JP2011057793A - Adhesive composition, and sheet for forming semiconductor protective film using the same - Google Patents

Abstract

A semiconductor wafer protective film forming sheet that can form a protective film having excellent flatness and cutting characteristics and free from color unevenness after curing, and an adhesive composition that can realize such a protective film and sheet. Offer things.
SOLUTION: (A) Phenoxy resin, (B) Epichlorohydrin copolymer type epoxy resin having aromatic ring in skeleton, (C) Epoxy resin not containing aromatic ring in skeleton, (D) Curing of epoxy resin An adhesive composition containing a predetermined amount of a catalyst, (E) an inorganic filler, and (F) a polar solvent having a boiling point of 70 to 180 ° C. and a surface tension of 20 to 30 dyne / cm at 25 ° C.
[Selection figure] None

Description

  The present invention relates to a protective sheet for a semiconductor wafer for forming a film (film) that protects the back surface of a wafer when dicing a semiconductor wafer, and particularly has excellent flatness, excellent cutting characteristics with a dicer, and poor appearance. It is related with the sheet | seat for semiconductor protective film formation which can form the protective film which does not generate | occur | produce unevenness on the cured | curing material surface.

  In order to reduce the mounting area of the semiconductor chip, a flip chip connection method is used. In this connection method, usually, (1) a circuit and connection bumps are formed on the surface of a semiconductor wafer, (2) the back surface of the semiconductor wafer is polished to a predetermined thickness, and (3) the semiconductor wafer is diced to form a semiconductor chip. (4) After the chip is connected to the substrate with the circuit formation surface facing the substrate side, (5) resin sealing or the like is performed to protect the semiconductor chip.

  However, in the polishing step (2), minute streak-like scratches are formed on the back surface of the chip, which may cause cracks after the dicing step or packaging. Therefore, a protective film (a protective film for a chip) is formed on the back surface after the polishing step (2) so that even if such a streak is generated in the polishing step, the subsequent steps are not adversely affected. Furthermore, as a sheet for forming such a protective film, a sheet comprising a release sheet and a protective film forming layer formed on the release surface is proposed (Patent Document 1, Patent Document). 2).

JP 2002-280329 A JP 2004-260190 A

  On the other hand, in the dicing process, it is known that the wafer may be damaged (hereinafter referred to as “chipping”) due to vibration of the rotary blade or the like.

  The chip protective film is also expected to prevent chipping in the dicing process. However, if the protective film is not flat, a gap is formed between the dicing film and the chip protective film, and the dicing film And a portion where the protective film is not in contact with each other occurs. Due to this non-flatness of the protective film, the air layer is unevenly applied between the chip protective film and the dicing film, resulting in a problem that the rotary blade is vibrated when the wafer is cut and the wafer is further damaged. is there.

  The above protective film for chips writes a symbol for identification with a laser mark or the like. However, if color unevenness occurs on the surface of the cured product, a difference in surface gloss will occur, causing a recognition error when reading the symbol after image processing. Occurs, causing the line to stop.

  Therefore, the present invention provides a semiconductor wafer protective film forming sheet that can solve such problems and can form a protective film that is excellent in flatness, cutting characteristics, and adhesiveness, and that is free from color unevenness after curing. In addition, an object of the present invention is to provide an adhesive composition capable of realizing such a protective film and sheet.

In order to achieve the above object, the present invention provides the following adhesive composition and semiconductor wafer protective film forming sheet.
[1] (A) Phenoxy resin 100 parts by mass (B) Epichlorohydrin copolymer type epoxy resin having an aromatic ring in the resin skeleton 4 to 150 parts by mass (C) Epoxy resin having no aromatic ring in the resin skeleton 1 to 50 parts by mass (D) epoxy resin curing catalyst effective amount, and (E) inorganic filler 5 to 5 parts by mass with respect to 100 parts by mass of the total amount of the components (A), (B), (C) and (D). 900 parts by mass (F) Polar solvent having a boiling point of 70 to 180 ° C. and a surface tension of 20 to 30 dyne / cm at 25 ° C. The components (A), (B), (C), (D) and (E) An adhesive composition containing 10 to 300 parts by mass with respect to 100 parts by mass of the total amount.
[2] The epoxy resin having no aromatic ring in the resin skeleton of the component (C) is an alicyclic epoxy resin having two or more epoxy groups and a weight average molecular weight of 3000 or less. Adhesive composition.
[3] The adhesive composition according to [1] or [2], wherein the epoxy resin curing catalyst of component (D) is dicyandiamide.
[4] The adhesive composition according to any one of [1] to [3], wherein the solvent of the component (F) is at least one selected from cyclohexanone, butyl acetate, and methyl ethyl ketone.
[5] A base film and a composition obtained by removing the solvent of the component (F) from the adhesive composition according to any one of [1] to [4], and formed on one side of the base film A semiconductor wafer protective film-forming sheet having a coating.

  According to the adhesive composition of the present invention, a semiconductor wafer protective film forming sheet capable of achieving the above object can be produced.

  According to the protective film-forming sheet of the present invention, a protective film having excellent flatness can be easily formed on the non-circuit surface of the semiconductor wafer. As a result, a gap is hardly generated between the dicing film and the protective film, and non-uniform vibration is not generated in the rotary blade during dicing. Therefore, chipping is unlikely to occur and a highly reliable semiconductor device can be obtained with high yield. Further, since there is little unevenness of the surface color after curing, image identification after laser marking is easy, and high productivity can be obtained.

  Hereinafter, the present invention will be described in more detail. In this specification, “weight average molecular weight” (sometimes abbreviated as Mw) means a polystyrene-reduced weight average molecular weight measured by gel permeation chromatography.

<Adhesive composition>
-(A) Phenoxy resin-
The phenoxy resin used as the component (A) in the present invention (hereinafter also abbreviated as “component (A)”) is a high molecular weight bisphenol A type epoxy resin or bisphenol F type epoxy resin, and has a weight average molecular weight. Usually 10,000 or more, preferably 10,000 to 200,000, particularly preferably 12,000 to 100,000.

  Examples of phenoxy resins include bisphenol type epoxy resins derived from epichlorohydrin and bisphenol A or bisphenol F. As such phenoxy resins, trade names PKHC, PKHH, PKHJ (all manufactured by Sakai Chemical Co., Ltd.), bisphenol A, bisphenol F mixed type trade names Epicoat 4250, Epicoat 4275, Epicoat 1255HX30, Epicoat 5580BPX40 using brominated epoxy (All manufactured by Nippon Kayaku Co., Ltd.), bisphenol A type trade names YP-50, YP-50S, YP-55, YP-70 (all manufactured by Toto Kasei), JER E1256, E4250, E4275, YX6954BH30, YL7290BH30 (Both manufactured by Japan Epoxy Resin Co., Ltd.).

  Preferable phenoxy resins are bisphenol A types such as PKHH, YP-50, YP-50S, YP-55, YP-70, and JER E1256.

  These phenoxy resins can be used singly or in combination of two or more.

-(B) Epichlorohydrin copolymer type epoxy resin having an aromatic ring in the resin skeleton-
The epichlorohydrin copolymer type epoxy resin (hereinafter also abbreviated as “component (B)”) used as the component (B) in the present invention is a compound having at least two epoxy groups in the molecule. In particular, the epoxy equivalent is preferably 50 to 5000 g / eq, more preferably 100 to 500 g / eq. Further, the aromatic ring in the skeleton may be monocyclic or polycyclic.

  The epoxy resin has a weight average molecular weight of usually less than 10,000, preferably 400 to 9000, more preferably 500 to 8000.

  Such epoxy resins include, for example, bis (4-hydroxyphenyl) methane, 2,2′-bis (4-hydroxyphenyl) propane, or diglycidyl ethers of these halides; Polymers (so-called bisphenol F type epoxy resin, bisphenol A type epoxy resin, etc.); resorcin diglycidyl ether; 1,4-bis (2,3-epoxypropoxy) benzene; 4,4′-bis (2,3- Epoxypropoxy) diphenyl ether; bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate; epoxy glycidyl ether or polyglycidyl ester obtained by condensation of polychlorophenol such as 1,2-dihydroxybenzene, resorcinol and epichlorohydrin ; Epoxy novolaks obtained by condensing novolak type phenolic resins (or halogenated novolak type phenolic resins) such as enolic novolaks and cresol novolaks with epichlorohydrin (ie novolac type epoxy resins); naphthalene ring-containing epoxy resins; biphenyl type epoxy resins Phenol aralkyl type epoxy resin; biphenyl aralkyl type epoxy resin; cyclopentadiene type epoxy resin and the like.

  Among these, bisphenol F type epoxy resin and bisphenol A type epoxy resin that are liquid at room temperature are preferable as the component (B).

  These epoxy resins can be used alone or in combination of two or more.

  (B) The compounding quantity of the epoxy resin of a component is 4-150 mass parts with respect to 100 mass parts of (A) component phenoxy resin, Preferably it is 8-120 mass parts, Most preferably, it is 10-100 mass parts. If the amount of the epoxy resin is too small, the adhesive strength of the adhesive composition may be inferior, and if it is too large, the flexibility of the adhesive layer may be insufficient.

-(C) Epoxy resin having no aromatic ring in the resin skeleton-
An epoxy resin having no aromatic ring in the resin skeleton used as the component (C) in the present invention (hereinafter also abbreviated as “component (C)”) is an aliphatic epoxy resin, such as an alicyclic epoxy. Examples thereof include resins, hydrogenated epoxy resins, and aliphatic polyhydric alcohol epichlorohydrin condensation type epoxy resins.

  The epoxy resin having no aromatic ring in the resin skeleton used as the component (C) in the present invention preferably has at least two epoxy groups in the molecule and has a weight average molecular weight of 3000 or less. Preferably it is 2000 or less. If there are no two or more epoxy groups in the molecule, the glass transition point is lowered and the composition is inferior in moisture resistance reliability. On the other hand, when the weight average molecular weight is greater than 3000, the viscosity of the film-like composition increases, and a high temperature is required at the time of bonding, which causes warping of the wafer after bonding.

  Examples of such alicyclic epoxy resins include Celoxide 2021P, Celoxide 3000, Celoxide 2080, Celoxide 2081, Celoxide 2083, Celoxide 2085, Epolide GT300, and EHPE3150 manufactured by Daicel Chemical Industries.

  Examples of the hydrogenated epoxy resin include ST-3000 and ST-4000D manufactured by Tohto Kasei Co., Ltd., and YX-8000, YX8034, YL7170, and YL6800 manufactured by Japan Epoxy Resins.

  Examples of the aliphatic polyhydric alcohol epichlorohydrin condensation type epoxy resin include AK-601 manufactured by Nippon Kayaku Co., Ltd. and Epicron U-125-60BT manufactured by DIC Corporation.

(C) The compounding quantity of a component is 1-50 mass parts with respect to 100 mass parts of (A) component phenoxy resin, It is preferable that it is especially 2-25 mass parts. If the amount of component (C) is too small, unevenness may occur on the surface after curing, or the flatness of the composition film after coating may be inferior. Moreover, when too large, the adhesive force before and after moisture-resistant reliability may be insufficient.
These (C) component epoxy resins can be used singly or in combination of two or more.

-(D) Epoxy resin curing catalyst-
Examples of the epoxy resin curing catalyst (D) component (hereinafter also abbreviated as “component (D)”) include phosphorus-based catalysts and amine-based catalysts.

  Examples of the phosphorus catalyst include triphenylphosphine, triphenylphosphonium triphenylborate, tetraphenylphosphonium tetraphenylborate, and a compound represented by the following formula.

(Wherein R ^{8 to} R ¹⁵ are each independently a halogen atom such as a hydrogen atom, fluorine, bromine or iodine, or an alkyl having 1 to 8 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group. Alkenyl groups having 2 to 8 carbon atoms such as groups, vinyl groups and allyl groups, alkynyl groups having 2 to 8 carbon atoms such as propynyl groups and butenyl groups, phenyl groups having 6 to 8 carbon atoms, and toluyl groups. A monovalent unsubstituted hydrocarbon group such as an aryl group, or a monovalent group such as a trifluoromethyl group in which at least a part of hydrogen atoms of these hydrocarbon groups is substituted with a halogen atom such as fluorine, bromine or iodine; Of the substituted hydrocarbon group, methoxy group, ethoxy group, propoxy group, butoxy group, etc. In the substituted monovalent hydrocarbon group, all the substituents are the same. It may be not.

  Specific preferred examples of the phosphorus catalyst include triphenylphosphine, triphenylphosphonium triphenylborate, tetraphenylphosphonium tetraphenylborate and the like.

  Examples of the amine catalyst include imidazole derivatives such as dicyandiamide, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, and 2-phenyl-4,5-dihydroxymethylimidazole. Can be mentioned. Among these, dicyandiamide and 2-phenyl-4,5-dihydroxymethylimidazole are preferable, and dicyandiamide is particularly preferable.

  (D) As a catalyst of a component, the catalyst mentioned above can be used individually by 1 type or in mixture of 2 or more types. Dicyandiamide is particularly preferably used from the viewpoints of storage stability, adhesiveness, and productivity.

  (D) The compounding quantity of the epoxy resin curing catalyst of a component is an effective amount, Preferably it is 5-50 mass parts with respect to 100 mass parts of (A) component.

-(E) Inorganic filler-
Examples of the inorganic filler used as the component (E) of the present invention (hereinafter also abbreviated as “component (E)”) include metal oxides such as silica, alumina and titanium oxide, and conductive particles such as carbon black and silver particles. Can be used. Silica is preferably fused silica or crystalline silica. Among these, metal oxides such as silica, alumina, and titanium oxide are particularly preferable.

  The average particle size of the inorganic filler is preferably from 0.1 to 10 μm, more preferably from 0.5 to 7 μm. When the average particle size of the inorganic filler is within this range, it is easy to maintain the surface property of the coating film as a coating film of the protective film forming sheet or a protective film provided on the semiconductor wafer, and to obtain a uniform coating film. . Further, in recent years, the thickness required of the coating as the adhesive layer is 15 to 50 μm. However, if the average particle size of the inorganic filler is within the above range, the desired thickness can be obtained even when aggregated secondary particles are present. Can be achieved without hindrance.

  The blending amount of the inorganic filler is 5 to 900 parts by weight, more preferably 10 to 700 parts by weight, most preferably 100 parts by weight of the total amount of the components (A), (B), (C) and (D). Preferably it is 100-500 mass parts. If the blending amount is less than 5 parts by mass, it is difficult to sufficiently achieve the purpose of blending the inorganic filler, resulting in high water absorption, high linear expansion coefficient, and low strength. Viscosity increases and handling becomes worse.

-(F) Solvent-
As the solvent of the component (F) (hereinafter also abbreviated as “component (F)”), a polar solvent having a boiling point of 70 ° C. to 180 ° C. and a surface tension of 20 to 30 dyne / cm at 25 ° C. is used.

  The boiling point of the solvent is preferably 70 to 160 ° C, more preferably 80 to 160 ° C. If the boiling point is too low, the solvent volatilizes from the coating liquid (composition) during coating, and a gel-like material is generated in the coating liquid, making it difficult to form a flat coating film. When the boiling point is too high, it is necessary to remove the solvent from the coating film after coating, and it is necessary to carry out the treatment at a high temperature, and the reaction proceeds in the composition, causing a functional deterioration as an adhesive film.

  The solvent has a surface tension at 20 ° C. of 20 to 30 dyne / cm. When the surface tension is less than 20 dyne / cm, it is difficult to maintain the shape of the coating film end portion after coating, and thus the coating film end portion after drying, and vertical stripes are likely to occur. When it exceeds 30 dyne / cm, the coating property with respect to the base film is lowered, and coating omission is likely to occur.

  As a compounding quantity of this solvent, it is preferable to contain 10-300 mass parts with respect to 100 mass parts of total amounts of (A), (B), (C), (D) and (E) component, Preferably it is 25-200 mass parts. If the blending amount is less than 10 parts by mass, the composition becomes a highly viscous composition, and vertical stripes are generated during coating, resulting in a problem in the flatness of the film. On the other hand, when the blending amount is more than 300 parts by mass, the viscosity is remarkably lowered and the substrate film is easily repelled during coating, and in this case, a smooth film surface cannot be obtained.

  Preferable specific examples of the polar solvent of component (F) include aromatic hydrocarbon solvents such as xylene, ethylbenzene, n-propylbenzene, isopropylbenzene, and styrene; perfluoroaromatic carbonization such as perfluorobenzene and perfluorotoluene. Hydrogen solvents: Carbon tetrachloride, ethyl chloride, 1,1,1-trichloroethane, isobutyl chloride, t-butyl chloride, vinyl chloride, bromoethyl and other halogenated hydrocarbon solvents; diethyl ether, diisopropyl ether and other ether solvents Cyclohexanone, methyl ethyl ketone, dibutyl ketone, methyl n-propyl ketone, methyl isobutyl ketone, methyl n-butyl ketone, methyl isoamyl ketone, methyl hexyl ketone, diisopropyl ketone, diisobutyl ketone Ketone solvents such emissions; acetate n- propyl, isopropyl acetate, n- butyl, butyl acetate, alkyl acetate solvents etc., and cyclohexanone. Of these, cyclohexanone, butyl acetate, and methyl ethyl ketone are preferable.

  These polar solvents can be used singly or in combination of two or more. However, it is preferable to use a combination of two or more. By using two or more kinds, particularly two kinds in combination, a difference in boiling point and solubility of the composition can be caused to form a smooth coating film. When using 2 or more types, it is preferable that each solvent is at least 25 mass%.

-Other optional components-
The adhesive composition of the present invention can contain other components and various additives as necessary in addition to the components described above.

・ Epoxy resin curing agent:
Although the curing agent is not essential, the addition of the curing agent makes it possible to control the resin matrix, and can expect effects such as a low linear expansion coefficient, a high Tg, and a low elastic modulus.

As this curing agent, conventionally known various curing agents for epoxy resins can be used. For example, diethylenetriamine, triethylenetetramine, diethylaminopropylamine, N-aminoethylpiperazine, bis (4-amino-3-methylcyclohexyl) methane, metaxylylenediamine, menthanediamine, 3,9-bis (3-aminopropyl) -Amine compounds such as 2,4,8,10-tetraoxaspiro [5.5] undecane; epoxy resins-modified aliphatic polyamines such as diethylenetriamine adduct, amine-ethylene oxide adduct, cyanoethylated polyamine; bisphenol A, tri Methylol allyloxyphenol, low polymerization degree phenol novolac resin, epoxidized or butylated phenol resin, “Super Becksite” 1001 [manufactured by Nippon Reichhold Chemical Co., Ltd.], “ Hitanol "4010 (manufactured by Hitachi, Ltd.), Scadoform L. Phenol resin containing at least two phenolic hydroxyl groups in the molecule known under the trade name such as 9 (manufactured by Scado Zwoll, The Netherlands), Methylon 75108 (manufactured by General Electric, USA); “Beckamine” P. 138 [manufactured by Nippon Reichhold Chemical Co., Ltd.], “Melan” [manufactured by Hitachi, Ltd.], “U-Van” 10R [manufactured by Toyo Kodan Kogyo Co., Ltd.], etc. resin; formula _{HS (C 2 H 4 OCH 2} OC 2 H 4 SS) n C 2 H 4 OCH 2 OC 2 H 4 SH (n = 1~10 integer); melamine resins, amino resins such as aniline resins Polysulfide resin having at least two mercapto groups in one molecule; phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, pyromellitic anhydride, methyl nadic acid, dodecyl succinic anhydride, chlorendic anhydride Examples thereof include organic acids such as acids or anhydrides (acid anhydrides) thereof.

  Among the curing agents described above, phenolic resins (particularly phenol novolak resins) give good molding workability to the composition of the present invention, give excellent moisture resistance, are non-toxic and relatively inexpensive. This is desirable.

  The above-mentioned curing agents may be used alone or in combination of two or more according to the curing performance of each curing agent.

  The amount of the curing agent is appropriately adjusted according to the type of the curing agent as long as the reaction between the (A) component phenoxy resin, the (B) component, and the (C) component epoxy resin is not hindered. Generally, it is used in the range of preferably 1 to 100 parts by mass, more preferably 5 to 50 parts by mass with respect to 100 parts by mass of the epoxy resin. If the amount of the curing agent used is less than 1 part by mass, it is usually difficult to expect the effect of adding the curing agent. On the other hand, when the amount exceeds 100 parts by mass, it is economically disadvantageous, and the epoxy resin is diluted to require a long time for curing, and further, there may be a disadvantage that the physical properties of the cured product are lowered.

・ Other additives:
The composition of the present invention includes colorants such as inorganic or organic pigments and dyes, silane coupling agents, antioxidants, flame retardants, antistatic agents, heat, and the like within the range not impairing the effects of the present invention. Stabilizers and the like can be added. For example, when a protective film is colored by blending pigments, dyes, etc., visibility and optical device recognition performance are improved when a laser mark or the like is engraved.

<Semiconductor wafer protective film forming sheet>
-Base film-
As the base film in the semiconductor wafer protective film forming sheet according to the present invention, for example, a synthetic resin film such as a polyethylene film, a polypropylene film, a polyvinyl chloride film, a polyethylene terephthalate film, and a polyimide film is used. When the substrate is peeled from the protective film after the protective film is cured, a polyethylene terephthalate film or a polyimide film excellent in heat resistance is preferably used. Alternatively, a release film may be formed by applying a silicone resin, a fluorine resin, or the like to the surface of the base film and performing a release treatment.

  The film thickness of the base film is usually about 5 to 200 μm, preferably about 10 to 150 μm, and particularly preferably about 20 to 100 μm.

-Protective film-
The protective film is applied to the base film by the known method such as a gravure coater so that the composition of the present invention is usually 5 to 100 μm, preferably 10 to 60 μm after coating and drying. Can be obtained.

  The drying conditions of the solvent in the composition are usually at room temperature for 2 hours or more, or at 40 to 130 ° C. for about 1 to 20 minutes, preferably at 50 to 120 ° C. for 1 to 20 minutes. In some cases, the reaction may proceed simultaneously with the addition reaction, but it is necessary to set the temperature within such a range that organic peroxide curing does not occur.

The semiconductor wafer protective film forming sheet of the present invention can be used by a method having the following steps.
(1) A step of affixing the back surface of a semiconductor wafer on which a circuit is formed on the protective film of the semiconductor wafer protective film forming sheet of the present invention
(2) a step of peeling the base film from the protective film,
(3) a step of curing the protective film by heating,
(4) A step of attaching a dicing film on the cured protective film,
(5) A step of dicing the semiconductor wafer and the protective film.
Here, steps (2) and (3) may be in reverse order.

  The heating in the step (3) is a condition that the curing agent effectively exhibits the curing performance, and is usually 120 to 200 ° C. for 10 to 120 minutes, particularly preferably 130 to 190 ° C. for 15 to 60 minutes.

  The wafer dicing in step (5) is performed by a conventional method using a dicing sheet. By using the protective film-forming sheet of the present invention, it becomes difficult for micro-cracks and chips (chipping) to occur on the chip cut surface. A semiconductor chip having a protective film on the back surface is obtained by dicing. The chip is picked up by general-purpose means such as a collet. As a result, a highly uniform protective film can be easily formed on the back surface of the chip, and chipping that occurs during dicing is reduced, resulting in a semiconductor device with a high yield with little damage to the circuit surface.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not restrict | limited to the following Example.

-Preparation method of adhesive composition The following components were mixed in the amounts shown in Table 1 to obtain a composition having a solid content of 50% by weight. Components (A) to (E) shown in Table 1 are as follows.

(A) component Phenoxy resin polymer: Mw 60000, JER1256 (manufactured by Japan Epoxy Resin Co., Ltd.)
(B) Epichlorohydrin copolymer type epoxy resin component RE310S (manufactured by Nippon Kayaku Co., Ltd.) having an aromatic ring in the skeleton, viscosity of 15 Pa · s at 25 ° C.
(C) Epoxy resin component having no aromatic ring in the resin skeleton Celoxide 2021P (bifunctional alicyclic epoxy resin) Mw252 YX-8000 (bifunctional hydrogenated epoxy resin) manufactured by Daicel Chemical Industries, Ltd. Mw360 AK-601 (polyol type epoxy resin) manufactured by Japan Epoxy Resin Co., Ltd. Mw252 (D) component manufactured by Nippon Kayaku Co., Ltd. Dicyandiamide (DICY-7): (E) component manufactured by Japan Epoxy Resin Co., Ltd. Silica: SE2050 average Particle size 0.5μm Maximum particle size 5μm KBM-403 treated product, manufactured by Admatechs

-Preparation of protective film The adhesive composition was coated on a 38 μm thick PET film whose surface was coated with a silicone release agent, and was heated and dried at 110 ° C. for 10 minutes to form a protective film having a thickness of 25 μm. Formed.

・ Flatness test ・ ・ Surface convex defect A protective film formed on a PET film was observed with a laser microscope (trade name: VK-8710) manufactured by Keyence Corporation, and a protrusion having a diameter of 100 μm or more and a height of 5 μm or more was projected. The number was counted as a defect. The observation unit area is 1 m ² .
· · Surface concave defects Observe the protective film formed on the PET film with a laser microscope (trade name: VK-8710) manufactured by KEYENCE, and count the number of concaves with a diameter of 300 µm or more and a depth of 15 µm or more as concave defects. It was. The observation unit area is 1 m ² .

Color unevenness test A protective film was transferred onto a glass plate and cured at 175 ° C for 4 hours in a hot air circulation dryer. The position of the color unevenness is identified by visual recognition, the protective film of the color unevenness portion and the non-color unevenness portion is observed with a laser microscope (product name: VK-8710) manufactured by Keyence, and the profile of the cross section is observed to measure 100 μm. The difference in the number of irregularities within 0.05 to 0.1 μm was observed in the range. Comparing the uneven color part and the non-color uneven part, if the difference in the number of irregularities within 0.05 to 0.1 μm is within 30, the color unevenness is described. did.

Chipping test A protective film formed on a PET film was bonded to a silicon wafer (8-inch unpolished wafer) having a thickness of 220 μm at 70 ° C. using an adhesive film attaching device (trade name: FM-114, manufactured by Technovision). After being attached to the surface of a wafer having a thickness of 220 μm by polishing # 2000 using DAG-810 manufactured by Disco Corporation, the PET film was peeled off from the protective film. The silicon wafer was diced into 10 mm × 10 mm square chips from the circuit forming surface side under the following conditions. Microscopic cross-sectional photographs of the 8 chips obtained were taken, and when there was a crack or chip having a length of 25 μm or more in the cross-sectional direction, the chipping was evaluated as “present”. The results are shown in Table 1.

[Dicing condition]
Device: DISCO Dicer DAD-341
Cutting method: Single Blade rotation speed: 40000 rpm
Blade speed: 50 mm / sec
Dicing film thickness 85μm
Cutting into dicing film: 15 μm

-Shear adhesive strength test The protective film surface of the protective film forming sheet was attached to the back surface of a silicon wafer having a diameter of 8 inches by the same method as described above, and then the base film was peeled off. The wafer to which the protective film was attached was cut into 3 mm × 3 mm square chips together with the protective film. Thereafter, the chip was picked up and thermocompression bonded at 170 ° C. under a pressure of 0.63 MPa for 1 second to the center of a 10 mm × 10 mm silicon wafer to obtain a laminate. The obtained laminate was heat-treated at 175 ° C. for 4 hours to cure the protective film and prepare a test piece. This test piece was measured for shear adhesion at a speed of 200 μm / sec and a height of 50 μm using a DAGE 4000 manufactured by DAGE.
The results are shown in Tables 1 and 2.

  Examples 1-8 all showed good film properties. On the other hand, Comparative Examples 1-2 and 6 not containing the component (C), Comparative Examples 3-5 in which the blending amount of the component (C) deviates from the scope of the present invention, and the solvent of the component (F) is within the scope of the present invention. Comparative Examples 6 to 8 that deviate all showed undesirable results in adhesive film performance, particularly color unevenness and chipping performance.

  The adhesive composition and the semiconductor wafer protective film forming sheet of the present invention are useful for manufacturing a highly reliable semiconductor device.

Claims (5)

(A) Phenoxy resin 100 parts by mass (B) Epichlorohydrin copolymer type epoxy resin having an aromatic ring in the resin skeleton 4 to 150 parts by mass (C) Epoxy resin having no aromatic ring in the resin skeleton 1 to 50 Mass part (D) Epoxy resin curing catalyst Effective amount, and (E) Inorganic filler 5 to 900 parts by mass with respect to 100 parts by mass of the total amount of the components (A), (B), (C) and (D) (F) A polar solvent having a boiling point of 70 ° C. to 180 ° C. and a surface tension of 20 to 30 dyne / cm at 25 ° C. The total amount of the components (A), (B), (C), (D) and (E) The adhesive composition which contains 10-300 mass parts with respect to 100 mass parts.   2. The adhesive according to claim 1, wherein the epoxy resin having no aromatic ring in the resin skeleton of component (C) is an alicyclic epoxy resin having two or more epoxy groups and a weight average molecular weight of 3000 or less. Composition.   The adhesive composition according to claim 1 or 2, wherein the epoxy resin curing catalyst of component (D) is dicyandiamide.   The adhesive composition according to claim 1, wherein the solvent of component (F) is at least one selected from cyclohexanone, butyl acetate, and methyl ethyl ketone.   A base film and a coating formed on one side of the base film, comprising a composition obtained by removing the solvent of the component (F) from the adhesive composition according to any one of claims 1 to 4, A sheet for forming a semiconductor wafer protective film.