JPH03253039A - Pickup and extension position measuring device to be used for that - Google Patents

Abstract

PURPOSE:To pick up reliably even a fine pellet and to perform properly a bonding on the pellet by a method wherein the positions of individual pellets subsequent to stretching of a wafer into a diced sheet are previously measured. CONSTITUTION:A TV camera 23 which is used as an imaging device is installed directly over an X-Y table 21 of an extension position measuring device 20 and this camera 23 is designed so as to photograph a wafer on a jig placed on the table 21. A pattern recognition device 24 is electrically connected to this camera 23 and individual pellets are recognized by the device 24 on the basis of an image signal from the camera 23. The device 24 is connected to a controller 22 and the recognized result is transmitted to the controller 22. The positions of the individual pellets can be recognized by the controller 22 by a signal from the device 24 and the movement of the table 21. Thereby, even a fine pellet 2 is reliably picked up 36 by measuring previously the positions of the individual pellets subsequent to stretching of the wafer into a diced sheet.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a pick-up method and an elongated position measuring device used therein. Concerning what can be effectively used for bonding.

[Conventional technology]

In the manufacturing process of semiconductor devices, a pellet bonding method for bonding pellets to a lead frame includes a process in which a stretchable sheet is adhered to a wafer, a dicing process in which the wafer is divided into a plurality of pellets, and the sheet. A jig mounting process in which the wafer is held in a frame-shaped jig via a sheet while the wafer is stretched, and the pellets in the wafer held in the jig are sequentially peeled off from the sheet and placed in a pick amplifier. The picking up process and the picking up of the pellets
There is a method that includes a step of transferring the lead frame onto the lead frame and bonding it to the lead frame.

There is also a pellet bonding method in which inspection data from a wafer inspection process is used when pellets within a wafer are picked up.

An example that describes dicing technology is "Electronic Materials November 1987 Special Edition" published by Kogyo Research Association Co., Ltd.
There are P40-P45 published on II/20/1986.

In addition, an example that describes pellet bonding technology is "Electronic Materials, November 1981," published by Kogyo Chosenkai Co., Ltd.
Monthly special edition” published November 10, 1981 P149-P1
There is 55.

[Problem to be solved by the invention]

However, in the above-mentioned pellet bonding method, after the wafer is divided into pellets, the sheet is stretched and the position of the pellets changes, so the positioning accuracy of the pellets becomes unstable when each pellet is pink-amplified, and the When pellets such as those for signal transistors and diodes are minute, picking up and bonding the pellets becomes impossible.

In addition, when picking up pellets while pushing them up, it takes time for the shape change of the sheet caused by pushing up to fully recover when pellets are picked up continuously, so the pellet pattern is recognized and the pellets are picked up. Even so, pattern recognition becomes unstable and pellet pickup and bonding become unstable.

An object of the present invention is to provide a pickup method that can reliably pick up even minute pellets, and an elongation position measuring device used therein.

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]

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

That is, a step in which a stretchable sheet is adhered to a plate-like object, a step in which the plate-like object is divided into a plurality of pellets, and a step in which the plate-like object is attached to the sheet in a stretched state. A pickup comprising: a jig mounting step in which the bereno L is held in a frame-shaped jig via the jig; and a pickup step in which the beleno L in the plate-shaped object held in the jig is sequentially peeled off from the sheet and picked up. The method is characterized in that the position of each pellet after the sheet is stretched after the jig mounting process is measured, and the measured position is used to carry out the pickup process.

[Effect]

According to the above-mentioned means, since the position of each pellet after the sheet is stretched is measured in advance, the positioning of each pellet is accurately executed when each pellet is pinked up based on the measured position. Therefore, even minute pellets can be reliably picked up.

[Example] Figure 1 is a process diagram showing a pellet bonding device that is an example of the present invention, Figure 2 is a schematic diagram showing an elongation position measuring device used therein, and Figure 3 is a diagram showing a wafer after dicing. FIG. 4 is a perspective view showing the sheet adhesion process, FIG. 5 is a plan view after dicing, FIG. 6 is a plan view after mounting the jig, and FIG. 7 is a perspective view showing the pellet bonding process. 8 are enlarged partial sectional views showing the main parts thereof.

In this embodiment, the extension position measuring device 20 according to the present invention
is configured to measure the position of a pellet within a wafer held in a jig to be described later, and as shown in FIG. 2, it is equipped with an XY table 21 on which this jig is placed. ing.

This XY table 21 is equipped with a feed shaft mechanism and a servo motor (not shown) such as a pulse motor or a stepping motor, and is controlled by a controller 22 controlled by a computer or the like to move the jig in the X and Y directions. It is configured to be movable. As will be described later, this controller 22 is equipped with a wafer inspection data recording medium such as a floppy disk, a pellet position data recording medium after sheet stretching, and a composite data recording medium.

A television camera 23 as an imaging device is installed directly above the XY table 21, and this television camera 23
The wafer on the jig placed on the Y child table 1 is photographed. A pattern recognition device 24 is electrically connected to the television camera 23.
is configured to recognize each pellet based on the imaging signal of the television camera 23. Pattern recognition device 2
4 is connected to the controller 22 and transmits the recognition result to the controller 22. The controller 22 recognizes the position of each pellet based on the signal from the pattern recognition device 24 and the amount of movement of the XY table 21.

In this embodiment, the pick-up method according to the present invention is applied to a pellet bonding apparatus that picks up pellets that fit after cutting a wafer so as to separate them from a sheet and bond them to a lead frame.

Next, a pele 7) pounding method according to an embodiment of the present invention will be described with reference to FIG. 1 in the case where the elongation position measuring device according to the above configuration is used.

In the so-called pre-process in the manufacturing process of semiconductor devices, the wafer 1 on which transistors, diodes, semiconductor integrated circuits, etc. are fabricated in each pellet 2 is subjected to electrical characteristic tests, visual inspections, etc. in the wafer inspection process 11, as shown in FIG. As shown in , the pellets are sorted into good pellets 2a and defective pellets 1-2b. At this time, a mark 3 is attached to the defective pellet 2b. Further, data regarding the positional coordinates of each pellet 2 and the position of defective products are recorded on the wafer inspection data recording medium 6.

In a sheet adhesion step 12, a sheet 4 is adhered to the back surface of the wafer 1 inspected in this way, as shown in FIG. The sheet 4 is made of a stretchable material such as resin, and is formed into a thin film having a diameter larger than that of the wafer, and is adhered to the back surface of the wafer 1 using a suitable adhesive.

Subsequently, in the post-dicing step 13, the wafer 1 is divided into pellets 2, as shown in FIG.

At this time, since the sheet 4 adhered to the back surface of the wafer 1 is not cut, the groups of barens 12 do not fall apart but remain in a group.

Next, in a jig mounting step 14, the wafer 1 is mounted on the jig 5 via the sheet 4, as shown in FIG. The jig 5 is made of a rigid material such as stainless steel, and is formed into a circular ring shape with a larger diameter than the wafer 1. The sheet 4 adhered to the wafer 1 is arranged to face each other within the frame of the jig 5, and then stretched outward in the radial direction, and its outer peripheral portion is fixed to the jig 5. At this time, the wafer 1 stuck to the sheet 4 is attached to each pellet 7.
Since the pellets 2 and 2 are divided into two parts, as the notebook 4 stretches, the adjacent pellets 2.2 will be separated and the positions of the pellets will change.

Thereafter, the jig 5 is sent to an elongation position measuring device 20 shown in FIG. 2, and the position of the pellet 2 after the sheet is elongated is measured. At this time, the wafer inspection data recording medium 6 created in the wafer inspection process 11 is attached to the controller 22 in the elongated position measuring device 20 and used for this measurement.

That is, the jig 5 sent to the elongated position measuring device 20 is placed and held on the XY table 21 in the elongated position measuring device 20, and each pellet 2 is photographed by the television camera 23.

Based on the imaging signal from the television camera 23, each pellet 2 is recognized by the pattern recognition device 24, and the XY child table 1 is operated by the controller 22 based on the recognition result. Then, based on the amount of operation of the XY child table 1 and pattern recognition, the position of each pellet 2 on the jig 5 after the sheet is stretched is measured.

At this time, the data regarding good and defective products of each pellet 2 and their position coordinates before sheet enlarging are read from the wafer inspection data recording medium 6, so that the data on each pellet 2 after sheet enlarging is retrieved. Used for position measurement.

In this way, data regarding the measured position of each pellet 2 is recorded on the post-stretched pellet position data recording medium 7 mounted on the controller 22. Further, the data after the sheet is stretched is recorded on the bottom data recording medium 8 together with the data before the sheet is stretched. And Pele after stretching the sheet created in this way 7)
The position data recording medium 7 and the composite data recording medium 8 are sent to a bullet bonding process 16.

In the pellet bonding step 16, a pellet bonding apparatus 30 shown in FIGS. 7 and 8 is used.
is used, and each Pelleno)-2 is peeled off from the sheet 4 and picked up from the jig 5 based on the data on the position of each pellet obtained from these recording media 7 and 8, and the data on good and defective products. and each lead frame 9L
Each of these is punched. At this time, since the position of each pellet 2 after the sheet is stretched has been accurately measured in advance, even if the pellets are minute, the pellets may be small.

Even if it is 2nd, it is reliably picked up and bonded.

The pellet bonding apparatus 30 includes a feeder (not shown) through which the lead frame 9 is pitch-fed, and an XY child table I is placed on the feeder at a position corresponding to the lead frame 9 in the XY direction under the control of the controller 32. Equipped to be moved. The medium 8 or 6 and 7 is attached to the controller 32. On the XY child table 1 is a bonding head 3 controlled by a controller 32.
3 is mounted, and this head 33 is equipped with a bonding arm 34 that is controlled by a controller 32. A bonding ink tool 35 for picking up the pellet and bonding it onto the lead frame 9 is attached to the tip of the bonding arm 34, and the bonding ink tool 35 is configured to be able to hold the pellet 2 by vacuum suction or the like. ing. A pickup stage 36 is set on one knee of the feeder, and the jig 5 is supplied to this stage 36 to be positioned and held. This stage 36 is equipped with a push-up pin 37 so as to push up each pellet 2 adhered to the sheet 4 within the jig 5.

Then, when the bullet 2 is bonded, the pin 37
The bellet 2 is pushed up from below the sheet 4. The raised bullet 2 is the bonding tool 35
It is picked up by the lead frame 9, transferred to the lead frame 9, and bonded onto the lead frame 9.

After the bullet 2 is picked up, the pin 37 is lowered once, so the sheet 4 returns to its original horizontal shape, but it takes some time to return. If an attempt is made to perform pattern recognition and recognition on Peresoto 2 to be picked up next time in a state where the recovery is insufficient, the pattern recognition and recognition will become inappropriate.

However, in this embodiment, since the position of the pellet 2 has been measured in advance, the next time the position of the pellet 2 is measured.

There is no need to perform pattern recognition on the pellets 2 to be pressed. Therefore, even if the return of the sheet 4 is insufficient, the pellets 2 to be pinked up next time can be picked up appropriately. As a result, the waiting time for the return of the sheet 4 can be omitted, so that the pellet bonding time can be shortened accordingly, and the pellet bonding time can be shortened as a whole.

According to the embodiment described above, the following effects can be obtained.

(1) By pre-measuring the position of each pellet after stretching the sheet from which the wafer has been diced, this measurement data can be used to align the bonding tool to each pellet during the pellet bonding process. Even minute pellets can be reliably picked up and bonding can be performed appropriately.

(2) In the pellet honding process, even if the pellets to be picked up are pushed up, by measuring the position of each pellet after the sheet is stretched, there is no need to wait for the sheet to recover from its deformation after being pushed up. It is possible to prevent a decrease in bonding speed and shorten the overall pellet bonding time.

(3) By sharing the pellet position measuring device after stretching for each pellet bonding device,
Since it is not necessary to install a dedicated pattern recognition device for recognizing the position of each pellet in each pellet bonding device, equipment costs can be significantly reduced.

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 Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, inspection data in the wafer inspection process is not limited to being recorded on a recording medium, but may also be used by attaching defective product marks to each pellet of the wafer.

If the ratio of non-defective products is high, the wafer inspection step may be omitted and all wafers may be considered non-defective, and the position of the pellets after sheet stretching may be measured.

The pellet position may be measured not for each pellet but once every n pellets, during which time the measurement results may be distributed proportionally.

Further, the work of measuring each position of each pellet after the sheet is stretched is not limited to the use of the stretched position measuring device according to the above configuration.

The above explanation has mainly been about the application of the invention made by the present inventor to the pellet bonding method technology, which is the background field of application, but the invention is not limited thereto. How to pack pellets into a storage jig, or how to mount pellets directly onto a printed wiring board? It can be applied to all pickup methods used in 1.

[Effects of the Invention] The following is a brief explanation of the effects obtained by the representative inventions disclosed in Mokkou.

By pre-measuring the position of each pellet after the wafer has been diced and stretched, the pellet bonding method can use this measurement data to align the bonding tool to each pellet, even if the Even pellets can be reliably picked up and bonding can be performed appropriately.

[Brief explanation of drawings]

FIG. 1 is a process diagram showing a pellet bonding method according to an embodiment of the present invention, FIG. 2 is a schematic diagram showing an elongation position measuring device used therein, and FIG. 3 is a plan view showing a wafer before dynoning. Fig. 4 is a perspective view showing the sheet adhesion process, Fig. 5 is a plan view after dyeing, Fig. 6 is a plan view after mounting the jig, Fig. 7 is a perspective view showing the pellet pounding process, FIG. 8 is an enlarged partial sectional view showing the main part. l... Wafer, 2... Pellet, 2a... Good pellet, 2b... Defective pellet, 3... Defective product mark, 4... Sheet, 5... Jig, 6...・Wafer inspection data recording medium, 7... Pellet position data recording medium after sheet elongation, 8... Synthetic data recording medium, 9.
...Lead frame, 11...Wafer inspection process, 12
... Sheet adhesion process, 13... Dicing process, 1
4... Jig installation process, 15... Pellet position measurement process after sheet stretching, 16... Pellet ponding process (binqua, pull process), 20... Stretching position measuring device, 21. ...χY table, 22... Controller, 23... Television camera (imaging device), 24... Pattern recognition device, 30... Wire bonding device,
31...XY table, 32...controller,
33...Bonding head 7.D, 34...Ponding arm, 35...Ponding tool, 36...
Pinoceanopustage, 37... push-up bottle.

Claims (1)

[Claims] 1. A step of adhering a stretchable sheet to a plate-like object; a step of dividing the plate-like object into a plurality of pellets; a jig mounting step in which the plate-like object is held in a frame-shaped jig via a sheet; and a pickup step in which the pellets in the plate-like object held in the jig are sequentially peeled off from the sheet and picked up. , The pickup method is characterized in that the position of each pellet after the sheet is stretched after the jig mounting step is measured, and this measured position is used to carry out the pickup step. How to pick up. 2. The pickup according to claim 1, wherein when measuring the position of each pellet after the sheet is stretched, inspection data regarding the plate-like object and position data of the pellet before dividing are used. Method. 3. Hold a frame-shaped jig in which a plate-shaped object divided into a plurality of pellets is held through the sheet and move it in the XY direction while the elastic sheet is stretched. a table; a controller that controls the movement of the XY table; an imaging device that images the pellets on the XY table; and a position of each pellet after the sheet is stretched based on the imaging signal of the imaging device and the movement of the XY table. An extension position measuring device comprising: a recognition device that recognizes; and a stretching position measuring device.