JP2015124296A - Adhesive and method for adhesion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesion, when a substrate and a film are adhered, usable even at a high temperature of 450°C while securing its productivity, and an adhesion method.SOLUTION: Provided is an adhesive for adhering a substrate and a film, including an oxydiphthalic anhydride as an aromatic anhydride and diamine, and also composed of a polyimide resin or the precursor of a polyimide resin in which weight loss starting temperature in differential thermal thermogravimetry simultaneous measurement is 450°C or higher, and it is provided between the substrate and the film at a thickness of 1 μm or lower.

Description

  The present invention relates to an adhesive and a bonding method.

  Conventionally, a technique of using thermocompression bonding polyimide for bonding a copper foil and a polyimide film has been disclosed (for example, see Patent Document 1 below). However, in the thermocompression bonding adhesive containing an aromatic tetracarboxylic acid disclosed in Patent Document 1 below, it is confirmed that peeling occurs in a process at a high temperature of 450 ° C., resulting in a process failure. ing. For this reason, when the adhesion treatment is performed in a process at a high temperature of 450 ° C., it is necessary to use an adhesive whose glass transition temperature Tg exceeds 400 ° C.

  In fact, there are coating agents based on polyimide having high heat resistance (see, for example, Patent Document 2 below). However, one side of the coating agent is open, whereas both sides are constrained by the adhesion of different materials. Therefore, the solvent cannot be removed sufficiently, or water generated by imidization cannot be sufficiently suppressed, and bubbles are generated at the bonding interface during the high temperature process, and the bonded portion is peeled off. There was a problem.

  As for joining different types of materials using an adhesive containing a solvent, a method has been proposed in which the generation of bubbles is suppressed by setting the drying time very long (see, for example, Patent Document 3 below). However, in situations where productivity is required, long drying times are not practically acceptable.

JP-A-11-99554 JP-A-2-247276 JP-A-2-271940

  Thus, there has been a demand for an adhesive that can be used at a high temperature of 450 ° C. while securing productivity when bonding a substrate and a film.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to use at a high temperature of 450 ° C. while securing productivity when bonding a substrate and a film. It is to provide an adhesive and a bonding method that are possible.

  In order to solve the above problems, according to one aspect of the present invention, an adhesive for bonding a substrate and a film, which includes an oxydiphthalic anhydride that is an aromatic acid anhydride and a diamine, And the adhesion | attachment provided with the film thickness of 1 micrometer or less between the said board | substrate and the said film which consists of a polyimide resin or the precursor of a polyimide resin whose weight reduction start temperature in a differential thermal-thermogravimetric simultaneous measurement is 450 degreeC or more An agent is provided.

  The adhesive according to the present invention includes a resin or a resin precursor having a weight reduction starting temperature of 450 ° C. or higher in simultaneous differential thermal-thermogravimetric measurement, and thus can be used even at a high temperature of 450 ° C. and has a thickness of Even if it is 1 micrometer or less, a board | substrate and a film can be adhere | attached ensuring productivity.

  It is preferable to be provided with a thickness of 100 nm or more between the substrate and the film.

  By providing the adhesive with such a film thickness, the substrate and the film can be more reliably bonded.

  The molar ratio of the oxydiphthalic anhydride and the diamine is preferably 1.1: 1 to 1: 1.1.

  By mixing oxydiphthalic anhydride and diamine at such a molar ratio, the substrate and the film can be more reliably bonded.

  The difference between the linear expansion coefficient of the film and the linear expansion coefficient of the substrate is preferably less than 50 ppm / ° C.

  When the difference between the linear expansion coefficients of the film to be bonded and the substrate is within the above range, the substrate and the film can be bonded more reliably.

  The linear expansion coefficient of the film is preferably less than 20 ppm / ° C.

  A board | substrate and a film can be adhere | attached more reliably because the linear expansion coefficient of the film which is adhesion | attachment object is the said range.

  The thickness of the film is preferably 75 μm or less.

  A board | substrate and a film can be more reliably adhere | attached because the thickness of the film which is adhesion | attachment object is the said range.

  The film may be a film made of a polyimide material, a polybenzoxazole material, or a polybenzoxazine material.

  By using such a film, the substrate and the film can be bonded more reliably.

  The substrate may be a semiconductor substrate or a glass substrate.

  By using such a substrate, the substrate and the film can be bonded more reliably.

In order to solve the above problems, according to another aspect of the present invention, there is provided an adhesion method for adhering a substrate and a film, which is an aromatic acid anhydride, oxydiphthalic anhydride and diamine. And an adhesive composed of a polyimide resin or a polyimide resin precursor having a weight reduction starting temperature of 450 ° C. or higher in simultaneous differential thermal-thermogravimetric measurement on the surface of the substrate or the film of 1 μm or less. 170, followed by a primary heating step of heating the substrate or film coated with the adhesive at 100 to 140 ° C. for 1 minute to 2 hours, and the primary heating step. Secondary heating step of heating at ˜250 ° C. for 30 minutes to 2 hours, and subsequent bonding of the substrate and the film through the adhesive following the secondary heating step And step, subsequent to the bonding step, 180 ° C. or higher temperatures and, in 9.8 × 10 4 ^Pa or more pressure bonding method comprising pressurizing step of pressurizing least 3 minutes, is provided.

  By using the adhesive according to the present invention and performing the bonding process according to the above flow, the substrate and the film can be bonded while securing the productivity.

  Subsequent to the pressurizing step, the method may further include a step of exposing in an unloaded state for 30 minutes in a nitrogen atmosphere at 350 ° C.

  By further performing such treatment, the substrate and the film can be more reliably bonded.

  As described above, since the adhesive according to the present invention includes a polyimide resin or a polyimide resin precursor having a weight reduction starting temperature of 450 ° C. or higher in simultaneous differential thermal-thermogravimetric measurement, the substrate and the film are bonded. In this case, it can be used at a high temperature of 450 ° C. while ensuring productivity.

It is explanatory drawing for demonstrating the adhesive agent which concerns on embodiment of this invention. It is a flowchart for demonstrating the flow of the adhesion | attachment method which concerns on embodiment of this invention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(About the knowledge obtained by the present inventor)
As a result of intensive studies to solve the above problems, the present inventor has no generation of bubbles or separation even during a process under a high temperature environment of 450 ° C., as described in detail below. The present inventors have come up with an adhesive and a bonding method capable of bonding a substrate to be bonded and a film (for example, a high heat resistant film).

  When the polyimide resin itself having high heat resistance is used as an adhesive, the heat resistance of the adhesive itself is required. On the other hand, in recent years, in the process of manufacturing a semiconductor element using various semiconductors, an operation of holding a product at a high temperature of 450 ° C. for a long time may be performed. However, a resin having heat resistance that can withstand severe environments such as holding at 450 ° C. for a long time requires a high temperature to complete imidization and does not exhibit thermocompression bonding after imidization. there were.

  In addition, because of the above-mentioned limitations in the bonding process, the existing method cannot sufficiently remove the residual solvent in the adhesive and the water generated during imidization, and the subsequent high temperature environment. In the process carried out in step 1, there is a problem that defects such as bubbles are generated at the bonding interface.

  As a result of intensive studies to solve these problems, the present inventor exhibits minute fluidity that contributes to adhesion in the vicinity of 150 to 300 ° C. in the precursor (polyamic acid) of the high heat-resistant polyimide. It has been found that there is a case where it has a good effect on the adhesion to both the substrate and the film to be bonded in a region where the thickness of the adhesive is less than 1 μm. Therefore, the present inventor has realized that it is possible to bond the substrate and the film using these properties, and has completed the adhesive described below.

(About adhesive)
Below, the adhesive agent which concerns on embodiment of this invention is demonstrated in detail, referring FIG. FIG. 1 is an explanatory diagram for explaining an adhesive according to an embodiment of the present invention.

  The adhesive 100 according to the present embodiment is used for bonding the substrate 10 and the film 20, and is a polyimide resin or polyimide resin containing an oxydiphthalic anhydride that is an aromatic acid anhydride and a diamine. It consists of a precursor. The polyimide resin or the precursor of the polyimide resin constituting the adhesive 100 according to the present embodiment is an inflection point of a temperature-weight reduction curve in a simultaneous differential thermal-thermogravimetric measurement (TG-DTA). The weight reduction start temperature corresponding to is 450 ° C. or higher.

  Here, the temperature-weight decrease curve by simultaneous differential thermal-thermogravimetric measurement can be obtained by using a known thermal analyzer capable of simultaneous differential thermal-thermogravimetric measurement.

  The adhesive 100 according to the present embodiment has a substrate 10 and a film even in a high temperature environment of 450 ° C. because the weight reduction starting temperature of the polyimide resin or polyimide resin precursor constituting the adhesive is 450 ° C. or higher. 20 can be bonded.

  In addition, by using such an adhesive 100, the substrate can be exposed at a temperature of 450 ° C. or less in a vacuum atmosphere or an atmosphere having an oxygen concentration of less than 2% by volume for 30 minutes or more (hereinafter also referred to as a high temperature exposure state). The adhesive state between the film 10 and the film 20 can be maintained.

  Here, the diamine used in the adhesive 100 according to the present embodiment is not particularly limited. For example, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 3,3′- Diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylsulfide, 4,4 '-Diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ketone, 2,2- (4,4'-diamino Diphenyl) propane, 2,2-bis (4-aminophen) E) Hexafluoropropane, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 2,2-bis (4- (4-aminophenoxy) Phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) Sulfone, 4,4′-bis (4-aminophenoxy) biphenyl, bis (4- (4-aminophenoxy) phenyl) ether, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, 4,4'-diaminobenzanilide, o-tolidine sulfone, p-phenylenediamine, m-phenyle Diamine, 2,4-dimethyl toluene, and (3,3'-dihydroxy-4,4'-diamino) biphenyl.

As shown in FIG. 1, the adhesive 100 is applied between the substrate 10 and the film 20 so that the thickness d ₁ is 1 μm. If the thickness d ₁ of the adhesive 100 is more than 1 μm, the ring closure reaction of the imide contained in the adhesive 100 may not be completed. In addition, when the thickness d ₁ of the adhesive 100 is more than 1 μm, a long process is required for bonding, and thus decomposition products generated during the process may vaporize and cause peeling. .

The thickness _{d 1} of the adhesive 100 according to the present embodiment, it is preferable that the 100nm or more. The thickness _{d 1} of the adhesive 100 by a least 100 nm, and the substrate 10 and the film 20, it becomes possible to bond more securely. The thickness d ₁ of the adhesive 100 is more preferably 400 nm to ₁ μm.

  The molar ratio of the oxydiphthalic anhydride and diamine is preferably 1.1: 1 to 1: 1.1. When the molar ratio of oxydiphthalic anhydride to diamine is less than 1.1: 1, excess oxydiphthalic anhydride remains in the reaction of oxydiphthalic anhydride and diamine, and gas is generated. The possibility that the adhesiveness is lowered is increased. On the other hand, when the molar ratio of oxydiphthalic anhydride to diamine exceeds 1: 1.1, diamine remains excessively in the reaction of oxydiphthalic anhydride and diamine, and the diamine is vaporized or decomposed. There is a high possibility that gas is generated and adhesiveness is lowered. The molar ratio of the oxydiphthalic anhydride and diamine is more preferably 1: 1.

(About manufacturing method of adhesive)
The adhesive 100 according to this embodiment is manufactured by dissolving oxydiphthalic anhydride and the diamine as described above in an organic solvent in the above molar ratio range. As the organic solvent used for the production of the adhesive 100, a known solvent can be used as long as it dissolves diamine. Examples of the organic solvent include N-methyl-2-pyrrolidone (NMP), N, N-dimethylformamide (N, N-dimethylformamide: DMF), dimethyl carbonate (DMC), and the like. be able to.

  The adhesive 100 according to this embodiment has been described in detail above.

  In addition, in the adhesive 100 which concerns on this embodiment, you may contain well-known additives, such as a stabilizer, in addition to the said component.

  For example, additives that evaporate all during the bonding process can be added, such as pyridine, picoline, acetic anhydride, and the like. In addition, inorganic materials that do not decompose even in a process at 450 ° C., such as silica, alumina, clay, and the like, can be added.

(About substrate and film)
Next, the substrate 10 and the film 20 to be bonded by the adhesive 100 according to the present embodiment will be described in detail.

  It is preferable that the difference between the linear expansion coefficient of the film 20 and the linear expansion coefficient of the substrate 10 is less than 50 ppm / ° C. for the substrate 10 and the film 20 to be bonded by the adhesive 100 according to the present embodiment. If the difference between the linear expansion coefficient of the film 20 and the linear expansion coefficient of the substrate 10 is less than 50 ppm / ° C., the adhesive 100 according to the present embodiment is used for both treatments in a high temperature environment of 450 ° C. Can be more reliably bonded. On the other hand, when the difference between the linear expansion coefficient of the film 20 and the linear expansion coefficient of the substrate 10 is 50 ppm / ° C. or more, the size of the linear expansion coefficient between the substrate 10 and the film 20 is too different. When the adhesive 100 is used below, the adhesiveness between the two cannot be ensured.

  The substrate 10 to be bonded by the adhesive 100 according to the present embodiment is a known semiconductor substrate (wafer) such as silicon or germanium, or a display such as alkali-free glass, quartz glass, pyrex, tempax, neoceram, or bicol. Or a known glass substrate used as a glass for a semiconductor substrate.

  The linear expansion coefficient of the film 20 to be bonded by the adhesive 100 according to this embodiment is preferably less than 20 ppm / ° C. By using such a film 20, the substrate 10 and the film 20 can be more reliably bonded even under a high temperature environment of 450 ° C. As the film 20, a known film can be used as long as it is stable under a high temperature environment of 450 ° C. As the film 20, for example, a polyimide material, a polybenzoxazole material, or An example of the film 20 is a polybenzoxazine-based material.

The thickness _{d 2} of the film 20 according to this embodiment, it is preferable to 75μm or less. The thickness d ₂ of the film 20 by a 75μm or less, it is possible by using an adhesive 100 of this embodiment, to securely bond the substrate 10 and the film 20. On the other hand, when the thickness d ₂ of the film 20 is 75μm exceeded, adhesion between the substrate 10 and the film 20 may be reduced.

  Heretofore, the substrate 10 and the film 20 to be bonded by the adhesive 100 according to the present embodiment have been briefly described.

(About bonding method)
Hereinafter, an adhesion method between the substrate 10 and the film 20 using the adhesive 100 according to the present embodiment will be described in detail with reference to FIG. FIG. 2 is a flowchart for explaining the flow of the bonding method according to the embodiment of the present invention.

  In order to bond the substrate 10 and the film 20 satisfactorily even in a high temperature environment of, for example, 450 ° C., the flatness is important. Therefore, the substrate 10 and the film 20 can be favorably bonded even in a high-temperature environment by performing the processing according to the following procedure using the adhesive 100 according to the present embodiment.

  In the bonding method according to the present embodiment, first, the adhesive 100 according to the present embodiment is applied onto the substrate 10 or the film 20 so that the thickness thereof is 1 μm or less (step S101).

  Thereafter, the substrate 10 or the film 20 to which the adhesive 100 is applied is heated at a temperature not lower than the temperature at which the solvent of the adhesive 100 evaporates and lower than the boiling point of the solvent under the working pressure. More specifically, the substrate 10 or the film 20 to which the adhesive 100 is applied is heated at 100 to 140 ° C. for 1 minute to 2 hours (step S103). By this treatment, the solvent is removed to such an extent that bubbles are not generated while part of the imide compound is closed. When the heating temperature is less than 100 ° C., it is difficult to remove the solvent of the adhesive 100, which is not preferable. In addition, when the heating temperature exceeds 140 ° C., the solvent of the adhesive 100 is vigorously vaporized, and the flatness of the surface of the adhesive 100 cannot be ensured. In addition, when the heating time is less than 1 minute, it is difficult to completely remove the solvent of the adhesive 100 in the end, and when the heating time exceeds 2 hours, the productivity of the processing is remarkably reduced. To do.

  Next, the substrate 10 or the film 20 to which the adhesive 100 is applied is heated at a temperature higher than the boiling point of the solvent of the adhesive 100 and a reaction speed at which imidization starts to a temperature lower than the subsequent pressing step. To do. More specifically, the substrate 10 or the film 20 to which the adhesive 100 is applied is heated at 170 to 250 ° C. for 30 minutes to 2 hours (step S105). When the heating temperature is less than 170 ° C., imidization cannot be completed while removing the solvent of the adhesive 100, which is not preferable. Moreover, when heating temperature is over 250 degreeC, the surface active state for adhesion | attachment cannot be maintained, and the board | substrate 10 and the film 20 cannot be adhere | attached favorably. Further, when the heating temperature is less than 30 minutes or when the heating time exceeds 2 hours, the substrate 10 and the film 20 cannot be bonded.

  After the second-stage heat treatment, the substrate 10 and the film 20 are bonded together via the adhesive 100 that has not completed imide ring closure and has micro surface fluidity (step S107).

Thereafter, the substrate 10-adhesive 100-film 20 integrated is pressed for 3 minutes or more at a temperature of 180 ° C. or more and a pressure of 9.8 × 10 ⁴ Pa (ie, 1 kgf / cm ² ) or more ( Step S109). Thereby, the layer which consists of the adhesive agent 100 does not embrace a bubble, and can obtain the adhesive force which does not peel even if it is a high temperature exposure state. The pressure treatment temperature is more preferably 180 ° C. to 270 ° C. The applied pressure is not particularly limited as long as the substrate 10 and the film 20 do not break.

  Although the substrate 10 and the film 20 can be satisfactorily bonded by the above treatment, the substrate 10 and the film 20 are preferably exposed for 30 minutes in a nitrogen atmosphere at 350 ° C. and under no load (step S11 1). By performing such processing, the substrate 10 and the film 20 can be bonded more reliably.

  As described above, in the bonding method according to the embodiment of the present invention, after removing the solvent in advance, the softening point of the polyamic acid that is the polyimide precursor or the surface / interface which becomes more prominent in the adhesive in the thin film state. The substrate 10 and the film 20 are bonded to each other by utilizing the effect to the maximum.

  The bonding method according to this embodiment has been described in detail above with reference to FIG.

  Hereinafter, the adhesive and the bonding method according to the embodiment of the present invention will be specifically described with reference to examples and comparative examples. In addition, the Example shown below is an example to the last of the adhesive agent and bonding method which concern on embodiment of this invention, Comprising: The adhesive agent and bonding method which concern on embodiment of this invention are not limited to the following example. Absent.

Example 1
As raw materials of the adhesive 100 according to the embodiment of the present invention, oxydiphthalic anhydride (OPDA) that is an acid anhydride and diaminodiphenyl ether (DDM) that is a diamine were prepared. Then, the polyamic acid NMP solution (namely, adhesive 100) was prepared using N-methyl-2-pyrrolidone (NMP) as a solvent. The obtained adhesive 100 was applied onto a glass substrate by spin coating and dried at 100 ° C. for 1 hour and 170 ° C. for 1 hour, and then a polyimide film was laminated. The thickness of the adhesive at that time was adjusted to 1 μm or less.

A test piece in which three layers of glass, an adhesive, and a polyimide film are laminated is subjected to thermocompression bonding with a heat press at 270 ° C. and 2.9 × 10 ⁵ Pa (30 kgf / cm ² ) for 10 minutes. Furthermore, it was exposed to an unloaded condition for 30 minutes in an oven at 350 ° C. in a nitrogen atmosphere.

  It was 500.4 degreeC when the thermal decomposition start temperature of the obtained adhesive cured material was measured using Seiko Instruments TGDTA6200AST-2. Moreover, when the test piece of the obtained cured adhesive product was exposed to a 450 ° C. nitrogen atmosphere (oxygen concentration of less than 2% by volume) for 1 hour and visually examined for the presence of peeling or bubble generation, peeling or bubble generation was observed. Neither was recognized. Furthermore, when the peel strength of the obtained cured adhesive was measured using a texture analyzer manufactured by Texture Technologies, it showed a good value of 1.3 N / 25 mm.

(Example 2)
A cured adhesive was produced in the same manner as in Example 1 except that the diamine used was 4,4′-diaminobenzoaniline (4,4DBA), and the thermal decomposition start temperature, peeling and generation of bubbles at high temperature exposure conditions were produced. The presence or absence and peel strength were measured.

  As a result, the thermal decomposition starting temperature was 497.3 ° C., and peeling and bubble generation were not observed in the high temperature exposure state. Moreover, the peel strength of the obtained adhesive cured product was 3.7 N / 25 mm.

(Example 3)
Except for drying conditions of 100 ° C. for 30 minutes and 250 ° C. for 1 hour, an adhesive cured product was produced in the same manner as in Example 1, thermal decomposition starting temperature, presence or absence of peeling or generation of bubbles in a high temperature exposure state, and Peel strength was measured.

  As a result, the thermal decomposition starting temperature was 500.4 ° C., which was the same as in Example 1, and no peeling or bubble generation was observed in the high temperature exposure state. Moreover, the peel strength of the obtained adhesive cured product was 1.2 N / 25 mm.

Example 4
Except for drying conditions of 140 ° C. for 30 minutes and 170 ° C. for 1 hour, an adhesive cured product was produced in the same manner as in Example 1, and the thermal decomposition start temperature, the presence or absence of exfoliation and bubble generation in a high temperature exposure state, and Peel strength was measured.

  As a result, the thermal decomposition starting temperature was 500.4 ° C., which was the same as in Example 1, and no peeling or bubble generation was observed in the high temperature exposure state. Moreover, the peel strength of the obtained adhesive cured product was 2.4 N / 25 mm.

(Example 5)
The same raw materials as in Example 1 were prepared and applied at a molar ratio of oxydiphthalic anhydride and diamine of 1: 1.05, and the drying conditions were 100 ° C. for 30 minutes and 200 ° C. for 1 hour. The subsequent procedures were the same as in Example 1, and the thermal decomposition starting temperature, the presence or absence of peeling or bubble generation under high temperature exposure conditions, and the peel strength were measured.

  As a result, the thermal decomposition starting temperature was 497.1 ° C., and peeling and bubble generation were not observed in the high temperature exposure state. Further, the peel strength of the obtained cured adhesive was 0.9 N / 25 mm.

(Example 6)
The same raw materials as in Example 1 were prepared and applied at a molar ratio of oxydiphthalic anhydride and diamine of 1.05: 1, and the drying conditions were 100 ° C. for 30 minutes and 200 ° C. for 1 hour. The subsequent procedures were the same as in Example 1, and the thermal decomposition starting temperature, the presence or absence of peeling or bubble generation under high temperature exposure conditions, and the peel strength were measured.

  As a result, the thermal decomposition starting temperature was 497.3 ° C., and peeling and bubble generation were not observed in the high temperature exposure state. Moreover, the peel strength of the obtained adhesive cured product was 1.2 N / 25 mm.

(Comparative Example 1)
An adhesive was prepared in the same manner as in Example 1 and applied onto glass by spin coating. After drying at 100 ° C. for 1 hour and 170 ° C. for 1 hour, a polyimide film was laminated. The thickness of the adhesive layer at that time was set to 2 μm or more. The subsequent procedure was the same as in Example 1.

  As a result, although the thermal decomposition starting temperature was 500.4 ° C. as in Example 1, the generation of bubbles was confirmed in the high temperature exposure state. Moreover, the peel strength of the obtained adhesive cured product was less than 0.1 N / 25 mm.

(Comparative Example 2)
As raw materials for the adhesive, cyclobutane and 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), which is a diamine, were prepared. Then, N-methyl-2-pyrrolidone (N-methylpyrrolidone: NMP) was used as a solvent to obtain an adhesive. The subsequent procedures were the same as in Example 1, and the thermal decomposition starting temperature, the presence or absence of peeling or bubble generation under high temperature exposure conditions, and the peel strength were measured.

  As a result, it was found that the thermal decomposition starting temperature was 432 ° C., and it could not be used in a high temperature exposure state of 450 ° C. In addition, scorching, peeling, and generation of bubbles were confirmed under high temperature exposure conditions. The peel strength of the obtained adhesive cured product was less than 0.1 N / 25 mm.

(Comparative Example 3)
As raw materials for the adhesive, pyromellitic anhydride (PMDA) as an acid anhydride and 4,4′-diaminobenzoaniline (4,4DBA) as a diamine were prepared. Then, N-methyl-2-pyrrolidone (N-methylpyrrolidone: NMP) was used as a solvent to obtain an adhesive. The subsequent procedures were the same as in Example 1, and the thermal decomposition starting temperature, the presence or absence of peeling or bubble generation under high temperature exposure conditions, and the peel strength were measured.

  As a result, it was found that the thermal decomposition starting temperature was 430 ° C., and it could not be used in a high temperature exposure state of 450 ° C. In addition, scorching, peeling, and generation of bubbles were confirmed under high temperature exposure conditions. The peel strength of the obtained adhesive cured product was less than 0.1 N / 25 mm.

  The experimental conditions of the examples and comparative examples described above and the obtained results are summarized in Table 1 below. In addition, the adhesive layer thickness in the following Table 1 is scratched until the glass surface comes out with a cutter knife on the adhesive layer coated and dried on the glass under the same conditions as each experimental condition. It is the value measured by measuring the depth of the groove with a manufactured surf coder.

  As is clear from the above results, when the thickness of the adhesive layer is larger than 1 μm, or when the thermal decomposition start temperature is lower than 450 ° C., the atmosphere is almost free of oxygen at 450 ° C. for 1 hour. Bubbles, scorching, and peeling after exposure, but the adhesive layer is sufficiently thin, and it is good even after exposure to high-temperature environments as described above by using an adhesive with a high thermal decomposition starting temperature. Adhesiveness could be secured.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

10 Substrate 20 Film 100 Adhesive

Claims (10)

An adhesive for bonding a substrate and a film,
It comprises an oxydiphthalic anhydride that is an aromatic acid anhydride and a diamine, and consists of a polyimide resin or a polyimide resin precursor having a weight loss starting temperature of 450 ° C. or higher in simultaneous differential thermal-thermogravimetric measurement,
An adhesive provided between the substrate and the film with a thickness of 1 μm or less.   The adhesive according to claim 1, which is provided with a thickness of 100 nm or more between the substrate and the film.   The adhesive according to claim 1 or 2, wherein a molar ratio of the oxydiphthalic anhydride and the diamine is 1.1: 1 to 1: 1.1.   The adhesive according to any one of claims 1 to 3, wherein a difference between a linear expansion coefficient of the film and a linear expansion coefficient of the substrate is less than 50 ppm / ° C.   The adhesive according to claim 4, wherein the film has a linear expansion coefficient of less than 20 ppm / ° C.   The adhesive according to any one of claims 1 to 5, wherein the film has a thickness of 75 µm or less.   The adhesive according to any one of claims 1 to 6, wherein the film is a film made of a polyimide-based material, a polybenzoxazole-based material, or a polybenzoxazine-based material.   The adhesive according to claim 1, wherein the substrate is a semiconductor substrate or a glass substrate. A bonding method for bonding a substrate and a film,
An adhesive comprising an oxydiphthalic anhydride, which is an aromatic acid anhydride, and a diamine, and a polyimide resin or a polyimide resin precursor having a weight reduction start temperature of 450 ° C. or higher in simultaneous differential thermal-thermogravimetric measurement Applying to the surface of the substrate or the film so as to have a thickness of 1 μm or less,
A primary heating step of heating the substrate or film coated with the adhesive at 100 to 140 ° C. for 1 minute to 2 hours;
Subsequent to the primary heating step, a secondary heating step of heating at 170 to 250 ° C. for 30 minutes to 2 hours,
Subsequent to the secondary heating step, an adhesion step of bonding the substrate and the film through the adhesive,
Following the bonding step, a pressurizing step of pressurizing for 3 minutes or more at a temperature of 180 ° C. or higher and a pressure of 9.8 × 10 ⁴ Pa or higher;
A bonding method.   The bonding method according to claim 9, further comprising a step of exposing to the non-loading state in a nitrogen atmosphere at 350 ° C. for 30 minutes following the pressing step.

Images