JP2001035815A - Dicing-oriented adhesive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a chip from being destroyed by electrostatic charges in the case of its pickup and make burnable a dicing-oriented adhesive film after the use thereof, by forming on a film-form supporter having a specific tensile elastic-modulus an antistatic agent and an adhesive agent layer in this order. SOLUTION: A film-form supporter is the one having a tensile elastic-modulus of 5-20 kgf/mm2 wherein the number of its constituent layers is not smaller than three and it has the outermost layer made of a crystalline polyolefine and the inner layer made of a low crystalline polyolefine. As the crystalline polyolefine, there is used preferably a low-density polyethylene, linear low- density polyethylene, polypropylene, or the mixtures thereof. As the low crystalline polyolefine, there is used the macromolecule of a comparably low molecular weight or the like wherein an amorphous poly-α-olefine, etc., are copolymerized with each other. As an antistatic layer, there is used preferably the crosslinked copolymer having a carboxylic group and a quarternary ammonium base. As an adhesive agent layer, an acrylic adhesive agent is used preferably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a silicon wafer,
The present invention relates to a dicing adhesive film for sticking and holding a wafer when a compound wafer or the like is cut and separated into chips.

[0002]

2. Description of the Related Art A semiconductor wafer made of silicon, gallium arsenide, or the like is cut and separated (diced) into small pieces such as IC chips after forming a fine circuit, and is transferred to the next die bonding step. At this time, each step of dicing, expanding, pickup, and die bonding is performed while the semiconductor wafer is pasted on an adhesive material such as a film, sheet, or tape to which an adhesive has been applied in advance. In this dicing process, a thin grindstone rotating at a high speed of tens of thousands of revolutions per minute moves while cutting the wafer, so that a large peeling force is applied to the wafer and the cut chips,
In order to counter this, an adhesive film having a necessary adhesive force (a material form such as a film, a sheet, or a tape is used depending on the use, but hereinafter, a film is used as an example) is used. In the die bonding process after dicing, the chip normally attached to the adhesive film is picked up from the back of the adhesive film by vacuum suction using a collet together with pushing up with a needle. There is a demand for a film having an adhesive strength that is not so strong that it can be peeled off, and an adhesive film suitable for the purpose has been supplied. However, since the adhesive film is an insulator, there has been a problem that static electricity is generated at the time of sticking or peeling, and the circuit is destroyed by the electrification of the semiconductor wafer. Further, polyvinyl chloride is generally used for the base film so that the adhesive film can be expanded in the expanding step, and there has been a problem of disposal treatment.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and in a die bonding process after dicing a semiconductor wafer, chip destruction due to static electricity when picking up chips is prevented, and An object of the present invention is to provide an adhesive film for dicing that can be incinerated.

[0004]

According to the present invention, an antistatic layer and an adhesive layer are formed in this order on a film-like support having a tensile modulus of elasticity of 5 to 20 kgf / mm ^2. This is achieved by using an adhesive film for dicing.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The film-like support used in the present invention is not particularly limited as long as it has a tensile modulus of 5 to ²⁰ kgf / mm ^2. Low crystalline polyolefin 3
It is preferable to use a support having more than two layers, since the strain due to plastic deformation is reduced, and a support extending uniformly in all directions can be obtained. That is, since the low-crystalline polyolefin layer of the inner layer does not remain strain even if it is plastically deformed, when compared with a support made of only crystalline polyolefin having the same thickness, the portion where the strain occurs is reduced, and the difference in elongation is reduced. Less support. In such a multilayer structure of three or more layers, the thickness of the low-crystalline polyolefin is 10 to 1
80 μm, and the thickness of the crystalline polyolefin is 10 to 3
It is preferably 0 μm. Further, the thickness of the entire support is preferably from 30 to 200 μm, more preferably from 60 to 150 μm.

As the material used for the support, low-density polyethylene, linear low-density polyethylene, polypropylene or a mixture thereof is preferably used as the crystalline polyolefin. As the low-crystalline polyolefin, it is preferable to use an amorphous poly-α-olefin (a relatively low molecular weight polymer obtained by copolymerizing propylene with ethylene, butene-1, or the like) or the like. Extrusion with a T die or a die for inflation is preferable. Machined. In addition, the support may include an antioxidant generally used as necessary,
It may contain additives such as a lubricant, an antioxidant, and a coloring agent.
In order to further obtain the adhesion with the antistatic layer, corona treatment,
Surface treatment such as plasma treatment may be performed. In order to prevent blocking, a back surface treatment agent or the like may be applied. Further, a release film (separator) may be laminated on the side having the adhesive in order to respond to use as a sheet piece. Tensile modulus of elasticity of film support is 5k
If it is less than gf / mm ^2, there is a problem that the holding of the chip becomes insufficient and chipping occurs during dicing. When the tensile modulus exceeds 20 kgf / mm ² ,
During expansion or pick-up, there is a problem that the film is insufficiently deformed and the peeling force is increased.

As the pressure-sensitive adhesive layer, an acrylic pressure-sensitive adhesive, a natural rubber-based pressure-sensitive adhesive, a synthetic rubber-based pressure-sensitive adhesive, a silicone rubber-based pressure-sensitive adhesive or the like is used, but the adherend such as a semiconductor wafer is hardly contaminated. Acrylic adhesives are preferred. Also various additives, such as tackifiers, antioxidants, crosslinking agents,
Separating agents, surfactants, emulsifiers and the like may be added as necessary. The thickness of the pressure-sensitive adhesive layer is preferably 0.1 to 25 μm. If it is less than 0.1 μm, the required initial adhesive strength cannot be obtained, and if it exceeds 25 μm, the peeling force at the time of pickup becomes too large, and it becomes difficult to peel.

The antistatic layer is preferably a crosslinkable copolymer having a carboxyl group and a quaternary ammonium base, and preferably has a thickness of 0.05 to 1.0 μm.
As such an antistatic agent, for example, Bondip P
A-100 (trade name of Konishi Co., Ltd.) or the like can be used. When the antistatic layer is a low molecular weight substance such as a surfactant, the pressure-sensitive adhesive layer peels due to cohesive failure or bleeds on the surface to cause contamination of the adherend. Similarly, when a surfactant is blended with the resin layer or the pressure-sensitive adhesive, it bleeds on the surface to contaminate the adherend, which is not preferable. If the thickness of the antistatic layer is less than 0.05 μm, good antistatic performance cannot be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
It should be noted that the present invention is not limited by these examples.

Example 1 [Preparation of Support] Polypropylene (shawomer FA432, MFR 9.0 g /
10 minutes: low-crystalline polyolefin (CAP350, MFR 14.0 g / 10) using Showa Denko KK
Using Ube Industries, Ltd. (trade name), a support having a three-layer structure in which crystalline polyolefin is laminated on both sides of a low-crystalline polyolefin layer, and having a total thickness of 1 by a multilayer T-die method.
It was prepared so as to be 00 μm (crystalline polyolefin 10 μm, low crystalline polyolefin 80 μm). [Preparation of antistatic layer] A crosslinkable copolymer having a carbonyl group and a quaternary ammonium salt group was obtained using an acrylic copolymer (Bondip PA-100: trade name of Konishi Co., Ltd.) as a polymer. It was applied to one surface of the support thus prepared, and was prepared so that the dry thickness was 0.3 μm. [Formation of Adhesive Layer] To 100 parts by weight of a copolymer consisting of 87 parts by weight of butyl acrylate, 10 parts by weight of acrylonitrile and 3 parts by weight of hydroxyethyl acrylate, 3 parts by weight of tolylene diisocyanate was added to obtain an acrylic pressure-sensitive adhesive. . Next, the pressure-sensitive adhesive was applied on the antistatic layer obtained above, and the dry thickness was 5 μm to obtain a dicing pressure-sensitive adhesive film of the present invention.

Example 2 An adhesive for dicing of the present invention was prepared in the same manner as in Example 1 except that polyethylene (SHOLEX F141, MFR 4.0 g / 10 min: trade name of Showa Denko KK) was used as the crystalline polyolefin. A film was obtained. Example 3 An adhesive film for dicing of the present invention was obtained in the same manner as in Example 1 except that the support was made of polyethylene (Showrex F141: manufactured by Showa Denko) having a thickness of 100 μm by an inflation method.

Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that the support was made of polypropylene (Showaromer FA432: trade name of Showa Denko KK) having a thickness of 100 μm by the T-die method. Comparative Example 2 A sample was prepared in the same manner as in Example except that the antistatic layer was not provided. Comparative Example 3 A cationic surfactant (Elegan 264W) was used for the antistatic layer.
AX: Nippon Oil & Fats Co., Ltd.)
A sample was prepared in the same manner as described above.

Measurement Method [Measurement of Tensile Modulus] The measurement method is based on JIS K711.
According to 3 (Plastic tensile test method), a tape-shaped test piece (10 mm in width) was gripped, and the jig distance was 50 mm.
It was measured by stretching at a speed of 500 mm / min. [Evaluation of Expandability] A semiconductor wafer was attached to the prepared dicing adhesive film sample, and dicing was performed. Thereafter, expansion was performed in an expanding step, and it was evaluated whether or not expansion was possible uniformly. A sample that could be uniformly expanded was evaluated as ○, and a sample that was unevenly expanded was evaluated as ×. [Evaluation of chip charge amount and chip destruction] The semiconductor chip after dicing was picked up, and the chip charge amount immediately after peeling was measured. After the measurement of the charge amount of the chip, the electrostatic damage of the chip was evaluated.場合 indicates that it was not destroyed, and x indicates that it was destroyed. [Evaluation of Chip Contamination] The prepared dicing adhesive film was adhered to a semiconductor wafer and treated at 80 ° C. for 1 hour. Thereafter, the adhesive film was peeled off, and the surface state of the semiconductor wafer was observed.も の indicates that the surface was not contaminated, and X indicates that the surface was contaminated by cloudiness or the like.

[0014]

[Table 1]

[0015]

The pressure-sensitive adhesive film for dicing of the present invention comprises:
Since the antistatic agent and the pressure-sensitive adhesive layer are formed on the support, it is possible to prevent the semiconductor chip from being charged due to the generation of static electricity at the time of sticking or peeling, thereby preventing the circuit from being broken. In addition, since the support is a laminate of three or more layers using a crystalline polyolefin for the outermost layer and a low-crystalline polyolefin for the inner side, distortion due to plastic deformation upon expansion is small, and good characteristics are obtained. Furthermore, since the support is a polyolefin, it can be incinerated, and the disposal can be facilitated as compared with a conventional PVC-based dicing adhesive film.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F100 AK03A AK03D AK03E AK07 AK25 AK25G AK27G AK51G AL01B BA05 BA07 BA10A BA10C BA13 BA26 CB05G EJ05B GB43 JA11A JA11D JA11E JG03B JK07A JL04 JA01 A04A03A04 GA08 KA09 NA20

Claims (3)

[Claims] 1. An adhesive film for dicing, comprising an antistatic layer and an adhesive layer formed in this order on a film support having a tensile modulus of 5 to 20 kgf / mm ² . 2. The pressure-sensitive adhesive film for dicing according to claim 1, wherein the support comprises at least three layers, two outermost layers are crystalline polyolefins, and the inner layer is one or more low-crystalline polyolefins. 3. The pressure-sensitive adhesive film for dicing according to claim 1, wherein the antistatic layer is a crosslinkable copolymer having a carboxyl group and a quaternary ammonium group.