JP6793022B2 - Adhesive tape for masking - Google Patents

Description

The present invention relates to an adhesive tape for masking. More specifically, the present invention relates to a masking adhesive tape used when forming a metal layer on a part of the surface of an electronic component.

Conventionally, an electromagnetic wave shield is provided on an electronic component (for example, a semiconductor package) to prevent malfunction of the electronic component due to an electromagnetic wave from the outside or leakage of the electromagnetic wave generated from the electronic component. In recent years, from the viewpoint of miniaturization of electronic components, an electromagnetic wave shield is directly formed on the electronic components by a method such as sputtering or plating (for example, Patent Document 1). At this time, a masking adhesive tape is attached to a surface such as an electrode forming surface that does not require the formation of an electromagnetic wave shield. As miniaturization progresses, methods for more precise masking of electronic components that require accurate electromagnetic wave shield formation are being studied, and masking adhesive tape that can be applied to precise masking methods is required. ing.

Japanese Unexamined Patent Publication No. 2014-183180

As one of the methods for precisely masking the bump forming surface (electrode forming surface) on the substrate, a semiconductor having a surface on which bumps are formed is defined in a partition wall provided on a tray and the upper part is open. A method of accommodating the package with the bumps facing up and masking the surface on which the bumps are formed can be mentioned. According to this method, the masking adhesive tape can be efficiently and uniformly attached to a plurality of semiconductor packages.

On the other hand, a conductive layer may be formed in the intermediate portion of the substrate of the semiconductor package. By forming the electromagnetic wave shield so as to come into contact with the end surface (exposed portion) of the conductive layer, grounding can be achieved, and a semiconductor package with an electromagnetic wave shield having excellent static elimination properties can be obtained.

In order to obtain an electromagnetic wave shielded semiconductor package having excellent static elimination properties as described above, more precise masking is required. Specifically, it is necessary that the bump forming surface is surely masked and the end surface of the conductive layer is not masked in the thickness direction of the semiconductor package. If the masking of the bump forming surface is insufficient, a metal layer as an electromagnetic wave shield is also formed on the bump forming surface, which causes a short circuit. On the other hand, when the end face of the conductive layer is masked, the electromagnetic wave shield cannot be formed so as to come into contact with the conductive layer.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is for masking that can reliably mask the bump forming surface of a semiconductor package and that it is difficult to mask the side surface of the semiconductor package. To provide adhesive tape.

In the masking adhesive tape of the present invention, a semiconductor package having a surface on which a bump is formed is housed in a plurality of compartments defined by a partition wall provided on a tray and whose upper portion is open, with the bump facing up. A masking adhesive tape used in a method of masking a surface on which the bumps are formed, which comprises a base material and an adhesive layer arranged on one side of the base material, and the base material is made of a polyester resin. The thickness of the base material is 30 μm to 80 μm, and the breaking strength of the masking adhesive tape is 70 N / 10 mm or more.
In one embodiment, the thickness of the pressure-sensitive adhesive layer is greater than the height of the bumps.
In one embodiment, the rigid body absorbability of the pressure-sensitive adhesive layer is 15% or more and less than 45%.
In one embodiment, the pressure-sensitive adhesive layer is composed of an active energy ray-curable pressure-sensitive adhesive.
According to another aspect of the present invention, there is provided a method for manufacturing an electromagnetic wave shielded semiconductor package. This manufacturing method uses the above-mentioned adhesive tape for masking.
In one embodiment, the manufacturing method comprises placing a semiconductor package having bumped surfaces in a plurality of compartments defined by partition walls provided on a tray and having an open top, with the bumps facing up. After accommodating, the masking adhesive tape includes masking the surface on which the bumps are formed.

According to the present invention, it is possible to provide a masking adhesive tape that can reliably mask the bump-forming surface of a semiconductor package with good embedding property and that is difficult to mask the side surface of the semiconductor package.

It is the schematic sectional drawing of the adhesive tape for masking according to one Embodiment of this invention. (A) is a schematic plan view of a tray used in the tray method according to one embodiment of the present invention, and (b) is a schematic cross-sectional view of the tray. FIG. 5 is a schematic cross-sectional view showing a state in which a masking adhesive tape is attached to a semiconductor package in one embodiment of the present invention. It is the schematic explaining the apparatus which measures the rigid body absorbability.

A. Overview Figure 1 of masking pressure-sensitive adhesive tape is a schematic cross-sectional view of a masking pressure-sensitive adhesive tape according to one embodiment of the present invention. The masking adhesive tape 100 includes a base material 10 and an adhesive layer 20 arranged on one side of the base material 10. The base material 10 is made of a polyester resin and has a thickness of 30 μm to 80 μm. Although not shown, the adhesive tape of the present invention may be provided with a separator on the outside of the adhesive layer for the purpose of protecting the adhesive surface until it is used. Further, although not shown, the masking adhesive tape may be provided with any suitable other layer (for example, an intermediate layer, a back surface treatment layer). Hereinafter, in the present specification, the masking adhesive tape may be simply referred to as an adhesive tape.

In the masking adhesive tape of the present invention, a semiconductor package having a bump forming surface is housed in a plurality of compartments defined by a partition wall provided on a tray and the upper portion is open, and the bumps are formed. It is preferably used in a method of masking a surface. Hereinafter, in the present specification, this method may be referred to as a tray method.

FIG. 2A is a schematic plan view of a tray used in the tray method according to one embodiment of the present invention, and FIG. 2B is a schematic cross-sectional view of the tray. In the tray 200, a plurality of partition walls 210 are provided, and the partition walls 210 define a plurality of compartments 211. The compartment 211 is provided so that the semiconductor package 300 can be accommodated. In FIG. 2B, one of the compartments 211 in which the semiconductor package 300 is housed is enlarged and shown. In one embodiment, the semiconductor package 300 is held by suction from the lower part of the compartment 211 (not shown).

In one embodiment, the semiconductor package 300 includes bumps 312. More specifically, in one embodiment, as shown in FIG. 2B, the semiconductor package 300 includes a first substrate layer 310, a conductive layer 320, a second substrate layer 330, and a sealing layer. 340 and 340 are provided in this order. The first substrate layer 310 includes a first substrate 311 and bumps 312 provided on the surface of the first substrate 311. Although not shown, the first substrate layer 310 may have any suitable circuit formed on its surface. The sealing layer 340 has a structure in which a fragmented semiconductor chip (not shown) is sealed with an insulating material. The semiconductor chip can be electrically connected to the second substrate layer 320 (not shown). Area in plan view of the semiconductor package 300 (the area when viewed from the plane above in FIG. 2 (b)) is, for ^example, a 10mm ² ~50mm 2. The height H1 of the semiconductor package 300 is, for example, 250 μm to 550 μm.

The height H2 of the partition wall 210 is preferably higher than the thickness H3 of the portion of the semiconductor package 300 other than the bumps. The difference between H2 and H3 is, for example, 100 μm to 250 μm, preferably 120 μm to 220 μm, and more preferably 140 μm to 190 μm.

The area of one compartment 211 in a plan view (the area of FIG. 2A when viewed from the vertical direction of the paper surface) is, for example, 1.3 to 2 times the area of the semiconductor package 300 in a plan view. is there.

At the upper end of the first substrate layer 310, the distance L between the partition wall 210 defining the compartment 211 and the semiconductor package 300 housed in the compartment 211 is, for example, 0.5 mm to 2 mm, preferably 0.6 mm. It is ~ 1 mm.

The width W of the partition wall 210 is, for example, 0.2 mm to 10 mm, preferably 0.5 mm to 5 mm.

The height H4 of the bump 312 of the semiconductor package 300 is, for example, 50 μm to 200 μm, preferably 70 μm to 170 μm, and more preferably 90 μm to 150 μm.

The thickness T of the first substrate layer 310 of the semiconductor package 300 is, for example, 40 μm to 120 μm, preferably 60 μm to 100 μm, and more preferably 70 μm to 90 μm.

The adhesive tape 100 of the present invention can be used for masking the bump forming surface of the semiconductor package 300. In one embodiment, the adhesive tape 100 is placed on the semiconductor package 300 arranged on the tray as described above, and a predetermined pressure (for example, linear pressure of 0.1 MPa to 0.5 MPa) is applied. The bump forming surface of the semiconductor package 300 is masked. In another embodiment, the adhesive tape 100 is placed on the semiconductor package 300 arranged on the tray as described above, and the pressure-reducing treatment is performed to attach the masking adhesive tape to the semiconductor package (so-called so-called). Vacuum pasted).

In one embodiment, the adhesive tape may be attached to the bump-forming surface of the semiconductor package, and then the adhesive layer of the adhesive tape may be cured. The curing treatment of the pressure-sensitive adhesive layer is performed, for example, by irradiation with active energy rays (typically ultraviolet rays).

The breaking strength of the masking adhesive tape of the present invention is 70 N / 10 mm or more, preferably 75 N / 10 mm or more, and more preferably 80 N / 10 mm or more. Within such a range, when masking the bump-forming surface of the semiconductor package, the bump-forming surface can be reliably masked with good embedding property, and the end face is masked in the thickness direction of the semiconductor package. An adhesive tape that is difficult to obtain can be obtained. The upper limit of the breaking strength of the masking adhesive tape is, for example, 200 N / 10 mm. If it is less than 70 N / 10 mm, it means that the rigidity of the base material is weak, and the base material is in a state of being excessively deformed by the stress at the time of sticking, and when the base material is stuck with a roller, the base material forms bumps. It will follow the unevenness of the surface and the gap between the semiconductor package and the partition wall, and the followability of the adhesive layer will increase. As a result, it may contaminate the ground when the adhesive tape is attached. When the breaking strength is larger than 200 N / 10 mm, the rigidity of the base material becomes high, and the base material is not easily deformed by the stress at the time of sticking. When the base material is stuck with a roller, the base material has irregularities on the bump forming surface. In addition, the adhesive layer does not follow the gap between the semiconductor package and the partition wall, and the followability of the adhesive layer deteriorates. As a result, the bumps are difficult to embed, and the adhesive tape may not adhere well to the substrate. The method for measuring the breaking strength is as follows. That is, the breaking strength is such that the adhesive tape is cut into a size of 10 mm in width × 60 mm in length to prepare an evaluation sample, and the evaluation sample is pulled at 25 ° C. using a tensile tester (Tencilon, manufactured by Shimadzu Corporation). A stress-strain curve is acquired and measured under the conditions of a speed of 300 mm / min and a distance between chucks of 50 mm.

The thickness of the masking adhesive tape of the present invention is preferably 40 μm to 1080 μm, and more preferably 85 μm to 675 μm. If it is thinner than 40 μm, the unevenness cannot be embedded and the adherend may not be protected. Further, if it is thicker than 1080 μm, the handleability as a masking material may deteriorate.

When the masking adhesive tape of the present invention is attached to a stainless steel plate, the 180-degree peeling adhesive force at 23 ° C. is preferably 0.4 N / 20 mm or more, and more preferably 0.5 N / 20 mm or more. Within such a range, an adhesive tape suitable for masking electronic components can be obtained. The masking adhesive tape of the present invention is difficult to peel off even if it is attached to an uneven surface of an electronic component (for example, a bump forming surface of a semiconductor package). When the masking adhesive tape is attached to a stainless steel plate, the upper limit of the 180-degree peeling adhesive force at 23 ° C. is, for example, 6N / 20 mm. The 180-degree peeling adhesive strength is measured according to JIS Z 0237: 2000. Specifically, the adhesive tape was attached to a stainless steel plate (arithmetic mean surface roughness Ra: 50 ± 25 nm) by one reciprocation of a 2 kg roller, left at 23 ° C. for 30 minutes, and then the peeling angle was 180 ° and the peeling speed (peeling speed). The adhesive tape is peeled off and measured under the condition of (tensile rate) 300 mm / min. As will be described later, the adhesive tape may be provided with an adhesive layer that can be cured by irradiation with active energy rays to reduce the adhesive strength, but in this case, unless otherwise specified, the "adhesive layer" is adhesive. It means the adhesive layer before the force is reduced (before irradiation with active energy rays). Therefore, the above-mentioned adhesive force means the adhesive force before the decrease in the adhesive force (before irradiation with the active energy ray).

B. Base material As described above, the base material is composed of a polyester resin and has a thickness of 30 μm to 80 μm. By using such a base material, an adhesive tape having appropriate rigidity can be obtained. By using such an adhesive tape, as shown in FIG. 3, when masking the bump-forming surface of the semiconductor package, the bump-forming surface can be reliably masked, and the end face is masked in the thickness direction of the semiconductor package. An adhesive tape that is difficult to obtain can be obtained. If such an adhesive tape is used for masking a semiconductor package (for example, the semiconductor package 300) provided with a conductive layer (earth) on a substrate, the end face of the conductive layer (earth) can be exposed. If a semiconductor package with an exposed end face of the conductive layer is subjected to an electromagnetic wave shield forming step, an electromagnetic wave shield is formed in a state where the conductive layer and the electromagnetic wave shield are in contact with each other, and a semiconductor package with an electromagnetic wave shield that provides good grounding and excellent static elimination is provided. Can be obtained.

Further, by using the base material having the above structure, it is possible to obtain an adhesive tape that follows the bumps well and can satisfactorily fill the unevenness caused by the bumps. In the present invention, when the base material is too thin, the base material rigidity (tensile strength) becomes low, the base material is easily deformed by the stress at the time of sticking, and when the base material is stuck with a roller, the base material is a bump forming surface. It will be along the unevenness of the surface and the gap between the semiconductor package and the partition wall, and the followability of the adhesive layer will be improved. As a result, the ground may be contaminated when the adhesive tape is attached. On the other hand, if the base material is too thick, the rigidity (tensile strength) of the base material becomes high, and the base material is less likely to be deformed by the stress at the time of sticking. In addition, the adhesive layer does not follow the gap between the semiconductor package and the partition wall, and the followability of the adhesive layer deteriorates. As a result, the bumps are difficult to embed, and the adhesive tape may not adhere well to the substrate.

Further, if a polyester resin is used as the base material, it is possible to obtain an adhesive tape that is not easily damaged by heating when forming the electromagnetic wave shield.

Examples of the polyester-based resin include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polytributylene terephthalate (PTT), polyhydroxyalkanoate (PHA), and the like. Of these, PET or PEN is preferable.

The thickness of the base material is preferably 32 μm to 77 μm, more preferably 35 μm to 75 μm. Within such a range, the above effect becomes more remarkable.

The breaking strength of the base material is 70 N / 10 mm or more, preferably 75 N / 10 mm or more. Within such a range, it is possible to obtain an adhesive tape that can satisfactorily mask the bump-forming surface of the semiconductor package, prevent masking of the side surface of the semiconductor package, and have excellent handleability. The upper limit of the breaking strength of the base material is, for example, 200 N / 10 mm. If it is less than 70 N / 10 mm, it means that the rigidity of the base material is weak, and the base material is in a state of being excessively deformed by the stress at the time of sticking, and when the base material is stuck with a roller, the base material forms bumps. It will follow the unevenness of the surface and the gap between the semiconductor package and the partition wall, and the followability of the adhesive layer will increase. As a result, the ground may be contaminated when the adhesive tape is attached. When the breaking strength is larger than 200 N / 10 mm, the rigidity of the base material becomes high, and the base material is not easily deformed by the stress at the time of sticking. When the base material is stuck with a roller, the base material has irregularities on the bump forming surface. In addition, the adhesive layer does not follow the gap between the semiconductor package and the partition wall, and the followability of the adhesive layer deteriorates. As a result, the bumps are difficult to embed, and the adhesive tape may not adhere well to the substrate. The breaking strength was such that the base material was cut into a size of 10 mm in width × 60 mm in length to prepare an evaluation sample, and the evaluation sample was subjected to a tensile tester (Tencilon, manufactured by Shimadzu Corporation) at 25 ° C. and a tensile speed of 300 mm. A stress-strain curve is obtained and measured under the condition of / min and a distance between chucks of 50 mm.

C. Adhesive layer The thickness of the adhesive layer is preferably 10 μm to 1000 μm, more preferably 30 μm to 800 μm, and even more preferably 50 μm to 600 μm. Within such a range, it is possible to obtain an adhesive tape that can fill the unevenness caused by bumps and has excellent handleability. If it is thinner than 10 μm, the unevenness cannot be embedded and the adherend may not be protected. Further, if it is thicker than 1000 μm, the handleability as a masking material may deteriorate.

The thickness ratio of the pressure-sensitive adhesive layer to the bump height H4 (thickness of the pressure-sensitive adhesive layer / bump height H4) is preferably 0.8 to 2.5, and more preferably 1 to 2. In one embodiment, the thickness of the pressure-sensitive adhesive layer is preferably thicker than the bump height H4 masked by the pressure-sensitive adhesive tape. With this configuration, it is possible to obtain an adhesive tape that can mask bumps well. When the thickness of the pressure-sensitive adhesive layer is thicker than the bump height H4, the thickness ratio of the pressure-sensitive adhesive layer to the bump height H4 (thickness of the pressure-sensitive adhesive layer / bump height H4) is preferably more than 1 and 2 or less. ..

The rigid body absorbency of the pressure-sensitive adhesive layer is preferably 15% or more and less than 45%, more preferably 20% to 40%, and further preferably 25% to 35%. Within such a range, the effect of the present invention becomes more remarkable. The rigid body absorbency of the pressure-sensitive adhesive layer is an index showing the degree of shock absorption when a rigid body is made to collide with the pressure-sensitive adhesive tape from the pressure-sensitive adhesive layer side. In the present specification, the flexibility of the pressure-sensitive adhesive layer is evaluated by the rigid body absorbability of the pressure-sensitive adhesive layer. A large value of rigid body absorbency means that the pressure-sensitive adhesive layer is highly flexible. In the present invention, since the rigid body absorbency of the pressure-sensitive adhesive layer is within the above range, when masking the bump-forming surface of the semiconductor package, the bump-forming surface can be masked more reliably, and the thickness direction of the semiconductor package It is possible to obtain an adhesive tape whose end face is more difficult to mask. Further, it is possible to obtain an adhesive tape that can satisfactorily fill the unevenness (for example, bump) of the sticking surface. If the rigid body absorbency is too small, the adhesive layer's ability to follow the unevenness of the sticking surface becomes poor, and the substrate surface cannot be completely protected and spattered, which may cause a short circuit. Further, when the rigid body absorbency is too large, it means that the fluidity of the pressure-sensitive adhesive layer is too high, and the shape of the pressure-sensitive adhesive layer cannot be maintained, and glue flows, so that the pressure-sensitive adhesive tape may not be formed. Rigid body absorbability is measured by the following method.
<Measurement method of rigid body absorbency>
Using the impact tester (pendulum tester) shown in FIG. 4, the impact force (F0) when the steel ball collided only with the support plate, and the adhesive tape was inserted between the fixing jig and the support plate. The impact force (F1) when the steel ball is made to collide with the support plate in this state is measured, and the rigid body absorbability is obtained by the equation (1).
Rigid body absorbency (%) = (F0-F1) / F0 × 100 (1)
The size of the adhesive tape 100 as an evaluation sample is 20 mm square.
In the impact test device 400, a steel ball 420 having a diameter of 19 mm and a weight of 0.27 N (28 g) is attached to the tip of a support rod 410 (length: 350 mm).
The impact force is measured as follows. That is, the base material side of the evaluation sample 100 is attached to the fixing jig 430 (made of aluminum), and the acrylic support plate 440 (manufactured by Mitsubishi Rayon Co., Ltd., trade name "Acrylite"; thickness) is attached to the adhesive layer side of the evaluation sample 100. (3 mm) is pasted together, the steel ball 420 is made to collide with the acrylic plate 440, the impact force at the time of the collision is detected by the pressure sensor 450, and the MULTI-Purpose FTT Analyzer (manufactured by Ono Sokki Co., Ltd.) Measure at 460.
The evaluation sample 100 is fixed to the fixing jig 430 by adhering an adhesive tape so as to cover the entire width of the upper and lower ends of the evaluation sample.
The collision of the steel balls 420 is performed by swinging up and fixing the support rod 410 until the angle with respect to the vertical direction becomes 20 °, and then releasing the fixing.

The pressure-sensitive adhesive layer is formed from any suitable pressure-sensitive adhesive. Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer include acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, and epoxy-based pressure-sensitive adhesives. Of these, an acrylic pressure-sensitive adhesive is preferable.

The acrylic pressure-sensitive adhesive contains an acrylic polymer as a base polymer. Acrylate-based polymers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and s-butyl (meth). Acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) Acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, Of alkyl (meth) acrylates (preferably C1-C20 alkyl (meth) acrylates) such as hexadecyl (meth) acrylates, heptadecyl (meth) acrylates, octadecyl (meth) acrylates, nonadesyl (meth) acrylates, and ecocil (meth) acrylates. Alone or copolymer; examples thereof include a copolymer of the alkyl (meth) acrylate and another copolymerizable monomer. Other copolymerizable monomers include, for example, carboxyl group- or acid anhydride group-containing monomers such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic anhydride; and hydroxyls such as 2-hydroxyethyl (meth) acrylate. Group-containing monomers; amino group-containing monomers such as morpholyl (meth) acrylate; amide group-containing monomers such as (meth) acrylamide and the like can be mentioned. The content ratio of the structural unit derived from the copolymerizable monomer is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, still more preferably 0.1 parts by weight, based on 100 parts by weight of the base polymer. It is 10 parts by weight.

The weight average molecular weight of the acrylic polymer is preferably 200,000 to 1,500,000, more preferably 400,000 to 1.4 million. The weight average molecular weight can be measured by GPC (solvent: THF).

The pressure-sensitive adhesive may optionally contain any suitable additive. Examples of the additive include a cross-linking agent, a catalyst (for example, a platinum catalyst), a tackifier, a plasticizer, a pigment, a dye, a filler, an anti-aging agent, a conductive material, an ultraviolet absorber, a light stabilizer, and peeling adjustment. Examples thereof include agents, softeners, surfactants, flame retardants, antioxidants, solvents (for example, toluene) and the like.

In one embodiment, the pressure-sensitive adhesive further comprises a cross-linking agent. Examples of the cross-linking agent include an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, an aziridine-based cross-linking agent, and a chelate-based cross-linking agent. The content ratio of the cross-linking agent is preferably 0.1 part by weight to 15 parts by weight, more preferably 0.5 parts by weight to 10 parts by weight, based on 100 parts by weight of the base polymer contained in the pressure-sensitive adhesive. More preferably, it exceeds 0.2 parts by weight and less than 0.8 parts by weight. The flexibility of the pressure-sensitive adhesive layer can be controlled by the content ratio of the cross-linking agent, and as a result, a pressure-sensitive adhesive tape capable of fully exerting the effects of the present invention can be obtained.

(Active energy ray-curable adhesive)
In one embodiment, the pressure-sensitive adhesive layer is composed of an active energy ray-curable pressure-sensitive adhesive. The active energy ray-curable pressure-sensitive adhesive may include a base polymer and a photopolymerization initiator. If an active energy ray-curable adhesive is used, it has low elasticity, high flexibility and excellent handleability at the time of sticking, and can satisfactorily fill the unevenness due to bumps of the semiconductor package, while it is active in situations where peeling is required. By irradiating with energy rays, it is possible to obtain an adhesive tape that can reduce the adhesive strength. Examples of the active energy ray include gamma ray, ultraviolet ray, visible ray, infrared ray (heat ray), radio wave, alpha ray, beta ray, electron beam, plasma flow, ionization ray, particle beam and the like. It is preferably ultraviolet light.

In one embodiment, as an active energy ray-curable pressure-sensitive adhesive, an active energy ray-curable type containing a base polymer as a base material and an active energy ray-reactive compound (monomer or oligomer) capable of binding to the base polymer. The pressure-sensitive adhesive (A1) is used. In another embodiment, an active energy ray-curable pressure-sensitive adhesive (A2) containing an active energy ray-reactive polymer is used as a base polymer. Preferably, the base polymer has a functional group capable of reacting with the photopolymerization initiator. Examples of the functional group include a hydroxyl group and a carboxyl group.

Examples of the base polymer used in the pressure-sensitive adhesive (A1) include natural rubber, polyisobutylene rubber, styrene / butadiene rubber, styrene / isoprene / styrene block copolymer rubber, recycled rubber, butyl rubber, polyisobutylene rubber, and nitrile rubber. Examples include rubber-based polymers such as (NBR); silicone-based polymers; acrylic-based polymers. These polymers may be used alone or in combination of two or more. Of these, an acrylic polymer is preferable. When an acrylic polymer is used, a pressure-sensitive adhesive layer having properties suitable for a semiconductor process (for example, adhesive strength, elastic modulus, etc.) can be formed. As the acrylic polymer, the acrylic polymer described above can be used.

Examples of the active energy ray-reactive compound that can be used in the pressure-sensitive adhesive (A1) include functional groups having a polymerizable carbon-carbon multiple bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group, and an acetylene group. Examples thereof include photoreactive monomers or oligomers having. Specific examples of the photoreactive monomer include trimethylolpropantri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol mono. Hydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, etc. Examples thereof include an esterified product of a meta) acrylic acid and a polyhydric alcohol; a polyfunctional urethane (meth) acrylate; an epoxy (meth) acrylate; and an oligoester (meth) acrylate. Further, monomers such as methacryloisocyanate, 2-methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate), m-isopropenyl-α, and α-dimethylbenzylisocyanate may be used. Specific examples of the photoreactive oligomer include 2 to pentamers of the above-mentioned monomers.

Further, as the active energy ray-reactive compound, a monomer such as epoxidized butadiene, glycidyl methacrylate, acrylamide, vinyl siloxane; or an oligomer composed of the monomer may be used.

Further, as the active energy ray-reactive compound, a mixture of an organic salt such as an onium salt and a compound having a plurality of heterocycles in the molecule may be used. In the mixture, the organic salt is cleaved by irradiation with active energy rays (for example, ultraviolet rays and electron beams) to generate ions, which act as a starting species to cause a ring-opening reaction of a heterocycle to form a three-dimensional network structure. Can be done. Examples of the organic salts include iodonium salt, phosphonium salt, ammonium salt, sulfonium salt, borate salt and the like. Examples of the heterocycle in the compound having a plurality of heterocycles in the molecule include oxylane, oxetane, oxolane, thiirane, and aziridine.

In the pressure-sensitive adhesive (A1), the content ratio of the active energy ray-reactive compound is preferably 0.1 part by weight to 500 parts by weight, and more preferably 1 part by weight to 300 parts by weight with respect to 100 parts by weight of the base polymer. It is by weight, more preferably 4 to 200 parts by weight.

As the active energy ray-reactive polymer (base polymer) contained in the pressure-sensitive adhesive (A2), for example, a functional group having a carbon-carbon multiple bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group, or an acetylene group can be used. Examples include polymers having. Specific examples of the polymer having an active energy ray-reactive functional group include a polymer composed of a polyfunctional (meth) acrylate; a photocationically polymerized polymer; a cinnamoyl group-containing polymer such as polyvinyl cinnamate; and a diazotized aminonovalac. Resins; polyacrylamides; and the like.

The pressure-sensitive adhesive (A2) may further contain the active energy ray-reactive compound (monomer or oligomer).

D. Method for Producing Masking Adhesive Tape The masking adhesive tape can be produced by any suitable method. The masking adhesive tape can be obtained, for example, by applying an adhesive solution to a separator, drying it to form an adhesive layer on the separator, and then attaching it to a substrate. Alternatively, the adhesive solution may be applied onto the substrate and dried to obtain a masking adhesive tape. Various methods such as bar coater coating, air knife coating, gravure coating, gravure reverse coating, reverse roll coating, lip coating, die coating, dip coating, offset printing, flexographic printing, and screen printing are adopted as the coating method of the adhesive solution. can do. As the drying method, any suitable method can be adopted. In one embodiment, the pressure-sensitive adhesive layer can be formed through any suitable curing process.

E. Method for Manufacturing Electromagnetic Wave Shielded Semiconductor Package According to another aspect of the present invention, there is provided a method for manufacturing an electromagnetic wave shielded semiconductor package using an adhesive tape for masking. This manufacturing method includes masking the bump-forming surface of the semiconductor package by the tray method using the masking adhesive tape. The details of the tray method, the structure of the semiconductor package applied to the tray method, and the masking adhesive tape used are as described above.

In one embodiment, in the above manufacturing method, after masking the bump forming surface, a metal layer is formed on a surface other than the surface to which the masking adhesive tape for semiconductor package is attached by a vacuum film forming method. including. Examples of the vacuum film forming method include a sputtering method, a vacuum vapor deposition method, an ion plating method, and the like, and a sputtering method is preferable. In one embodiment, the metal layer is a layer that can function as an electromagnetic wave shield.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Further, in the examples, unless otherwise specified, "parts" and "%" are based on weight.

[Production Example 1] Preparation of Adhesive A 371 parts of butyl acrylate, 27 parts of -2-hydroxylethyl acrylate, and 0.8 of a polymerization initiator (2,2'-azobis-isobutyronitrile (AIBN)) Parts and 315 parts of a solvent (methyl ethyl ketone (MEK)) were mixed to prepare a monomer composition.
The monomer composition is placed in a 1 L round bottom separable flask in an experimental apparatus for polymerization equipped with a separable cover, a separating funnel, a thermometer, a nitrogen introduction tube, a Liebig condenser, a vacuum seal, a stirring rod, and a stirring blade. The mixture was charged and replaced with nitrogen at room temperature for 6 hours with stirring. Then, nitrogen was introduced and stirred at 65 ° C. for 6 hours for polymerization to obtain a resin solution.
The obtained resin solution was cooled to room temperature. Then, 18 parts of 2-isocyanatoethyl methacrylate (manufactured by Showa Denko Co., Ltd., trade name "Karenzu MOI") was added to the resin solution as a compound having a polymerizable carbon-carbon double bond. Further, 0.11 part of dibutyltin dilaurate IV (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was stirred at 50 ° C. for 24 hours under an air atmosphere. Then, 0.42 parts of a polymerization inhibitor (trade name "Irganox 1010" manufactured by Ciba Japan Co., Ltd.) was added to obtain an ultraviolet curable acrylic polymer.
100 parts of the above ultraviolet curable acrylic polymer, 0.4 parts of a cross-linking agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L"), and a photopolymerization initiator (manufactured by Ciba Japan, trade name "Irgacure 360") 1 part and 0.1 part of a polymerization inhibitor (manufactured by Ciba Japan, trade name "Irganox 1010") were mixed to obtain an adhesive A.

[Production Example 2] Preparation of Adhesive B Adhesive B was obtained in the same manner as in Production Example 1 except that the amount of the cross-linking agent was 0.2 parts.

[Production Example 3] Preparation of Adhesive C An adhesive C was obtained in the same manner as in Production Example 1 except that the amount of the cross-linking agent was 0.8 parts.

[Example 1]
The above adhesive A is applied to the silicone-treated surface of a PET film as a separator (manufactured by Mitsubishi Plastics, trade name "MRF38"; thickness: 38 μm), and then the coated layer is heated at 150 ° C. for 5 minutes. It was dried to form a pressure-sensitive adhesive layer having a thickness of 150 μm. Next, the pressure-sensitive adhesive layer was attached to the corona-treated surface of a PET base material (manufactured by Toray Industries, Inc., trade name "Lumilar S10"; thickness: 38 μm; corona-treated product), and then aged at 50 ° C. for 2 days for masking. I got an adhesive tape.

[Example 2]
Instead of the PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S10"; thickness: 38 μm; corona-treated product), the PET base material (manufactured by Toray Industries, Inc., trade name “Lumirror S10”; thickness: 50 μm; corona-treated product) An adhesive tape for masking was obtained in the same manner as in Example 1 except that the above was used.

[Example 3]
Instead of the PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S10"; thickness: 38 μm; corona-treated product), the PEN base material (manufactured by Teijin DuPont, trade name “Theonex Q51”; thickness: 50 μm; corona-treated product) ) Was used, and a masking adhesive tape was obtained in the same manner as in Example 1.

[Example 4]
Instead of the PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S10"; thickness: 38 μm; corona-treated product), the PET base material (manufactured by Toray Industries, Inc., trade name “Lumirror S10”; thickness: 75 μm; corona-treated product) An adhesive tape for masking was obtained in the same manner as in Example 1 except that the above was used.

[Example 5]
A masking adhesive tape was obtained in the same manner as in Example 1 except that the adhesive B was used instead of the adhesive A.

[Example 6]
A masking adhesive tape was obtained in the same manner as in Example 1 except that the adhesive C was used instead of the adhesive A.

[Comparative Example 1]
Instead of the PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S10"; thickness: 38 μm; corona-treated product), the PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S10"; thickness: 25 μm; corona-treated product) An adhesive tape for masking was obtained in the same manner as in Example 1 except that the above was used.

[Comparative Example 2]
Instead of the PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S10"; thickness: 38 μm; corona-treated product), the PET base material (manufactured by Toray Industries, Inc., trade name “Lumirror S10”; thickness: 100 μm; corona-treated product) An adhesive tape for masking was obtained in the same manner as in Example 1 except that the above was used.

[Comparative Example 3]
Instead of the PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S10"; thickness: 38 μm; corona-treated product), the PET base material (manufactured by Toray Industries, Inc., trade name “Lumirror S10”; thickness: 188 μm; corona-treated product) An adhesive tape for masking was obtained in the same manner as in Example 1 except that the above was used.

[Comparative Example 4]
Except for the use of a linear low-density polyethylene base material (thickness: 55 μm; corona-treated product) instead of the PET base material (manufactured by Toray Industries, Inc., trade name “Lumira S10”; thickness: 38 μm; corona-treated product). , An adhesive tape for masking was obtained in the same manner as in Example 1.

[Comparative Example 5]
Instead of PET base material (manufactured by Toray Industries, Inc., trade name "Lumira S10"; thickness: 38 μm; corona-treated product), ethylene-vinyl acetate copolymer resin base material (manufactured by Mitsui DuPont Chemical Co., Ltd., trade name "Evaflex P1007") A masking adhesive tape was obtained in the same manner as in Example 1 except that (thickness: 115 μm; corona-treated product) was used.

[Comparative Example 6]
Example 1 except that an olefin base material A (thickness: 80 μm; corona-treated product) was used instead of the PET base material (manufactured by Toray Industries, Inc., trade name “Lumilar S10”; thickness: 38 μm; corona-treated product). In the same manner as above, an adhesive tape for masking was obtained. The olefin base material A is an olefin-based multilayer film in which a layer made of a mixed resin of polypropylene and ethylene / propylene rubber (thickness 60 μm) and a layer made of LLDPE (linear low density polyethylene) (thickness 20 μm) are laminated. Was used.

[Comparative Example 7]
Example 1 except that an olefin base material B (thickness: 150 μm; corona-treated product) was used instead of the PET base material (manufactured by Toray Industries, Inc., trade name “Lumilar S10”; thickness: 38 μm; corona-treated product). In the same manner as above, an adhesive tape for masking was obtained. The olefin base material includes a layer (thickness 50 μm) made of SEBS (styrene elastomer) and MBS (copolymer resin made of methacrylic acid ester-butadiene styrene), a layer made of SEBS (thickness 85 μm), and PE. A multilayer film in which a layer (thickness 15 μm) made of (polyethylene) was laminated in this order was used.

[Comparative Example 8]
Instead of PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S10"; thickness: 38 μm; corona-treated product), polyvinyl chloride base material (manufactured by Ronseal, trade name “HL film”; thickness: 70 μm; corona-treated product) An adhesive tape for masking was obtained in the same manner as in Example 1 except that the product) was used.

<Evaluation>
After peeling the separator from the masking adhesive tapes obtained in Examples and Comparative Examples, the adhesive tape was subjected to the following evaluation. The results are shown in Table 1.

(1) Breaking strength The adhesive tape was cut into a size of 10 mm in width × 60 mm in length to prepare an evaluation sample. The stress-strain curve of the evaluation sample was measured using a tensile tester (Tencilon, manufactured by Shimadzu Corporation) at 25 ° C., a tensile speed of 300 mm / min, and a distance between chucks of 50 mm to obtain a breaking strength.

(2) Rigid body absorption The impact force (F0) when a steel ball is made to collide only with the support plate using the impact tester (pendulum tester) shown in FIG. 4, and between the fixing jig and the support plate. The impact force (F1) when the steel ball was made to collide with the support plate with the adhesive tape inserted was measured, and the rigid body absorbability was determined by the formula (1).
Rigid body absorbency (%) = (F0-F1) / F0 × 100 (1)
The size of the adhesive tape 100 as an evaluation sample was 20 mm square.
In the impact test device 400, a steel ball 420 having a diameter of 19 mm and a weight of 0.27 N (28 g) is attached to the tip of a support rod 410 (length: 350 mm).
The impact force was measured as follows. That is, the base material side of the evaluation sample 100 is attached to the fixing jig 430 (made of aluminum), and the acrylic support plate 440 (manufactured by Mitsubishi Rayon Co., Ltd., trade name "Acrylite"; thickness) is attached to the adhesive layer side of the evaluation sample 100. (3 mm) is pasted together, the steel ball 420 is made to collide with the acrylic plate 440, the impact force at the time of the collision is detected by the pressure sensor 450, and the MULTI-Purpose FTT Analyzer (manufactured by Ono Sokki Co., Ltd.) It was measured at 460.
The evaluation sample 100 was fixed to the fixing jig 430 by adhering an adhesive tape so as to cover the entire width of the upper and lower ends of the evaluation sample.
The collision of the steel balls 420 was carried out by swinging up and fixing the support rod 410 until the angle with respect to the vertical direction became 20 °, and then releasing the fixing.

(3) Stickability (embedding)
As shown in FIG. 2B, the semiconductor package 300 is housed in the compartment 211 of the tray 200 with the bump forming surface facing up, and then an adhesive tape is attached to the bump forming surface to improve the adhesiveness of the adhesive tape. evaluated. The adhesive tape was attached by using a hand roller (weight: 2.4 kg, width: 235 mm) and reciprocating the hand roller once at a speed of 50 mm / sec.
The area of the compartment 211 is 49 mm ² , the height H2 of the partition wall 210 is 470 μm, the area of the semiconductor package 300 is 30.3 mm ² , the height H1 of the semiconductor package 300 is 420 μm, and the thickness H3 of the portion other than the bump of the semiconductor package 300 is. The height H4 of the bump 312 was set to 300 μm, the thickness T of the first substrate layer 310 was set to 80 μm, and the distance L between the first substrate layer 310 and the partition wall 210 was set to 0.75 mm.
As described above, the adhesive tape was attached, and the followability of the adhesive tape to the bumps was observed with an optical microscope (50 times). A (pass) when the bumps are well followed and no voids are generated, voids are confirmed, but B (pass) when the substrate near the bottom of the bumps is stuck, and the followability to the step The case where the sticking to the substrate was not recognized was C (failed).

(4) Evaluation of Adhesive Contamination to Earth After the above evaluation of adhesiveness, the adhesive tape was irradiated with light of 500 mJ / cm ² from the base material side using an ultraviolet irradiation device UM-810. Then, the adhesive sheet was peeled off to obtain a replica of the adhesive sheet attachment surface. From the cross section of the replica, the state of the pressure-sensitive adhesive layer when the pressure-sensitive adhesive sheet was attached, specifically, the amount of deformation of the pressure-sensitive adhesive layer in the vicinity of the first base material layer in the thickness direction was evaluated. In the evaluation, when the deformation of the pressure-sensitive adhesive layer near the first base material layer of the semiconductor package 300 is less than 80 μm in the thickness direction, it can be determined that the pressure-sensitive adhesive layer does not mask the conductive layer 320. it can.
When the deformation of the pressure-sensitive adhesive layer was 20 μm or less in the thickness direction, it was evaluated as A (pass), when it was larger than 20 μm and less than 80 μm, it was evaluated as B (pass), and when it was 80 μm or more, it was evaluated as C (fail).

As is clear from Table 1, if an adhesive tape composed of a polyester resin and having a base material having a specific thickness is used, a desired surface (bump forming surface) can be satisfactorily masked. Such an effect becomes even more remarkable by setting the rigid body absorbability of the adhesive tape within a specific range.

The masking adhesive tape of the present invention is suitably used as an adhesive tape for masking a surface that does not require the formation of a metal layer when a metal layer is formed on a part of the surface of an electronic component by a vacuum film forming method. obtain.

10 Base material 20 Adhesive layer 100 Adhesive tape

Claims (5)

A semiconductor package having a surface on which a bump is formed is housed in a plurality of compartments defined by a partition wall provided on a tray and the upper part is open, and the surface on which the bump is formed is masked. It is an adhesive tape for masking used in the method of
A base material and an adhesive layer arranged on one side of the base material are provided.
The base material is composed of a polyester resin,
The thickness of the base material is 30 μm to 80 μm.
The breaking strength of the masking adhesive tape is 70 N / 10 mm or more.
Adhesive tape for masking. The masking adhesive tape according to claim 1, wherein the pressure-sensitive adhesive layer is thicker than the height of the bump. The masking adhesive tape according to claim 1 or 2 , wherein the pressure-sensitive adhesive layer is composed of an active energy ray-curable pressure-sensitive adhesive. A method for manufacturing an electromagnetic wave shielded semiconductor package using the masking adhesive tape according to any one of claims 1 to 3 . After accommodating a semiconductor package having a surface on which a bump is formed in a plurality of compartments defined by a partition wall provided on a tray and having an open top, the bumps face up.
The masking adhesive tape comprises masking the surface on which the bumps are formed.
The method for manufacturing a semiconductor package with an electromagnetic wave shield according to claim 4 .

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