JP2008201899A - Surface-protecting adhesive tape for solid state image pickup device and method for mounting solid state image pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-protecting adhesive tape for solid state image pickup devices, effective for protecting the surface of an image sensor from contamination with foreign materials and damage in the production process of a solid state image pickup device in a high-temperature atmosphere and resistant to the peeling of the adhesive tape from the image sensor, and to provide a method for mounting a solid state image pickup device by using the adhesive tape. <P>SOLUTION: The surface-protecting adhesive tape for solid state image pickup devices has an adhesive layer on one surface of a substrate and the adhesive layer contains an lipophilic laminar clay mineral. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a surface protective adhesive tape for a solid-state imaging device and a method for mounting a solid-state imaging device using the same.

  In the manufacturing process of a solid-state imaging device, a surface protective adhesive tape having an adhesive layer is bonded to the light receiving part side of the image sensor in order to prevent dust from adhering to the surface of the image sensor during mounting and manufacturing processes. The method is taken.

  At this time, in the component mounting process, a method of connecting and mounting at a time by using a solder reflow furnace in a state where the terminal portion of the image sensor and the mounting substrate are aligned is often used, and a high temperature region such as soldering is used. Therefore, heat resistance is required for the film and the pressure-sensitive adhesive layer that are base materials. However, since many of the current surface protective adhesive tapes do not have the heat resistance equivalent to the above process, the surface protective adhesive tape is once peeled off during the component mounting process, and again after the component mounting process. A surface protective adhesive tape will be attached.

  Currently, as an improvement measure, a method using a surface-protective adhesive tape using a high heat-resistant film mainly composed of polyimide is also adopted, but the visibility is low because the polyimide film has a brownish hue. Unfortunately, the total light transmittance is low when performing optical inspection after component mounting. For this reason, optical inspection in a tape application form is difficult.

  Then, the method of using the film excellent in transparency like a polyethylene terephthalate and a polyethylene naphthalate is proposed (patent document 1).

  However, if the heat resistance of the pressure-sensitive adhesive layer is low in a process in a high-temperature atmosphere, the pressure-sensitive adhesive tape may be peeled off from the surface of the image sensor, which may cause problems such as scratches and dust adhesion.

JP-A-2005-341523

  The present invention protects the surface of a video sensor from contamination and scratches due to foreign matters in the manufacturing process of a solid-state imaging device in a high-temperature atmosphere, and the adhesive tape for surface protection for a solid-state imaging device in which the adhesive tape does not peel from the video sensor, and It aims at providing the mounting method of the solid-state imaging device using this adhesive tape.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved with an adhesive tape, and have completed the present invention.

  That is, the present invention is a surface protective adhesive tape for a solid-state imaging device having an adhesive layer on one side of a substrate, wherein the adhesive layer contains a lipophilic layered clay mineral.

  In the surface protective pressure-sensitive adhesive tape for a solid-state imaging device of the present invention, the pressure-sensitive adhesive layer preferably contains 1 to 40 parts by weight of a lipophilic layered clay mineral with respect to 100 parts by weight of the pressure-sensitive adhesive.

  In the surface protective adhesive tape for a solid-state imaging device according to the present invention, the lipophilic layered clay mineral is preferably a layered silicate.

  The solid-state imaging device mounting method of the present invention is characterized by using the surface protective adhesive tape for a solid-state imaging device.

  The surface protective pressure-sensitive adhesive tape for solid-state imaging device of the present invention contains a lipophilic layered clay mineral in the pressure-sensitive adhesive layer, so that the cohesive force of the pressure-sensitive adhesive is increased, and the adherend is subjected to high temperature conditions in the component mounting process. For example, since the adhesive force can be maintained with respect to the light receiving portion side of the image sensor, the surface of the image sensor can be protected from contamination and scratches by a foreign substance without being peeled off from the image sensor. Even after high-temperature heat treatment at about 180 ° C., the image sensor can be peeled off without causing adhesive residue, which is effective.

  Embodiments of the present invention will be described below.

  The pressure-sensitive adhesive tape of the present invention is basically formed of a base material and a pressure-sensitive adhesive layer provided on one side of the base material, and a release film having a release treatment applied to at least one side is used as a pressure-sensitive adhesive layer. You may stick together.

  Although the base material of an adhesive tape is not specifically limited, It is preferable that it is a film which has heat resistance in high temperature conditions, for example in the temperature range of 100-200 degreeC. Specifically, polyethylene terephthalate (PET) film, polyethylene naphthalate film (PEN), polyethersulfone (PES) film, polyetherimide (PEI) film, polysulfone (PSF) film, polyphenylene sulfide (PPS) film , A polyetheretherketone (PEEK) film, a polyarylate (PAR) film, an aramid film, a polyimide film, or a liquid crystal polymer (LCP) film.

  As for the thickness of a base material, 10-50 micrometers is preferable, More preferably, it is 30-45 micrometers, More preferably, it is desirable that it is 35-40 micrometers. When the thickness of the substrate is less than 10 μm, it is difficult to peel off when peeling. Moreover, when exceeding 50 micrometers, it will peel from a sensor in a high temperature atmosphere.

  The heat shrinkage rate of the substrate is preferably 1.0% or less, more preferably 0.5% or less, and still more preferably 0.3% or less. The heat shrinkage rate is measured in the form of a tape by cutting the adhesive tape into 20 mm square, pasting it on a BA plate, leaving it at 180 ° C. for 1 hour, and projecting the tape size before and after the heating. Both MD direction and TD direction are measured using a machine (Mitutoyo: PROFILE PROJECTOR PJ-H300F). The BA plate refers to a SUS304 plate (BA5 finish SUS304 manufactured by Nippon Metal Co., Ltd.) surface-finished to BA5 in accordance with JIS “BA finish”. In view of the shrinkage rate of the base material and sticking to the image sensor, the base material is preferably made of a base material mainly composed of polyethylene naphthalate having both heat resistance and visibility at the time of pasting.

  Although it will not specifically limit about the adhesive layer of this invention if it has adhesiveness and heat resistance, For example, an acrylic adhesive etc. are mentioned. Specifically, the acrylic pressure-sensitive adhesive is a pressure-sensitive adhesive made of an acrylic polymer obtained by copolymerization of a monomer containing at least an alkyl (meth) acrylate. Examples of the alkyl (meth) acrylate herein include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) ) Acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, and the like. The acrylic pressure-sensitive adhesive has relatively high heat resistance and is the most suitable pressure-sensitive adhesive for the present invention.

  The acrylic polymer may contain units corresponding to other monomer components copolymerizable with the (meth) acrylic acid alkyl ester, if necessary, for the purpose of modifying cohesive force, heat resistance and the like. . Examples of such monomer components include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; maleic anhydride Acid anhydride monomers such as itaconic anhydride; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate Hydroxyl group-containing monomers such as 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate; The Sulfonic acid groups such as lensulfonic acid, allylsulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamidepropanesulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalenesulfonic acid Containing monomer; Phosphoric acid group-containing monomer such as 2-hydroxyethylacryloyl phosphate; (meth) acrylic acid glycidyl ester, (meth) acrylamide, (meth) acrylic acid N-hydroxymethylamide, (meth) acrylic acid alkylaminoalkyl ester (For example, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, etc.), N-vinylpyrrolidone, acryloylmorpholine, vinyl acetate, vinyl propionate, styrene, acryloni Lil; (meth) acrylic acid cycloalkyl esters (e.g., cyclopentyl ester and cyclohexyl ester) and the like, such as. One or more of these copolymerizable monomer components can be used. The amount of the copolymerizable monomer used is preferably 70% by weight or less, more preferably 40% by weight or less based on the total monomer components.

  Furthermore, since the acrylic polymer is crosslinked, a polyfunctional monomer or the like can be included as a monomer component for copolymerization as necessary. Examples of such polyfunctional monomers include hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) Examples include acrylates. These polyfunctional monomers can also be used alone or in combination of two or more. The amount of the polyfunctional monomer used is preferably 70% by weight or less, more preferably 30% by weight or less, based on the adhesive properties and the like.

  Further, these acrylic pressure-sensitive adhesives can contain an appropriate crosslinking agent. For example, an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine-based compound, a chelate-based crosslinking agent and the like are examples.

  Although the usage-amount of a crosslinking agent in particular is not restrict | limited, For example, 0.1-15 weight part is preferable with respect to 100 weight part of said acrylic polymers, and 1-10 weight part is more preferable.

  Although it does not specifically limit as a lipophilic layered clay mineral, It is a preferable aspect to use a layered silicate. Examples of layered silicates include sabonite, saconite, stevensite, hectorite, margarite, talc, phlogopite, muscovite, chrysotile, chlorite, vermiculite, kaolinite, zansophyllite, dickite, nacrite, bayophyllite, Examples include montmorillonite, hydelite, nontonite, tetrasilic mica, sodium teniolite, antigolite, and halloysite. The layered silicate may be either a natural product or a synthetic product, and even if one or more of these are used at the same time, there is no problem, but it is particularly preferable to use montmorillonite.

  The average particle size of the layered silicate is preferably 0.01 to 100 μm, more preferably 0.05 to 10 μm, and the aspect ratio is preferably 20 to 500, more preferably 50 to 200.

  The amount of the layered clay mineral used is not particularly limited, but the amount used is appropriately determined in order to obtain heat resistance and a releasing effect according to the adherend. For example, it is preferable to contain 1-40 weight part with respect to 100 weight part of said acrylic copolymers, More preferably, it is 10-30 weight part. When the amount used is less than 1 part by weight, the heat resistance is hardly exhibited. It is a preferable aspect to adjust appropriately according to the peeling effect based on the amount used. In addition, the amount used is preferably less than 100 parts by weight because it is difficult to apply the pressure-sensitive adhesive or to adjust the adhesive strength, but the amount used is not particularly limited. It is possible to add more than parts by weight.

  Furthermore, as necessary, various additives such as an initiator, a filler, an antiaging agent, a pigment, a dye, and a silane coupling agent can be added as necessary.

  The solvent used for preparing the pressure-sensitive adhesive is not particularly limited, but an organic solvent is usually used. As an organic solvent, what can melt | dissolve an adhesive composition uniformly may be sufficient at the surface of the coating-film stability at the time of film forming. Examples of the organic solvent include butane, hexane, heptane, toluene, o-xylene, m-xylene, p-xylene, cyclohexane, methanol, ethanol, isopropyl alcohol, 1-pentanol, cyclohexanol, 2-methylcyclohexanol, Diethyl ether, isopropyl ether, dibutyl ether, dibenzyl ether, tetrahydrofuran, acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone (methylpentyl ketone), diisobutyl ketone, cyclohexanone, methylcyclohexanone, cyclopentanone, amyl acetate, methyl acetate, Ethyl acetate, propyl acetate, butyl acetate, N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methylpyrrole Down, 2-methoxyethanol, 2-ethoxyethanol, and 2-butoxyethanol and the like. As the organic solvent, ethyl acetate, toluene, xylene and the like are preferable. Depending on the solvent, the pressure-sensitive adhesive composition is usually prepared in a solution having a solid concentration of 5 to 50% by weight, preferably 5 to 30% by weight, and more preferably 10 to 25% by weight.

  The pressure-sensitive adhesive layer is formed by applying an acrylic pressure-sensitive adhesive on a base material to form a pressure-sensitive adhesive composition layer. Various methods can be adopted as the forming method. For example, when a continuous coating apparatus is used for forming the pressure-sensitive adhesive composition layer, the pressure-sensitive adhesive composition (solution) is continuously supplied, and the sheet base is continuously formed by a discharge means such as a die attached to the front end of the apparatus. The method of extruding to a thin layer on a material is mentioned. When a batch method is adopted as a method for forming the pressure-sensitive adhesive composition layer, the pressure-sensitive adhesive composition (solution) is cast on the base material, and an applicator, a Meyer bar, or a knife is used. A method of forming with a coater is mentioned. Thus, after laminating | stacking the thinned adhesive composition on a base material, it heats and removes a solvent.

  The thickness of the pressure-sensitive adhesive layer is preferably 3 to 20 μm, more preferably 5 to 15 μm, and still more preferably 8 to 12 μm. If it is less than 3 μm, it will be peeled off from the sensor in a high temperature atmosphere. Moreover, when exceeding 20 micrometers, when peeling, it cannot peel.

  The thickness of the pressure-sensitive adhesive tape of the present invention is preferably at least 5 μm or more in order to prevent breakage or tearing, and further preferably 10 to 100 μm in view of suitable handling properties.

  Furthermore, in this invention, it is preferable that the thermal contraction rate of an adhesive tape is 1.0% or less, More preferably, it is 0.5% or less, More preferably, it is preferable that it is 0.3% or less. The heat shrinkage referred to here is based on the value after bonding to a BA plate in the form of an adhesive tape and leaving it at 180 ° C. for 1 hour. Specifically, the heat shrinkage rate is measured by cutting an adhesive tape into 20 mm square, sticking it to a BA plate, heating it at a temperature of 180 ° C., and measuring the size of the tape before and after the heating by a projector (Mitutoyo: Both the MD direction and the TD direction are measured using PROFILE PROJECTOR PJ-H300F).

  Moreover, in this invention, it is preferable that the adhesive force of the adhesive tape after implementing a heating at 180 degreeC for 1 hour is 0.5 N / 19mm or more, More preferably, it is 0.5-5.0 N / 19mm. More preferably, it is 1.0 to 2.5 N / 19 mm. If it is less than 0.5 N / 19 mm, the adhesive tape may be peeled off from the image sensor during the heating process. When the adhesive strength exceeds 5.0 N / 19 mm, it is difficult to remove the tape from the adherend in the process, and the adhesive layer may remain on the adherend surface. The adhesive force here is based on a value measured according to JIS Z0237.

  The light transmittance of the pressure-sensitive adhesive tape in the present invention is preferably 50% or more, and more preferably 70% or more. This is because, even when optically inspecting the interior after component mounting, the optical tape can be inspected without peeling of the adhesive tape by securing the light transmittance of the adhesive tape to a predetermined value or more. Here, the light transmittance means light transmittance in the visible light region, and means a light transmittance in the wavelength range of 400 to 700 nm. In the present invention, any transmittance in this wavelength region is preferably 50% or more. This is because, when the transmittance is less than 50%, it is difficult to confirm the connection process or the like of the solid-state imaging device via the adhesive tape. The light transmittance here is based on the value measured by the following measurement method.

<Measurement method of light transmittance>
(1) Measuring apparatus: spectrophotometer (manufactured by Shimadzu Corporation, MPS-2000)
(2) Measurement range: Wavelength range of 400 nm to 700 nm (3) Sample size: Cut to an appropriate size for the measuring device (4) Measurement of the adhesive tape was performed from the adhesive side. In addition, about the measurement of a base material, it measured from the side in which an adhesive was apply | coated or exists.

  Moreover, when using a release film for an adhesive tape, you may use any well-known thing as a release film. Specifically, it is possible to use a release film base material having a release coat layer, for example, a silicone layer formed on the bonding surface with the pressure-sensitive adhesive layer. Examples of the substrate for the release film include paper materials such as glassine paper and resin films made of polyethylene, polypropylene, polyester, and the like.

  The pressure-sensitive adhesive tape of the present invention may be processed according to the size of the target solid-state imaging device. The processing method is not particularly limited as long as it is a method that maintains a uniform shape and does not leave a pressure-sensitive adhesive in the processed cross section, but punching is preferable in view of productivity.

  Examples and the like specifically showing the configuration and effects of the present invention will be described below. Moreover, the evaluation method in an Example etc. was performed as follows. In addition, it cannot be overemphasized that this invention is not limited to this Example and evaluation method.

<Example 1>
A substrate made of polyethylene naphthalate having a thickness of 25 μm (thermal shrinkage of substrate 0.4%: 150 ° C.-30 minutes) was used. Moreover, as an adhesive layer, butyl acrylate 50 weight part, ethyl acrylate 50 weight part, 2-hydroxyethyl acrylate 0.1 weight part, trimethylol propane triacrylate 0.3 weight part, acrylic acid 5 weight part An acrylic polymer, which is a base polymer obtained from a monomer mixed solution consisting of With respect to 100 parts by weight of this acrylic polymer, 10 parts by weight of layered clay mineral montmorillonite (Kunimine Industries, Kunipia G, average particle size 0.1 μm), polyisocyanate compound (manufactured by Nippon Polyurethane Industry, trade name: 1 part by weight of Coronate L), 4 parts by weight of a polyepoxy compound (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name: Tetrad C) and methyl ethyl ketone as a solvent were prepared to a solution concentration of 19% by weight. The obtained acrylic pressure-sensitive adhesive solution was applied onto the substrate and further dried to prepare a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer having a thickness of 10 μm. After the adhesive tape was heated at 180 ° C. for about 1 hour, and the adhesive strength was measured according to JIS Z0237, it was 1.00 N / 19 mm, and the thermal shrinkage of the adhesive tape was 0.15%.

<Example 2>
An adhesive tape was prepared in the same manner except that the content of montmorillonite of the layered clay mineral of Example 1 was 1 part by weight. When the adhesive strength of this adhesive tape was measured, it was 0.55 N / 19 mm, and the thermal shrinkage of the adhesive tape was 0.15%.

<Example 3>
A pressure-sensitive adhesive tape was prepared in the same manner except that the content of montmorillonite of the layered clay mineral of Example 1 was 40 parts by weight. When the adhesive strength of this adhesive tape was measured, it was 0.75 N / 19 mm, and the thermal shrinkage rate of the adhesive tape was 0.15%.

<Example 4>
A pressure-sensitive adhesive tape was prepared in the same manner except that the content of montmorillonite in the layered clay mineral of Example 1 was 30 parts by weight. When the adhesive strength of this adhesive tape was measured, it was 1.20 N / 19 mm, and the thermal shrinkage rate of the adhesive tape was 0.15%.

<Comparative Example 1>
An adhesive tape was prepared in the same manner except that it did not contain the layered clay mineral montmorillonite of Example 1. When the adhesive strength of this adhesive tape was measured, it was 0.03 N / 19 mm, and the thermal shrinkage of the adhesive tape was 0.15%.

<Comparative example 2>
Except that the content of the montmorillonite of the layered clay mineral of Example 1 is 1000 parts by weight, an attempt was made to create an adhesive layer by the same method, but coating as an adhesive was difficult, and the adhesive was uniformly applied. The layer could not be created.

From the above results, according to the surface protective adhesive tape for solid-state imaging device of the present invention, even when used in a component mounting process under a high temperature atmosphere of 180 ° C., the adhesive film and the heat shrinkage rate are excellent. It was confirmed that the adhesive tape could not be peeled off and the sensor could be suitably protected.

Claims (4)

A surface protective adhesive tape for a solid-state imaging device having an adhesive layer on one side of a substrate,
A surface protective adhesive tape for a solid-state imaging device, wherein the adhesive layer contains an adhesive and a lipophilic layered clay mineral. The surface-protective pressure-sensitive adhesive tape for a solid-state imaging device according to claim 1, wherein the pressure-sensitive adhesive layer contains 1 to 40 parts by weight of a lipophilic layered clay mineral with respect to 100 parts by weight of the pressure-sensitive adhesive. The surface-protective pressure-sensitive adhesive tape for a solid-state imaging device, wherein the lipophilic layered clay mineral according to claim 1 or 2 is a layered silicate. The mounting method of the solid-state imaging device using the surface protection adhesive tape for solid-state imaging devices in any one of Claims 1-3.