JPH0878508A - Wafer holding plate - Google Patents

Abstract

PURPOSE: To protect a large diameter wafer against crack when it is handled or transferred by means of a wafer holding plate comprising a transparent board applied, on the surface thereof, with an adhesive having adhesive strength lowering upon irradiation with UV ray with holes being arranged at a pitch corresponding to that of a chip in the wafer. CONSTITUTION: A wafer holding plate 1 is coated, on the surface thereof, with an organic adhesive 2 having viscosity lowering upon heating and adhesive strength lowering upon irradiation with UV ray one or more small holes 4 are arranged in the wafer holding plate 1 at a pitch corresponding to that of a chip 5 in the wafer 3. The adhesive 2 is irradiated with ultraviolet ray in order to reduce adhesive strength between the back face of a diced chip 5 and the wafer holding plate 1. Furthermore, pressurized air 7 is fed from the back side of the plate 1 through the holes 4 to float the chip 5 slightly and a chip passed the characteristic test is handled by means of a dance bonder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer holding plate used for carrying and aligning a wafer after a wafer dicing process in a semiconductor manufacturing process.

In recent years, with the increase in diameter of wafers and the reduction in thickness, when handling wafers by a currently used handling robot, problems such as cracking of the wafer may occur.

Therefore, a wafer holding plate for handling which does not cause cracking of the wafer is provided even if the diameter of the wafer and the thickness thereof are further reduced.

[0004]

2. Description of the Related Art FIG. 5 is an explanatory view of a conventional example. In the figure, 3 is a wafer, 14 is a wafer carrier, 15 is a dicing frame, 16 is a tape, and 17 is a dicing blade.

Conventional wafer handling is shown in FIG.
A multi-stage wafer carrier 14 as shown in the perspective view on the left side of (a) and a cross-sectional view on the right side, and a handling cassette according to each purpose have been used.

[0006] In the future, as the diameter of wafers increases, the carrier for storing wafers will become larger, and the carrier for storing several tens of wafers at present will become larger and heavier.

Also, in the dicing process of cutting the wafer into chips, as shown in FIG. 5B, the dicing frame 15 used in the wafer mounter, the dicer, the ultraviolet irradiation, and the dice bonding is shown in FIG. As shown in c), when dicing the wafer 3 on the tape 16 loaded in the dicing frame 15, a distance Z is provided between the wafer 3 and the dicing frame 15 so that the dicing blade 17 does not contact the dicing frame 15. Since it is provided, the inner diameter thereof is larger than the diameter of the wafer 3 by several cm.

Further, a highly accurate sensor and several steps of processing are required for the alignment of the wafer 3 loaded on the dicing frame 15 during dicing.

[0009]

Therefore, in wafer handling, as the diameter of the wafer becomes larger and the wafer becomes thinner, the wafer bends, resulting in handling errors and wafer cracking.

Further, the size of the dicing frame becomes large, which is a major obstacle to downsizing of the above-mentioned apparatus, and a highly accurate sensor and processing of several steps are required for alignment during wafer dicing.

Further, it is difficult to store and carry the wafer if the wafer carrier is the same as the current system. The present invention
It is provided for the purpose of obtaining means for solving the above problems.

[0012]

FIG. 1 is a diagram for explaining the principle of the present invention. In the figure, 1 is a wafer holding plate, 2
Is an adhesive, 3 is a wafer, and 4 is a hole.

In order to solve the above problems, the wafer holding plate 1 is prepared for each wafer 3 which can be handled and aligned in common in the wafer dicing process and the subsequent dicing process. .

The wafer holding plate 1 has an adhesive on the surface thereof so as to be applied to ultraviolet ray irradiation for reducing the adhesive strength of the adhesive 2 in the dicing process, picking up dicing chips, and subsequent handling. , A transparent quartz plate or a plus rack plate having a large number of holes arranged corresponding to the pitch of the chips is used, and the shape is such that the wafer holding plates can be easily stacked.

That is, as shown in FIG. 1, an object of the present invention is to have an adhesive 2 whose adhesive strength is reduced by irradiation of ultraviolet rays on the surface thereof, and to arrange the adhesive 2 corresponding to the pitch of chips in the wafer 3. By using the wafer holding plate 1 made of a transparent substrate having holes 4 formed therein, and by having a fitting mechanism capable of superimposing a plurality of the transparent substrates on the outer periphery of the transparent substrate, This is achieved by providing an optically readable code number on the outer peripheral surface of the transparent substrate.

[0016]

When the wafer holding plate of the present invention is used in the dicing process as in the present invention, the strength of the wafer is substantially increased, and the wafer holding plate is provided with a stacking mechanism on the outer periphery thereof. Furthermore, by attaching a code number to the outer peripheral surface, automatic handling is consistently and easily performed, the conventional large-sized and heavy-handling wafer carrier is not required, and the process is shortened.

[0017]

2 to 4 are explanatory views of some embodiments of the present invention. In the figure, 1 is a wafer holding plate, 2
Is an adhesive, 3 is a wafer, 4 is a hole, 5 is a chip, 6 is a dicing plate, 7 is air (compressed air), 8 is a collet, 9 is an alignment stage, 10 is a cylindrical guide, 11 is a reference number, and 12 is A carrier table 13 is a transfer robot.

FIG. 2 is an explanatory view of the first embodiment of the present invention. The wafer holding plate 1 of the present invention, as shown in FIG. 2, is slightly larger than the 8-inch wafer 3 used.
It is made of a transparent quartz plate having a diameter of 1 cm and a thickness of 5 mm or a plastic plate. An adhesive 2 is applied to the surface of the wafer holding plate 1 in advance by using a spinner, and the adhesive 2 is made of an organic substance whose viscosity is reduced by heating and whose adhesive strength is reduced by ultraviolet irradiation. It can be washed off with boiling water or an organic solvent.

The wafer holding plate 1 is arranged corresponding to the pitch of the chips 5 in the wafer 3.
Individual or more small holes 4 are opened. The wafer 3 to be diced is placed on the wafer holding plate 1. Then, the wafer holding plate 1 is set as it is on the dicing plate 6 of the dicer, and chips are cut out at a predetermined pitch with a dicing blade.

Then, the wafer holding plate 1 is set in an ultraviolet irradiator, and the transparent wafer holding plate 1 is irradiated from the back side, and the adhesive 2 on the transparent wafer holding plate 1 is irradiated with ultraviolet rays. The adhesive force with the wafer holding plate 1 is reduced.

Then, pressurized air 7 is sent from the back surface of the wafer holding plate 1 through the holes 4 to float the chips 5 a little, and one good chip 5 which has passed the arbitrary characteristic test by using the collet 8 is obtained one by one. Vacuum suction and handle to die bonder. In this way, only good chips 5 are sequentially adsorbed and transferred to the die bonder.

FIG. 3 is an explanatory diagram of the second embodiment of the present invention. A position adjusting mechanism is added so that the wafer holding plates 1 can be stacked vertically.
As shown in FIG. 3 (a), a concave step is formed on the side of the wafer holding plate 1 on which the wafer 3 is mounted and a convex step is formed on the back surface as a fitting part. The wafer holding plates 1 are stacked in multiple layers in combination.

FIG. 3B shows an alignment mechanism for aligning the wafer 3. When the alignment stage 9 is automatically chucked along the cylindrical guide 10, the wafer 3 is relatively aligned with the alignment stage 9. Set to none.

Therefore, a cylindrical guide 10 as shown in a plan view of FIG. 3 (c) is used. FIG. 4 shows a wafer holding plate 1 for automatic identification of the wafer 3. Used for process control of the wafer 3 mounted on the wafer holding plate 1 and automatically transferring the wafer 3
The code number of is identified by an optical reader and input to the dicer number identification machine, and based on the non-defective chip test map of the primary test, only non-defective chips are picked up and supplied to the die bonder as described above.

Further, as shown in the plan view of FIG. 4B and the sectional view of FIG. 4C, the transfer robot 13 is used to recognize the code number 11, and the wafer holding plate 1 is arranged in any order. It can also be transported and transshipped.

[0026]

As described above, according to the present invention,
When handling or transporting a large-diameter wafer, it is possible to suppress the occurrence of handling mistakes, wafer cracks, and the like, and to reliably handle the wafer, which greatly contributes to the performance improvement of the semiconductor manufacturing apparatus.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 is an explanatory diagram of a first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a third embodiment of the present invention.

FIG. 5 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 In the figure 1 wafer holding plate 2 adhesive 3 wafer 4 hole 5 chip 6 dicing plate 7 air 8 collet 9 alignment stage 10 cylindrical guide 11 code number 12 carrier table 13 transfer robot

Claims (3)

[Claims] 1. A wafer comprising a transparent substrate having an adhesive whose adhesive strength is reduced by irradiation of ultraviolet rays on its surface and having holes arranged corresponding to chips in the wafer. Holding plate. 2. The wafer holding plate according to claim 1, further comprising a fitting mechanism capable of superposing a plurality of the transparent substrates on an outer periphery of the transparent substrate. 3. The wafer holding plate according to claim 1, wherein an optically readable code number is attached to the outer peripheral surface of the transparent substrate.