JP3522127B2 - Photosensitive film and lamination method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive film and a method for laminating the same, and more particularly to a photosensitive film having excellent coverage on a concave and convex substrate under reduced pressure and a method for laminating the same.

[0002]

2. Description of the Related Art 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 prevent corrosion of conductors and maintenance of insulation between conductors. In addition, a protective film is formed on the surface of a conductor or the like. 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. Photosensitive film is used. When a protective film is formed using this photosensitive film, in order to prevent air bubbles from being entrapped between the conductor patterns on the printed wiring board, a decompression chamber as described in JP-B-53-31670 is used. An apparatus is used in which a photosensitive layer of a photosensitive film from which a protective film has been removed is passed between heated and pressurized rolls so that the photosensitive layer is passed over the printed wiring board so as to cover and embed the conductor. Since this device can laminate a printed wiring board and a photosensitive film at the same time, it is generally called a continuous vacuum laminator. On the other hand, even for flexible printed wiring boards, in order to prevent solder bridging, corrosion of conductors, and insulation between conductors, a polyimide film with an adhesive layer is punched out in a predetermined pattern using a mold, etc. Although a protective film is formed by pressure bonding, a photosensitive film called a photosensitive coverlay has come to be used in response to the recent demand for higher definition. In order to laminate this photosensitive cover lay on a flexible printed wiring board, it is generally called a batch type as described in Japanese Patent Publication No. 55-13341 and Japanese Patent Laid-Open Publication No. 1332531 which have less curl during lamination. A known vacuum laminator is used. The continuous vacuum laminator removes the protective film of the photosensitive film and laminates the photosensitive layer on the substrate under reduced pressure, but the batch type vacuum laminator has the photosensitive layer with the protective film of the photosensitive film removed on the substrate under the atmosphere. Are brought into contact with each other and then placed under reduced pressure to be laminated. Therefore, when using a batch type vacuum laminator, the photosensitive layer of the photosensitive film and the substrate,
In particular, if the tack of the conductor of the protrusion is strong, even if the conductor is placed under reduced pressure, the atmosphere of the recess cannot be removed to form air bubbles, and the conductor of the protrusion cannot be sufficiently covered to serve as a protective film. Generally, the photosensitive layer of a photosensitive film used for a substrate having irregularities has high fluidity in order to obtain good embeddability, and therefore tends to have strong tack. In addition, even with a photosensitive film for the purpose of forming a circuit on a printed wiring board, a vacuum laminator may be used with a high fluidity to fill scratches on the surface of a smooth copper-clad laminate, and in this case as well, the photosensitive layer is high. It becomes tacky, and as a result, air bubbles remain inside the scratch.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned problems of the prior art and to provide a photosensitive film capable of sufficiently covering the irregularities of a substrate without bubbles and a method for laminating the same.

[0004]

SUMMARY OF THE INVENTION The present invention is a flexible support.
Adhesion to body, photosensitive composition layer and photosensitive composition layer
Is more than the adhesiveness of the flexible support to the photosensitive composition layer.
Printed wiring with small protective films laminated in this order
A photosensitive film for laminating on a plate, the protective film
The surface roughness of the surface of the film that contacts the photosensitive composition layer is
Toff value is 0.08 to 8 mm, evaluation length is 0.4 mm to
With arithmetic mean roughness (Ra) in the measuring range of 40 mm
0.5 μm or more, and the photosensitive composition layer has a temperature of 30 ° C.
In the photosensitive composition layer having a layer thickness of 2 mm in
When a static load of kg / mm ² is applied, after applying the load
Amount of film thickness change over time from 10 seconds to 600 seconds
Has a fluidity in the range of 50 to 800 μm and protects
The film gives the photosensitive composition layer surface roughness,
Is held on the printed wiring board before lamination, and pressure is applied during lamination.
The present invention relates to a photosensitive film which is erased by

The present invention also removes the protective film of the photosensitive film to remove the protective film of the photosensitive composition layer so that the surface having the surface roughness of the photosensitive composition layer contacts the substrate. And a method for laminating a photosensitive film, which comprises laminating under a reduced pressure.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Generally, a photosensitive film has a structure in which a flexible support, a photosensitive composition layer, and a protective film are laminated in this order. Heating the composition layer in contact with the substrate surface,
Pressure treatment is performed for lamination. Then, in order to cover the unevenness without entraining air bubbles, it is generally performed to stack under a reduced pressure. Especially when using a batch type vacuum laminator,
When the fluidity of the photosensitive composition layer is increased in order to fill the irregularities, the adhesive force with the convexes becomes strong, and it becomes difficult to deaerate the concaves even under reduced pressure, so that sufficient coverage cannot be achieved.

In the present invention, the surface of the photosensitive composition layer on the side in contact with the surface of the substrate to be laminated is given a surface roughness within a certain range and laminated under reduced pressure so that the irregularities of the substrate are sufficiently formed without bubbles. Can be coated. The surface roughness given to this photosensitive composition layer must be eliminated by the pressure applied during lamination in order to sufficiently cover the irregularities of the substrate, but the surface roughness must be maintained before lamination. I won't.
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, the photosensitive composition layer having fluidity is provided with a primary surface roughness, thereby having fluidity. The photosensitive composition layer follows the surface roughness of the protective film to obtain the required surface roughness at the time of lamination, and the surface roughness disappears due to the pressure at the time of lamination to sufficiently cover the unevenness of the substrate without bubbles. it can. However, the protective film having this surface roughness must be less adhesive to the photosensitive composition layer than the flexible support.

The surface roughness of this protective film is represented by the arithmetic mean roughness (Ra) defined in Japanese Industrial Standard JIS B0601-1994, and the cutoff value is 0.08 to 8 m.
It is necessary that the arithmetic mean roughness (Ra) is 0.5 μm or more in a measurement range of m and an evaluation length of 0.4 mm to 40 mm. The arithmetic average roughness (Ra) is preferably in the range of 0.1 to 50% of the layer thickness of the photosensitive composition layer,
More preferably, it is 1 to 20%. In addition, the ten-point average roughness (Rz) defined in Japanese Industrial Standard JIS B0601-1994 is 0.5 in a measuring range of a reference length of 0.08 to 8 mm and an evaluation length of 0.4 mm to 40 mm.
It is preferably in the range of not less than μm or not less than 0.1% and not more than 50% of the layer thickness of the photosensitive composition layer, and more preferably not less than 1% and not more than 20%. Furthermore, the maximum height (Ry) defined in Japanese Industrial Standards JIS B0601-1994 has a reference length of 0.08 to 8 mm and an evaluation length of 0.4 mm to 40 mm in a measurement range of a photosensitive composition layer. It is preferable that the thickness is less than twice the layer thickness.

Here, the cutoff value is the Japanese Industrial Standard JI.
The cut-off value of the roughness curve defined in SB0601-1994, which indicates the wavelength corresponding to the frequency at which the gain of the phase compensation type high-pass filter becomes 50%.

The surface roughness is generally measured by the Japanese Industrial Standard JI.
A stylus-type surface roughness meter based on S B0601-1994 can be used, and the tip radius of the stylus used for measurement is preferably 2 μm.

The surface roughness of the photosensitive composition layer has a cutoff value of 0.08 to 8 mm and an evaluation length of 0.4 mm to 40 mm.
0.5 μm in arithmetic mean roughness (Ra) in the measurement range of
If it is less than the range, bubbles are likely to be entrained during lamination on the substrate. On the other hand, if it is less than 0.1% of the layer thickness of the photosensitive composition layer, bubbles tend to be easily entrained during lamination on the substrate, and the layer thickness of 5
If it exceeds 0%, it tends to be difficult to sufficiently cover the unevenness of the substrate.

The photosensitive composition layer of the photosensitive film used enhances the followability and embeddability of the unevenness of the substrate to be laminated, and temporarily maintains the surface roughness to sufficiently cover the unevenness of the substrate. Since it is embedded, it is necessary to have fluidity. The fluidity is such that 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., 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 amount of change in film thickness is in the range of 100 to 500 μm.

When the change in film thickness is less than 50 μm, it is difficult not only for the photosensitive composition layer to follow the surface roughness of the protective film but also for it to be difficult to sufficiently cover or embed the irregularities of the substrate. is there. In addition, the film thickness change is 800μ
When it exceeds m, it becomes difficult to temporarily maintain the surface roughness of the photosensitive composition layer after removing the protective film,
The surface roughness of the photosensitive composition layer on the surface in contact with the substrate disappears, the effect of the surface roughness cannot be obtained, and it tends to be difficult to sufficiently cover or embed the irregularities of the substrate.

When the protective film having surface roughness is laminated on the surface of the photosensitive composition layer, heating and pressurization may be performed within a range in which the characteristics of the photosensitive composition are not changed.

Known materials can be used for the flexible support, photosensitive composition layer and protective film of the photosensitive film used in the present invention. 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, 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 flexible support, and a polyethylene film is preferably used as the protective film.

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

According to another method, fine particles can be uniformly dispersed in the film to obtain a film for a protective film having a surface roughness, but the method for obtaining a protective film having a surface roughness is limited to these methods. I can't.

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

Examples of the thermoplastic polymer (a) include vinyl copolymers, and the copolymer monomers used include acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate and butyl methacrylate. , 2-ethylhexyl methacrylate, lauryl methacrylate, methyl acrylate, ethyl acrylate, styrene, α-methylstyrene, vinyltoluene, N-vinylpyrrolidone, acrylamide, acrylonitrile, methacrylonitrile, dimethylaminoethyl methacrylate, dimethylaminoethyl. Acrylate etc. are mentioned. Further, a half ester of a styrene / maleic acid copolymer and the like can also be mentioned.

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. is there.

Examples of the unsaturated group-containing monomer of the component (b) include compounds 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), dipenta Erythritol pentaacrylate, dipentaerythritol hexaacrylate, etc.), bisphenol A polyoxyethylene diacrylate (bisphenol A dioxyethylene diacrylate, bisphenol A trioxyethylene diacrylate) , Bisphenol A decaoxyethylene diacrylate, etc.), compounds obtained by adding α, β-unsaturated carboxylic acid to a glycidyl group-containing compound (trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether acrylate, etc.), 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, polyvalent carboxylic acids (phthalic anhydride, etc.) and compounds having hydroxyl groups and ethylenically unsaturated groups (β-hydroxyethyl acrylate, etc.)
And an ester of acrylic acid (methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc.), trimethylhexamethylene diisocyanate, a dihydric alcohol, and a divalent acrylic acid monoester. Examples of the urethane diacrylate compound obtained by reacting with and a methacrylate corresponding thereto.

The compounding amount of the component (a) in the present invention is 4
The amount is preferably 0 to 80 parts by weight (the total amount of the component (a), the component (b) and the component (c) is 100 parts by weight), and more preferably 50 to 70 parts by weight. Particularly preferably, the amount is 55 to 65 parts by weight.

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's ketone), N, N). ′ -Tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2-ethylanthraquinone, phenanthrenequinone, etc., benzoin (benzoin methyl ether, benzoin ethyl ether, benzoinphenyl ether, etc.) Benzoin ether, methylbenzoin, ethylbenzoin, etc.), benzyl derivatives (benzyldimethylketal, 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), acridine derivative (9-phenylacridine, 1,7-bis (9,9'-acridinyl) Heptane, etc.), ethyl dimethylaminobenzoate, diethylthioxanthone and the like. These are used alone or in combination of two or more.

The blending amount of the component (c) in the present invention is
The total amount of the components (a) and (b) is 100 parts by weight, preferably 0.10 to 20 parts by weight, and 0.15 parts by weight.
It is more preferable to set to 15 parts by weight, and 0.20 to 1
It is particularly preferable that the amount is 0 part by weight.

The photosensitive composition layer of the photosensitive film used in the present invention contains a thermosetting component such as hexamethoxymethylmelamine, a dye, a pigment, a plasticizer, a stabilizer, and 2-amino-.
Adhesion improvers such as 5-mercapto-1,3,4-thiadiazole, fillers and the like are added as necessary.

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

The photosensitive film comprising the flexible support, the photosensitive composition layer and the protective film having surface roughness used in the present invention is a photosensitive composition having surface roughness transferred after removing the protective film. The material layer is laminated on the substrate and brought into close contact with it by heating and pressurization, but it is effective to perform it under reduced pressure in order to sufficiently fill and cover the irregularities of the substrate. The pressure, temperature, and time at this time may be within the range where a film thickness that can maintain the characteristics of the photosensitive composition layer can be obtained.

The thus laminated photosensitive film is then imagewise exposed to actinic light using a negative or positive film. At this time, the exposure may be carried out except for the flexible support on the photosensitive composition layer. After exposure,
If there is a flexible support on the photosensitive composition layer, the unexposed portion is removed by a known method such as spraying, oscillating dipping, brushing, or scrubbing, except for the flexible support. Alternatively, the exposed portion is removed and development is performed.
Thereafter, in order to improve the characteristics, heating by further irradiating with light and curing is also performed.

[0030]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

Example 1

[0032]

[Table 1] A solution 6 having a composition containing the materials shown in Table 1 was uniformly applied onto a polyethylene terephthalate film 12 having a thickness of 25 μm by using the apparatus shown in FIG. 1 and dried by a hot air circulation dryer 7 at 100 ° C. The solvent was removed by drying for 5 minutes, and the thickness of the photosensitive composition layer was adjusted to 25 μm.
In FIG. 1, 1 is a polyethylene terephthalate film feeding 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 the photosensitive composition, 7 is a drier, 8
Is a polyethylene film feeding roll, and 11 is a photosensitive film winding roll.

This photosensitive composition layer is laminated to form a layer thickness of 2
When a static load of 0.25 kg / mm ² was applied to the sample having a size of mm, the amount of change in film thickness was 288 μm with the lapse of time from 10 seconds to 600 seconds after the load was applied. Then, using the apparatus shown in FIG. 1, a polyethylene film 13 (protective film) was further laminated on the photosensitive composition layer to obtain a photosensitive film. The protective film used at this time is the surface roughness measuring device Surfcoder SE-30D.
(Made by Kosaka Laboratory Ltd.) using a stylus tip radius of 2μ
m, the scanning speed was 0.1 mm / sec, and the surface roughness was measured. As a result, the cutoff value was 0.08 mm and the evaluation length was 2.5 m.
Arithmetic mean roughness (Ra) is 1.2μ in the measuring range of m
m (4.8% of the photosensitive composition layer). Further, the maximum height (Ry) is 10.5 μm (21 of the photosensitive composition layer).
%)Met.

Next, using the apparatus shown in FIG. 2, on the photosensitive composition layer excluding the protective film of the photosensitive film,
A printed wiring board having copper circuits with a thickness of 18 μm formed on both sides is placed and sent to a pressure / heating / vacuum chamber, and a photosensitive composition layer excluding the protective film of the photosensitive film is also provided on the upper surface of the printed wiring board. After contacting, 1T inside the chamber
The layers were laminated while heating to 100 ° C. while drawing a vacuum to orr and further maintaining a state of 3.5 kg / cm ² pressure for 3 minutes. After this, the chamber was released, 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 visually observed and observed with a 50 × microscope. In FIG. 2, 14 is a substrate, 15 and 16 are pressure / heating / vacuum chambers, 17 is a fixed film, 18 is a pressure film, 19 is a vacuuming part, 20 is an air pressurizing part, 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.

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

Example 2 The surface roughness was 3.4 μm in arithmetic mean roughness (Ra) (13.6% of the thickness of the photosensitive composition layer), and 22 in maximum height (Ry).
Except for the use of a protective film having a thickness of 8 μm (45.6% of the photosensitive composition layer), the same procedure as in Example 1 was carried out.
The appearance after solder dipping was visually observed and observed with a 50 × microscope. The results are shown in Table 2.

Example 3 The surface roughness was 4.5 μm in arithmetic mean roughness (Ra) (18.0% of the thickness of the photosensitive composition layer) and 2 in maximum height (Ry).
The same procedure as in Example 1 was carried out except that a protective film having a thickness of 7.5 μm (55% of the photosensitive composition layer) was used.
The appearance after solder dipping was visually observed and observed with a 50 × microscope. The results are shown in Table 2.

Example 4 Example 1 except that the thickness of the photosensitive composition layer was 50 μm and a printed wiring board having a copper circuit thickness of 35 μm was used.
The same procedure as above was performed to obtain a photosensitive film having a fluidity of the photosensitive composition layer of 312 μm. This photosensitive film was used in Example 1.
In the same manner as above, the printed wiring board was laminated, and the presence or absence of air bubbles and the appearance after immersion in solder were visually observed and observed with a 50 × microscope.
The results are shown in Table 2.

Example 5 Surface roughness was 9.8 μm in arithmetic mean roughness (Ra) (19.6% of the thickness of the photosensitive composition layer), and 7 in maximum height (Ry).
The same procedure as in Example 4 was carried out except that a protective film having a thickness of 0.1 μm (140.2% of the photosensitive composition layer) was used, and the presence / absence of bubbles and the appearance after solder immersion were visually observed and observed with a 50 × microscope. . The results are shown in Table 2.

Comparative Example 1 Surface roughness was 0.1 μm in arithmetic mean roughness (Ra) (0.4% of photosensitive composition layer thickness) and 1.3 in maximum height (Ry).
The same procedure as in Example 1 was carried out except that a protective film having a thickness of 2.6 μm (2.6% of the photosensitive composition layer) was used, and the presence or absence of air bubbles and the appearance after immersion in solder were visually observed and observed with a 50 × microscope.
The results are shown in Table 2.

Example 6 The same procedure as in Example 4 was carried out except that the fluidity was changed to 205 μm by changing the drying time after coating the photosensitive film, and the presence / absence of bubbles and the appearance after solder immersion were visually and 50 times as large. It was observed with a 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 compounding 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 shown in FIG.
It heated at 0 degreeC and stuck the protective film. The fluidity at this time was 114 μm. After that, the same procedure as in Example 4 was performed, and the presence or absence of air bubbles and the appearance after dipping the solder were visually inspected.
It was observed under a 0 × microscope. The results are shown in Table 2.

Example 8 The same procedure as in Example 4 was carried out except that the fluidity was changed to 520 μm by changing the drying time after coating the photosensitive film, and the presence / absence of bubbles and the appearance after immersion in solder were visually and 50 times. It was observed with a microscope. The results are shown in Table 2.

[0044]

[Table 2] As is clear from Table 2, when the photosensitive film and the laminating method of the present invention are used, the uneven substrate can be sufficiently covered without bubbles.

The protective film having the specific surface roughness used above is commercially available and is produced by passing the film between a metal roll and a rubber roll whose surface is sandblasted. At this time, the protective film having different surface roughness can be obtained by adjusting the grain size of the sand in the sand blast treatment and the spraying time to change the unevenness of the roll surface.

[0046]

By using the photosensitive film and the laminating method of the present invention, it is possible to obtain a sufficiently coated photosensitive resin layer without bubbles on the surface of a substrate having irregularities especially under reduced pressure.

[Brief description of drawings]

FIG. 1 is a schematic view of a photosensitive film manufacturing apparatus used in Examples.

FIG. 2 is a schematic diagram of a laminating apparatus used in the examples.

[Explanation 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 Pressurizing / heating / vacuum chamber 17 Fixed film 18 Pressurizing film 19 Vacuuming part 20 Air pressurizing part 21, 22 Photosensitive film feeding roll 23, 24 Protective film winding roll 25, 26 Photosensitive film

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H05K 3/28 H05K 3/28 F (56) Reference JP-A-5-118884 (JP, A) JP-A-62-229127 ( JP, A) JP 10-128897 (JP, A) JP 8-123025 (JP, A) JP 63-266448 (JP, A) JP 9-325491 (JP, A) JP Flat 9-325489 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (6)

(57) [Claims] 1. A flexible support, a photosensitive composition layer, and a protective film having adhesion to the photosensitive composition layer lower than that of the flexible support to the photosensitive composition layer are laminated in this order. , a photosensitive film for laminating the printed wiring board, the surface roughness cut-off value of the surface in contact with the photosensitive composition layer of the protective film 0.08～8Mm, evaluation length 0.
Arithmetic mean roughness (R
Ri der 0.5μm or more a), the photosensitive composition layer, and a 2mm layer thickness at a temperature 30 ° C.
A static load of 0.25 kg / mm ² was applied to the formed photosensitive composition layer.
When added, 10 seconds to 600 seconds after applying the load
Up to 50-800 μm
The protective film provides surface roughness to the photosensitive composition layer,
Roughness is retained on the printed wiring board before lamination, and
A photosensitive film , which disappears when pressure is applied . 2. The arithmetic mean roughness (Ra) of the protective film is 0.1 to 50% of the layer thickness of the photosensitive composition layer.
The photosensitive film described. 3. 10-point average roughness of protective film (Rz)
Has a reference length of 0.08 to 8 mm and an evaluation length of 0.4 m
Layer of the photosensitive composition layer in the measurement range of m to 40 mm
The thickness is in the range of 0.1% or more and 50% or less, or
2. The photosensitive film as described in 2. 4. The maximum height (Ry) of the protective film is
Quasi-length 0.08-8mm, evaluation length 0.4mm-4
In the measurement range of 0 mm, the layer thickness of the photosensitive composition layer is 2
4. The photosensitivity according to any one of claims 1 to 3, which is less than or equal to twice.
Sex film. 5. Flexible printed wiring board
The photosensitive material according to claim 1, which is a wiring board.
Sex film. 6. The protective film of the photosensitive film according to any one of claims 1 to 5 is removed, and the surface of the photosensitive composition layer having surface roughness is brought into contact with a substrate under reduced pressure. A method for laminating a photosensitive film, which comprises laminating.