TWI596187B - Temperature-sensitive adhesive sheet for manufacturing ceramic electronic parts and method for manufacturing ceramic electronic parts - Google Patents

Description

Temperature-sensitive adhesive sheet for manufacturing ceramic electronic parts and method for manufacturing ceramic electronic parts

The present invention relates to a temperature sensitive adhesive sheet in which a laminate is temporarily fixed in order to cut a laminate including a ceramic molded piece in a process of manufacturing a ceramic electronic component such as a ceramic capacitor, and a ceramic electronic component using the temperature sensitive adhesive sheet. Production method.

A ceramic capacitor is usually produced by printing a predetermined green electrode on a ceramic green sheet (ceramic molded sheet) obtained by molding a mixture of ceramic powder, a binder, and a solvent, and laminating and pressing it on a susceptor. (Lamination step), the obtained laminate is cut into a wafer shape (cutting step), the cut sheet is peeled off (peeling step), and fired, and finally, an external electrode is formed on the end surface of the cut sheet.

In the cutting step after the laminating step, in order to prevent the cut pieces from being scattered, it is necessary to firmly fix the laminate to the susceptor. Therefore, in the cutting step, the laminate is fixed to the susceptor using an adhesive sheet. On the other hand, in the peeling process of peeling a cut piece from a sheet, it is necessary to reduce the adhesive force of an adhesive sheet.

In particular, recently, with the miniaturization and high performance of electronic components, it is required to improve the cutting accuracy in the cutting process of workpieces such as ceramic electronic components. In other words, the adhesive tape is required to be strongly fixed in order to improve the accuracy at the time of cutting, and then to be easily peeled off in order to prevent damage to the workpiece.

Patent Document 1 discloses an adhesive sheet comprising an adhesive layer containing a temperature sensitive adhesive and a foaming agent, wherein the temperature sensitive adhesive comprises a pressure-sensitive adhesive and a side chain crystalline polymer, and the adhesive The adhesion of the sheet to a temperature above the melting point of the side chain crystalline polymer is lowered.

However, the adhesive sheet disclosed in Patent Document 1 has a problem that variation in the laminate tends to occur at the time of cutting in the cutting step. Further, when the fixing force of the laminate on the susceptor is insufficient, the laminate tends to float at the time of cutting, and conversely, if the fixing force on the susceptor is too strong, the peeling property is lowered, so that at the time of peeling It is possible to cause damage to electronic components. The variation or floating of the laminate at the time of cutting causes a decrease in cutting accuracy, and it is not possible to cope with the expectation of downsizing and high performance of electronic components.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2008-13590

An object of the present invention is to provide a temperature sensitive adhesive sheet and a ceramic electronic component using the temperature sensitive adhesive sheet. In the manufacturing process of the ceramic electronic component, the temperature-sensitive adhesive sheet can be used to cut the laminate including the ceramic molded article, and the laminate can be temporarily fixed without being floated or unevenly removed, and can be easily peeled off during peeling. .

The temperature-sensitive adhesive sheet of the present invention is a sheet in which a laminate is temporarily fixed in order to cut a laminate including a ceramic molded sheet in a process of manufacturing a ceramic electronic component, and at least one surface of the base film is provided with temperature-sensitive adhesive. The adhesive layer of the agent and the foaming agent, wherein the temperature sensitive adhesive comprises a pressure-sensitive adhesive and a side chain crystalline polymer, and the temperature adhesive force at a temperature equal to or higher than a melting point of the side chain crystalline polymer is lowered. The blowing agent expands or foams at a temperature higher than the melting point of the above-mentioned side chain crystalline polymer. The foaming agent has a particle diameter smaller than the thickness of the pressure-sensitive adhesive layer, and is contained in a ratio of more than 10 parts by weight and less than 30 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive. The thickness of the above adhesive layer is greater than 5 μm and less than 30 μm. The side chain crystalline polymer is contained in an amount of 10 parts by weight or less based on 100 parts by weight of the pressure-sensitive adhesive, and the adhesive layer has an adhesive strength at 23 ° C of 1 to 6 N/25 mm.

The method for producing a ceramic electronic component according to the present invention includes the step of fixing a plurality of ceramics in a state in which the side chain crystalline polymer is crystallized on the surface of the temperature sensitive adhesive layer of the temperature sensitive adhesive sheet. a laminate of sheets; a step of cutting the laminate to obtain a cut sheet; and after the cutting, heating the adhesive sheet to foam the foaming agent at a temperature higher than a melting point of the side chain crystalline polymer; The step of peeling the cut piece from the foamed adhesive sheet.

The temperature-sensitive adhesive sheet of the present invention is set to an appropriate range by the thickness of the adhesive layer and the blending amount of the compounding component contained in the adhesive layer, and the laminate including the ceramic formed sheet can be float-free or It is temporarily fixed firmly in the deviation, and can be easily peeled off at the time of peeling, whereby the cutting accuracy of the laminated body is improved, and the damage due to peeling can be reduced. Therefore, the temperature-sensitive adhesive sheet of the present invention can be suitably used as an adhesive sheet in which a laminate is temporarily fixed in order to cut a laminate including a ceramic molded sheet in a manufacturing process of a ceramic electronic component.

Hereinafter, the temperature sensitive adhesive sheet of the embodiment of the present invention used in the manufacturing process of the ceramic electronic component will be described in detail. In the temperature sensitive adhesive sheet, the adhesive layer is provided on one or both sides of the base film.

In the present embodiment, the ceramic electronic component is manufactured by a process of cutting a laminate of a ceramic molded piece (hereinafter sometimes referred to as a green sheet), such as a ceramic capacitor or a ceramic inductor. Electronic parts.

<Adhesive layer>

The adhesive layer of the present embodiment contains a temperature sensitive adhesive and a foaming agent, and has a thickness of more than 5 μm and less than 30 μm, preferably 10 to 28 μm, more preferably 10 to 25 μm. Temperature sensitive adhesive means that the adhesion is based on temperature Adhesive that changes and changes. The temperature sensitive adhesive of the present embodiment contains a pressure-sensitive adhesive and a side chain crystalline polymer, and the adhesive strength is lowered at a temperature equal to or higher than the melting point of the side chain crystalline polymer.

(pressure-sensitive adhesive)

The pressure-sensitive adhesive is not particularly limited as long as it is a polymer having adhesiveness, and examples thereof include a natural rubber bonding agent; a synthetic rubber bonding agent; a styrene/butadiene latex-based bonding agent; and a block copolymer type. Thermoplastic rubber; butyl rubber; polyisobutylene; acrylic binder; copolymer of vinyl ether. In particular, in the present embodiment, the acrylic binder is preferably an acrylate and/or methacrylate having a carbon number of 1 to 12 (hereinafter referred to as (meth) acrylate] as a main component. The copolymer is preferably a copolymer obtained by polymerizing one or more of ethyl hexyl (meth) acrylate, hydroxyethyl (meth) acrylate, and methyl (meth) acrylate.

(side chain crystalline polymer)

The side chain crystalline polymer preferably crystallizes at a temperature lower than the melting point and exhibits fluidity at a temperature higher than the melting point. That is, a polymer which reversibly causes a crystal state and a flow state depending on a temperature change may be used. Therefore, since the side chain crystalline polymer is in a crystalline state at a temperature lower than the melting point, the temperature sensitive adhesive can ensure a predetermined adhesive force, and the side chain crystalline polymer becomes in a flowing state at a temperature equal to or higher than the melting point. Therefore, the adhesive force of the temperature sensitive adhesive can be sufficiently lowered. Therefore, the adhesive layer of the present embodiment exhibits stickiness at a temperature equal to or higher than the melting point of the side chain crystalline polymer. Reduce the effort.

In the present embodiment, the melting point indicates a temperature at which a specific portion of the polymer which is initially integrated into an ordered arrangement is disordered by a certain equilibrium process, and is a differential thermal scanning calorimeter (DSC) at 10 ° C / min. The value obtained by measuring the measurement conditions. In the present embodiment, the side chain crystalline polymer has a melting point of 45 ° C or higher, preferably 50 to 70 ° C. Therefore, since the side chain crystalline polymer is crystallized at room temperature, workability is improved.

The composition of the side chain crystalline polymer is, for example, 30 to 99 parts by weight of a (meth) acrylate having a linear alkyl group having 16 or more carbon atoms, preferably 16 to 22 carbon atoms. A polymer obtained by polymerizing 0 to 70 parts by weight of an acrylate or methacrylate having an alkyl group having 1 to 6 carbon atoms, and 1 to 10 parts by weight of a polar monomer.

Examples of the (meth) acrylate having a linear alkyl group having 16 or more carbon atoms as a side chain include hexadecyl (meth) acrylate and octadecyl (meth) acrylate. (Meth) acrylate having a linear alkyl group having 16 to 22 carbon atoms such as eicosyl (meth)acrylate or behenyl (meth)acrylate. Examples of the (meth) acrylate having an alkyl group having 1 to 6 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and (methyl). ) hexyl acrylate and the like. Examples of the polar monomer include carboxyl group-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid; and 2-hydroxyethyl (meth)acrylate. An ethylenically unsaturated monomer having a hydroxyl group such as an ester, 2-hydroxypropyl (meth)acrylate or 2-hydroxyhexyl (meth)acrylate.

The weight of the above polymer, that is, the side chain crystalline polymer The average molecular weight is from 3,000 to 30,000, preferably from 5,000 to 25,000. When the weight average molecular weight is within this range, when the side chain crystalline polymer exhibits fluidity at a temperature equal to or higher than the melting point, the adhesive strength of the adhesive layer is sufficiently lowered. On the other hand, when the weight average molecular weight is less than 3,000, when the adhesive sheet is removed from the component, the amount of the residual adhesive remaining on the component may increase. Further, if the weight average molecular weight is more than 30,000, the adhesion may be difficult to reduce. The weight average molecular weight is measured by gel permeation chromatography (GPC) for a side chain crystalline polymer, and the obtained measured value is a value in terms of polystyrene.

The side chain crystalline polymer may be contained in an amount of 10 parts by weight or less, preferably 2 to 10 parts by weight, based on 100 parts by weight of the pressure-sensitive adhesive. Therefore, when the side chain crystalline polymer exhibits fluidity at a temperature higher than the melting point, the adhesive force of the adhesive layer is sufficiently lowered. On the other hand, when the content of the side chain crystalline polymer is less than 2 parts by weight, even if the adhesive layer is heated to a temperature equal to or higher than the melting point of the side chain crystalline polymer, the adhesive strength is hardly lowered, and the peeling property is lowered. . On the other hand, if it is more than 10 parts by weight, there is a large amount of residual glue.

The side chain crystalline polymer is preferably incompatible with the pressure sensitive bonding agent described above. Therefore, the side chain crystalline polymer is dispersed in a non-compatible (non-continuous island) with respect to the pressure-sensitive adhesive (sea) which is a base material, and is in a state of forming a so-called sea-island structure, and therefore, temperature-sensitive adhesiveness When the shape compliance and adhesion of the agent are improved, and the side chain crystalline polymer exhibits fluidity, the adhesion of the temperature sensitive adhesive is liable to lower.

(foaming agent)

The foaming agent is not particularly limited, and any of a usual chemical foaming agent and a physical foaming agent can be used. The chemical foaming agent includes a pyrolysis type and a reaction type organic foaming agent, and an inorganic foaming agent.

Examples of the pyrolysis type organic foaming agent include various azo compounds (such as azodiamine amide) and nitroso compounds (N, N'-dinitrosopentamethylenetetrazide). Amine, etc., anthracene derivative [4,4'-oxo bis(benzenesulfonate), etc., semicarbazide compound (deuterium diamine amide), azide compound, tetrazole compound, etc. Examples of the organic foaming agent include an isocyanate compound and the like.

Examples of the thermally decomposable inorganic foaming agent include hydrogencarbonate, carbonate (such as sodium hydrogencarbonate), nitrite, and hydride. For the reactive inorganic foaming agent, for example, A combination of sodium hydrogencarbonate and an acid, a combination of hydrogen peroxide and a yeast, a combination of a zinc powder and an acid, etc. are mentioned.

Examples of the physical foaming agent include aliphatic hydrocarbons such as butane, pentane, and hexane; chlorinated hydrocarbons such as dichloroethane and dichloromethane; and chlorofluorocarbons such as chlorofluorocarbon. It is a physical foaming agent; an inorganic physical foaming agent such as air, carbon dioxide gas or nitrogen.

Further, as the other foaming agent, microencapsulated heat-expandable fine particles (so-called microsphere foaming agent) can be used. The microsphere foaming agent refers to a foaming agent in which a heat-expandable substance made of a solid, a liquid or a gas is sealed inside a polymer shell made of a thermoplastic or thermosetting resin. The microsphere foaming agent is heated by a volume expansion of 40 times or more to obtain a foam in the form of a closed cell. Therefore, the microsphere foaming agent is compatible with the usual foaming agent. The ratio has a characteristic that the expansion ratio becomes quite large.

In the present embodiment, the side chain crystalline polymer contained in the temperature sensitive adhesive exhibits fluidity at a temperature equal to or higher than the melting point, whereby the adhesive force is sufficiently lowered, so that foaming in the adhesive layer can be reduced. The content of the agent. Specifically, the foaming agent is contained in a proportion of more than 10 parts by weight and less than 30 parts by weight, preferably 10 to 25 parts by weight, more preferably 10 to 20 parts by weight, based on 100 parts by weight of the pressure-sensitive bonding agent. can. Therefore, the laminate including the ceramic molded piece can be temporarily fixed firmly without being floated or unevenly, and can be easily peeled off at the time of peeling.

The temperature at which the foaming agent expands or foams is not particularly limited, but may be higher than the melting point of the side chain crystalline polymer, and is usually 180 ° C or lower. In terms of suppressing foaming at the time of coating drying, it may be 75 ° C or higher, preferably 100 ° C or higher. The average particle diameter of the foaming agent is not particularly limited and may be less than the thickness of the adhesive layer. Therefore, the surface of the pressure-sensitive adhesive layer can be made smooth, and the temporary fixation of the laminate can be firmly fixed. Further, the average particle diameter of the foaming agent is obtained by measurement using a fineness distribution measuring apparatus.

<Substrate film>

Examples of the substrate film include polyethylene, polypropylene, polyester, polyamine, polyimine, polycarbonate, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, and ethylene polypropylene. A sheet of a synthetic resin film such as a copolymer or polyvinyl chloride. Further, the film system may be a single layer body or a multilayer body of these, and has a thickness of usually about 5 to 500 μm. because The adhesion to the adhesive layer is improved, and the surface of the base film may be subjected to corona discharge treatment, plasma treatment, sandblasting treatment, chemical etching treatment, primer treatment, or the like.

The above-described adhesive layer is provided on one or both sides of the base film. In order to provide the adhesive layer on the base film, a blade coater, a roll coater, a calender coater, a comma coater, or the like is usually used. Further, depending on the coating thickness and the viscosity of the material, it can be carried out by a gravure coater or a bar coater. The thickness of the adhesive layer is greater than 5 μm and less than 30 μm as described above. On the other hand, when the thickness is 5 μm or less, the above-mentioned laminated body cannot be fixed, and conversely, when it is 30 μm or more, variation or protrusion of the adhesive layer is likely to occur.

For the adhesive layer provided on one or both sides of the substrate film as described above, it is preferred that the adhesive layer has an adhesive strength of 1 to 6 N/25 mm at 23 °C. Therefore, when the above-mentioned laminated body is cut at room temperature, it can be firmly fixed without floating or unevenness, and the cutting accuracy is improved.

The adhesive strength is a value obtained by measuring the 180° adhesive strength of polyethylene terephthalate at 23 ° C in accordance with JIS Z0237. In order to set the melting point and the adhesive force to a predetermined value, the structure of the side chain crystalline polymer and the formulation of the adhesive layer (for example, the composition of the pressure-sensitive adhesive, the thickness of the adhesive layer, and the blending) can be changed. And proceed arbitrarily.

Further, in order to increase the cohesive force of the above adhesive layer, a crosslinking agent may be added. Examples of the crosslinking agent include an isocyanate compound, an aziridine compound, an epoxy compound, and a metal chelate compound. In the adhesive layer, a plasticizer, a tackifier, or a plasticizer may be added as needed. Any component such as a filler or the like. Examples of the tackifier include a special rosin ester system, a terpene phenol system, a petroleum resin system, a high hydroxyl value rosin ester system, and a hydrogenated rosin ester system.

Next, an example of using the temperature sensitive adhesive sheet of the present embodiment will be described. First, a slurry of ceramic powder is spread thinly by a doctor blade to form a ceramic green sheet, and an electrode is printed on the surface of the green sheet. Next, a plurality of green sheets including green sheets on which electrodes are printed are laminated to form a laminate of green sheets. After the laminate is heated and pressurized, the laminate is fixed to the susceptor via the temperature sensitive adhesive sheet of the present embodiment.

In this case, in the temperature sensitive adhesive sheet, since the adhesive layer is provided on both surfaces of the base film, the adhesive layer provided on one surface is bonded to the laminated body 3 with a predetermined adhesive force, and the adhesive layer is provided on the other surface. The agent layer is attached to the susceptor with a predetermined adhesive force. In this case, since the thickness of the pressure-sensitive adhesive layer is more than 5 μm and less than 30 μm, variation and protrusion of the pressure-sensitive adhesive layer are suppressed, and the surface of the pressure-sensitive adhesive layer is excellent in smoothness. Therefore, the laminated system is surely sandwiched between the temperature-sensitive adhesive sheets. Fixed to the base.

After fixing, the laminate was cut. The cutting system may be a press cut by a cutting blade or a cutting by a rotary blade. Here, at the time of cutting, it is possible to suppress the laminated body from being pressed by the cutting blade and moving in the lateral direction by the adhesive sheet. Thereby, a plurality of cut pieces (wafers) are formed.

Next, the temperature sensitive adhesive sheet is subjected to heat treatment. Heating is a temperature which is heated to a temperature above the melting point of the side chain crystalline polymer in the adhesive layer and the blowing agent expands or foams. Therefore, the side chain crystalline polymer exhibits fluidity at a temperature above the melting point, and the blowing agent swells or develops The foam is so that the adhesion of the adhesive layer is sufficiently reduced. In this state, since the cut piece is removed from the temperature sensitive adhesive sheet, the cut piece can be easily removed from the temperature sensitive adhesive sheet. Subsequently, the cut piece is subjected to a preliminary firing step through a pre-baking step, and is fired, and an external electrode is formed on the end surface to obtain a wafer-shaped ceramic electronic component.

Further, in the above description, the case of the ceramic capacitor has been described, but the present invention is not limited thereto, and the ceramic inductor, the resistor, the ferrite, the sensor element, the thermistor, and the pressure sensitive The same can be applied to the manufacture of ceramic electronic parts such as electric resistors and piezoelectric ceramics.

[Examples]

Hereinafter, the temperature sensitive adhesive sheet of the present invention will be described in detail by way of Synthesis Examples and Examples, and the present invention is not limited to the following Synthesis Examples and Examples. In addition, in the following description, "part" means a weight part.

(Synthesis Example 1: Pressure-sensitive bonding agent)

52 parts of 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 40 parts of methyl acrylate (manufactured by Nippon Oil & Fats Co., Ltd.), 8 parts of 2-hydroxyethyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), and PERBUTYL ND (Japan) 0.3 parts of the oil company was mixed in this ratio to 230 parts of ethyl acetate / toluene (= 7 / 3), and stirred at 60 ° C for 5 hours to polymerize these monomers. The obtained copolymer had a weight average molecular weight of 460,000.

(Synthesis Example 2: side chain crystalline polymer)

40 parts of behenyl acrylate (manufactured by Nippon Oil & Fats Co., Ltd.), 35 parts of octadecyl acrylate (manufactured by Nippon Oil & Fats Co., Ltd.), 20 parts of methyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), and acrylic acid 5 parts, 5 parts of dodecyl mercaptan (manufactured by Nippon Oil & Fats Co., Ltd.) and 1 part of PERHEXYL PV (manufactured by Nippon Oil & Fats Co., Ltd.) were mixed in this ratio to 100 parts of toluene, and stirred at 80 ° C for 5 hours to make these Monomer polymerization. The obtained copolymer had a weight average molecular weight of 7,600 and a melting point of 48 °C.

The copolymers of Synthesis Examples 1 and 2 are shown in Table 1. Further, the weight average molecular weight is a value obtained by measuring a copolymer by gel permeation chromatography (GPC) and converting the obtained measured value into polystyrene. Further, the melting point of the copolymer of Synthesis Example 2 was measured under a measurement condition of 10 ° C/min using a differential thermal scanning calorimeter (DSC).

[Examples 1 to 3 and Comparative Examples 1 to 4] <Production of Adhesive Sheet>

First, a copolymer solution was prepared using the pressure-sensitive adhesive and the side chain crystalline polymer obtained above in accordance with the combination shown in Table 2. Next, a foaming agent was added to the copolymer solution in accordance with the combination shown in Table 2. Further, as the foaming agent, microencapsulated heat-expandable fine particles ("461DU20" manufactured by EXPANCEL Co., Ltd.) were used. In addition, in Table 2, the addition amount of the side chain crystalline polymer and the foaming agent is a value with respect to 100 weight part of pressure-sensitive adhesive.

The copolymer solution was applied to one surface of a base film (polyethylene terephthalate film) and dried to form an adhesive layer having the thickness shown in Table 2, thereby obtaining each temperature sensitive adhesive sheet. .

<evaluation>

The adhesive strength, the peeling property, and the surface property of each of the adhesive sheets obtained above were evaluated. Each evaluation method is shown below, and the results are shown together in Table 2.

(23°C adhesion strength based on 180° peel angle peeling)

The 180° adhesion strength (adhesion) of polyethylene terephthalate at 23 ° C was measured in accordance with JIS Z0237. That is, the temperature sensitive adhesive sheet was used as the upper side of the adhesive layer, and was fixed to the stainless steel plate by a commercially available double-sided tape. Next, a polyethylene terephthalate film having a thickness of 25 μm was bonded to the pressure-sensitive adhesive layer. Subsequently, the polyethylene terephthalate film was peeled from the adhesive layer in the 180° direction at a speed of 300 mm/min using a force measuring sensor. in accordance with JIS Z0237 measured the peel strength at this time, and evaluated the 180 peel strength at the 23 ° C atmosphere temperature of the adhesive layer.

(peelability)

The adhesive sheet was fixed to a stainless steel plate at 23 ° C in the same manner as the above-described method, and after bonding the polyethylene terephthalate film, the temperature was raised to 130 ° C (that is, the melting point of the side chain crystalline polymer or more). The temperature of the foaming agent is a temperature at which the foaming agent is expanded. Thus, it is visually observed whether or not the polyethylene terephthalate film bonded to the adhesive sheet is peeled off by itself only by its own weight. The judgment criteria are as follows.

○: peeling occurs only by the weight of the film itself

×: Not peeled off.

(fixed)

In the ceramic capacitor manufacturing process, after the laminate is heated and the cutting step is completed, it is visually observed whether or not the adhesive sheet has no floating or air bubbles, and whether or not the diced wafers are all bonded together. The judgment criteria are as follows.

○: There is no floating or air bubble in the adhesive sheet, and all the wafers after cutting are bonded.

×: A part of the bonding failure occurred due to floating or air bubbles.

(cutting deviation)

After the laminate was cut, the shape and the like of the obtained wafer were observed with a microscope. The judgment criteria are as follows.

○: The wafer shape and the internal electrode have no problem and can be used.

△: A part of the wafer shape and the internal electrode were confirmed to be defective.

×: Cannot be used.

(fitness)

When the laminate was bonded to the adhesive sheet, whether or not floating or air bubbles occurred during the bonding was visually observed. The judgment criteria are as follows.

○: No floating or air bubbles occur when bonding.

×: A float or a bubble occurs when it is bonded.

The following can be clarified from Table 2.

In Comparative Example 1, since the foaming amount was small, the peeling property at 130 ° C was inferior due to the high adhesion force when the laminate was fixed, and the wafer was damaged due to the peeling failure.

In Comparative Example 2, since the foaming amount was large, the adhesive strength at 23 ° C was low, so that the fixability was poor, and the laminate was floated.

In Comparative Example 3, since the thickness of the adhesive layer was thick, the variation in the cutting occurred, and the adhesive strength at 23 ° C was high, so the peeling property was inferior.

In Comparative Example 4, since the thickness of the adhesive layer was small and the amount of foaming was small, peeling property and adhesion were inferior.

On the other hand, in the temperature-sensitive adhesive sheets of Examples 1 to 3, the foaming amount and the amount of the side chain crystalline polymer were appropriate, and the adhesive strength at 23 ° C was also appropriate, so that there was no cutting drift or cutting deviation, peeling property and Good fit.

Claims (2)

A method for producing a ceramic electronic component includes the temperature sensing property of a temperature sensitive adhesive sheet in which an adhesive layer containing a temperature sensitive adhesive and a foaming agent is provided on at least one surface of a base film. a step of fixing a laminate of a plurality of ceramic molded sheets in a crystallized state in a side chain crystalline polymer included in the temperature sensitive adhesive on the surface of the pressure-sensitive adhesive layer, and a step of cutting the laminate to obtain a cut sheet After the cutting, the step of heating the adhesive sheet to foam the foaming agent at a temperature higher than a melting point of the side chain crystalline polymer, and a step of peeling the cut sheet from the foamed adhesive sheet, wherein The temperature sensitive adhesive includes a pressure-sensitive adhesive and the side chain crystalline polymer, and the temperature adhesive force at a temperature equal to or higher than a melting point of the side chain crystalline polymer is lowered, and the foaming agent is higher than the above. The temperature of the melting point of the side chain crystalline polymer may swell or foam, and the foaming agent has a particle diameter smaller than the thickness of the above-mentioned adhesive layer, and is greater than 10 with respect to 100 parts by weight of the pressure-sensitive bonding agent. The ratio of the amount of the adhesive layer is more than 5 μm and less than 30 μm, and the weight average molecular weight of the side chain crystalline polymer is from 3,000 to 30,000, and the side chain crystalline polymer is relatively Pressure sensitive joint 100 parts by weight of the agent is contained in a proportion of 10 parts by weight or less, and the adhesive strength of the pressure-sensitive adhesive layer at 23 ° C is 1 to 6 N / 25 mm. The method for producing a ceramic electronic component according to the first aspect of the invention, wherein the temperature at which the foaming agent is expanded or foamed is a temperature higher than a melting point of the side chain crystalline polymer by 30 ° C or higher.