JP2017149041A - Layered body and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means for obtaining a flexible electronic device having both favorable yield and favorable quality in a method of producing a flexible electronic device by allowing a polymeric film to temporarily adhere to a rigid substrate to make a layered plate, forming an electronic device on the film, and then peeling the electronic device from the rigid substrate.SOLUTION: A flexible electronic device with high yield and low edge warping is obtained by using a layered body of a polymeric film and an inorganic substrate, in which a transition region width G between a favorable adhesive portion having high adhesive strength between the film and the substrate and an easy peeling portion having low adhesive strength between the film and the substrate is 4 mm or less. The layered body having a low transition region width G is actualized by partially treating, in a direct writing manner, the inorganic substrate treated with a silane coupling agent in specific atmospheric pressure plasma.SELECTED DRAWING: None

Description

The present invention relates to a laminate comprising a polyimide film and a substrate made of an inorganic material and a method for producing the same, and more specifically, a device comprising a thin film such as a semiconductor element, a MEMS element or a display element, which requires fine processing. In order to obtain a laminate used for manufacturing a flexible device that is peeled after device formation, temporarily forming a polyimide film on a substrate made of an inorganic material as a support. It is invention regarding the manufacturing method of this.
Specifically, a thin film such as polyimide having excellent heat resistance and insulation and a substrate made of a kind of inorganic material selected from a glass plate, a ceramic plate, a silicon wafer, and a metal having approximately the same linear expansion coefficient. The present invention relates to a laminated body excellent in dimensional stability, heat resistance and insulation, and a manufacturing method for obtaining the laminated body, on which a laminated fine circuit can be mounted.

In recent years, for the purpose of reducing the weight and flexibility of functional elements such as semiconductor elements, MEMS elements, and display elements, technological development for forming these elements on a polymer film has been actively conducted.
When forming functional elements such as semiconductor elements, MEMS elements, and display elements on the surface of polymer films, it is ideal to process them using a so-called roll-to-roll process that uses the flexibility of polymer films. It is said that. However, in the semiconductor industry, the MEMS industry, and the display industry, process technologies have been constructed for wafer-based or glass substrate-based rigid planar substrates. As a realistic choice, the polymer film is bonded to a rigid support substrate made of an inorganic material such as a metal plate, wafer, glass substrate, etc., and after forming a desired element, the existing infrastructure is removed. It becomes possible to obtain a functional element formed on the polymer film by using it.
In laminating a polymer film and a support substrate made of an inorganic material, the level of surface smoothness, cleanliness, resistance to process temperature, and resistance to chemicals used for microfabrication are not problematic for the formation of such functional elements. Tolerance is required. In particular, when the formation temperature of the functional element is high, not only the heat resistance of the polymer film but also the bonding surface of the laminate must withstand the processing temperature.
Among semiconductor thin films, Si has a linear expansion coefficient of about 3 ppm / ° C. When this thin film is deposited on a substrate, if the difference in the linear expansion coefficient between the substrate and the thin film is large, stress is generated in the thin film. It causes accumulation, deterioration of performance, warping of the thin film, and peeling. In particular, when a high temperature is applied during the thin film formation process, stress due to a difference in linear expansion coefficient between the substrate and the thin film increases during the temperature change.
In the production of a low-temperature polysilicon thin film transistor, a process of 450 ° C. for 2 hours may be required in the dehydrogenation process. Further, it is possible to apply a temperature of about 200 ° C. to 300 ° C. to the hydrogenated amorphous silicon thin film. At this time, the thermoplastic resin as the polymer film does not satisfy the performance.
Conventionally, it has been widely performed to bond a polymer film to an inorganic substrate using an adhesive or an adhesive (Patent Document 1). However, in the case where a process in a temperature range of about 200 to 500 ° C. is required, such as polysilicon and oxide semiconductor, a bonding adhesive and pressure-sensitive adhesive having sufficient resistance enough for practical use was used. The method is not known.
Forming a resin substrate on a fixed substrate with an amorphous silicon film serving as a release layer as a technique for avoiding a heat resistance problem without using an adhesive, an adhesive, and the like; Forming at least a TFT element, and irradiating the amorphous silicon film with a laser beam to peel the resin substrate from the fixed substrate in the amorphous silicon film, Although it is disclosed in (Patent Document 2) that a flexible display device using a material is produced, the adhesive layer is subjected to laser irradiation or etching means at the time of peeling, causing a complicated process and high cost. become.

In view of such a situation, the present inventors use a bonding method that can withstand a high temperature process of 400 ° C. to 500 ° C. and a method for bonding a polyimide film and an inorganic substrate such as a glass substrate using a silane coupling agent treatment. We have been making proposals regarding laminated bodies. (Patent Documents 3 to 5)
In addition, as an application of such a technique, the surface treatment and selective deactivation treatment are used in combination on the inorganic substrate side, a good adhesion portion with a relatively strong adhesion strength between the polyimide film and the inorganic substrate, and a relatively weak easily peelable portion. After forming the good adhesion part mainly on the outer peripheral part of the inorganic substrate and the easy peeling part in the inner area, and performing the device forming processing required for the easy peeling part, the good adhesion part and the easy peeling part We proposed a technology that can cut the device part formed in the easy peelable part with low stress with a low stress. (Patent Document 6)

JP 2008-159935 A JP 2009-260387 A Japanese Patent No. 5152104 Japanese Patent No. 5126555 Japanese Patent No. 5152429 JP2015-37841A

In the technique disclosed in Patent Document 6, the surface of the inorganic substrate treated with the silane coupling agent is partially covered with a mask or the like, blast treatment, vacuum plasma treatment, atmospheric pressure plasma treatment, corona treatment, actinic radiation irradiation treatment, By performing at least one deactivation process selected from the group consisting of an active gas process and a chemical process, the part covered with the mask is well bonded and the part subjected to the deactivation process is easily peeled off. Part.
The laminate obtained by this method is sufficiently resistant to semiconductor device manufacturing processes including vacuum processes, wet processing processes, high temperature processing processes, etc., and the easy peeling part can be easily peeled from the substrate. The present invention is extremely useful in the industry that makes it possible to manufacture a flexible device without destroying the device.
However, in such a technique, since the mask is used, the mask and the surface treatment surface of the inorganic substrate are in contact with each other, and contamination such as scratches or foreign matter adhesion may occur on the inorganic substrate side. Such contamination hinders the adhesion of the film when the film is attached in the next process, and air remains on the film and the substrate surface, resulting in a blister-like defect. The boundary between the bonded part and the easily peeled part sometimes became ambiguous.
In addition, when the mask is floated so as not to be in direct contact with the inorganic substrate, the deactivation process goes around the gap between the mask and the inorganic substrate, and the boundary between the well-bonded portion and the easily peeled portion is still ambiguous and unclear. Occurred.
If the boundary between the good adhesion part and the easy peeling part is ambiguous, the surrounding part that should be strongly bonded peels off during the process, or stress is applied to the device during the peeling operation of the part that should be easy to peel off. It becomes a problem that leads to a decrease in yield, such as causing destruction.

As a result of intensive studies, the present inventors have determined that heat resistance and insulation are obtained by laminating a polyimide film having a higher level of heat resistance and flexibility and an inorganic substrate such as a glass plate, a ceramic plate, a silicon wafer, and a metal. In addition, the present inventors have found a laminate having a good adhesion portion and an easily peelable portion having a clear boundary and useful for forming a flexible device, and a method for producing the laminate.
That is, the present invention has the following configuration.
[1] A laminate comprising at least a substrate made of an inorganic material and a polyimide film, and a silane coupling agent layer between them, and a good adhesive portion having a high adhesive strength of the polyimide film to the substrate, and an adhesive strength Has a low easy peeling part,
T1 is the average adhesive strength of the good adhesion part,
Let T2 be the average adhesive strength of the easily peelable part,
Adhesive strength difference T = T1-T2
A laminate having a distance G of 4 mm or less from a position having an adhesive strength of T1-0.1 × T to a position having T1-0.9 × T.
[2] The laminate according to [1], wherein the silane coupling agent layer has a thickness of 50 nm or less.
[3] The laminate according to [1] or [2], wherein an area of the inorganic substrate is 1700 square cm or more.
[4] At least
(1) forming a silane coupling agent layer having a thickness of 50 nm or less on a substrate made of an inorganic material;
(2) A step of partially irradiating the surface of the substrate treated with the coupling agent with plasma,
(3) a step of superimposing, pressurizing and / or heating the polyimide film and the substrate made of the inorganic material,
In the manufacturing method of the laminated board which consists of a polyimide film / inorganic substrate containing
The plasma treatment is a treatment for irradiating a substrate with plasma generated by an alternating electric field having a frequency in an atmospheric pressure of 8 kHz to 300 kHz in a state where the electric field intensity is less than 45 kV / m [1]. To [3]. The method for producing a laminate according to any one of [3].

In the present invention, in a laminated plate in which a polyimide film and an inorganic substrate such as glass are bonded via an extremely thin silane coupling agent layer, a good bonding portion and an easy peeling portion are provided in the bonding state, and exist at the boundary portion between them. It is characterized by a very narrow transition region from strong adhesion to easy peeling. In order to obtain a flexible electronic device by peeling a polyimide film from an inorganic substrate after fine device processing such as a fine circuit and a thin film TFT is performed on the polyimide film surface by adhering and holding a polyimide film using an inorganic substrate as a temporary support. Used for. Since the transition region is narrow and the boundary between the good adhesion portion and the easy peeling portion is clear, the margin outside the device formation region can be reduced, so that the effective area is increased, the product yield is increased, and the productivity is improved. As a result of providing a clearer boundary, it becomes easier to obtain a trigger for peeling when the region where the fine device is formed is peeled off, and the production efficiency is improved.
In addition, in the past, a slight curl was often seen at the end of the film peeled off from the easy peelable portion, but when the transition region of the present invention was peeled off from the narrow laminate, the curl at the end was conspicuous. It has been found that the flatness of the resulting product is improved.

  The laminate having a narrow transition region at the boundary of the good adhesion portion / easy peeling portion of the present invention is obtained by inactivating the surface treatment layer on the surface of the inorganic substrate in a direct drawing manner using a specific atmospheric pressure plasma treatment. As a specific plasma treatment, a direct drawing method is achieved by irradiating a substrate with plasma generated by an alternating electric field having a frequency in the atmospheric pressure of 8 kHz to 300 kHz in a state where the electric field strength is less than 45 kV / m. In addition, it is a process of irradiating a portion desired to be an easily peelable part with plasma irradiation, and it can be obtained by forming a latent image of adhesion strength and laminating a polyimide film by the plasma process. Atmospheric pressure plasma processing does not require a vacuum chamber compared to vacuum plasma processing, so the equipment configuration is simple, and it is well known that it has the advantage of being excellent in processing large items and continuous processing and having high productivity. Since the atmospheric pressure plasma treatment used in the present invention is far from the plasma generation source and the irradiation position, it is less susceptible to discharge fluctuations, the plasma flow rate can be controlled by the gas flow rate, and the plasma flow is controlled by the nozzle or slit shape. As a result, it is possible to form a plasma flow with a high degree of convergence. As a result, the boundary between the plasma irradiation part and the irradiated part becomes clear, so a laminate with a strong and weak boundary can be realized without using a mask. can do. In addition, as a comparison, the method of performing exposure to plasma through the substrate to be processed between the electrodes for generating plasma. When an object to be irradiated is inserted between the electrodes, the discharge state depends on the dielectric constant of the object to be irradiated. Since the plasma changes, it is difficult to maintain the stability of the plasma, and the plasma state changes when there are places with different thickness and dielectric properties on the irradiated object, which may cause problems in processing uniformity. There is. In particular, when a conductive substrate such as a metal or a substrate having a conductive portion is used, abnormal discharge may occur.

  In the present invention, a pattern is formed by directly scanning a plasma processing unit without using a mask or the like, so that scratches, contamination, and adhesion of foreign substances do not occur on the surface of the object to be processed. In addition, a plasma flow hits the directly irradiated portion substantially without an electric field, and the plasma flow is mechanically converged. On the other hand, a secondary processing effect due to the plasma leaking from the processing portion is Since it can be reduced by being forcibly excluded by the gas, the difference in intensity between the irradiated portion and the non-irradiated portion becomes clear, and a clear boundary with a narrow transition region as in the present invention can be formed.

FIG. 1 is a conceptual diagram showing an example of a measurement result obtained by the present invention and showing a difference in adhesive strength between a good bonded portion and an easily peelable portion.

  As a substrate made of an inorganic substance in the present invention, a glass plate, a ceramic plate, a silicon wafer, a metal mainly, and a glass plate, a ceramic plate, a silicon wafer, a composite of these, a laminate of these, The thing in which these are disperse | distributed, the thing which these fibers contain, the board | substrate with which the thin film which consists of these materials was formed in the surface, etc. can be used.

  As a glass plate as a substrate made of the inorganic substance in the present invention, quartz glass, high silicate glass (96% silica), soda lime glass, lead glass, aluminoborosilicate glass, borosilicate glass (Pyrex (registered trademark)) , Borosilicate glass (non-alkali), borosilicate glass (microsheet), and aluminosilicate glass. Among them, those having a linear expansion coefficient of 5 ppm / ° C. or lower are desirable, and liquid crystal glass Corning 7059, 1737, EAGLE, Asahi Glass AN100, Nippon Electric Glass OA10, SCHOTT AF32, and the like are desirable.

As the ceramic plate as the substrate made of the inorganic material in the present invention, alumina, mullite, AlN, SiC, Si3N4, BN, crystallized glass, Cordierite, Spodumene, Pb-BSG + CaZrO3 + Al2O3, Crystallized glass + AL2O3, Crystallized Ca-BSG , BSG + Quartz, BSG + Quartz, BSG + AL2O3, Pb + BSG + AL2O3, Glass-ceramic, Zero-durer substrate ceramics, TiO2, strontium titanate, calcium titanate, magnesium titanate. Capacitor materials such as alumina, MgO, steatite, BaTi4O9, BaTiO3, BaTi4 + CaZrO3, BaSrCaZrTio3, Ba (TiZr) O3, PMN-PT PFN-PFW, PbNb2O6, Pb0.5Be0.5Nb2O6, PbTiO3, BaTiO3, PZ. This includes piezoelectric materials such as 95PT-0.5BT, 0.873PZT-0.97PT-0.3BT, PLZT.

  The silicon wafer as the inorganic substrate in the present invention includes all n-type or p-type doped silicon wafers and intrinsic silicon wafers, and a silicon oxide layer on the surface of the silicon wafer or various types of silicon wafers. In addition to silicon wafers including silicon wafers on which thin films are deposited, germanium, silicon-germanium, gallium-arsenic, aluminum-gallium-indium, and nitrogen-phosphorus-arsenic-antimony are often used. General-purpose semiconductor wafers such as InP (indium phosphorus), InGaAs, GaInNAs, LT, LN, ZnO (zinc oxide), CdTe (cadmium tellurium), and ZnSe (zinc selenide) are included.

  Examples of the metal as the substrate made of the inorganic material in the present invention include single element metals such as W, Mo, Pt, Fe, Ni, and Au, Inconel, Monel, Nimonic, carbon copper, Fe-Ni-based Invar alloy, and Super Invar alloy. Alloys such as are included. Moreover, the multilayer metal plate which added the other metal layer and the ceramic layer to said metal is also contained.

A silane coupling agent treatment is required on at least the adhesive surface side of the inorganic substrate of the present invention with the polyimide film.
The coupling agent preferably used in the present invention is preferably one having an amino group or an epoxy group. Specific examples of the coupling agent include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, and N-2- (aminoethyl). ) -3-Aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine, 2- ( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane vinyltrichlorosilane, vinyltri Methoxysilane, vinyltriethoxysilane, 2- (3,4-epoxy (Cyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyl Methyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltri Methoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3 -Merka Topropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, tris- (3-trimethoxysilylpropyl) isocyanurate, chloromethylphenethyltrimethoxysilane, chloromethyltrimethoxysilane, etc. Is mentioned.
Other usable coupling agents include 1-mercapto-2-propanol, methyl 3-mercaptopropionate, 3-mercapto-2-butanol, butyl 3-mercaptopropionate, 3- (dimethoxymethylsilyl)- 1-propanethiol, 4- (6-mercaptohexaloyl) benzyl alcohol, 11-amino-1-undecenethiol, 11-mercaptoundecylphosphonic acid, 11-mercaptoundecyltrifluoroacetic acid, 2,2 ′-( (Ethylenedioxy) diethanethiol, 11-mercaptoundecyltri (ethylene glycol), (1-mercaptoundec-11-yl) tetra (ethylene glycol), 1- (methylcarboxy) undec-11-yl) hexa ( Ethylene glycol), hydroxy Cyundecyl disulfide, carboxyundecyl disulfide, hydroxyhexadodecyl disulfide, carboxyhexadecyl disulfide, tetrakis (2-ethylhexyloxy) titanium, titanium dioctyloxybis (octylene glycolate), zirconium tributoxy monoacetylacetonate, zirconium mono Examples include butoxyacetylacetonate bis (ethylacetoacetate), zirconium tributoxymonostearate, acetoalkoxyaluminum diisopropylate, and the like.

Among these, preferred are N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl). ) -3-Aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine, 2- ( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, aminophenyltrimethoxysilane , Aminophenethyl trimethoxysilane, aminophenyl Such as amino methyl phenethyltrimethoxysilane the like. In the case where heat resistance is required in the process, those in which Si and an amino group are connected with an aromatic group can be preferably used. In the present invention, these silane coupling agents can be used alone or in combination.

The silane coupling agent treatment in the present invention means that a thin layer made of a silane coupling agent is formed on the substrate surface, and may be called application. Examples of the method for treating a coupling agent in the present invention include a method in which a solution of a coupling agent is applied and dried on a substrate made of an inorganic material and heat-treated, a method in which a substrate is immersed in the solution of the coupling agent and then dried and heat-treated. it can.
In the atmospheric pressure plasma processing used in the present invention, the plasma density is relatively low because the plasma source is separated from the processing section. Therefore, in order to effectively realize the present invention, there is an upper limit to the thickness of the silane coupling agent layer. The thickness of the silane coupling agent layer in the present invention is essential to be 100 nm or less, preferably 60 nm or less, more preferably 25 nm or less, and further preferably 12 nm or less. As a method for uniformly forming such a thin region of the silane coupling agent layer, a gas phase coating method of a silane coupling agent can be exemplified. The film thickness of the silane coupling agent layer can be determined by ellipsometry.

  In this invention, the method of apply | coating a silane coupling agent to the substrate surface via a gaseous phase can be preferably used as a silane coupling agent processing method. In other words, this is a technique in which a substrate made of an inorganic substance is exposed to a silane coupling agent vapor, that is, a substantially gaseous silane coupling agent. The vapor of the silane coupling agent can be obtained by a bubbling method, a baking method, or the like, but when accompanied by heating at 200 ° C. or higher, it may cause a side reaction of the silane coupling agent. Is preferred. More preferably, the silane coupling agent vapor is obtained at 100 ° C. or lower, more preferably 40 ° C. or lower.

The carrier gas used for obtaining the silane coupling agent vapor is preferably a dry gas having a dew point of −5 ° C. or lower. More preferably, it is preferable to use a dry gas having a dew point of −30 ° C. or lower, more preferably a dew point of −50 ° C. or lower. Moisture mixing into the carrier gas causes a side reaction of the silane coupling agent, hinders stable supply of the silane coupling agent vapor, and also causes generation of foreign substances derived from the silane coupling agent in the apparatus.

Further, since many silane coupling agents are flammable liquids, it is preferable to use an inert gas as a carrier gas, particularly when a heat source is used. When the silane coupling agent layer is formed on the substrate by introducing the silane coupling agent vapor into the apparatus in which the substrate made of an inorganic material is installed, the exposure is performed in order to obtain a thickness of 100 nm or less required by the present invention. The time for the treatment is preferably within 18 minutes, more preferably within 6 minutes, further preferably within 2 minutes, and even more preferably within 40 seconds.

The substrate temperature during the formation of the silane coupling agent layer on the substrate made of an inorganic material is an appropriate temperature between −50 ° C. and 200 ° C. depending on the type of silane coupling agent and the desired thickness of the silane coupling agent layer. It is preferable to control. However, from the viewpoint of work efficiency, it is preferable to set the temperature lower than the temperature at which the silane coupling agent vapor is generated. The temperature is preferably set to 5 ° C. or higher, more preferably 10 ° C. or lower.

The substrate made of an inorganic material on which the silane coupling agent layer is formed is preferably heated to 70 ° C. to 200 ° C., more preferably 75 ° C. to 150 ° C. after exposure. By such heating, the hydroxyl group on the substrate surface reacts with the alkoxy group or silazane group of the silane coupling agent, and the silane coupling agent treatment is completed. The time required for heating is 0.1 second or more and 10 minutes or less. If the temperature is too high or the time is too long, the coupling agent may be deteriorated. If the temperature is too low or the time is too short, the treatment effect cannot be obtained. If the substrate temperature being exposed to the silane coupling agent is already 80 ° C. or higher, the subsequent heating can be omitted.

  Cleaning the surface of the inorganic substrate before the silane coupling agent treatment by means such as short wavelength UV / ozone irradiation or cleaning with a liquid cleaning agent is a preferred operation.

In the present invention, a portion where the adhesive strength of the polyimide film to the inorganic substrate is relatively high is referred to as a good adhesive portion, and a portion where the adhesive strength is relatively low is referred to as an easily peelable portion.
FIG. 1 is an example of a typical measurement result when the adhesive strength of a polyimide film is measured in the laminate of the present invention. A region S having a high adhesive strength is a good adhesive portion, a region W having a low adhesive strength is an easily peelable portion, and G is a transition region between the two.
The average bond strength of good adhesion portion in the present invention as T _1, the average bond strength of the easy peeling portion and T _2, when the adhesive strength difference T = T ₁ -T _2, the adhesion strength T ₁ -0. It is essential that the distance G from the position of 1 × T to the position of T ₁ −0.9 × T, that is, the width of the transition region G is 4 mm or less. The width G of the transition region is preferably 3 mm or less, more preferably 2.4 mm or less, and further preferably 1.5 mm or less.

  In this invention, the adhesive strength of the part which irradiated the atmospheric pressure plasma to the inorganic substrate falls, it becomes an easily bonding part, and the part which is not irradiated with atmospheric pressure plasma becomes a favorable adhesion part. In the atmospheric pressure plasma treatment of the present invention, the boundary between the treated part and the untreated part is very clear, and therefore it is possible to clarify the boundary between the good adhesion part and the easy peeling part without using a mask. . Further, by not using a mask, it is possible to reduce the risk of scratches, contamination, and foreign matter adhesion on the film surface. The required adhesive strength varies depending on each process. However, as a general theory, it is preferable that the 90 degree adhesive strength of the good adhesion portion between the polyimide film of the laminate and the substrate made of an inorganic material is 0.5 N / cm or more and 5 N / cm or less, more preferably 0.8 N. / Cm or more and 2 N / cm or less. The 90-degree adhesive strength of the easily peelable portion is preferably 1/2 or less than that of the good adhesive portion, and when the adhesive strength of the good adhesive portion is 1 N / cm, the easy peelable portion is 0.01 N / cm or more and 0 .4 N / cm or less is preferable, and the adhesive strength of the easily peelable portion is more preferably 1/2 or less and 0.01 N / cm or more and 0.2 N / cm or less of the good adhesion portion. However, the lower limit of the adhesive strength of the easily peelable portion is a value that takes into account the bending energy of the polyimide film.

The atmospheric pressure plasma treatment in the present invention refers to a treatment in which an object to be treated is exposed to plasma generated under a pressure in the range of 0.3 atm to 3 atm.
In the present invention, it is essential to irradiate the substrate with plasma generated by an alternating electric field having a frequency in the atmospheric pressure of 8 kHz to 300 kHz in a state where the electric field strength is less than 45 kV / m. In the present invention, the electric field strength is preferably less than 20 kV / m, and more preferably less than 5 kV / m. In the present invention, it is preferable not to positively accelerate the electric field of the plasma and not to apply an external electric field that is higher than the electric field generated by charging by plasma irradiation.

The frequency of the alternating electric field for generating plasma in the atmospheric pressure plasma treatment in the present invention is preferably 8 kHz or more and 300 kHz or less, more preferably 12 kHz or more and 120 kHz or less, and further 20 kHz or more and 80 kHz or less. Is preferred. If the frequency is below this range, the stability of the discharge is reduced and plasma is difficult to stand up. Further, when the frequency exceeds this range, the leakage current in the processing apparatus increases, so that the energy efficiency is lowered.

In the present invention, the shape of the outlet through which plasma is supplied to the substrate to be processed is preferably a slit shape or a spot shape. In the case of the slit shape, the width of the plasma supply port is preferably 0.2 mm or more and 10 mm or less, more preferably 0.4 mm or more and 5 mm or less, and further preferably 0.5 mm or more and 3 mm or less. In the case of a spot shape, the diameter of the plasma supply port is preferably 0.2 mm or more and 10 mm or less, more preferably 0.4 mm or more and 5 mm or less, and further preferably 0.5 mm or more and 3 mm or less. If the width or diameter of the plasma supply port is too small, it is not preferable because the amount of plasma to be supplied is limited, and if it is too large, the plasma density in the gas is lowered and the effect of lowering the adhesive strength is reduced.
The plasma flow rate in the present invention is defined by the flow rate of the gas supplied to the plasma generated by the alternating electric field, preferably 10 L / min or more and 300 L / min or less, more preferably 30 L / min or more and 250 L / min or less, More preferably, it is 50 L / min or more and 200 L / min or less. If the plasma flow rate is too small, the amount of plasma to be supplied is limited and the plasma stays in the vicinity of the processing part, and the transition region of the adhesive strength becomes unclear. This is not preferable, and if it is too large, the plasma density in the gas decreases. This is not preferable because the effect of reducing the adhesive strength is diminished.
In addition, since a large amount of gas containing plasma is generated, it is preferable to provide a forced exhaust function in equipment for performing this plasma treatment so that the atmosphere is constantly switched.

Examples of the plasma processing gas used in the present invention include hydrogen, helium, nitrogen, oxygen, argon, carbon tetrafluoride, dry air, and a mixed gas thereof, and nitrogen or dry air is preferable. The dew point of the dry air is preferably −5 ° C. or lower, more preferably −10 ° C. or lower, still more preferably −20 ° C. or lower.

  In the atmospheric pressure plasma treatment of the substrate in the present invention, the treatment may be performed for a certain time without moving both the electrode and the substrate, or the treatment may be performed while moving one or both of the electrode and the substrate at a constant speed. . Assuming that the irradiation time is the time from the start of plasma irradiation to an arbitrary point within the atmospheric pressure plasma irradiation range on the substrate until the irradiation is completed, the preferable irradiation time is 0.1 seconds or more and 10.0 seconds or less, More preferably, it is 0.3 second or more and 8.0 second or less. Here, the time from the start of plasma irradiation to the end of the irradiation refers to the time during which the object to be processed passes between the opposing electrodes that generate plasma. More precisely, in the traveling direction of the object to be processed, the time required to pass between the surface connecting the electrode edges on the entrance side of the opposing electrode and the surface connecting the edges of the electrode on the exit side of the opposing electrode. is there.

The polyimide film used in the present invention is a polyamic acid film which is made self-supporting by applying a polyamic acid solution obtained from tetracarboxylic dianhydride and diamine to a base material and then drying, and then dehydrating and condensing by heat treatment etc. It is a condensate obtained by reacting. The polyimide used in the present invention is preferably a condensate obtained from an aromatic tetracarboxylic dianhydride and a diamine.
Examples of aromatic tetracarboxylic acids include pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride, 3,3. ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-diphenylsulfone tetracarboxylic dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) ) Phenyl] propanoic anhydride and the like can be used. These tetracarboxylic dianhydrides may be used alone or in combination of two or more. In the case of placing importance on heat resistance, the aromatic tetracarboxylic acids are, for example, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of all tetracarboxylic acids.

  In the present invention, a polyimide film comprising an alicyclic tetracarboxylic acid can be used. Examples of the alicyclic tetracarboxylic acids include alicyclic tetracarboxylic acids such as cyclobutanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, and 3,3 ′, 4,4′-bicyclohexyltetracarboxylic acid. Carboxylic acids and their acid anhydrides are mentioned. Among these, dianhydrides having two anhydride structures (for example, cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4 '-Bicyclohexyltetracarboxylic dianhydride and the like) are preferred.

  As the diamine preferably used in the present invention, phenylenediamine, diphenylaminoether, and aromatic diamines having a benzoxazole structure can be used. Specific examples of aromatic diamines having a benzoxazole structure include the following, and these diamines can be used alone or in combination of two or more.

  The molecular structure of aromatic diamines having a benzoxazole structure is not particularly limited, and specific examples include the following. For example, 5-amino-2- (p-aminophenyl) benzoxazole, 6-amino-2- (p-aminophenyl) benzoxazole, 5-amino-2- (m-aminophenyl) benzoxazole, 6-amino 2- (m-aminophenyl) benzoxazole, 2,2′-p-phenylenebis (5-aminobenzoxazole), 2,2′-p-phenylenebis (6-aminobenzoxazole), 1- (5 -Aminobenzoxazolo) -4- (6-aminobenzoxazolo) benzene, 2,6- (4,4'-diaminodiphenyl) benzo [1,2-d: 5,4-d '] bisoxazole, 2,6- (4,4′-diaminodiphenyl) benzo [1,2-d: 4,5-d ′] bisoxazole, 2,6- (3,4′-diaminodiphenyl) Benzo [1,2-d: 5,4-d ′] bisoxazole, 2,6- (3,4′-diaminodiphenyl) benzo [1,2-d: 4,5-d ′] bisoxazole, 2 , 6- (3,3′-diaminodiphenyl) benzo [1,2-d: 5,4-d ′] bisoxazole, 2,6- (3,3′-diaminodiphenyl) benzo [1,2-d : 4,5-d '] bisoxazole and the like.

    Among these, from the viewpoint of easy synthesis, each isomer of amino (aminophenyl) benzoxazole is preferable, and 5-amino-2- (p-aminophenyl) benzoxazole is more preferable. Here, “each isomer” refers to each isomer in which two amino groups of amino (aminophenyl) benzoxazole are determined according to the coordination position (eg, the above “formula 1” to “formula 4”). Each compound described in the above. These diamines may be used alone or in combination of two or more.

  In the present invention, one or two or more diamines exemplified below may be used in combination as long as they are 30 mol% or less of the total diamine. Examples of such diamines include 4,4′-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, and bis [4- (3-aminophenoxy) phenyl]. Sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3′-diamino Diphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-dia Nodiphenyl sulfide, 3,3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide, 4,4′-diaminodiphenyl sulfoxide, 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4 , 4′-diaminodiphenylsulfone, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4, 4′-diaminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-amino) Phenoxy) phenyl] ethane, 1,1-bis [4- 4-aminophenoxy) phenyl] propane, 1,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,1-bis [4- (4-aminophenoxy) phenyl] butane, 1,3-bis [4- (4-aminophenoxy) phenyl] butane, , 4-bis [4- (4-aminophenoxy) phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,3-bis [4- (4-aminophenoxy) phenyl ] Butane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (4-a Minophenoxy) -3-methylphenyl] propane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2- Bis [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexa Fluoropropane, 1,4-bis (3-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4 -Aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (4-amino) Enoxy) phenyl] sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1, 3-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] Benzene, 4,4′-bis [(3-aminophenoxy) benzoyl] benzene, 1,1-bis [4- (3-aminophenoxy) phenyl] propane, 1,3-bis [4- (3-aminophenoxy) ) Phenyl] propane, 3,4'-diaminodiphenyl sulfide, 2,2-bis [3- (3-aminophenoxy) phenyl -1,1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1 , 2-bis [4- (3-aminophenoxy) phenyl] ethane, bis [4- (3-aminophenoxy) phenyl] sulfoxide, 4,4′-bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-Amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, bis [4- {4- (4-aminophenoxy) phenoxy} fe Sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethyl Benzyl] benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-fluoro) Phenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4 -Amino-6-cyanophenoxy) -α, α-dimethylbenzyl] benzene, 3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-dipheno Cibenzophenone, 3,4'-diamino-4,5'-diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino- 4-phenoxybenzophenone, 3,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4′-diamino-4,5′-dibiphenoxybenzophenone, 3,3′-diamino-4-biphenoxybenzophenone, 4,4′-diamino-5-biphenoxybenzophenone, 3,4′-diamino-4 -Biphenoxybenzophenone, 3,4'-diamino-5'-biphenoxybenzophenone 1,3-bis (3-amino-4-phenoxybenzoyl) benzene, 1,4-bis (3-amino-4-phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-phenoxybenzoyl) Benzene, 1,4-bis (4-amino-5-phenoxybenzoyl) benzene, 1,3-bis (3-amino-4-biphenoxybenzoyl) benzene, 1,4-bis (3-amino-4-bi) Phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-biphenoxybenzoyl) benzene, 1,4-bis (4-amino-5-biphenoxybenzoyl) benzene, 2,6-bis [4- ( 4-amino-α, α-dimethylbenzyl) phenoxy] benzonitrile and some or all of the hydrogen atoms on the aromatic ring of the aromatic diamine are halogen atoms, An alkyl group having 1 to 3 carbon atoms, an alkoxyl group, a cyano group, or an alkyl group or an alkoxyl group having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of the alkyl group or alkoxyl group are substituted with halogen atoms. Examples thereof include substituted aromatic diamines.

  The solvent used when the polyamic acid is obtained by reacting (polymerizing) the aromatic tetracarboxylic acid and the aromatic diamine is not particularly limited as long as it dissolves both the raw material monomer and the produced polyamic acid. Is preferably a polar organic solvent, such as N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, Examples include hexamethylphosphoric amide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, and halogenated phenols. These solvents can be used alone or in combination. The amount of the solvent used may be an amount sufficient to dissolve the monomer as a raw material. As a specific amount used, the weight of the monomer in the solution in which the monomer is dissolved is usually 5 to 40% by weight, The amount is preferably 10 to 30% by weight.

  The polyimide film of the present invention preferably has a linear expansion coefficient (both in the film length direction and width direction) of −5 ppm / ° C. to +20 ppm / ° C. In the polyimide film of the present invention, it is preferable that a glass transition temperature is not observed in a region where the glass transition temperature is 250 ° C. or higher, preferably 300 ° C. or higher, more preferably 350 ° C. or higher, or 500 ° C. or lower. The glass transition temperature in the present invention is determined by differential thermal analysis (DSC).

  Although the thickness of the polyimide film in this invention is not specifically limited, 1 micrometer-200 micrometers are preferable, More preferably, they are 3 micrometers-60 micrometers. The thickness unevenness of these polyimide films is also preferably 20% or less. When the thickness is 1 μm or less, it is difficult to control the thickness, and it is difficult to peel off the substrate made of an inorganic substance. When the thickness is 200 μm or more, the polyimide film is easily bent when the polyimide film is peeled off. By using these polyimide films, it is possible to greatly contribute to the enhancement of the performance of elements such as sensors and the miniaturization of electronic parts.

In the polyimide film in the present invention, in order to ensure handling and productivity, a layer (polyimide film) in which a lubricant is added to and contained in the polyimide and fine protrusions are given to the surface of the layer (polyimide film). It is preferable to ensure slipperiness. The protrusions due to such lubricant particles may be on both sides of the film or only on one side. By passing through a multi-layer polyamic acid in which a polyamic acid containing a lubricant and a polyamic acid not containing a lubricant are laminated, a film having a lubricant projection only on one side can be obtained.

  In the present invention, it is preferable to perform vacuum plasma treatment on the polyimide film. The plasma treatment to the film surface to be used is not particularly limited, but there are RF plasma treatment in vacuum, microwave plasma treatment, microwave ECR plasma treatment, atmospheric pressure plasma treatment, corona treatment, etc. Gas treatment including fluorine, ion implantation using an ion source, treatment using a PBII method, flame treatment, and intro treatment are also included. Among these, RF plasma treatment, microwave plasma treatment, and atmospheric pressure plasma treatment in vacuum are preferable.

  In the present invention, the pressure heat treatment preferably used when laminating a polyimide film on an inorganic substrate refers to pressing, laminating, and roll laminating, each of which is performed while applying temperature, and preferably these are performed in a vacuum. The operation is performed. For pressing in vacuum, for example, a press using 11FD manufactured by Imoto Seisakusho, or a film laminator that can be evacuated, or a film laminator that can apply pressure to the entire surface of the glass with a thin rubber film after it has been evacuated. A method such as vacuum laminating by Machine Works MVLP can be used. In the present invention, the pressurization step and the heating step may be performed sequentially. For example, after laminating with a roll laminator, a method of heating in a dry oven can be exemplified.

A preferable pressurizing method includes a normal press in the air or a press in a vacuum, but in order to obtain a stable adhesive strength on the entire surface, a press in a vacuum is more preferable. As the degree of vacuum, a vacuum by a normal oil rotary pump is sufficient, and it is sufficient if it is about 10 Torr or less. A preferable pressure for pressing the sample is 1 MPa to 20 MPa, more preferably 3 MPa to 10 MPa. If the pressure is high, the substrate may be damaged. If the pressure is low, a part that does not adhere may come out. The preferred heating temperature of the present invention is 150 ° C to 400 ° C, more preferably 250 ° C to 350 ° C.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited by a following example. In addition, the evaluation method of the physical property in the following examples is as follows.

<Reduced viscosity of polyamic acid solution>
A solution dissolved in N, N-dimethylacetamide so that the polymer concentration was 0.2 g / dl was measured at 30 ° C. using an Ubbelohde type viscosity tube.

<Thickness of polyimide film>
The thickness of the polyimide film was measured using a micrometer (“Millitron 1245D” manufactured by FineLuf).

<Tension modulus, tensile strength and tensile elongation at break of polyimide film>
From the film to be measured, strip-shaped test pieces each having a flow direction (MD direction) and a width direction (TD direction) of 100 mm × 10 mm were cut out, and a tensile tester (“Autograph (registered trademark)” manufactured by Shimadzu Corporation) was cut out. ; Model name AG-5000A "), and the tensile modulus, tensile strength, and tensile elongation at break in each of the MD and TD directions were measured under the conditions of a tensile speed of 50 mm / min and a distance between chucks of 40 mm.

<Linear expansion coefficient (CTE) of polyimide film>
About the flow direction (MD direction) and the width direction (TD direction) of the polymer film to be measured, the stretch rate is measured under the following conditions, and the intervals of 15 ° C. (30 ° C. to 45 ° C., 45 ° C. to 60 ° C., ...) was measured, and this measurement was performed up to 300 ° C., and an average value of all measured values measured in the MD direction and the TD direction was calculated as a linear expansion coefficient (CTE).
Device name: “TMA4000S” manufactured by MAC Science
Sample length; 20mm
Sample width: 2 mm
Temperature rise start temperature: 25 ° C
Temperature rising end temperature: 400 ° C
Temperature increase rate: 5 ° C./min Atmosphere: Argon initial load: 34.5 g / mm 2

<Evaluation of polyimide film: slipperiness>
Two polyimide films are overlapped on different surfaces (that is, not on the same surface but on the wound outer surface and the wound inner surface when wound as a film roll), and the overlapped polyimide film is sandwiched between the thumb and forefinger, When the film was rubbed lightly, the case where the polymer film slipped was evaluated as “◯” or “good”, and the case where it did not slip was evaluated as “x” or “bad”. In addition, although it may not slip on winding outer surfaces or between winding inner surfaces, this is not made into an evaluation item.

<Appearance of laminate>
Visual inspection of the laminate by an adult inspector with a visual acuity of 1.0 or more, and blisters that correlate with the contamination of the substrate surface, especially the amount of adhering foreign matter (film lift: the film is caused by relics entering between the substrate and the film) A place where a space was created between the substrate and the film, which was lifted like a tent, also called “bubble” or “floating”). In terms of the number per 100 square centimeters, 0 to 3 blisters with a diameter of 0.2 mm or more were minimal, 4 to 10 were small, 10 to 20 were many, and 21 or more were many.

<Easily peeled part, film appearance after peeling, edge curl>
A visual inspection of the appearance of the film after peeling was performed by an adult inspector with a visual acuity of 1.0 or more. The point of interest is the presence or absence of curl on the film edge. Neutralize the peeled film with a static elimination brush and place it on a flat metal surface plate with the surface affixed to the board. Visually observe the presence or absence of floating film edges and no curl is observed. In the case of “浮”, the case where the lift of the edge is less than 0.5 mm is indicated by “◯”, the case of 0.5 mm or more and less than 1.0 mm is indicated by “Δ”, and 1.0 mm or more is indicated by “X”.
<Adhesive strength, transition area width>
According to the 90 degree peeling method of JIS K6854, the laminate substrate and film were peeled off, and the force required for peeling (power) was recorded on a chart. The size of the actually produced material varies depending on the substrate, but the measurement location is positioned so that the boundary between the good adhesion part and the easy peeling part is almost the center of the measurement part, and the length is 40 mm at least across the boundary. The distance was peeled off and measured.
The measurement apparatus used was an autograph AG-IS manufactured by Shimadzu Corporation, the measurement environment was a room temperature standard environment in the atmosphere, the peeling rate was 100 mm / min, and the measurement sample width was 10 mm.
The chart obtained typically has the format shown in FIG. 1, where T ₁ is the adhesion strength in the good adhesion region S, T ₂ is the adhesion strength in W, which is the easy peeling region, and T = T ₁ −T _The transition region G was defined as the distance from the location where the adhesive strength was “T ₁ −0.1 × T” to the location where the adhesive strength was “T ₁ −0.9 × T”.

<Thickness of coupling layer>
The thickness (nm) of the coupling treatment layer (SC layer) was prepared by separately preparing a sample obtained by applying and drying a coupling agent on a cleaned Si wafer in the same manner as in each example and comparative example, About the film thickness of the coupling process layer formed on this Si wafer, it measured by the ellipsometry method on condition of the following using the spectroscopic ellipsometer ("FE-5000" by Photo company).
Reflection angle range: 45 ° to 80 °
Wavelength range: 250 nm to 800 nm
Wavelength resolution: 1.25 nm
Spot diameter: 1mm
tan Ψ; Measurement accuracy ± 0.01
cosΔ; Measurement accuracy ± 0.01
Measurement: Method Rotating analyzer method Deflector angle: 45 °
Incident angle: 70 ° fixed Analyzer: 0-360 ° in 11.25 ° increments
Wavelength: 250 nm to 800 nm
The film thickness was calculated by fitting by a non-linear least square method. At this time, the model is Air / thin film / Si,
n = C3 / λ4 + C2 / λ2 + C1
k = C6 / λ4 + C5 / λ2 + C4
The wavelength dependence C1 to C6 was determined by the following formula.

<Pretreatment of inorganic materials>
Before applying the silane coupling agent to the substrate made of inorganic material, the surface is irradiated with UV light for 2 minutes using a UV / ozone cleaning reformer “SKR1102N-03” manufactured by LAN Technical Service Co. to remove dirt. Used after.

<Application example 1>
Using a device for generating silane coupling agent vapor, a silane coupling agent layer was formed on the substrate under the following conditions.
A 370 mm × 470 mm × 0.7 mmt non-alkali glass (OA-10G manufactured by Nippon Electric Glass Co., Ltd.) was used for the substrate, and it was set vertically on a glass stand and placed in a chamber for introducing a silane coupling agent vapor. Next, a silane coupling agent (“KBM-903” manufactured by Shin-Etsu Chemical Co., Ltd .: 3-aminopropyltrimethoxysilane) is generated in a device that generates a silane coupling agent vapor by sending a carrier gas to the liquid surface of the silane coupling agent. After 100 g was added and the temperature was adjusted to 40 ° C., nitrogen gas was fed at a flow rate of 10 L / min. The generated silane coupling agent vapor was introduced into the chamber through piping and held for 20 minutes. Thereafter, the substrate was taken out of the chamber and subjected to a heat treatment with a hot plate at 110 ° C. for 1 minute to obtain a substrate S1 on which a silane coupling agent layer was formed.

<Application example 2>
A substrate S2 was obtained in the same manner as in Application Example 1 except that the time for holding the alkali-free glass substrate in the chamber into which the silane coupling agent vapor was introduced was changed to 10 minutes.

<Application example 3>
A substrate S3 was obtained in the same manner as in Application Example 1 except that the time for holding the alkali-free glass substrate in the chamber into which the silane coupling agent vapor was introduced was changed to 5 minutes.

<Application example 4>
Silane coupling agent (“KBM-903” manufactured by Shin-Etsu Chemical Co., Ltd .: 3-aminopropyltrimethoxysilane) 0.5 parts by mass and 99.5 parts by mass of isopropyl alcohol were stirred and mixed in a clean glass container. A coupling agent solution was obtained. On the other hand, a Pyrex glass plate of 300 mm × 350 mm × 0.7 mmt was set on a spin coater manufactured by Japan Create Co., Ltd. First, 50 ml of isopropyl alcohol was dropped onto the center of the glass and washed by shaking off at 500 rpm, and then prepared in advance. About 30 ml of the silane coupling agent solution was dropped on the center of the glass plate, and the solution was shaken off by shaking the silane coupling agent solution at 500 ml for 10 seconds and then rotating the rotation speed to 1500 rpm for 20 seconds. Next, the glass plate is taken out from the stopped spin coater, placed on a hot plate at 100 ° C. in a clean environment with the silane coupling agent applied surface facing up, and heat-treated for about 3 minutes to form a silane coupling agent layer. The obtained inorganic substrate S4 was obtained.

<Manufacture of polyimide film>
[Production Example 1]
(Preparation of polyamic acid solution)
After the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, 398 parts by mass of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) and paraphenylenediamine ( PDA) 147 parts by mass is dissolved in 4600 parts by mass of N, N-dimethylacetamide, and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (“Snowtex (registered trademark)” manufactured by Nissan Chemical Industries, Ltd. DMAC-ST30 ") is added so that the silica (lubricant) is 0.15% by mass with respect to the total amount of polymer solids in the polyamic acid solution, and stirred at a reaction temperature of 25 ° C for 24 hours. A brown and viscous polyamic acid solution V1 having a reduced viscosity was obtained.

(Preparation of polyimide film)
The polyamic acid solution V1 obtained above is applied to the final film thickness (imide) on the smooth surface (non-lubricant surface) of a long polyester film (“A-4100” manufactured by Toyobo Co., Ltd.) having a width of 1050 mm using a slit die. The film thickness after conversion was 25 μm, dried at 105 ° C. for 20 minutes, and then peeled from the polyester film to obtain a self-supporting polyamic acid film having a width of 920 mm.
Next, the obtained self-supporting polyamic acid film was heated stepwise by a pin tenter in a temperature range of 150 ° C. to 420 ° C. (first stage 180 ° C. × 5 minutes, second stage 270 ° C. × 10 minutes, (Third stage 420 ° C. × 5 minutes) Heat treatment was performed to imidize, and pin grip portions at both ends were dropped with a slit to obtain a long polyimide film F1 (1000 m roll) having a width of 850 mm. Table 1 shows the characteristics of the obtained film F1.

[Production Example 2]
(Preparation of polyamic acid solution)
After the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, 223 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole (DAMBO), N, N-dimethylacetamide 4416 Next, a dispersion obtained by dispersing colloidal silica in dimethylacetamide as a lubricant together with 217 parts by mass of pyromellitic dianhydride (PMDA) (“Snowtex” manufactured by Nissan Chemical Industries, Ltd.) (Registered trademark) DMAC-ST30 ") so that silica (lubricant) is 0.12% by mass in the total amount of polymer solids in the polyamic acid solution, and stirred at a reaction temperature of 25 ° C for 24 hours, A brown and viscous polyamic acid solution V2 having a reduced viscosity shown in Table 1 was obtained.

(Preparation of polyimide film)
Instead of the polyamic acid solution V1, the polyamic acid solution V2 obtained above was used to obtain a polyamic acid film by the same method, and then the first stage 150 ° C. × 5 minutes and the second stage 220 ° C. × 5 minutes, 3rd stage 485 ° C. × 10 minutes) was subjected to heat treatment to imidize, and pin grip portions at both ends were dropped by slits to obtain a long polyimide film F2 (1000 m roll) having a width of 850 mm. Table 1 shows the characteristics of the obtained film F2.

[Production Example 3]
(Preparation of polyamic acid solution)
The same procedure as in Production Example 2 was carried out except that a dispersion obtained by dispersing colloidal silica in dimethylacetamide (“Snowtex (registered trademark) DMAC-ST30” manufactured by Nissan Chemical Industries, Ltd.) was added, and the polyamic acid solution V3 Got.

(Preparation of polyimide film)
The final film thickness (imidization) of the polyamic acid solution V2 obtained above on the smooth surface (non-lubricant surface) of a long polyester film (“A-4100” manufactured by Toyobo Co., Ltd.) having a width of 1050 mm using a comma coater (After film thickness) was applied so as to correspond to 5 μm, and then the polyamic acid solution V3 was applied using a slit die so that the final film thickness was 38 μm including V2, and dried at 105 ° C. for 25 minutes. Then, it peeled from the polyester film and obtained the self-supporting polyamic-acid film of width 920mm.
Next, the obtained self-supporting polyamic acid film was subjected to heat treatment with a pin tenter and subjected to imidization by performing heat treatment at the first stage 180 ° C. × 5 minutes, the second stage 220 ° C. × 5 minutes, the third stage 495 ° C. × 10 minutes, The pin grip portions at both ends were dropped with a slit to obtain a long polyimide film F3 (1000 m roll) having a width of 850 mm. The properties of the obtained film F3 are shown in Table 1.

<Manufacture of plasma-treated film>
One side of the obtained polyimide films F1 to F3 was subjected to vacuum plasma treatment to obtain a plasma-treated polyimide film, and the plasma-treated surface was used as an adhesive surface with an inorganic substrate. In F3, vacuum plasma treatment was performed on the side using the polyamic acid solution V2. As the vacuum plasma processing, RIE mode using parallel plate type electrodes and RF plasma processing are adopted, nitrogen gas is introduced into the vacuum chamber, high frequency power of 13.54 MHz is introduced, and the processing time is 30 seconds. For F1, a level processed under the same conditions as described above except that the vacuum plasma processing time was 60 seconds was also produced, and this film was designated as F1 ′.

<Example 1>
Using the atmospheric pressure plasma surface treatment apparatus “AP-T05-S320 type” manufactured by Sekisui Chemical Co., Ltd. with a modified plasma blowing nozzle and power supply, the silane coupling agent layer side of the obtained substrate S1 was used in the following procedure. Atmospheric pressure plasma treatment was performed.
A substrate 1 was placed on an XY stage installed in a box chamber having an internal capacity of 3 cubic meters having a ventilation function, and a plasma blowing nozzle having a nozzle diameter of 1 mmφ was placed on the XY stage with a distance of 1.5 mm from the substrate surface.
A plasma was generated by applying a voltage of 240 V between electrodes at a frequency of 30 kHz while flowing nitrogen gas with a dew point of −20 ° C. at a flow rate of 130 L / min between a pair of electrodes with a distance between electrodes of the plasma source of 2 mm. Was guided to the plasma blowing nozzle, and the XY stage was operated so that the nozzle moved at a relative speed of 100 mm / min on the substrate treated with the silane coupling agent, thereby drawing a predetermined easily peelable portion pattern. The time (irradiation time) from the start of irradiation of plasma to an arbitrary point within the irradiation range to the end of irradiation was 0.6 seconds.
The vacuum plasma treated surface of the polyimide film 1 obtained in Production Example 1 was applied to the atmospheric pressure plasma treated substrate thus obtained using a precision single wafer laminating machine (SE650nH manufactured by Crime Products), and the roll pressure was 8 kgf / cm 2. A temporary laminate substrate was obtained by laminating a film 10 mm from the outer periphery of the glass at a roll speed of 5 mm / sec. Thereafter, the obtained temporary laminate substrate was put in a clean oven, heated at 200 ° C. for 1 hour in a nitrogen atmosphere, and then allowed to cool to room temperature, thereby obtaining a laminate L1 of the present invention. The results of evaluating the obtained laminate are shown in Table 2.
Similarly, laminates were produced and evaluated under the same conditions. The results are shown in Table 2.
In Table 2, Dry N2 is dry nitrogen and Dry Air is dry air. As a mask in the comparative example, a protective film “FIXFILM HG1” (base material thickness: 50 μm) manufactured by Fuji Copian Co., Ltd. was attached to a range where a good adhesion portion on the substrate was formed during atmospheric pressure plasma treatment. The UV ozone treatment of the inactivation treatment in the comparative example was performed by irradiating with UV light for 2 minutes using a UV / ozone cleaning reformer “SKR1102N-03” manufactured by LAN Technical Service.

<Application example>
Each laminated body obtained in Examples 1, 2, 3 and Comparative Examples 1, 4, and 5 was covered with a stainless steel frame having an opening and fixed to a substrate holder in the sputtering apparatus. The substrate holder and the inorganic substrate side of the laminate are fixed in close contact with each other, and a coolant is allowed to flow through the substrate holder so that the temperature of the laminate film can be set. Set to. First, plasma treatment was performed on the film surface. The plasma treatment conditions were as follows: argon gas, frequency 13.56 MHz, output 200 W, gas pressure 1 × 10 −3 Torr, treatment temperature 2 ° C., treatment time 2 minutes.

Next, under the conditions of a frequency of 13.56 MHz, an output of 450 W, and a gas pressure of 3 × 10 −3 Torr, a nickel-chrome (chromium 10 mass%) alloy target is used to perform a DC magnetron sputtering method in an argon atmosphere at 1 nm / A nickel-chromium alloy film (underlayer) having a thickness of 11 nm was formed by a sputtering method at a rate of seconds. Subsequently, copper was vapor-deposited at a rate of 10 nm / second to form a copper thin film having a thickness of 0.22 μm. Thus, the laminated board with a base metal thin film formation film was obtained from each film. The thicknesses of the copper and nickel-chromium alloy layers were confirmed by the fluorescent X-ray method.
Next, a laminated board with a base metal thin film forming film from each film is fixed to a Cu frame, and an electroplating solution (copper sulfate 80 g / l, sulfuric acid 210 g / l, HCl, gloss, using a copper sulfate plating bath). A thick copper plating layer (thickening layer) having a thickness of 4 μm was formed by immersing in a small amount of the agent and passing 1.5 Adm 2 of electricity. Then, it heat-processed for 10 minutes at 120 degreeC, it dried, and the metallized polyimide film inorganic board | substrate laminated body was obtained.

After applying and drying a photoresist (“FR-200” manufactured by Shipley Co., Ltd.) to each of the obtained metallized polyimide film inorganic substrate laminates, it was closely exposed with a glass photomask, and further 1.2% by mass. Development was performed with an aqueous KOH solution. Next, etching was performed with a cupric chloride etching line containing hydrochloric acid and hydrogen peroxide at a spray pressure of 40 ° C. and 2 kgf / cm 2 to form a line array of lines / space = 20 μm / 20 μm as a test pattern. Next, after electroless tin plating was performed to a thickness of 0.7 μm, annealing treatment was performed at 125 ° C. for 1 hour.

The test pattern is formed from the inorganic substrate by slitting the film at the midpoint of the transition area between the good adhesion part and the easy peeling part of the metallized polyimide film inorganic substrate laminate after the formation of the test pattern. The polyimide film was peeled off.
When the laminates of Examples 1, 2, and 3 were used, good fine lines were formed, and the curl of the film edge was also ◎ level.
On the other hand, in the laminates of Comparative Examples 1 and 4, fine line formation was successfully performed, but peeling was difficult and edge curling was remarkable after peeling.
In the laminate of Comparative Example 5, there were many places where fine lines were partially disconnected or short-circuited. This is a result of the resist mask formation being hindered due to insufficient adhesion of the exposure mask due to the unevenness of the blisters on the film surface.

From the results of the above application examples, the laminate in which the peeling strength between the support and the polyimide film is appropriately adjusted by the production method of the present invention can withstand each process such as metallization, and the subsequent pattern It was confirmed that a good pattern can be formed even during fabrication, and that edge curl is also suppressed.

  The laminated plate of the present invention is extremely useful when a flexible electronic device is manufactured using a processing apparatus corresponding to a hard substrate such as a glass substrate or a silicon wafer. This is very useful when the boundary of the peeling portion is clear and the curl of the film after peeling is small, or when a large number of flexible electronic devices are allocated and manufactured in a single substrate.

Claims (4)

A laminate comprising at least a substrate made of an inorganic material, a polyimide film, and a silane coupling agent layer between the two, and a good adhesion portion with a high adhesion strength of the polyimide film to the substrate, and a low adhesion strength. Having a peeling part,
Let T ₁ be the average bond strength of good bonded parts,
Let T ₂ be the average adhesive strength of the easily peelable part,
When the adhesive strength difference T = T ₁ −T ₂ ,
A laminate having a distance G of 4 mm or less from a position having an adhesive strength of T ₁ −0.1 × T to a position having T ₁ −0.9 × T. The laminate according to claim 1, wherein the thickness of the silane coupling agent layer is 50 nm or less. The laminate according to claim 1 or 2, wherein an area of the inorganic substrate is 1700 square cm or more. at least,
(1) forming a silane coupling agent layer having a thickness of 50 nm or less on a substrate made of an inorganic material;
(2) A step of partially irradiating the surface of the substrate treated with the coupling agent with plasma,
(3) a step of superimposing, pressurizing and / or heating the polyimide film and the substrate made of the inorganic material,
In the manufacturing method of the laminated board which consists of a polyimide film / inorganic substrate containing
The plasma treatment is a treatment in which a substrate is irradiated with plasma generated by an alternating electric field having a frequency in an atmospheric pressure of 8 kHz to 300 kHz in a state where the electric field intensity is less than 45 kV / m. 4. A method for producing a laminate according to any one of items 1 to 3.