JP3900151B2 - Photosensitive film and method for laminating the same - Google Patents

Description

  The present invention relates to a photosensitive film and a method for laminating the photosensitive film, and more particularly to a photosensitive film having excellent coverage on a concavo-convex substrate under reduced pressure and a method for laminating the same.

Conventionally, in the printed wiring board industry, in order to prevent solder bridges that are likely to occur during soldering when mounting components on a printed wiring board, and to maintain the insulation between conductors and conductors, A protective film is formed on the surface. As such a permanent protective film, a photosensitive layer is provided on a flexible support such as a polyethylene terephthalate film, and a protective film such as a polyethylene film is provided on the photosensitive layer to temporarily protect the photosensitive layer. A photosensitive film is used. When a protective film is formed using this photosensitive film, heating and pressurization are performed in a decompression chamber as described in Patent Document 1 in order to prevent entrainment of bubbles between conductor patterns on the printed wiring board. An apparatus is used that performs conductor coating and conductor embedding by passing a photosensitive layer of a photosensitive film from which a protective film has been removed between the rolls on a printed wiring board. Since this apparatus can simultaneously laminate a printed wiring board and a photosensitive film, it is generally called a continuous vacuum laminator. On the other hand, in order to prevent solder bridging, conductor corrosion, and insulation between conductors, a flexible printed wiring board is also used to punch out a predetermined pattern with a die or the like on a polyimide film provided with an adhesive layer, and heat it on the conductor. Although a protective film is formed by pressure bonding, a photosensitive film called a photosensitive cover lay has been used in response to the recent demand for higher definition. In order to laminate this photosensitive cover lay on a flexible printed wiring board, a vacuum laminator generally called a batch type as described in Patent Document 2, Patent Document 3 and the like with little curling at the time of lamination is used. . The continuous vacuum laminator removes the protective film of the photosensitive film on the substrate under reduced pressure, and the photosensitive layer is laminated. However, the batch type vacuum laminator removes the protective film of the photosensitive film from the substrate in the atmosphere. Are placed in a vacuum and laminated. For this reason, when using a batch-type vacuum laminator, if the tackiness of the photosensitive layer and substrate of the photosensitive film, especially the conductor of the convex portion, is strong, even if placed under reduced pressure, the air in the concave portion cannot be removed, resulting in bubbles, The protrusions such as conductors cannot be sufficiently covered and cannot serve as protective films. In general, a photosensitive layer of a photosensitive film used for a substrate having unevenness has a tendency to increase tackiness because it has high fluidity in order to obtain good embedding properties. In addition, a photosensitive film intended for circuit formation of a printed wiring board sometimes uses a vacuum laminator with a high flow rate in order to embed scratches on the surface of a smooth copper-clad laminate. As a result, bubbles remain inside the scratch.
Japanese Patent Publication No.53-31670 Japanese Patent Publication No.55-13341 Japanese Patent Laid-Open No. 8-132531

  An object of the present invention is to eliminate the problems of the prior art and to provide a photosensitive film and a method for laminating the same that sufficiently cover the irregularities of the substrate without bubbles.

  In the present invention, a photosensitive film comprising a flexible support, a photosensitive composition layer, and a protective film in which the adhesiveness to the photosensitive composition layer of the flexible support is smaller than the adhesiveness to the photosensitive composition layer is laminated in this order. In the protective film, the surface roughness of the surface of the protective film that comes into contact with the photosensitive composition layer has an arithmetic average roughness (in the measurement range in which the cutoff value is 0.08 to 8 mm and the evaluation length is 0.4 mm to 40 mm). It is related with the photosensitive film characterized by being 0.5 micrometer or more in Ra).

  The present invention also removes the protective film of the photosensitive film, removes the protective film of the photosensitive composition layer, and reduces the pressure so that the surface having the surface roughness of the photosensitive composition layer is in contact with the substrate. It is related with the lamination method of the photosensitive film characterized by laminating | stacking.

  When the photosensitive film and the lamination method of the present invention are used, a photosensitive resin layer can be obtained in which the substrate surface having irregularities is sufficiently covered without bubbles, particularly under reduced pressure.

  In general, a photosensitive film has a structure in which a flexible support, a photosensitive composition layer, and a protective film are laminated in this order, and when laminated on a substrate or the like, the photosensitive composition layer is placed on the substrate surface except for the protective film. It is made to contact, is heated and pressurized and laminated. And in order to coat | cover an unevenness | corrugation without enclosing a bubble, laminating | stacking under reduced pressure is generally performed. In particular, when using a batch-type vacuum laminator, increasing the fluidity of the photosensitive composition layer to embed the unevenness increases the adhesive strength with the protrusions, making it difficult to degas the recesses even under reduced pressure. Is impossible.

  In the present invention, the surface of the photosensitive composition layer on the side in contact with the substrate surface to be laminated is given a certain range of surface roughness and laminated under reduced pressure to sufficiently cover the irregularities of the substrate without bubbles. Can do. The surface roughness given to this photosensitive composition layer must disappear by pressurization during lamination in order to sufficiently cover the unevenness of the substrate, but the surface roughness must be maintained before lamination. Don't be. Therefore, the photosensitive composition layer needs to have a certain fluidity. Therefore, by using a protective film having a surface roughness on the side facing the photosensitive composition layer, a primary surface roughness is given to the photosensitive composition layer having fluidity, thereby having fluidity. The photosensitive composition layer follows the surface roughness of the protective film to obtain the required surface roughness during lamination, and the surface roughness disappears due to the pressure applied during lamination, covering the substrate irregularities sufficiently without bubbles. it can. However, the protective film having this surface roughness must have a lower adhesion to the photosensitive composition layer than the flexible support.

  The surface roughness of this protective film is represented by arithmetic mean roughness (Ra) defined in Japanese Industrial Standard JIS B0601-1994, with a cut-off value of 0.08-8 mm and an evaluation length of 0.4 mm-40 mm. The arithmetic average roughness (Ra) must be 0.5 μm or more in the measurement range. The arithmetic average roughness (Ra) is preferably in the range of 0.1 to 50%, more preferably 1 to 20% of the layer thickness of the photosensitive composition layer. Further, the ten-point average roughness (Rz) defined in Japanese Industrial Standard JIS B0601-1994 has a standard length of 0.08 to 8 mm and an evaluation length of 0.4 mm to 40 mm in a measurement range of 0.5 μm. It is preferably in the range of 0.1% to 50% of the thickness of the photosensitive composition layer, more preferably 1% to 20%. Furthermore, in the measurement range where the maximum height (Ry) defined in Japanese Industrial Standard JIS B0601-1994 is a reference length of 0.08 to 8 mm and an evaluation length of 0.4 mm to 40 mm, the photosensitive composition layer It is preferable that it is 2 times or less of the layer thickness.

  Here, the cutoff value is a cutoff value of a roughness curve defined in Japanese Industrial Standard JIS B0601-1994, and indicates a wavelength corresponding to a frequency at which the gain of the phase compensation type high-pass filter is 50%. Is.

  In general, the surface roughness can be measured by using a stylus type surface roughness meter based on Japanese Industrial Standard JIS B0601-1994, and the tip radius of the stylus used for measurement is preferably 2 μm.

  When the surface roughness of the photosensitive composition layer is 0.08 to 8 mm in the cut-off value and the evaluation length is 0.4 mm to 40 mm and the arithmetic average roughness (Ra) is less than 0.5 μm, lamination to the substrate is performed. Sometimes it becomes easy to entrain bubbles. Further, when the thickness of the photosensitive composition layer is less than 0.1%, bubbles tend to be easily involved when laminated on the substrate, and when the thickness exceeds 50%, it is difficult to sufficiently cover the unevenness of the substrate. Tend.

The photosensitive composition layer of the photosensitive film used enhances the followability and embedding of the substrate to be laminated, and also keeps the surface roughness temporarily to sufficiently cover and embed the substrate unevenness. It is necessary to have fluidity. This fluidity is measured when a static load of 0.25 kg / mm ² is applied to a photosensitive composition layer having a layer thickness of 2 mm at a temperature of 30 ° C., and the time elapses from 10 seconds to 600 seconds after the load is applied. It is preferable that the amount of change in film thickness is in the range of 50 to 800 μm. More preferably, the film thickness variation is in the range of 100 to 500 μm.

  If the amount of change in film thickness is less than 50 μm, it becomes difficult not only to follow the photosensitive composition layer to the surface roughness of the protective film, but also it becomes difficult to sufficiently cover or embed the unevenness of the substrate. Moreover, when the amount of change in film thickness exceeds 800 μm, it becomes difficult to temporarily maintain the surface roughness of the photosensitive composition layer after removing the protective film, and the photosensitive composition layer on the surface in contact with the substrate The surface roughness of the substrate disappears, and the effect of the surface roughness cannot be obtained, so that it is difficult to sufficiently cover or embed the unevenness of the substrate.

  When a protective film having a surface roughness is laminated on the surface of the photosensitive composition layer, the protective film may be heated and pressurized within a range in which the characteristics of the photosensitive composition do not change.

  As the flexible support, the photosensitive composition layer, and the protective film of the photosensitive film used in the present invention, known ones can be used. The film thickness of the flexible support is preferably 12 to 25 μm, the film thickness of the photosensitive composition layer is preferably 5 to 30 μm, and the film thickness of the protective film is preferably 15 to 50 μm.

  As the flexible support and protective film of the photosensitive film used in the present invention, for example, polymer films such as polyethylene, polyethylene terephthalate film, polyimide film, polyamide film, polypropylene film, and polystyrene film are used. A polyethylene terephthalate film is preferably used as the conductive support, and a polyethylene film is preferably used as the protective film.

  A protective film having a surface roughness can be obtained, for example, by passing a stretched polyethylene film between a metal roll and a rubber roll, which have a pattern or the like called satin on the surface. The film thus obtained is called a satin finish film or an embossed film.

  In another method, the protective film having surface roughness can be obtained by uniformly dispersing fine particles in the film, but the method for obtaining the protective film having surface roughness is not limited to these methods.

  The photosensitive composition layer of the photosensitive film used in the present invention is composed of, for example, (a) a thermoplastic polymer, (b) an unsaturated group-containing monomer, (c) a photopolymerization initiator, and the like.

  (A) As a thermoplastic polymer, a vinyl copolymer is mentioned, for example, As a copolymer monomer used, acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylic acid 2-ethylhexyl, lauryl methacrylate, methyl acrylate, ethyl acrylate, styrene, α-methyl styrene, vinyl toluene, N-vinyl pyrrolidone, acrylamide, acrylonitrile, methacrylonitrile, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, etc. Can be mentioned. Moreover, the half ester of a styrene / maleic acid copolymer is mentioned.

  Moreover, the weight average molecular weight (measured in terms of standard polystyrene using GPC) of the thermoplastic polymer is preferably 20,000 to 300,000, more preferably 50,000 to 150,000.

  As the unsaturated group-containing monomer of component (b), for example, a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid (polyethylene glycol diacrylate (the number of ethylene groups is 2 to 14). ), Trimethylolpropane diacrylate, trimethylolpropane triacrylate, tetramethylolmethane triacrylate, tetramethylolmethane tetraacrylate, polypropylene glycol diacrylate (having 2 to 14 propylene groups), dipentaerythritol pentaacrylate , Dipentaerythritol hexaacrylate, etc.), bisphenolΑpolyoxyethylene diacrylate (bisphenolΑdioxyethylene diacrylate, bisphenolΑtrioxyethylene diacrylate, bisphenol) Decaoxyethylene diacrylate, etc.), compounds obtained by adding α, β-unsaturated carboxylic acid to glycidyl group-containing compounds (trimethylolpropane triglycidyl ether triacrylate, bisphenol diglycidyl ether acrylate, etc.), Esterified product of 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, polyvalent carboxylic acid (such as phthalic anhydride) and a compound having a hydroxyl group and an ethylenically unsaturated group (such as β-hydroxyethyl acrylate); Obtained by reacting acrylic acid alkyl ester (methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc.), trimethylhexamethylene diisocyanate, dihydric alcohol and divalent acrylic monoester. Urethane diac Relate compounds and the corresponding methacrylates.

  The blending amount of the component (a) in the present invention is preferably 40 to 80 parts by weight (so that the total amount of the component (a), the component (b) and the component (c) is 100 parts by weight). 50 to 70 parts by weight is more preferable, and 55 to 65 parts by weight is particularly preferable.

  Examples of the photopolymerization initiator used as the component (c) in the present invention include aromatic ketones (benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl). Benzoin ethers such as -4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-ethylanthraquinone, phenanthrenequinone, etc., benzoin (benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, etc.) , Methylbenzoin, ethylbenzoin, etc.), benzyl derivatives (benzyldimethyl ketal, etc.), 2,4,5-triarylimidazole dimer (2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2 -(O-chlorophenyl) 4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole Dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4- Dimethoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methylmercaptophenyl) -4,5-diphenylimidazole dimer, etc.), acridine derivatives (9-phenylacridine, 1,7-bis ( 9,9'-acridinyl) heptane and the like), ethyl dimethylaminobenzoate, diethylthioxanthone and the like. These are used alone or in combination of two or more.

  The amount of component (c) in the present invention is preferably 0.10 to 20 parts by weight, and 0.15 to 15 parts by weight with respect to 100 parts by weight of the total amount of components (a) and (b). More preferably, it is 0.20-10 weight part.

  In the photosensitive composition layer of the photosensitive film used in the present invention, thermosetting components such as hexamethoxymethylmelamine, dyes, pigments, plasticizers, stabilizers, 2-amino-5-mercapto-1,3, An adhesion improver such as 4-thiadiazole, a filler and the like are added as necessary.

  The photosensitive film used in the present invention is, for example, a photosensitive composition comprising (a) a thermoplastic polymer, (b) an unsaturated group-containing monomer, (c) a photopolymerization initiator, and the like. A solution uniformly dissolved in a solvent or the like is uniformly applied onto a flexible support, and then the solvent is removed by heating and / or hot air blowing to form a dry film. The thus obtained photosensitive film comprising two layers of the flexible support and the photosensitive composition layer is stored as it is or a protective film is laminated on the photosensitive composition layer and wound into a roll. Is done.

  A photosensitive film comprising a flexible support, a photosensitive composition layer, and a protective film having a surface roughness used in the present invention is obtained by removing the protective film and then transferring the photosensitive composition layer to which the surface roughness is transferred. The substrate is laminated and adhered by heating and pressing, but it is effective to perform under reduced pressure in order to sufficiently fill and cover the unevenness of the substrate. The pressure, temperature, and time at this time may be in a range where a film thickness that can maintain the characteristics of the photosensitive composition layer is obtained.

  The photosensitive film thus laminated is then imagewise exposed with actinic light using a negative film or a positive film. In this case, exposure may be performed except for the flexible support on the photosensitive composition layer. After exposure, if there is a flexible support on the photosensitive composition layer, it is removed by using a known method such as spraying, rocking dipping, brushing, scrubbing, etc. using an organic solvent or an alkaline aqueous solution. An unexposed part or an exposed part is removed and developed. Thereafter, in order to improve the characteristics, the resin is further cured by heating with light irradiation.

EXAMPLES Next, although an Example demonstrates this invention in detail, this invention is not limited to these.
Example 1

  A solution 6 having a composition containing the materials shown in Table 1 was uniformly applied on a polyethylene terephthalate film 12 having a thickness of 25 μm using the apparatus shown in FIG. The solvent was removed by drying for 5 minutes, and the film thickness of the photosensitive composition layer was adjusted to 25 μm. In FIG. 1, 1 is a polyethylene terephthalate film feed roll, 2 is a feed roll, 3 is a backing roll, 4 is a doctor roll, 9 and 10 are rolls, 5 is a knife, 6 is a solution of a photosensitive composition, and 7 is a dryer. , 8 is a polyethylene film feed roll, and 11 is a photosensitive film take-up roll.

When a static load of 0.25 kg / mm ² was applied to a sample in which the photosensitive composition layer was overlaid and the layer thickness was 2 mm, the film was obtained over time from 10 seconds to 600 seconds after the load was applied. The amount of change in thickness was 288 μm. Next, using the apparatus shown in FIG. 1, a polyethylene film 13 (protective film) was further bonded onto the photosensitive composition layer to obtain a photosensitive film. The protective film used was measured for surface roughness at a stylus tip radius of 2 μm and a scanning speed of 0.1 mm / sec using a surface roughness measuring device Surfcoder SE-30D (manufactured by Kosaka Laboratory). As a result, the arithmetic average roughness (Ra) was 1.2 μm (4.8% of the photosensitive composition layer) in the measurement range where the cutoff value was 0.08 mm and the evaluation length was 2.5 mm. The maximum height (Ry) was 10.5 μm (21% of the photosensitive composition layer).

Next, using the apparatus shown in FIG. 2, a printed wiring board in which 18 μm thick copper circuits are formed on both sides is placed on the photosensitive composition layer excluding the protective film of the photosensitive film, and then pressed and heated. After sending to the vacuum chamber and bringing the photosensitive composition layer excluding the protective film of the photosensitive film into contact with the upper surface of the printed wiring board, the chamber was heated to 100 ° C. while evacuating to 1 Torr. Lamination was performed while maintaining a pressurized state of 5 kg / cm ² for 3 minutes. Thereafter, the chamber was opened and the printed wiring board on which the photosensitive film was laminated was taken out, and the presence or absence of bubbles on the circuit or between the circuits was observed visually and with a 50 × microscope. In FIG. 2, 14 is a substrate, 15 and 16 are pressurization / heating / vacuum chambers, 17 is a fixed film, 18 is a pressurization film, 19 is a vacuuming section, 20 is an air pressurization section, and 21 and 22 are photosensitive. Film feed rolls, 23 and 24 are protective film take-up rolls, and 25 and 26 are photosensitive films.

Next, the printed wiring board on which the photosensitive film was laminated was exposed to 80 mJ / cm ² through a negative mask using an ultra-high pressure mercury lamp, and further sprayed with a 1% by weight aqueous sodium carbonate solution to a spray pressure of 1.0 kg / cm ^2. The film was developed at a liquid temperature of 30 ° C. Thereafter, ultraviolet rays of 1 J / cm ² were irradiated with a high-pressure mercury lamp and further heated at 150 ° C./60 minutes to form a cured film. The printed wiring board on which this cured film was formed was immersed in a solder bath at 260 ° C. for 10 seconds, and the appearance was observed visually and with a 50 × microscope. These results are shown in Table 2.

Example 2
The surface roughness is 3.4 μm in arithmetic average roughness (Ra) (13.6% of the photosensitive composition layer thickness), and 22.8 μm in maximum height (Ry) (45.6% in the photosensitive composition layer). ) Was used in the same manner as in Example 1 except that the presence of bubbles and the appearance after solder immersion were observed visually and with a 50 × microscope. The results are shown in Table 2.

Example 3
Surface roughness is 4.5 μm in arithmetic mean roughness (Ra) (18.0% of photosensitive composition layer thickness)), and 27.5 μm in maximum height (Ry) (55% of photosensitive composition layer) Except that the protective film was used, it was carried out in the same manner as in Example 1, and the presence / absence of bubbles and the appearance after immersion in the solder were observed visually and with a 50 × microscope. The results are shown in Table 2.

Example 4
A photosensitive film in which the flow rate of the photosensitive composition layer is 312 μm, except that the thickness of the photosensitive composition layer is 50 μm and a printed wiring board having a copper circuit thickness of 35 μm is used. Got. This photosensitive film was laminated on a printed wiring board in the same manner as in Example 1, and the presence / absence of bubbles and the appearance after immersion in solder were observed visually and with a 50 × microscope. The results are shown in Table 2.

Example 5
Surface roughness is arithmetic mean roughness (Ra) 9.8 μm (19.6% of photosensitive composition layer thickness)), and maximum height (Ry) is 70.1 μm (140.2 of photosensitive composition layer). %) Was used in the same manner as in Example 4, and the presence of bubbles and the appearance after solder immersion were observed visually and with a 50 × microscope. The results are shown in Table 2.

Comparative Example 1
The surface roughness is 0.1 μm (0.4% of the photosensitive composition layer thickness) in arithmetic mean roughness (Ra), and 1.3 μm (2.6 in the photosensitive composition layer) in the maximum height (Ry). %) Was used in the same manner as in Example 1, and the presence of bubbles and the appearance after solder immersion were observed visually and with a 50 × microscope. The results are shown in Table 2.

Example 6
Except for changing the drying time after coating of the photosensitive film and changing the fluidity to 205 μm, it was carried out in the same manner as in Example 4, and the presence or absence of bubbles and the appearance after solder immersion were observed visually and with a 50 × microscope. The results are shown in Table 2.

Example 7
A photosensitive film was produced in the same manner as in Example 1 except that the amount of 2,2-bis [4- (methacryloxy polyethoxy) phenyl] propane in Table 1 was changed to 25 parts by weight. At this time, the protective film laminating roll of FIG. 2 was heated to 70 ° C. to bond the protective film. The fluidity at this time was 114 μm. Then, it carried out similarly to Example 4, and observed the presence or absence of a bubble and the external appearance after solder immersion with the microscope of 50 times. The results are shown in Table 2.

Example 8
The procedure was the same as in Example 4 except that the drying time after application of the photosensitive film was changed and the fluidity was changed to 520 μm. The presence of bubbles and the appearance after immersion in the solder were observed visually and with a 50 × microscope. The results are shown in Table 2.

  As is apparent from Table 2, when the photosensitive film and the lamination method of the present invention are used, the uneven substrate can be sufficiently coated without bubbles.

  In addition, the protective film which has the specific surface roughness used above is marketed, and is manufactured by passing a film between the metal roll and rubber roll which processed the surface by sandblasting. Under the present circumstances, the protective film which has different surface roughness is obtained by adjusting the particle size and spraying time of the sand of a sandblasting process, and changing the unevenness | corrugation of a roll surface.

The schematic of the manufacturing apparatus of the photosensitive film used in the Example. Schematic of the laminating apparatus used in the examples.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polyethylene terephthalate film feeding roll 2 Feed roll 3 Backing roll 4 Doctor roll 5 Knife 6 Photosensitive composition solution 7 Dryer 8 Polyethylene film feeding roll 9, 10 roll 11 Photosensitive film winding roll 12 Polyethylene terephthalate film 13 Polyethylene film 14 Substrate 15, 16 Pressurization / heating / vacuum chamber 17 Fixed film 18 Pressurization film 19 Vacuum drawing part 20 Air pressurization part 21, 22 Photosensitive film feed rolls 23, 24 Protective film winding rolls 25, 26 Photosensitive film

Claims (8)

A printed wiring board in which a flexible support, a photosensitive composition layer, and a protective film having less adhesion to the photosensitive composition layer of the flexible support in this order are laminated in this order. A photosensitive coverlay for stacking,
The protective film is an embossed film;
The surface roughness of the surface of the protective film that comes into contact with the photosensitive composition layer has an arithmetic average roughness (Ra) of 0 in the measurement range where the cut-off value is 0.08 to 8 mm and the evaluation length is 0.4 mm to 40 mm. A photosensitive cover lay having a thickness of 0.5 μm or more and an arithmetic average roughness (Ra) of 1 to 20% of a layer thickness of the photosensitive composition layer . The printed wiring board is a flexible printed wiring board, a photosensitive coverlay according to claim 1, wherein. The photosensitive coverlay of Claim 1 or 2 whose film thickness of the said photosensitive composition layer is 5-30 micrometers. The photosensitive composition according to claim 1, wherein the photosensitive composition layer comprises (a) a thermoplastic polymer, (b) an unsaturated group-containing monomer, and (c photopolymerization initiator. Sex coverlay. The photosensitive coverlay of Claim 4 in which the said photosensitive composition layer further contains a thermosetting component. (A) The photosensitive coverlay of Claim 4 or 5 whose weight average molecular weights of a thermoplastic polymer are 20,000-300,000. The amount of the thermoplastic polymer (a) is 40 to 80 parts by weight when the total amount of the component (a), the component (b) and the component (c) is 100 weights. A photosensitive cover lay according to claim 1. The protective film of the photosensitive coverlay according to any one of claims 1 to 7 is removed, and lamination is performed under reduced pressure so that the surface having the surface roughness of the photosensitive composition layer is in contact with the substrate. A method for laminating a photosensitive coverlay.

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