JP2016201465A - Temperature-sensitive adhesive sheet for dicing ceramic electronic parts and method for producing ceramic electronic parts - Google Patents

Abstract

Disclosed is a temperature-sensitive adhesive sheet for dicing and a method for producing a ceramic electronic component that can firmly fix a workpiece without floating or misalignment at the time of dicing at room temperature and can be easily peeled off at the time of peeling. A thermosensitive pressure-sensitive adhesive sheet for dicing ceramic electronic components, comprising 30 to 70 parts by weight of a (meth) acrylate ester having a linear alkyl group having 18 or more carbon atoms, and 2 to 8 carbon atoms. A weight average molecular weight of 400,000 to 800,000 obtained by polymerizing 30 to 70 parts by weight of an alkyl group-containing (meth) acrylic acid ester and 0 to 10 parts by weight of a polar monomer, and a melting point of 35 ° C. or higher. A temperature-sensitive pressure-sensitive adhesive layer containing a side-chain crystalline polymer is provided on at least one side of the base film. [Selection figure] None

Description

  The present invention relates to a temperature-sensitive adhesive sheet for dicing used in a dicing process of a ceramic electronic component and a method for producing a ceramic electronic component using the same.

  Ceramic capacitors are usually printed on a ceramic green sheet (ceramic molding sheet) obtained by molding a mixture of ceramic powder, binder and solvent, and then laminated and pressure-bonded onto a pedestal (lamination process) Then, the obtained laminate is cut into chips with a dicing saw (dicing step), this cut piece is peeled off (peeling step), fired, and finally an external electrode is formed on the end face of the cut piece. Manufactured.

  In the dicing process after the stacking process, it is necessary that the stacked body is firmly fixed to the base so that the cut pieces are not scattered. For this reason, at the cutting process, the laminated body is being fixed on the base using the adhesive sheet. On the other hand, in the peeling step of peeling the cut piece from the sheet, it is necessary to reduce the adhesive strength of the pressure-sensitive adhesive sheet.

  In particular, recently, with the miniaturization and high performance of electronic components, improvement in dicing accuracy is also required in the dicing process of workpieces such as ceramic electronic components. That is, there is a demand for an adhesive tape that is strongly fixed to improve accuracy during dicing and can be easily peeled to prevent damage to the workpiece.

  Conventionally, re-peeling tapes such as foam tapes and UV tapes have been used as pressure-sensitive adhesive sheets. However, due to the lack of hardness of the pressure-sensitive adhesive at room temperature, that is, the storage elastic modulus G ′ is low, it is processed during dicing. Deviation occurs in the object, and the shape accuracy of the electronic component is lowered, causing a defect.

  In order to solve such problems, it has been proposed to use a temperature-sensitive adhesive sheet containing a foaming agent in a temperature-sensitive adhesive layer containing a side-chain crystalline polymer that crystallizes below the melting point. (Patent Document 1). That is, since the pressure-sensitive adhesive layer contains a side-chain crystallizable polymer, the side chain crystalline polymer is in a crystalline state in the laminating process, and the ceramic green sheet can be laminated on the pressure-sensitive adhesive sheet. The sheet can be heated to increase the adhesiveness and the laminate of green sheets can be fixed on the adhesive sheet. On the other hand, in the peeling step after dicing, the pressure-sensitive adhesive sheet is further heated to foam the foaming agent, and in this state, the anchoring effect of the pressure-sensitive adhesive sheet is reduced and the cut piece can be peeled off by cooling below the melting point. .

  However, since the temperature-sensitive adhesive tape disclosed in Patent Document 1 contains a foaming agent, the work piece is liable to be lifted or misaligned during dicing. That is, due to the addition of the foaming agent, unevenness is generated on the surface, so that the adhesion is lowered, and the workpiece is lifted during dicing. In addition, the addition of the foaming agent reduces the elastic force at 23 ° C., causing a deviation during dicing, resulting in a defective chip shape and a defective electrode. The floating is visually confirmed during dicing or immediately after dicing. After the chip is peeled off, the chip is observed with a microscope to visually check whether there is any shape deformation or electrode shift.

  In addition, in a normal pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer containing a side chain crystallizable polymer, if the pressure-sensitive adhesive layer is harder than the melting point, the anchor effect at the time of application is low, and the pressure-sensitive adhesive layer at room temperature is also present. If it is hard, the adhesive strength at room temperature is insufficient, and the workpiece tends to float during dicing. Further, since the pressure-sensitive adhesive layer develops an adhesive force even when the melting point is exceeded, there is a risk of damaging the electronic component during peeling.

JP 2006-241387 A

  The present invention provides a temperature-sensitive adhesive sheet for dicing capable of firmly fixing a workpiece without floating or misalignment when dicing a ceramic electronic component at room temperature, and a method for producing a ceramic electronic component that can be easily peeled when peeled. For the purpose.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. That is, the present invention has the following configuration.
(1) 30 to 70 parts by weight of a (meth) acrylic acid ester having a linear alkyl group having 18 or more carbon atoms, and 30 to 70 parts by weight of a (meth) acrylic acid ester having an alkyl group having 2 to 8 carbon atoms Based on a thermosensitive pressure-sensitive adhesive layer containing a side chain crystalline polymer having a molecular weight of 400,000 to 800,000 and a melting point of 40 ° C. or higher, obtained by polymerizing 0 to 10 parts by weight of a polar monomer. A temperature-sensitive adhesive sheet for dicing ceramic electronic parts, characterized by being provided on at least one side of a material film.
(2) The temperature-sensitive adhesive sheet according to (1), wherein the temperature-sensitive adhesive layer has a thickness of 1 to 100 μm.
(3) The thermosensitive adhesive sheet according to (1) or (2), wherein the thermosensitive adhesive layer has a storage elastic modulus at 23 ° C. of 1 × 10 ⁶ to 1 × 10 ⁹ Pa.
(4) The temperature-sensitive adhesive layer has an adhesive strength at 23 ° C. of 0.6 N / mm or more with respect to polyethylene terephthalate (PET) measured according to JIS Z0237, and the melting point of the side chain crystalline polymer The temperature-sensitive adhesive sheet according to any one of (1) to (3), wherein the adhesive strength at a temperature exceeding 1 is 0.4 N / mm or less.
(5) A ceramic molded sheet is laminated on the surface of the temperature-sensitive adhesive layer in the temperature-sensitive adhesive sheet according to any one of (1) to (4), with the side-chain crystalline polymer crystallized. And heating the temperature-sensitive adhesive sheet to a temperature equal to or higher than the melting point of the side chain crystalline polymer to develop the adhesive force of the temperature-sensitive adhesive layer. A step of dicing the laminate in a state of being fixed to the temperature-sensitive adhesive sheet, and after the dicing, the temperature-sensitive adhesive sheet is further heated to peel the diced cut pieces from the surface of the temperature-sensitive adhesive layer. A process for producing a ceramic electronic component comprising the steps of:

The thermosensitive pressure-sensitive adhesive sheet for dicing of the present invention has an effect that the workpiece can be firmly fixed without being lifted or displaced at the time of dicing at room temperature, and can be easily peeled at the time of peeling.
According to the method for manufacturing a ceramic electronic component according to the present invention, dicing and peeling can be performed with high shape accuracy, so that the manufacturing efficiency of the ceramic electronic component is improved.

Hereinafter, the temperature-sensitive adhesive sheet for dicing of the present invention applied to the production of ceramic electronic components will be described in detail. In this pressure-sensitive adhesive sheet, a temperature-sensitive pressure-sensitive adhesive layer containing a side-chain crystalline polymer that crystallizes at a melting point or lower is provided on one side or both sides of a base film.
In the present invention, the ceramic electronic component is an electronic manufactured through a process of dicing a laminate of ceramic molded sheets (hereinafter sometimes referred to as green sheets) such as a ceramic capacitor and a ceramic inductor. Refers to parts.

  Examples of the base film include a single synthetic resin film such as polyethylene, polypropylene, polyester, polyamide, polyimide, polycarbonate, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene polypropylene copolymer, and polyvinyl chloride. Examples thereof include a sheet having a thickness of 5 to 500 μm composed of a layered body or a multilayered body thereof.

  The surface of the base film may be subjected to corona discharge treatment, plasma treatment, blast treatment, chemical etching treatment, primer treatment, etc. in order to improve the adhesion to the pressure-sensitive adhesive layer.

  A temperature-sensitive adhesive layer is applied to at least one side of the base film. The temperature-sensitive pressure-sensitive adhesive layer in the present invention refers to a pressure-sensitive adhesive layer that reversibly causes a fluid state and a crystalline state in response to a temperature change. In the case of the present invention, the side-chain crystalline polymer contained in the temperature-sensitive adhesive layer is crystallized at a melting point or lower to have a high elastic modulus, and when it exceeds the melting point, exhibits fluidity and develops adhesiveness. It has the property to become.

That is, after laminating ceramic green sheets with the side chain crystalline polymer crystallized to obtain a laminate, the side chain crystalline polymer is flowed at a temperature equal to or higher than the melting point of the side chain crystalline polymer, The temperature-sensitive adhesive layer develops adhesive force, and the laminate can be attached. Further, when the side chain crystalline polymer is flowed at the above temperature, the temperature-sensitive pressure-sensitive adhesive layer follows the fine uneven shape present on the surface of the laminate well.
When the temperature-sensitive pressure-sensitive adhesive layer is cooled to a temperature lower than the melting point from this state, the side chain crystalline polymer is crystallized, so that a so-called anchor effect appears, and as a result, the laminate is formed into the temperature-sensitive pressure-sensitive adhesive layer. It becomes possible to fix to the surface.

  Specifically, the side chain crystalline polymer has a melting point of 35 ° C to 70 ° C, preferably 40 to 60 ° C. When the melting point is 35 ° C. or higher, crystallization is performed at room temperature, so that it can be firmly fixed during dicing.

  The set temperature for switching the temperature-sensitive adhesive layer to the crystalline state or the fluid state can be changed depending on the temperature at the time of cutting the green sheet laminate. For example, at temperatures below 40 ° C. it will be almost crystalline and fluidized at temperatures above 50 ° C., or at temperatures below 50 ° C. it will be almost crystalline and fluidized at temperatures above it. It may be. These temperature changes can be arbitrarily performed by changing the polymer structure, the formulation of the adhesive layer, and the like as shown below.

  In the present invention, the “melting point” refers to a temperature at which a specific portion of a polymer that is initially aligned in an ordered arrangement becomes disordered by an equilibrium process. The melting point in the present invention is measured with a differential thermal scanning calorimeter (DSC) under measurement conditions of 10 ° C./min.

Specific examples of the side chain crystalline polymer include 30 to 70 parts by weight of a (meth) acrylic acid ester having a linear alkyl group having 18 or more carbon atoms, preferably 18 to 22 carbon atoms, and 2 to 8 carbon atoms. A polymer obtained by polymerizing 30 to 70 parts by weight of a (meth) acrylic acid ester having an alkyl group and 0 to 10 parts by weight of a polar monomer is preferable.
In addition, (meth) acrylic acid ester means acrylic acid ester or methacrylic acid ester.

The (meth) acrylic acid ester having a linear alkyl group having 18 or more carbon atoms as a side chain is a line having 18 to 22 carbon atoms such as stearyl (meth) acrylate, eicosyl (meth) acrylate, and behenyl (meth) acrylate. (Meth) acrylic acid ester having an alkyl group is preferably used.
Examples of the (meth) acrylic acid ester having an alkyl group having 2 to 8 carbon atoms include ethyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth) acrylate.
Examples of polar monomers include carboxyl-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meta ) Ethylenically unsaturated monomers having a hydroxyl group such as acrylate and 2-hydroxyhexyl (meth) acrylate are used.

  The polymer preferably has a weight average molecular weight of 400,000 to 800,000. If the weight average molecular weight of the polymer is less than 400,000, the cutting accuracy of the laminate may be deteriorated due to insufficient cohesive force. Moreover, when the weight average molecular weight of a polymer exceeds 800,000, there exists a possibility that solution viscosity may become high and coating may become difficult. The weight average molecular weight is a value obtained by measuring the polymer by gel permeation chromatography (GPC) and converting the obtained measurement value to polystyrene.

Moreover, in order to raise the cohesion force of the said thermosensitive adhesive layer, you may add a crosslinking agent. Examples of the crosslinking agent include isocyanate compounds, aziridine compounds, epoxy compounds, metal chelate compounds, and the like. Moreover, arbitrary components, such as a plasticizer, a tackifier, a filler, can be added to a temperature sensitive adhesive layer as needed. Examples of the tackifier include special rosin ester, terpene phenol, petroleum resin, high hydroxyl value rosin ester, and hydrogenated rosin ester.
Further, in order to better adhere the lowermost layer of the laminate in a crystalline state below the melting point, a small amount of an acrylic or rubber-based general pressure-sensitive adhesive may be added.

  In general, a knife coater, a roll coater, a calendar coater, a comma coater or the like is often used to provide a temperature-sensitive adhesive layer on a base film. Depending on the coating thickness and material viscosity, a gravure coater or a rod coater can be used. The thickness of the temperature sensitive pressure-sensitive adhesive layer is 1 to 100 μm, preferably 5 to 50 μm.

The temperature-sensitive adhesive layer preferably has a storage elastic modulus of 1 × 10 ⁶ to 1 × 10 ⁹ Pa at 23 ° C. which is lower than the melting point of the side chain crystalline polymer. When the elastic modulus is less than 1 × 10 ⁶ Pa, the cohesive force is inferior, so that a deviation occurs during dicing of the green sheet laminate, and a shape defect, an electrode deviation, and the like are likely to occur. On the other hand, it is impossible for the present invention that the elastic modulus exceeds 1 × 10 ⁹ Pa.

Moreover, when the adhesive strength with respect to the polyethylene terephthalate (PET) measured based on JIS Z0237 was measured, the adhesive strength in 23 degreeC which is below melting | fusing point of a side chain crystalline polymer is 0. The adhesive strength measured in the same manner at a temperature exceeding 6 N / 25 mm and exceeding the melting point of the side chain crystalline polymer is 0.4 N / 25 mm or less.
When the adhesive strength at 23 ° C. is 0.6 N / 25 mm or more, it is possible to prevent the laminate from being lifted or displaced due to a strong fixing force during dicing of the laminate. On the other hand, when the adhesive strength is 0.4 N / 25 mm or less at a temperature exceeding the melting point of the side chain crystalline polymer, easy peeling becomes possible and damage to electronic components can be suppressed.

  Next, a method for producing a multilayer ceramic capacitor using the pressure-sensitive adhesive sheet of the present invention will be described.

  First, a ceramic powder slurry is thinly spread with a doctor blade to form a ceramic green sheet, and electrodes are printed on the surface of the green sheet. Next, a plurality of green sheets are laminated on the pedestal via the temperature-sensitive adhesive sheet of the present invention to form a green sheet laminate. At this time, the temperature of the pressure-sensitive adhesive sheet is preferably in a crystallized state where the side chain crystalline polymer is not higher than the melting point.

Next, the temperature-sensitive adhesive sheet is heated to the melting point or higher to bond and fix the laminate on the pedestal. Heating is performed, for example, by heating a laminated body with a heat source (heater plate) attached thereto or by placing the pedestal in a hot atmosphere. The heating temperature should be a relatively high temperature above the melting point (for example, 50 to 80 ° C.), which increases the fluidity of the side chain crystalline polymer and enters the unevenness of the workpiece, and the laminate is not sensitive. Adheres well to the temperature-sensitive adhesive layer of the temperature-sensitive adhesive sheet.

Thereafter, the side chain crystalline polymer is crystallized by cooling below the melting point, the hardness (storage elastic modulus) of the temperature-sensitive adhesive layer is greatly increased, and is firmly fixed. After fixing, the laminated body is thermocompression bonded and diced (cut) with a dicing saw (cutting blade). During dicing, the temperature-sensitive adhesive sheet can suppress the raw sheet from being pushed by the dicing saw and moving laterally. In this way, a plurality of cut pieces (chips) are formed.
At this time, in the present invention, since the foaming agent as described in Patent Document 1 is not contained, the deviation at the time of dicing due to insufficient hardness at a temperature below the melting point (room temperature or the like) can be eliminated. . That is, the temperature-sensitive adhesive layer in the present invention does not contain a foaming agent, thereby improving the adhesive force and hardness at a temperature below the melting point, and suppressing floating and deviation of the laminate during dicing. Can do. That is, since the foaming agent has a lower elastic modulus than the crystallized side-chain crystalline polymer, the hardness at a temperature below the melting point is reduced, and unevenness due to the foaming agent is generated on the surface. The adhesive strength at a temperature below the melting point cannot be sufficiently developed.

  Next, by heating the temperature-sensitive adhesive sheet to the melting point or higher again, the adhesive is greatly softened and easily peeled. At this time, even if the temperature-sensitive pressure-sensitive adhesive layer in the present invention does not contain a foaming agent, the adhesive strength decreases to such an extent that it can be peeled without damage due to a large decrease in elastic modulus above the melting point. In this way, the temperature-sensitive adhesive layer of the pressure-sensitive adhesive sheet is made non-tacky. In this state, the cut piece is taken out from the pressure-sensitive adhesive sheet, and then the cut piece is sent to a temporary firing step and a main firing step and fired, and external electrodes are formed on the end face to obtain a chip-shaped ceramic electronic component. When the pressure-sensitive adhesive sheet is cooled, it can be peeled off by natural cooling, for example.

  In the above description, the pressure sensitive adhesive layer is provided on one side of the base film to form the pressure sensitive adhesive sheet. However, the pressure sensitive adhesive layer may also be provided on the other side of the base film and used as a double sided adhesive sheet. . In this case, as the second pressure-sensitive adhesive layer laminated on the other surface of the base film, (1) a commercially available pressure-sensitive adhesive layer and (2) a commercially available pressure-sensitive adhesive and the side used in the present invention. An adhesive layer composed of a mixture of a chain crystalline polymer and a foaming agent, or (3) a temperature-sensitive adhesive layer used in the present invention can be used.

  Examples of pressure sensitive adhesives include natural rubber adhesives; synthetic rubber adhesives; styrene / butadiene latex-based adhesives; block copolymer type thermoplastic rubbers; butyl rubbers; polyisobutylenes; acrylic adhesives; Can be given.

  In the above description, the production of the multilayer ceramic capacitor as the ceramic electronic component has been described. However, the present invention is not limited to this, and the ceramic capacitor, ceramic inductor, resistor, ferrite, sensor element, thermistor, varistor, piezoelectric ceramic, etc. It can be similarly applied to the manufacture of ceramic electronic components.

  Hereinafter, although the temperature-sensitive adhesive sheet of the present invention will be described in detail with reference to Examples and Comparative Examples, the present invention is not limited only to the following Examples. In the following description, “part” means part by weight.

  The copolymers used in the following Examples and Comparative Examples are the three types obtained in Synthesis Examples 1 to 3 below.

(Synthesis Example 1)
Ethyl acetate at a ratio of 45 parts behenyl acrylate (manufactured by NOF Corporation), 50 parts of butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 5 parts of acrylic acid, and 0.5 part of perbutyl ND (manufactured by NOF Corporation). After mixing with 230 parts and stirring at 55 ° C. for 4 hours, the temperature was raised to 80 ° C., and then 0.5 part of perhexyl PV (manufactured by NOF Corporation) was added and stirred for 2 hours. Was polymerized. The obtained copolymer had a weight average molecular weight of 650,000 and a melting point of 43 ° C.

(Synthesis Example 2)
45 parts of behenyl acrylate (manufactured by Nippon Oil & Fats Co., Ltd.), 50 parts of butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 5 parts of 2-ethylhexyl acrylate (2HEA, manufactured by Nippon Shokubai Co., Ltd.), and perbutyl ND (Nippon Oil & Fats) (Compared with 0.5 parts by weight) with 230 parts of ethyl acetate, stirred at 55 ° C. for 4 hours, heated to 80 ° C., and then perhexyl PV (manufactured by NOF Corporation) was added to 0.5 parts. A portion was added and stirred for 2 hours to polymerize these monomers. The obtained copolymer had a weight average molecular weight of 650,000 and a melting point of 42 ° C.

(Synthesis Example 3)
Ethyl acetate at a ratio of 45 parts behenyl acrylate (manufactured by NOF Corporation), 50 parts of methyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 5 parts of acrylic acid, and 0.5 part of perbutyl ND (manufactured by NOF Corporation). After mixing with 230 parts and stirring at 55 ° C. for 4 hours, the temperature was raised to 80 ° C., and then 0.5 part of perhexyl PV (manufactured by NOF Corporation) was added and stirred for 2 hours. Was polymerized. The resulting copolymer had a weight average molecular weight of 650,000 and a melting point of 54 ° C.
The copolymers of Synthesis Examples 1 to 4 are shown in Table 1.

  A copolymer solution was prepared from the copolymer obtained in Synthesis Example 1 using ethyl acetate so that the solid content was 30%. Next, 0.7 parts of an aziridine compound (PZ-33 manufactured by Nippon Shokubai Co., Ltd.) as a crosslinking agent was added to the copolymer solution with respect to 100 parts of the copolymer to obtain a temperature-sensitive adhesive composition. It was. This temperature-sensitive adhesive composition was applied to one side of a substrate film (PET film having a thickness of 100 μm) and dried to form a temperature-sensitive adhesive layer having a thickness of 40 μm.

Instead of the copolymer obtained in Synthesis Example 1, the copolymer obtained in Synthesis Example 2 was used, and an isocyanate compound (L45 manufactured by Nippon Polyurethane Co., Ltd.) was used instead of the aziridine compound as a crosslinking agent. A temperature-sensitive adhesive layer having a thickness of 40 μm was formed on one side of the base film in the same manner as in Example 1 except that 2.5 parts were added to 100 parts of the combined body.
[Comparative Example 1]

A commercially available foam tape (adhesive layer thickness: 45 μm) was used. The pressure-sensitive adhesive layer of the foamed tape is obtained by providing a pressure-sensitive adhesive layer having a thickness of 45 μm on the surface of a substrate film (PET film) having a thickness of 100 μm.

[Comparative Example 2]
A copolymer solution was prepared from the copolymer obtained in Synthesis Example 1 using ethyl acetate so that the solid content was 30%, and an aziridine compound (Nippon Shokubai Co., Ltd.) was used as a cross-linking agent. 0.5 parts of PZ-33) manufactured by Co., Ltd. is added to 100 parts of the above copolymer, and as a foaming agent, a thermally expandable microsphere ("551DU40" manufactured by EXPANCEL), foaming temperature: 130 ° C, average (Particle size: 13 μm) was added so as to be 40% by weight with respect to the total solid content to obtain a temperature-sensitive adhesive composition. Others were carried out similarly to Example 1, and formed the 40-micrometer-thick thermosensitive adhesive layer in the single side | surface of a base film.

[Comparative Example 3]
Instead of the copolymer obtained in Synthesis Example 1, the copolymer obtained in Synthesis Example 3 was used, except that the amount of the crosslinking agent was added so as to be 0.5% by weight. Similarly, a thermosensitive adhesive layer having a thickness of 40 μm was formed on one side of the base film.

Each temperature-sensitive adhesive sheet obtained in Examples and Comparative Examples was evaluated by the following evaluation methods.
(I) Adhesive strength The adhesive strength with respect to PET film when a thermosensitive adhesive sheet was heated at 23 degreeC and 60 degreeC was measured according to JISZ0237. That is, first, at an atmospheric temperature of 60 ° C., the thermosensitive adhesive sheet was fixed to a stainless steel plate with a commercially available double-sided tape with the separator as the upper surface. Next, the separator was removed, and a PET film having a thickness of 25 μm was attached to the exposed surface of the temperature-sensitive adhesive layer. Then, the PET film was peeled 180 ° at a rate of 300 mm / min using a load cell, and the 180 ° peel strength at 60 ° C. was evaluated. Next, it was cooled to an ambient temperature of 23 ° C., peeled 180 ° in the same manner, and 180 ° peel strength at 23 ° C. was evaluated.
(ii) Storage modulus The storage modulus (G ′) at 23 ° C. and 60 ° C. was measured as follows.
Device name: Thermo SCIENTIFIC HAAKE MARS III, load: 1.00N, frequency: 1.00Hz, heating rate: 5 ℃ / min, temperature process: 0 ℃ → 150 ℃, measurement thickness: 800μm
(Iii) Dicing float In the ceramic chip capacitor manufacturing process, after the green sheet laminate was diced, it was visually confirmed whether the green sheet laminate attached to the surface of the temperature-sensitive adhesive layer was floating. As a result, the case where the laminate did not float was rated as “◯”, the case where partial lifting occurred was Δ, and the case where the entire surface was lifted was rated “X”.
(Iv) Dicing displacement In the ceramic chip capacitor manufacturing process, after dicing the laminated body, the chip was peeled off by heating, and the chip was observed with a microscope to visually confirm that there was no shape deformation or electrode displacement. . As a result, the case where there was no shape deformation or electrode misalignment was marked with ◯, and the shape deformation or electrode misalignment was marked with x.
(V) Peelability In the peeling process in the production of a ceramic chip capacitor, the case where it was completely peeled off was marked with ◯, the case where it was not partly peeled was marked with Δ, and the case where it was not peeled off was marked with ×. The dicing chip was peeled off by heating the temperature-sensitive adhesive layer to 60 ° C. in Examples 1 and 2 and Comparative Example 3, but in Comparative Examples 1 and 2, the foaming agent was foamed. And further heating to 130 ° C. These test results are shown in Table 2.

From Table 2, the following points become clear.
Since Comparative Example 1 lacks the storage elastic modulus below the melting point (23 ° C.), there is a problem of deviation during dicing.
Since Comparative Example 2 has insufficient adhesive strength and storage elastic modulus below the melting point (23 ° C.), there is a problem of floating and misalignment during dicing. (23 ° C adhesive strength, insufficient elastic modulus)
Comparative Example 3 has a problem of floating at the time of dicing because of insufficient adhesive strength below the melting point (23 ° C.), and further has a problem in peelability.
On the other hand, the temperature-sensitive adhesive sheets of Examples 1 and 2 were free from dicing or shifting, and had good peelability.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. That is, the present invention has the following configuration.
(1) 30 to 70 parts by weight of a (meth) acrylic acid ester having a linear alkyl group having 18 or more carbon atoms, and 30 to 70 parts by weight of a (meth) acrylic acid ester having an alkyl group having 2 to 8 carbon atoms Based on a thermosensitive pressure-sensitive adhesive layer containing a side chain crystalline polymer having a molecular weight of 400,000 to 800,000 and a melting point of 40 ° C. or higher, obtained by polymerizing 0 to 10 parts by weight of a polar monomer. A temperature-sensitive adhesive sheet for dicing ceramic electronic parts, characterized by being provided on at least one side of a material film.
(2) The temperature-sensitive adhesive sheet according to (1), wherein the temperature-sensitive adhesive layer has a thickness of 1 to 100 μm.
(3) The thermosensitive adhesive sheet according to (1) or (2), wherein the thermosensitive adhesive layer has a storage elastic modulus at 23 ° C. of 1 × 10 ⁶ to 1 × 10 ⁹ Pa.
(4) The temperature-sensitive adhesive layer has an adhesive strength at 23 ° C. of 0.6 N / mm or more with respect to polyethylene terephthalate (PET) measured according to JIS Z0237, and the melting point of the side chain crystalline polymer The temperature-sensitive adhesive sheet according to any one of (1) to (3), wherein the adhesive strength at a temperature exceeding 1 is 0.4 N / mm or less.
(5) A plurality of ceramic molded sheets in which the side-chain crystalline polymer is crystallized on the surface of the temperature-sensitive adhesive layer in the temperature-sensitive adhesive sheet according to any one of (1) to (4) above. A step of obtaining a laminate by heating the temperature-sensitive adhesive sheet to a temperature equal to or higher than the melting point of the side chain crystalline polymer to develop the adhesive force of the temperature-sensitive adhesive layer, and then the melting point Cooling to the following temperature, the step of dicing the laminate in a state where the laminate is fixed to the temperature-sensitive adhesive sheet, and after dicing, the temperature-sensitive adhesive sheet is again heated to a temperature equal to or higher than the melting point. And a step of peeling the diced cut piece from the surface of the temperature-sensitive adhesive layer.

Claims (5)

  30 to 70 parts by weight of a (meth) acrylic acid ester having a linear alkyl group having 18 or more carbon atoms, 30 to 70 parts by weight of a (meth) acrylic acid ester having an alkyl group having 2 to 8 carbon atoms, and a polar monomer The base material is a temperature-sensitive adhesive layer containing a side chain crystalline polymer having a weight average molecular weight of 400,000 to 800,000 and a melting point of 35 ° C. or higher, obtained by polymerizing 0 to 10 parts by weight. A temperature-sensitive adhesive sheet for dicing ceramic electronic parts, characterized in that it is provided on at least one side of a film.   The temperature-sensitive adhesive sheet according to claim 1, wherein the temperature-sensitive adhesive layer has a thickness of 1 to 100 μm. 3. The temperature-sensitive adhesive sheet according to claim 1, wherein the temperature-sensitive adhesive layer has a storage elastic modulus at 23 ° C. of 1 × 10 ⁶ to 1 × 10 ⁹ Pa. 4.   The temperature-sensitive pressure-sensitive adhesive layer has a pressure-sensitive adhesive strength at 23 ° C. of 0.6 N / 25 mm or more against polyethylene terephthalate measured according to JIS Z0237, and is a pressure-sensitive adhesive at a temperature exceeding the melting point of the side chain crystalline polymer. The temperature-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the strength is 0.4 N / 25 mm or less. The laminated body is obtained by laminating a ceramic molded sheet with the side chain crystalline polymer in a crystallized state on the surface of the thermosensitive adhesive layer in the thermosensitive adhesive sheet according to any one of claims 1 to 4. Process,
In the state where the thermosensitive adhesive sheet is heated to a temperature equal to or higher than the melting point of the side chain crystalline polymer, the adhesive force of the thermosensitive adhesive layer is expressed, and the laminate is fixed to the thermosensitive adhesive sheet. Dicing the laminate,
After the dicing, further heating the thermosensitive adhesive sheet, and peeling the diced cut pieces from the surface of the thermosensitive adhesive layer;
A method for producing a ceramic electronic component comprising: