JPH02106938A - Pellet bonding method and equipment - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technique that is particularly effective when applied to the assembly process of semiconductor devices, particularly so-called pellet bonding in which a pellet is attached to a mounting member such as a tab.

[Conventional technology]

Examples of this type of pellet bonding technology described include, for example, JP-A-53-102671;
There is a publication.

According to the general pellet bonding technology including the above-mentioned publication, after the pellet is picked up from the wafer, its posture is first corrected in an intermediate pocket or an intermediate stage, and then the above posture correction is performed with a bonding arm. Work is being carried out to attach the pellets to the mounting members.

[Problem to be solved by the invention]

However, as semiconductor devices become more diverse and multifunctional,
There are many different types of package structures, but in package assembly, especially in the pellet bonding process, each time the product is changed, the lead frame that is the mounting member, the collet that corresponds to the size of the pellet, etc., and It was necessary to adjust the movement control amount of the bonding arm.

Particularly when processing small quantities of a wide variety of products, product changes become frequent, which is a factor in reducing the efficiency of the package assembly process.

The present invention has been made with a focus on the above-mentioned problems, and its purpose is to recognize product type information and control the movement of a bonding arm in accordance with the product type information, thereby reducing the amount of manual movement required each time the product type is changed. The purpose of the present invention is to provide a technology that can make the package assembly process more efficient by avoiding the need for manual setup and speeding up the process when changing product types.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, after dividing the pellets from the wafer and correcting the posture at an intermediate position, the amount of movement of the pellets from the intermediate position to the attachment member is corrected based on the product type information registered on the attachment member.

Further, after the pellet is mounted on the mounting member, the product type information is updated.

[Effect]

According to the above-mentioned means, even if the size, arrangement, etc. of pellets and mounting members differ depending on the product type, by recognizing the registered product information, the pellets can be optimally moved from the intermediate position to the mounting member. The amount of movement can be determined, and pellet bonding can be automated even when wiping between various types. Therefore, in the manufacturing process of semiconductor devices,
Package assembly can be performed efficiently.

Furthermore, by updating the product type information after the pellets are attached, it becomes possible to mechanically recognize the completion of the pellet bonding work, thereby promoting the efficiency of subsequent processing.

〔Example〕

Fig. 1 is a perspective view showing the main parts of a pellet bonding device that is an embodiment of the present invention, Fig. 2 is an explanatory diagram showing a positioning method according to this embodiment, and Fig. 3 is a pellet bonding device used in this embodiment. 4 is a flow diagram showing the pellet bonding process in this embodiment, FIG. 5 is a block diagram showing signal processing in the optical system, and FIG. 6 is a side view showing the configuration of the bonding head portion of the device. FIG. 7 is an explanatory diagram showing the state of positional deviation correction on the tab.

As shown in FIG. 1, the pellet bonding apparatus 1 of this embodiment includes a rotary transfer arm 5 that picks up pellets 4 one by one from a dicing-completed wafer 3 supported by a wafer stage 2. The transport arm 5 has a transport collet 7 removably attached to the distal end of the transport arm 5. Within one rotational radius of the transport arm 5, there are a plurality of replacement transport cholera) 7a.
The transport collet 7 mounted on the tip of the transport arm 5 can be replaced as appropriate under the control of the control unit 10.

Note that the control section 10 is provided with a storage section, and the storage section stores various control data corresponding to product type information.

The wafer 3 on the wafer stage 2 is attached to an adhesive film 12 stretched over a ring-shaped frame 11. At this time, the wafer 3 is in a state where dicing has been completed for each pellet 4, and in this embodiment, this dicing form is a so-called semi-full cut state in which each pellet 4 is connected with a thickness of about 30 μm. It becomes.

On the adhesive film 12 in the frame 11, a barcode label 13a is attached together with the wafer 3, and this barcode label 13a l: is attached to the pellet 4.
A barcode is printed that encodes the function, size, etc. On the side of the wafer stage 2, there is a barcode reader 14a that reads the contents of the barcode label 13H.
is provided, and the read content is output to the control unit 10. Note that the barcode reader 14a
This may be either a stationary reading type using infrared irradiation or a scanning reading type using a laser beam. The static reading type has the advantage that the reading mechanism can be simplified, and the scan reading type has the advantage of increasing the reading speed.

An intermediate stage 15 is provided within the other rotation radius of the transport arm 5 for correcting the posture of the pellet 4 transported by the transport head 6.

This intermediate stage 15 is equipped with an L-shaped pellet guide 16 that can move on the stage surface in the XY force directions, and by moving the pellet guide 16 by a predetermined amount in the Y direction and the It is configured to guide the position and bring the pellet 4 into a predetermined bonding standby posture.

A bonding stage 17 is provided on the side of the intermediate stage 15, on which a lead frame 9, which is a mounting member, is placed. This bonding stage 17 is formed as a part of a chute 18 which is a means for transporting the lead frame 9. The chute 18 is arranged between the loader side and the unloader side, and a rack 20a in which a plurality of lead frames 9 are stored is arranged on the loader side, and product type information is registered on the outer peripheral surface of the rack 20a. A barcode label 13b is attached as a means.

The barcode printed on the barcode label 13b encodes product/standard data of the lead frame 9 as product type information.

The barcode label 1 is placed on the side of the rack 20a.
A barcode reader 14b for reading 3b is arranged. The product type information read by the barcode reader 14b is recognized by the control section 10 and each section is controlled, which will be described later.

The lead frame 9 supplied onto the chute 18 from the rack 20a on the loader side is placed on the bonding stage 17.
After the pellets 4 are loaded at the site, they are stored again on the unloader side through the system 18. An empty rack 20b for accommodating the lead frame 9 after the pellets 4 have been mounted is arranged on the unloader side, and a bar code is provided on the side of the rack 20b on the outer peripheral surface of the rack 20b. A barcode label issuing unit 21 is provided for attaching the label 13c, and when a predetermined number of lead frames 9 are stored in the rack 2Ob, the barcode label 13c with new product information written thereon is attached. It can be attached to the rack 20b.

A heat block 22 as a heating source is provided at the lower part of the bonding stage 17 in the middle of the chute 18, and the lead frame 9 on the bonding stage 17 is heated to a predetermined temperature.

Above the bonding stage 17, there is a bonding head 24 placed on an XY table 23, and a bonding collet 25 and a paste dripping nozzle 26 are attached to a portion facing the surface of the bonding stage 17. .

The movement of the bonding head 24 in the horizontal direction (XY-axis direction) is controlled by an X-axis motor 27x and a Y-axis motor 27y provided on the XY table 23, and
Movement in the vertical direction (Z-axis direction) is controlled by a Z-axis motor 27z on the Y-table 23. Therefore, these X-axis, Y-axis, Z-axis motors 27x, 27y, 27z
The bonding collet 25 and the paste dripping nozzle 26 move on the bonding stage 17 in the XYZ direction by driving the
It is possible to move in the direction. The operation of the three systems of motors 27x, 27y, and 27z is controlled by the control unit 10.

Further above the bonding stage 17, an optical system 28 consisting of a TV left camera is arranged, and is configured to detect the position of the tab 35 of the lead frame 9 as a mounting member.

As shown in FIG. 5, the optical system 28 includes a tab center calculation section 30, a teaching tab center data storage section 31,
Comparison/deviation amount calculation section 32, XY child table movement amount calculation section 3
3. The XY table motor driver 34 and the operation panel key manual section 39 are connected, and the X-axis motors 27X and Y
The shaft motor 27y is driven and controlled to correct positional deviation.

Note that in this embodiment, all of these mechanisms are provided inside the control section 10.

Next, the procedure of pellet bonding work using the pellet bonding apparatus 1 will be explained with reference to FIG. 4.

First, when the lead frame 9 is housed in the rack 20H and mounted on the loader side (step 401), the barcode label 13b affixed to the rack 20a is read by the barcode reader 14b (402).
The type information of the lead frame 9 thus obtained is recognized by the control unit 10. On the other hand, wafer stage 2
A wafer 3 adhered to an adhesive film 12 stretched over a ring-shaped frame 11 is placed on top. At this time, the barcode label 13a attached to the adhesive film 12 together with the wafer 3 is read by the barcode reader 14a (403), and this read data is transferred to the wafer 3.
It is output to the control unit 10 as product type information. The control unit 10 compares the type information of the wafer 3 and the type information of the lead frame 90 based on this read data. At this time, the control unit 10 determines whether the wafer 3 and the lead frame 9 are a correct combination, that is, they are mutually compatible products, based on the above-mentioned information on both types (4).
04). At this time, if the product type is incompatible, it is determined that the product type is incorrect and the work is stopped (405).

If the control unit 10 determines that the product type is compatible,
Based on the product type information, data corresponding to the product type is read from the storage section and instructions are given to adjust each mechanism (406). Here, the adjustment specifically refers to adjusting the sinito width in the chute 18 (406a), replacing the stock section 8 with a replacement conveying collet 7a (406b), and
The amount of movement of the f-pull 23, that is, the bonding head 24
(406c), and in the conventional device structure, all of these changes were made for each product type through manual operations by the operator.

Next, the lead frame 9 is fed onto the chute 18,
When the frame 11 is stopped on the bonding stage 17 after passing through steps 18 and 18, paste application is performed (4).
07). This work will be further explained based on the flow shown in FIG. First, the tab 35 of the lead frame 9 is recognized by the optical system 28, and the center position of the tab 35 is corrected in order to perform optimal potting of the resin paste 36.

The optical system 28 first recognizes the positions of the four sides of the tab 35 on the bonding stage 17 (407A) and outputs this position data to the tab center calculation 11s30.

The tab center calculation unit 30 calculates the center C1 of the tab 35 from the values of the dimensions x and y of the tab 35 in FIG. 7, and obtains recognition data for the tab center. The comparison/deviation amount calculation unit 32 compares the recognition data with the teaching data indicating the tab center C2 obtained by the manual teaching in the teaching tab center data storage unit 31 (407).
B) Calculate the deviation between the centers of both tabs C1 and C2 (
407C). Note that the tab center C2 determined by the teaching at this time is the center of the tab 35 where the paste dripping nozzle 26 provided in the bonding head 24 should originally be placed.

In order to correct the deviation calculated as described above by adjusting the XY child table 3, the XY child table movement calculation unit 33 calculates the required movement amount of the XY table 23, and based on the calculated value, the The X-axis motor 27x and the Y-axis motor 27y are driven through the table motor driver 34, and the XY child table 3 is moved so that the centers C1 and C2 of the tabs 35 coincide (407D). At this time, the calculated value of the amount of movement of the XY child table 3 is stored in the storage section, and is also used as a correction amount for pellet bonding, which will be described later.

In this state, when the Z-axis motor 27z is driven and the paste dropping nozzle 26 is lowered to a predetermined position relative to the tab 35, a predetermined amount of resin paste 36 is dropped onto the tab 35 (407E).

Next, the state of adhesion of the resin paste 36 is inspected by the optical system 28 (appearance inspection 407F), and the process moves to a bonding step (408).

In the bonding process, first, a predetermined pellet 4 is pushed upward from the lower surface side of the wafer 3 by the push-up pin 37, and then the transport collet 7 adsorbs this pellet 4 from above.

With the transport collet 7 adsorbing the pellet 4, the transport arm 5 is rotated to place the pellet 4 on the intermediate stage 15. In the state in which the pellets 4 are placed in this manner, the state of attraction by the transport collet 7 varies depending on the position on the wafer 3 and the push-up conditions, so the posture of the pellets 4 on the intermediate stage 15 varies. There are also variations.

In this embodiment, the posture of the pellet 4 is corrected by moving the pellet guide 16 on the intermediate stage 15 in the child direction of the XY axes in FIG. 2 (408A).

Due to this posture correction, the tab center CI of the lead frame 9 is positioned on the extension of the central axis m of the pellet 4.

In this state, the X-axis motor 27 is controlled by the control unit 10.
The x- and Y-axis motors 27y are driven to first position the bonding collet 25 on the central axis m, and then the X-axis motor 27x is driven to position the bonding collet 25 on the central axis m.
5 along the X axis. At this time, the total amount of movement of the bonding collet 25 in the X-axis direction is l+Δ! It becomes. Here, l is a specified value, but Δl differs from product to product depending on the size of the pellet 4 and the like.

In this embodiment, since the control unit 10 recognizes the size of the pellet 4 at the stage of reading the type information of the wafer 3, the corresponding value of Δβ must be calculated as the correction value.
8B), give this correction amount, that is, Δl, to the XY table motor driver 34 to move the XY child table 3 (
408C). Therefore, in this embodiment, the bonding collet 25 moves on the central axis m based on the product type information and is reliably stopped directly above the pellet 4.

Subsequently, the Z-axis motor 27z is driven, and the bonding collet 25 is lowered by a predetermined amount relative to the pellet 4, and vacuum suction is started from the tip of the bonding collet 25. Along with this, the pellet 4 is attracted to the bonding collet 25 (408D). The bonding collet 25 with the pellet 4 attracted to its tip in this manner is driven by the X-axis motor 27x until the center C3 of the pellet 4 coincides with the tab center C2 by the teaching explained in FIG. 7 above. will be moved.

Here, since the tab center C2 according to the teaching is deviated from the actual tab center C1 as described above, the control unit 10 moves the XY child table 3 stored when applying the resin paste 36 described above. The calculated value of the amount is read out again from the storage unit, and the X-axis motor 27x and the Y-axis motor 27
y and the bullet center C3 is the actual tab center C1.
(408E).

Subsequently, the Z-axis motor 27z is driven to lower the bonding collet 25 relative to the tab 35, and when the lower surface of the pellet 4 is bonded to the tab 35 via the resin paste 36, the vacuum suction of the bonding collet 25 is stopped. be done. Next, the bonding collet 25 is raised by the reverse drive of the Z-axis motor 27z, and the attachment of the pellet 4 to one lead frame 9 is completed (408F). In this state, the position of the pellet 4 on the tab 35 is recognized by the optical system 28, and it is inspected whether or not the pellet 4 is attached within the specified value range (appearance inspection 409). Next, the lead frame 9 is transferred on the chute 18 and coated with resin paste 36 by the heat block 22, and then stored in the rack 20b on the unloader side (
410).

In this way, after the pellets 4 have been loaded onto a predetermined number (10 tons) of lead frames 9, the barcode label issuing section 21 located near the rack 20b on the unloader side is activated. New barcode label 13
c is attached to the rack 20b (411). The contents of the barcode printed on this barcode label 13C have been updated to a code indicating completion of loading the pellet 4 based on this embodiment. As the contents of this code, it is assumed that, for example, the lot number of 90 lead frames that are found to be defective in pellet bonding as a result of the visual inspection after the pellets have been attached is registered.

By updating the product type information on the barcode label 13b with the barcode label 13c in this way, in the subsequent wire bonding process, based on the pellet bonding failure data obtained from the read content of the barcode label 13c, The defective lead frame 9 can be processed more efficiently by empty feeding or the like without wire bonding.

Note that the above explanation assumes that a pellet bonding defect is detected during the visual inspection in the pellet bonding process, and that the subsequent wire bonding process is performed in a lofted state with the defective lead frame as it is. A mechanism for removing defective lead frames from within the loft may be provided between the bonding process and the wire bonding process.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, we explained that barcode labels were used as a means of registering product information, but
Information registration means based on other code systems, or type information registration means such as a magnetic card or an IC card may also be used.

Further, although the case where the above-mentioned product information is registered in units of racks or lofts using barcode labels has been described, the method is not limited to this, and the method of registering product information in units of lead frames is also possible.

In this case, individual information such as the amount of pellet misalignment can be registered for each lead frame, so subsequent package assembly work (for example, wire bonding process, etc.)
In this case, it becomes possible to control individual devices for each lead frame, and it becomes possible to improve assembly reliability and assembly efficiency in the package assembly process.

In the above description, the invention made by the present inventor was mainly applied to the field of application, which is a pellet bonding process in which a pellet is attached to a tab of a lead frame, but the invention is not limited to this. For example, it can also be applied to a pellet bonding process in which a ceramic package substrate or the like is used as a mounting member.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

In other words, according to the present invention, even if the size, arrangement, etc. of pellets and mounting members differ from product to product, by recognizing the registered product information, it is possible to optimally move the pellets from the intermediate position to the mounting member. The amount of movement can be determined, and pellet bonding can be automated even between a wide variety of products.

Therefore, package assembly can be performed efficiently in the semiconductor device manufacturing process.

Furthermore, by updating the product type information after the pellets are attached, it becomes possible to mechanically recognize the completion of the pellet bonding work, thereby promoting the efficiency of subsequent processing.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the main parts of a pellet bonding device which is an embodiment of the present invention, Fig. 2 is an explanatory diagram showing a positioning method according to the embodiment, and Fig. 3 is a bonding diagram of a pellet bonding device which is an embodiment of the present invention. A side view showing the structure of the head part, Fig. 4 is a flow diagram showing the pellet bonding process in the example, Fig. 5 is a block diagram showing signal processing in the optical system of the example, and Fig. 6 is a paste in the example. Flowchart showing the procedure of coating. 7th rgJ is an explanatory diagram showing the state of positional deviation correction on the tab in the embodiment. DESCRIPTION OF SYMBOLS 1... Pellet bonding device, 2... Wafer stage, 3... Wafer 4... Bullet, 5...
Transfer arm, 6... Transfer head, 7... Transfer collet, 7a... Replacement transfer collet, 8... Stock section, 9... Lead frame, 10... System? 1llll
B, 11...Frame, 12...Adhesive film, 1
3a, 13b, 13C... Barcode label, 14a
, 14b... Barcode league, 15... Intermediate stage, 16... Pellet guide, 17... Bonding stage, 18... Shoot, 20a 20b.
... Rack, 21 ... Barcode label issuing department, 22
... Heat block, 23 ... XY table, 24
... Bonding head, 25... Bonding collet, 26... Paste dripping nozzle, 27x...
X-axis motor, 27y...Y-axis motor, 27z...Z
Axis motor, 28... Optical system, 30... Tab center calculation unit, 31... Tab center data storage unit for teaching,
32... Comparison/deviation amount calculation unit, 33... XY child table movement calculation unit, 34... XY child table motor driver, 35... Tab, 36... Resin paste, 37...
...Push-up bottle, 39...Operation panel key Human power section. Agent Patent Attorney Daiwa Tsutsui

Claims (1)

[Claims] 1. A pellet bonding method in which pellets divided from a wafer are once corrected in posture at an intermediate position and then mounted on a mounting member on a bonding stage, and product type information is registered on the mounting member. The pellet bonding method is characterized in that the amount of movement of the pellet from the intermediate position to the attachment member is corrected by recognizing the product type information. 2. The pellet bonding method according to claim 1, wherein after the pellet is mounted on the mounting member, product type information registered on the mounting member is updated. 3. The pellet bonding method according to claim 1 or 2, wherein the product type information is a barcode. 4. A transport arm that picks up pellets divided from a wafer, an intermediate table that corrects the posture of the pellets transported by the transport arm, a bonding stage on which mounting members with product type information registered are arranged, and the above-mentioned A pellet bonding apparatus comprising: a bonding arm that transfers pellets between an intermediate table and a bonding stage; and a control section that controls the amount of movement of the bonding arm based on recognition of the product type information.