JPS62204542A - Method and apparatus for dividing wafer - Google Patents

Abstract

PURPOSE:To divide a wafer in high reliability by picking up only a pellet of a position which is subjected to spot irradiation to prevent the wafer from damaging due to the movement of the wafer. CONSTITUTION:A transparent plastic tape 9 which reduces its bonding strength by irradiation of ultraviolet rays is bonded on a frame 8, and its adhesive surface is coated with a wafer 2 in which an element forming surface is disposed upside. After a dicing is completed, the frame 8 is fed to an irradiation unit 5. The unit 5 has a framelike XY table 15 having an irradiation window 14 and an ultraviolet irradiation lamp 16. The position of the wafer 2 is detected, and spot irradiation of ultraviolet rays 4 is selectively performed by means of the lamp 16. After the irradiation of the ultraviolet rays 4 is performed predetermined times, the frame 8 is fed to a pickup unit 7. A lifting pin 18 sequentially moves the back surface of the wafer 2 on which spot irradiation of the rays 4 is performed by means of the unit 5 to protrude only good pellets 6. They are sucked by vacuum by means of a collet 19.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a technique commonly and effectively used for dividing semiconductor wafers in the manufacture of semiconductor devices.

[Conventional technology]

Regarding semiconductor wafer dividing technology, see, for example, Kogyo Kenkyukai Co., Ltd., "IC Mounting Technology" (Japan Microelectronics Association), January 15, 1980, P1.
00 to PIOI, and here, after dividing the wafer on a plastic adhesive sheet and stretching the sheet, the pellet portion is pushed up from the back side of the sheet using a push-up tool, and then adsorbed from above with a collet. The technology to do this is introduced.

The present inventor studied wafer dividing technology. Although the following is not a publicly known technique, it is a technique studied by the present inventor, and its outline is as follows.

That is, it is known that when dividing a wafer, dicing and pick amplifier are performed while the wafer is adhered to an adhesive tape stretched over a frame member made of an aluminum alloy or the like.

By the way, when picking up wafers, if the adhesive strength of the adhesive tape is too strong, the pellets being picked up will not easily separate from the adhesive tape, which may deform the adhesive tape and cause misalignment of the entire wafer. be.

For this reason, UV tape (UltraV
One possibility is to attach the wafer to a transparent plastic tape called iolet tape, whose adhesive strength can be reduced by irradiation with ultraviolet light.

In other words, maintain strong adhesive strength during dicing.
Immediately before pick-up, the back side of the UV tape is irradiated with ultraviolet rays to reduce the adhesive strength and make it easier to pick up the pellets.

[Problem that the invention seeks to solve]

However, in the above technique, the adhesive strength of the entire adhesive surface of the UV tape decreases due to ultraviolet irradiation, so when picking up a pellet, adjacent pellets may also separate from the adhesive surface at the same time. In particular, the TBG region (Testing [!Iem
If a test element formation area called an ent group is provided, there is a risk that the TBG portion, which is diced independently of the pellet, may move as the pellet is picked up and damage other wafer surfaces. be.

The present invention has been made focusing on the above problems,
The purpose is to provide a reliable wafer splitting technique.

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 for solving problems]

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

That is, a wafer is diced while being adhered to the adhesive surface of a translucent tape whose adhesive strength decreases when irradiated with a predetermined light, and a predetermined light is selectively applied only to predetermined areas from the back side of the adhesive surface of the tape. This method performs spot irradiation and picks up only the pellets in the area where the spot irradiation was performed.

[Effect]

According to the above-mentioned means, by spot irradiation with the predetermined light,
Because it is possible to reduce the adhesive strength of only the necessary parts of the tape's adhesive surface while maintaining strong adhesive strength on other parts, it is possible to pick up only the necessary pellets without affecting other parts. It can be easily done without.

[Embodiment 1] FIG. 1 is a schematic diagram showing a wafer dividing apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view showing a wafer attached to a frame.

The wafer division bag rIt1 of the first embodiment includes, for example, a dicing section 3 for cutting the wafer 2, as shown in FIG.
It consists of an irradiation section 5 that irradiates ultraviolet rays 4 and a pickup section 7 that takes out pellets 6.

The wafer 2 is provided in a frame 8 as shown in FIG. 2, and this frame 8 has a UV tape 9 (Ultra
Vio! eL Tape), that is, a transparent plastic tape whose adhesive strength decreases when irradiated with ultraviolet rays 4 is stretched, and the wafer 2 is attached to the adhesive surface of the UV tape 9 with the surface on which the elements are formed facing upward. ing.

In the wafer 2 of the first embodiment, a large number of pellets 6 having a memory capacity of, for example, 1 megabyte are formed as one unit in the vertical and horizontal directions, and the rectangular adjacent area of each pellet 6 has a TEG section. 10 are formed. On the surface of this TEG section 10, a large number of alignment marks, inspection elements, etc. (not shown) are formed. Here, for example, the test element is formed in the same process and with the same structure as a predetermined element formed on the pellet 6, and by testing the test element, the pellet 6
It is possible to indirectly inspect the formation state of the upper element.

Specifically, for this TBG portion, for example, in a pellet in which a memory element having a capacity of about 1 megabyte is formed, the Belen Hn region has five vertical cranes.

If the width is about 10++■, a TEC region with a width of about 1.5 mm is required adjacent to the short side of the pellet.

The frame 8 is moved fi! to a predetermined position on the dicing stage 11 of the dicing unit 3 by a transfer means (not shown).
Once placed, the disk-shaped dicing blade 12 descends to a predetermined position on the wafer 2 while rotating at high speed, and further moves in the horizontal direction to perform dicing of the wafer 2.

Here, the dicing of this embodiment is not so-called full dicing in which the front surface of the wafer 2 is completely separated from the back surface, but a cut is formed from the front surface to the vicinity of the back surface, and each wafer portion is slightly separated from the back surface portion. are connected,
This is so-called semi-dicing.

Further, dicing is performed for each pellet 5 and TEG section 10 along the boundary area thereof. Therefore, after dicing, the pellet 6 and the TEC part IO are connected in a block state.

After dicing is completed as described above, the frame 8
is sent to the irradiation section 5.

The irradiation unit 5 is a frame-shaped XY with an irradiation window 14 in the center.
It has a table 15 and an ultraviolet irradiation lamp 16 provided below the XY table 15. The irradiation window 14 of the XY table 15 is opened in a size that approximately corresponds to the inner peripheral edge of the frame member 8a, and the frame 8 is placed on the XY table 15 so as to match this! 3! z will be done. Therefore, the back side of the UV tape 9 adhered to the wafer 2 is exposed downward from the irradiation window 14 of the XY table 15.

The ultraviolet ray irradiation lamp 16 is installed so that its irradiation lens 16a faces the irradiation window 14 of the XY table 15 located above from an oblique direction, and can irradiate a spot of ultraviolet 4 in the form of a beam onto a predetermined position of the irradiation window 14. It has a structure.

When the frame 8 is placed on the XY table 15, a control unit (not shown) detects the position of the wafer 2, and based on the detected information, the XY table 15 operates to
Ultraviolet rays 4 are selectively and sequentially spot-irradiated onto predetermined positions on the back surface of the tape 9 by an ultraviolet irradiation lamp 16.

In the first embodiment, this spot irradiation region is a portion of the UV tape 9 corresponding to the back surface of the non-defective pellet 6 that has been detected in advance. A short time is sufficient for the irradiation time of the ultraviolet rays 4 at one location, and after such irradiation with the ultraviolet rays 4 has been performed a predetermined number of times, the frame 8 is sent to the pickup section 7.

In the pickup section 7, a push-up pin 18 is located below the frame 8 fixed by the fixing means 17. The push-up pins 18 sequentially move over the back surface portions of the wafer 2 that have been spot-irradiated with the ultraviolet rays 4 by the irradiation unit 5, and push up only the pellet portions, that is, the good pellets 6.

By this pushing-up operation, the pellet 6 separates from the adhesive surface of the UV tape 9 and is vacuum-adsorbed by the collet 19 located above the pellet 6. At this time, in the first embodiment,
Because only the portion of the pellet 6 that is to be picked up has decreased adhesive strength due to spot irradiation with ultraviolet 4,
The pellet 6 is easily separated from the U-tape 9 and vacuum-adsorbed onto the collet 19. On the other hand, other portions of the UV tape 9 that are not picked up, ie, portions of the UV tape 9 corresponding to the TEG portion 10 or the defective pellet portion, still maintain strong adhesive strength. Therefore, these T
Even when the collet 19 picks up the non-defective pellet 6 portion, the BG portion 10 remains attached at a predetermined position on the UV tape 9 due to strong adhesive force. Therefore, damage to the wafer 2 due to movement of the TBG section 10 or defective pellets can be prevented.

In addition, only the part of the good pellet 6 with reduced adhesive strength is selectively picked up, and the other parts are picked up with strong adhesive strength.
Since the pellets remain on the V-tape 9, it is possible to prevent the entire wafer 2 from shifting on the UV tape 9, and it is possible to pick up the pellets 6 at an accurate position, thereby preventing pick-up mistakes.

As described above, according to this embodiment, the following effects can be obtained.

(1) By selectively spot-irradiating ultraviolet light 4 only on the part corresponding to the good pellet 6 on the back side of the UV tape 9 using the ultraviolet irradiation lamp 16, the parts of the wafer 2 other than the good pellet 6 have strong adhesive strength. U while maintaining
Since they are left on the V-tape 9, only good pellets 6 can be easily picked up.

(2) According to (1) above, only the good pellets 6 can be picked up while the TEG section 10 or the defective pellet remains strongly attached to the UV tape 9. Damage to the wafer 2 due to movement of defective pellets can be prevented.

(3) According to (11) above, when picking up only the good pellets 6 from the wafer 2, since the other parts are adhered to the UV tape 9 with strong adhesive force, the entire position of the wafer 2 may be misaligned. It is possible to prevent pickup mistakes.

(4), above +11. (21 and (3)) makes it possible to achieve highly reliable wafer division.

[Embodiment 2] FIG. 3 is a schematic diagram showing a pickup section applied to a wafer dividing apparatus according to another embodiment of the present invention.

In the second embodiment, the pickup section 21 also performs spot irradiation with ultraviolet 4 rays.

That is, the pickup section 21 of the second embodiment has a push-up pin 22, and the push-up pin 22 has a built-in ultraviolet irradiation lamp 23. The push-up pin 22 is made of a translucent pin body 24 made of quartz or the like.
It has a large number of pin parts 25 protruding from the pin part 25, and the ultraviolet rays 4 emitted from the built-in ultraviolet irradiation lamp 23 pass through the pin body 24 and are further directed toward the pin parts 25, that is, in the pushing up direction. The structure allows for spot irradiation.

On the other hand, in the frame 28, a UV tape 29 is stretched on a frame member 28a made of an aluminum alloy as in the first embodiment, and a wafer 32 is attached on the adhesive surface of the UV tape 29 with its circuit forming surface facing upward. However, unlike the wafer 2 of Example 1, the wafer 32 of Example 2 is TF.

Part 0 10 is not formed.

The pickup unit 21 is provided with the frame in a state where dicing has been completed on the second day, and quality information regarding the pellets 36 of the wafer 32 is inputted in advance to a control unit (not shown) of the pick amplifier unit 21. The frame 28 is sequentially moved in the XY predetermined directions based on the quality information of the control unit, and the push-up pins 22 are selectively installed in the zero-order push-up pins 22 located directly below the non-defective pellets 36a in the wafer 32. The ultraviolet ray irradiation lamp 23 then irradiates a spot of ultraviolet 4 onto the back side of the adhesive surface of the UV tape 29 in a portion of a predetermined non-defective pellet 36a.

By this spot irradiation, the UV tape 2 of the irradiated area
The adhesive strength of No. 9 is significantly reduced.

After the spot irradiation is completed, the push-up pin 22 performs a push-up operation toward the direction of the spot irradiation, and the good pellet I-36a in the irradiated area is separated from the UV tape 29, and the collet is located above the good pellet 36a. (
(not shown) is vacuum-adsorbed.

At this time, as in Example 1, only the portion of the pellet to be picked up, that is, the portion of the good pellet 36a, has its adhesive strength reduced by the spot irradiation with the ultraviolet 4, so the good pellet 36a is not pushed up by the push-up pin. 22
By pushing up the UV tape 29, it is easily separated from the adhesive surface of the UV tape 29. In addition, other parts that are not subjected to big amplification, such as the part of the defective pellet 36b, are exposed to ultraviolet 4
Since no irradiation is performed, the UV tape 29 is adhered to the UV tape 29 while maintaining its strong adhesive strength.

Therefore, when picking up only the good pellets 36a, the pick-up operation can be performed without affecting the adjacent wafer portions such as the defective pellets 36b.

In this way, the same effects as in the first embodiment can be obtained in the second embodiment as well.

Furthermore, according to the second embodiment, since the push-up pin 22 has the ultraviolet irradiation lamp 23 built-in, it is possible to perform the ultraviolet 4 irradiation process and the pick-up process with the same mechanism, and the transfer of the frame 28, etc. It is possible to rationalize and perform efficient wafer division.

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. For example, in each of the embodiments, so-called semi-dicing, in which cuts are formed along the boundaries of each wafer part to maintain a connected state, has been described; So-called full dicing, in which the wafer is divided into independent parts, may also be used.

In the above explanation, the invention made by the present inventor was mainly applied to its field of application, which is the division of wafers used in the manufacture of semiconductor devices, but the present invention is not limited to this, and other It may also be a wafer used for manufacturing electronic devices.

〔Effect of the invention〕

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

That is, a wafer is diced while being adhered to the adhesive surface of a translucent tape whose adhesive strength decreases when irradiated with a predetermined light, and a predetermined light is selectively applied only to predetermined areas from the back side of the adhesive surface of the tape. By performing spot irradiation and picking up only the pellets in the area where the spot irradiation was performed, the tape on the part of the wafer that is not being picked up can maintain strong adhesive strength, so the wafer can be Damage due to misalignment or movement of wafer parts can be prevented, and wafer division can be performed with high reliability.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a wafer dividing apparatus which is an embodiment of the present invention, FIG. 2 is a plan view showing a frame with a wafer attached thereto used in this embodiment, and FIG. FIG. 2 is a schematic diagram showing a pickup section applied to a wafer dividing apparatus according to an embodiment of the present invention.

Claims (1)

[Claims] 1. Dice the wafer with the wafer adhered to the adhesive surface of a translucent tape whose adhesive strength decreases when irradiated with a predetermined light, and select from the back side of the adhesive surface of the tape. A wafer dividing method in which a spot of predetermined light is irradiated only on a predetermined region, and only pellets in the region where the spot irradiation is performed are picked up. 2. The wafer dividing method according to claim 1, wherein the spot irradiation of the predetermined light is performed from an oblique direction with respect to the back surface of the tape. 3. The wafer dividing method according to claim 1 or 2, wherein the spot irradiated light is ultraviolet light. 4. A dicing mechanism that dices a wafer with the wafer adhered to the adhesive surface of a translucent tape whose adhesive strength decreases when irradiated with a predetermined light, and an arbitrary dicing mechanism on the back side of the tape to which the wafer is adhered an irradiation mechanism that performs spot irradiation of a predetermined light onto a predetermined region selected in the above, and a pickup mechanism that includes a pick-up pin that pushes up the pellet at the region where the spot irradiation of the predetermined light has been performed from the back side of the adhesive surface of the tape. A wafer dividing device comprising: 5. The wafer dividing apparatus according to claim 4, wherein the irradiation mechanism is a light source that irradiates a spot of predetermined light from an oblique direction onto an irradiated area on the back side of the adhesive surface of the tape. 6. The wafer dividing apparatus according to claim 4, wherein the irradiation mechanism has an integral structure with a pickup pin. 7. The wafer dividing apparatus according to claim 4, 5 or 6, wherein the light spot irradiation means is an ultraviolet spot irradiation means.