subsequent pick-up step, the back surface of the chip 25a to be picked up first is pushed up by the pushing-up mechanism (not shown) through the dicing tape 23 by the pushing-up mechanism (not shown).
The chips 25a are separated one by one, and the chips 25a are sucked by the pickup head 52 of the pickup section 38 at the same time as the separation. Then, the pickup arm 51 is rotated, and the chip 25 a picked up is transferred to the suction plate 58 of the rotating body 57 of the chip temporary placement section 37 located at the temporary placement position 60, and the suction port 59 is moved.
Hold by suction.

On the other hand, in the frame feeding section 31, first, in the frame supply step, the lead frames 41 stacked and stocked by the loading arm 42 of the frame loader 28 are suctioned and separated one by one and transferred to the position of the guide 43, and the frame feeder is moved. Send to 29.

In the next dispensing step, the island 46 is moved along the guide 44 of the frame feeder 29 by the feed mechanism (not shown) to the dispensing position 4.
Then, the silver paste 47 is supplied to the island 46 by the dispense head 40, and thereafter, the feeding operation and the supply of the silver paste 47 are repeatedly performed.

Subsequently, in the bonding step, the chip 25a sucked and held by the suction plate 58 of the chip temporary placement section 37 is held.
Is corrected by the gauging mechanism, and is picked up by the bonding head 39 and taken up.
island 4 located at die bonding position 48 of FIG.
6 is die-bonded via a silver pace and 47. This bonding process is repeated by sending the lead frames 41a so that the islands 46 are positioned one by one in the die bonding position 48, and the chips 25a are mounted on all the islands 46 of the lead frame 41a.

Thereafter, in a frame storing step, the lead frames 41a having the chips 25a mounted on all the islands 46 are sequentially stored in the special magazine 49a of the characteristic A of the frame unloader 30.

Each of the above steps is performed by using the F
The control unit calculates the total number of the chips 25a having the characteristic A based on the map data or the like stored in the D or H / C, and executes the calculation as far as the chips 25a can be mounted on all the islands 46 of the lead frame 41a based on the calculation result. I do. The chip 2 having a fraction of the characteristic A less than the number of islands of the frame
At the stage where 5a occurs, the rotating body 57 is rotated by driving by the pulse motor 55, and the chip 25 is attached to the suction plate 58 while changing the suction plate 58 located at the temporary placement position 60 by one pitch.
a is sucked and held one by one, and all the chips 25 a of the characteristic A, which are fractions of the wafer 21, are stocked in the rotating body 57.

Next, in the magazine switching step, the magazine 49 of the frame unloader 30 is switched to the dedicated magazine 49b for the characteristic B. Further, the rotating body 57 of the chip temporary placement section 37 is rotated by one pitch, and the empty suction plate 58 is positioned at the temporary placement position 60.

Subsequently, die bonding of the chip B of the characteristic B remaining on the first wafer 21 is performed based on the characteristic division and the arrangement information of the map data, as in the case of the chip 25a of the characteristic A. That is, the leading chip 25b is picked up and temporarily placed at the temporary
The position is corrected, picked up by the bonding head 39, mounted on the island 46 at the die bonding position 48 of the lead frame 41b, and then the mounting of the chip b on the lead frame 41b is continued. Then, the lead frame 41b on which the chip b is mounted is attached to the dedicated magazine 49b of the characteristic B of the frame unloader 30.
To be stored sequentially.

Similarly to the case of the chip 25a having the characteristic A, when the chip 25b having the characteristic B has a fraction,
7 is rotated by the drive of the pulse motor 55, and the chips 25b are sucked and held one by one on the suction plate 58 while changing the suction plate 58 located at the temporary placement position 60 by one pitch. All of the B chips 25b are stocked in the rotating body 57, and at the end of this stocking, the frame unloader 30 is switched to the dedicated magazine 49a for the characteristic A, and the classification from the first wafer 21 is completed.

Next, in the wafer storing step, the wafer ring 22 that has been completely classified from the wafer 21 is stored in the wafer loader 32, a second wafer 21 is newly taken out from the wafer loader 32, and the same as the first wafer is loaded. Die bonding of the chip 25a to the lead frame 41a is performed through the steps. At this time, first, the chip 25a stocked in the chip temporary placing portion 37 is picked up by the bonding head 39 after correcting the chip position by a gauging mechanism (not shown) while sequentially rotating the pulse motor 55 from the temporary placing position 60. Then, die bonding is performed.

When the pickup of the fractional chip 25a has been completed, the chip 25a at the pickup position 53 is picked up and die-bonded.
Then, the storage operation is performed again and continuously in the special magazine 49a for the characteristic A in which the lead frame 41a is stored halfway. Dedicated magazine 49a in this case
Is kept at the number of stages stored last time,
It is not necessary to adjust the number of stages at the time of switching.

Similarly, in the chip 25b having the characteristic B, a fractional chip 25b stocked in the chip temporary storage section 37 is first picked up from the temporary storage position 60 and die-bonded, and then picked up from the pickup position 53. In this case, bonding is performed, and the magazines are sequentially stored in the dedicated magazine 49b having the characteristic B.

That is, in the normal bonding step, the rotating body 57 of the temporary chip placement section 37 is stopped, and only when a fractional number of chips 25a and 25b are generated, it operates so as to be sucked, rotated, and stored. Chip 2 from 21
When the transfer of 5a and 25b is completed, the chip temporary storage unit 37 stores only the chips 25 (the number of classifications x the number of fractional chips).
Is temporarily placed. It is sufficient that the number of temporary storages of the rotating body 57 is at most [the number of classifications of the characteristic category × (the number of mounted chips on the lead frame−1)].
May be provided in multiple rows while the number of temporary storages is reduced, and the rotating body 57 may be made smaller.

With the above configuration, the dedicated magazines 49a and 49 corresponding to the number of classifications of the characteristic A and the characteristic B can be switched, and the lead frames 41a and 41 can be switched.
chips 25a and 25 having fractions less than the number of mounted chips of b
b can be picked up and temporarily placed in the chip temporary placement section 37 in sequence, and the chips 25a and 25b of a fraction generated for each wafer 21 can be efficiently die-bonded.

Further, since each wafer only needs to be taken out and stored once, and the dicing tape 23 does not need to be repeatedly expanded and contracted, the risk of chip damage such as chipping or cracking is reduced, and quality is concerned. Is reduced.

Similarly, since each wafer requires only one unloading / storing operation, the time can be reduced, and the operation rate of the apparatus can be greatly improved. Further, since it is not necessary to transfer the chips 25a and 25b to dedicated wafer rings for the characteristics A and B in advance, accompanying processes, tools and materials are not required, and there is no deterioration in quality due to increased handling.

In the above-described embodiment, the chips 25a and 25b are transferred from the wafer 21 so that the classification order from the characteristic A to the characteristic B, and from the characteristic A to the characteristic B is changed from AB to AB. After that, the number of changes of the magazine 49 in the unloader 30 may be reduced by changing the classification order from the characteristic B to the characteristic A to AB → BA. Further, when die bonding of fractional chips 25a and 25b is performed, the chip is preferentially picked up from the chip temporary holding portion 37, but is picked up first from the pickup position 53 on the wafer 21 side and finally picked up from the chip temporary holding portion 37. There is no problem.

[0060]

As is apparent from the above description, according to the present invention, classification of each semiconductor chip in each characteristic category can be easily performed while ensuring high quality, and the inventory of unnecessary semiconductor devices can be increased. Thus, it is possible to efficiently produce a desired semiconductor device, and to improve the efficiency of productivity, such as improving the operation rate of expensive equipment such as test evaluation equipment and reducing capital investment.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a perspective view of a main part in one embodiment of the present invention.

FIG. 3 is a perspective view of a wafer ring according to an embodiment of the present invention.

FIG. 4 is a perspective view of a ring cassette according to one embodiment of the present invention.

FIG. 5 is a side view of a lead frame to which a semiconductor chip according to one embodiment of the present invention is die-bonded.

FIG. 6 is a schematic configuration diagram for explaining a conventional die bonding method.

FIG. 7 is a schematic configuration diagram for explaining a transfer method according to the related art.

[Explanation of symbols]

 Reference Signs List 21 semiconductor wafer 25, 25a, 25b semiconductor chip 29 frame feeder 31 frame transfer unit 35 wafer ring holder 36 wafer transfer unit 37 chip temporary storage unit 38 pickup unit 41, 41a, 41b lead frame 48 ... Die bonding position 49a, 49b ... Special magazine 51 ... Pickup arm 52 ... Pickup head 53 ... Pickup position 57 ... Rotating body 58 ... Suction plate 59 ... Suction port 60 ... Temporary placement position

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/52 H01H 21/60 H05K 13/00

Claims (4)

(57) [Claims] 1. A semiconductor chip classified into a plurality of characteristic categories according to semiconductor element characteristics from a diced semiconductor wafer is picked up for each of the characteristic categories and die-bonded to a lead frame, and then the semiconductor chip is mounted. In the die bonding method for accommodating the lead frame in a dedicated magazine for each characteristic section, the semiconductor chips classified from the semiconductor wafer are picked up for each characteristic section and die-bonded to the lead frame for each characteristic section. A fractional semiconductor chip generated when a semiconductor chip of the same characteristic category of one semiconductor wafer is mounted on a lead frame is temporarily temporarily placed for each characteristic category, and a semiconductor chip of the same characteristic category in a new semiconductor wafer is temporarily placed. When mounting on a lead frame, temporarily place it on the previous semiconductor wafer. A die bonding method, wherein the fractional semiconductor chip is mounted on a lead frame. 2. A wafer holding means for holding a semiconductor wafer so as to position a semiconductor chip whose characteristics have been classified at a pickup position, a chip transfer means for picking up and transferring the semiconductor chip located at the pickup position, and the chip transfer Temporary placement means for supporting the semiconductor chip transferred by the means at a temporary placement position, and a predetermined portion of the lead frame corresponding to the characteristic division of the semiconductor chip at the die bonding position for the semiconductor chip supported at the temporary placement position. A frame carrying means for die bonding and sending out, and a frame accommodating means for accommodating the lead frame sent out from the frame carrying means in a dedicated magazine for each characteristic section of the semiconductor chip, and the temporary placing means, The semiconductor chips of the same characteristic category of the semiconductor wafer are A die bonding apparatus configured to hold a fraction of the semiconductor chips generated when the semiconductor chips are mounted on a lead frame for each characteristic category. 3. The temporary placing means includes a rotating body provided between a pickup position and a die bonding position, and holds a plurality of semiconductor chips by suction on an outer surface of the rotating body in a rotating direction. The die bonding apparatus according to claim 2, wherein: 4. The temporary placement means is configured to be able to hold at least [(the number of classifications of characteristic categories) × (the number of semiconductor chips mounted on a lead frame−1)] semiconductor chips. The die bonding apparatus according to claim 2 or 3.