JP3257777B2 - Heat-resistant release surface treated steel sheet with excellent transfer resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-treated steel sheet which has good release properties even when exposed to a high temperature, and has excellent transfer resistance and surface smoothness. Since the surface-treated steel sheet of the present invention is excellent in heat release properties, it is possible to prevent the mold and the copper foil or the like on the printed board from sticking to each other during hot pressing during the manufacturing process of the printed board, or In addition to being useful as an intermediate plate used to prevent the copper foils from sticking to each other when sandwiched between layers when hot-pressing the printed circuit board at once, it is also excellent in transfer resistance, It can also efficiently prevent the pattern of the inner layer circuit (mold material) on the printed board from being transferred to the intermediate plate and the roughness of the intermediate plate from being transferred to the copper foil; furthermore, it has excellent flatness and rigidity. This is extremely useful in that it is inexpensive and can be used repeatedly. Further, the surface-treated steel sheet of the present invention can be used for various applications as a highly oil-repellent steel sheet.

[0002]

2. Description of the Related Art Copper-clad laminates are known as printed wiring boards. The copper-clad laminate is manufactured by laminating a copper foil on a prepreg obtained by impregnating a base material such as paper or glass cloth with a thermosetting resin, and pressing and pressing with a press. For example, in the case of a double-sided copper-clad laminate, contact is made in the following order: mold of press machine-copper foil-prepreg-inner layer circuit (mold material)-prepreg-copper foil-mold of press machine. At this time, in order to prevent irregularities on the surface of the mold from being transferred to the copper foil, or to prevent the mold and the copper foil from sticking together, a member called an intermediate plate is provided between the mold and the copper foil. To reduce the pressure uniformly. In order to prevent the prepreg powder generated during lamination or the resin contained in the molten prepreg from adhering to the intermediate plate (release property), release materials may be used on both surfaces of the intermediate plate.

[0003] The properties required of the intermediate plate including the release material include good releasability, particularly good repetitive releasability.
Excellent heat resistance (resistant to hot pressing) and excellent transfer resistance, that is, the pattern of the inner layer circuit (mold material) does not transfer to the intermediate plate, and the roughness of the intermediate plate does not transfer to the copper foil of the product. Excellent in flatness and rigidity, and can uniformly lower the laminated plate.

On the other hand, as an intermediate plate that can satisfy the above characteristics and includes a release material, for example, the following ones can be mentioned.
Each of them has the following problems.

(I) A method using only a stainless steel (SUS) plate as an intermediate plate (without a mold release material) Since expensive SUS is used as a raw material, the cost is high; it is repeatedly used by washing after polishing. However, if the polishing is not performed uniformly, there is a problem that the flatness cannot be secured by repeated use.

(Ii) A method of using SUS as an intermediate plate and using release paper or a release film as a release material Raw materials are expensive, and since release films cannot be used repeatedly, they are disposable. When used repeatedly, separate washing and polishing steps are required.

(Iii) Method of Using Only Al Plate as Intermediate Plate (No Release Material) Since the raw material is somewhat expensive and cannot be used repeatedly, it is disposable.

(Iv) A method of using an Al plate or an Al foil as an intermediate plate and using a release coating resin as a release material The raw materials are somewhat expensive. It can be used repeatedly, but in the case of Al foil, it is easy to wrinkle, the flatness is insufficient and it is difficult to handle.

(V) Method of Using Release Paper or Release Film as an Intermediate Plate and Release Material Raw materials are expensive, and the release film cannot be used repeatedly. Moreover, it is easy to wrinkle and the degree of flatness is insufficient, so that handling is difficult.

As described above, when the release film, the release metal foil and the release paper are used among the above-mentioned conventional examples, a copper-clad laminate having insufficient flatness and excellent surface appearance is required. Not applicable if In addition, there is a problem that the workability is difficult due to the thinness. Moreover, since it is assumed to be disposable, there is no device for reusing it. On the other hand, a mirror-finished SUS plate is excellent in surface smoothness, but requires a polishing and washing step to reuse it, leading to an increase in cost.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the ability to be used repeatedly, such as transfer resistance, surface smoothness, heat resistance, and mold release properties. The object of the present invention is to provide a surface-treated steel sheet excellent in all of the above characteristics.

[0012]

Means for Solving the Problems A heat-resistant release-treated surface-treated steel sheet having excellent transfer resistance according to the present invention, which can solve the above-mentioned problems, comprises:
A surface-treated steel sheet used for a release plate for hot press of a copper-clad laminate for printed wiring, wherein the surface-treated steel sheet is Zn
A release resin film is formed on a galvanized steel sheet or a Zn alloy-coated steel sheet (hereinafter, may be represented by a Zn-coated steel sheet), and the surface roughness of the Zn-coated steel sheet is determined by IS-
By controlling the arithmetic average roughness Ra measured by a surface roughness test according to B0601 to 0.30 μm or less, the transfer resistance to the copper foil is enhanced, and / or for printed wiring. A surface-treated steel sheet used for an intermediate plate for hot pressing of a copper-clad laminate, wherein the surface-treated steel sheet has a release resin film formed on a Zn-plated steel sheet, and has a yield point of the Zn-plated steel sheet. By controlling the tensile strength to 200 N / mm ² or more and / or the tensile strength to 300 N / mm ² or more, the transfer resistance to the intermediate plate is enhanced.

[0013] As described above, the R
When the surface-treated steel sheet whose a is controlled to 0.30 μm or less is used as a release plate for hot pressing of a copper-clad laminate for printed wiring, it is possible to effectively prevent the roughness of the intermediate plate from being transferred to the copper foil. It is very useful. Further, as described above, the yield point of the Zn-plated steel sheet is 200 N / mm ² or more and / or
Alternatively, when a surface-treated steel sheet whose tensile strength is controlled to 300 N / mm ² or more is used as an intermediate board for hot pressing of a copper-clad laminate for printed wiring, it is effective to transfer the inner layer circuit pattern to the intermediate board during hot pressing. This is extremely useful because it can be prevented. Further, those satisfying the above requirements are most effective because both of these effects are exhibited.

Regarding the release resin film, when the contact angle of gear oil of viscosity grade ISO VG460 was measured at a steel sheet surface temperature of 180 ° C., the contact angle of the gear oil was 1%.
5 ° or more; epoxy resin, phenolic resin, polyimide resin, polyamide imide, ketone resin, wholly aromatic polyester, unsaturated polyester resin, which is a resin film; JIS K
A pencil scratch value obtained by performing a pencil scratch test method specified in 5400 and having a pencil scratch value of 2H or more; the arithmetic average roughness of the resin film measured by a test in accordance with JIS-B0601. In a.
Any having a size of 3 μm or less is a preferred embodiment of the present invention.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors provide a surface-treated steel sheet which can be used repeatedly and has excellent properties such as transfer resistance, surface smoothness, heat resistance and mold release properties. I've been working hard to study it. As a result, a surface-treated steel sheet having a release resin film formed on a Zn-plated steel sheet,
If the tensile properties and surface roughness of the plated steel sheet are controlled,
It is particularly useful for improving transfer resistance and surface smoothness; specifically, controlling the yield point of Zn-plated steel sheet to 200 N / mm ² or more and / or the tensile strength to 300 N / mm ² or more, The surface roughness of steel plate is 0.30μm in Ra
By controlling the following, the transfer of the inner layer circuit pattern to the intermediate plate, it has been found that it is possible to obtain a surface-treated steel sheet with excellent transfer resistance that can prevent the transfer of the intermediate plate roughness to the copper foil, the present invention. It was completed.

Hereinafter, each requirement for specifying the surface-treated steel sheet of the present invention will be described in detail.

First, the heat-resistant release surface-treated steel sheet having excellent transfer resistance according to the present invention is a surface-treated steel sheet used as an intermediate plate for hot pressing of a copper-clad laminate for printed wiring, Has a release resin film formed on a Zn-plated steel sheet, and has a yield point of 200 N /
By controlling the tensile strength to at least 300 mm ² and / or at least 300 N / mm ² , the transfer resistance to the intermediate plate is improved. That is, in order to effectively prevent the transfer of the inner layer circuit pattern to the intermediate plate during hot pressing, it is important to control the properties of the Zn-plated steel sheet. The most important point of the present invention lies in that it has been found that the above-mentioned transfer resistance characteristics can be obtained.

Specifically, in order to prevent the pattern of the inner circuit from being transferred to the intermediate plate by hot pressing, it is necessary to increase the tensile strength of the intermediate plate and make the material harder. The tensile strength of the Zn-plated steel sheet is controlled to 300 N / mm ² or more. This is because, if it is less than 300 N / mm ² , the transfer of the inner layer circuit pattern to the surface of the intermediate plate becomes remarkable. More preferably, it is 400 N / mm ² or more. On the other hand, the upper limit is not particularly limited from the viewpoint of transfer resistance, but if the tensile strength is too high, the steel sheet itself becomes too hard, and during the steel sheet manufacturing process,
It becomes difficult to ensure sufficient flatness by rolling flat. From such a viewpoint, the tensile strength of the Zn-plated steel sheet is preferably 1700 N / mm ² or less.

Further, in the present invention, the yield point of the Zn-plated steel sheet is controlled to 200 N / mm ² or more. This also
This is because the pattern of the inner layer circuit can be prevented from being transferred to the intermediate plate by the hot pressing. That is, in order to enhance the transfer resistance, the tensile strength of the Zn-plated steel sheet may be controlled, or the yield point may be controlled. Of course, if both requirements are controlled, a more excellent transfer resistance can be obtained. Property is obtained.

Incidentally, the yield point of the Zn-plated steel sheet is effective not only in improving the transfer resistance but also in improving the surface smoothness, and is useful in that the surface appearance of the surface-treated steel sheet can be enhanced as a result. . That is, in order to uniformly reduce the stacked substrates during hot pressing, it is necessary to increase the proof stress capable of improving the rigidity of the intermediate plate, and in the present invention, in view of both the transfer resistance and the surface appearance, Based on this, the yield point of the Zn-plated steel sheet was controlled to 200 N / mm ² or more. When the yield point is less than 200 N / mm ^2, not only the transfer resistance is reduced, but also the unevenness due to the prepreg remarkably emerges on the surface of the copper-clad laminate as a product, and the flatness is impaired. Preferably it is 300 N / mm ² or more. The upper limit is not particularly limited from the viewpoint of transfer resistance and surface appearance of the product, but if the yield point is too high, the steel sheet itself becomes too hard, and during the steel sheet manufacturing process, It is difficult to obtain a desired flatness by rolling the steel into a desired shape. From such a viewpoint, the yield point of the Zn-plated steel sheet is preferably 1500 N / mm ² or less.

Further, the heat-resistant release surface-treated steel sheet having excellent transfer resistance according to the present invention is a surface-treated steel sheet used for a hot press release sheet of a copper-clad laminate for printed wiring. In the steel sheet, a release resin film is formed on a Zn-plated steel sheet, and the surface roughness of the Zn-plated steel sheet is determined by IS-B.
By controlling the arithmetic average roughness Ra measured by a surface roughness test based on No. 0601 to 0.30 μm or less, the transfer resistance to the copper foil is improved. That is,
In order to effectively prevent the roughness of the intermediate plate from being transferred to the copper foil during hot pressing, it is important to control the surface roughness Ra of the Zn-plated steel sheet. The most important point of the present invention lies in the finding that it can be obtained.

Specifically, in order to prevent the surface roughness of the intermediate plate from being transferred to the copper foil by hot pressing, it is necessary to make the surface roughness of the Zn-plated steel sheet fine and smooth. For this reason, the surface roughness of the Zn-plated steel sheet is 0.1 in Ra.
Control to 30 μm or less. If Ra exceeds 0.30 μm, the surface roughness of the intermediate plate is transferred to the surface of the copper-clad laminate as a product, and the pattern resulting from the transfer becomes remarkable. Preferably it is 0.2 μm or less. On the other hand, the lower limit is not particularly limited from the viewpoint of transfer resistance. However, if the Ra of the Zn-plated steel sheet is too small, the flaws generated on the surface of the Zn-plated steel sheet become more conspicuous. From this point of view, the Ra of Zn-plated steel sheet
Is preferably 0.05 μm or more.

As described above, in the present invention, in order to provide a heat-resistant release surface-treated steel sheet having excellent transfer resistance, in order to prevent the transfer of the inner layer circuit pattern to the intermediate sheet during hot pressing, it is necessary to use a Zn-plated steel sheet. It is important to control the tensile properties. On the other hand, it is important to control the surface roughness Ra of the Zn-plated steel sheet in order to prevent the roughness of the intermediate plate from being transferred to the copper foil during hot pressing. It is up to them to identify these requirements. Therefore, those having both tensile properties and Ra controlled within the scope of the present invention are particularly useful,
As a result, not only the transfer resistance to the product itself but also the transfer resistance to the intermediate plate can be effectively exhibited.

As described above, the surface-treated steel sheet according to the present invention is a surface-treated steel sheet in which a release resin film is formed on a Zn-coated steel sheet. The greatest feature is that the transfer resistance and surface appearance are improved by controlling the tensile properties and Ra of the steel sheet. Other requirements (type of Zn-plated steel sheet, release resin film, etc.) There is no particular limitation as long as the operation of the present invention is not impaired. Hereinafter, these requirements will be described.

As described above, the surface-treated steel sheet of the present invention
A release resin film is formed on a Zn-plated steel sheet. When the steel sheet of the present invention is used as an intermediate plate, the aluminum plate has a large thermal conductivity and the heat of the press die is transmitted quickly to the laminated plate, which is preferable in terms of thermal efficiency.However, the coefficient of linear expansion is larger than that of the copper foil. The foil and the intermediate plate are displaced from each other, which is not preferable, and is therefore excluded from the scope of the present invention. On the other hand, the steel sheet has a moderately good thermal conductivity, a coefficient of linear expansion of 12.5 × 10 ⁻⁶ , and a coefficient of linear expansion of copper foil of 12.5.
Since it is close to 7 × 10 ⁻⁶ , no inconvenience such as displacement of the copper foil and the intermediate plate occurs. As the Zn-plated steel sheet used in the present invention, a cold-rolled steel sheet, a stainless steel sheet having excellent corrosion resistance, and a steel sheet other than the stainless steel sheet can be used by Zn plating. The plating may be performed by a known method using a single metal or various alloys, and the plating method is not particularly limited. Zn plated steel sheet and Zn alloy plated steel sheet
Particularly excellent in corrosion resistance during storage when used repeatedly. Note that a chromate treatment may be performed before the resin film is provided on the Zn plating layer. This is because the presence of the chromate film improves the adhesion to the resin film and also imparts a rust-preventive effect.

The release resin film used in the present invention is not particularly limited as long as it has the releasability and heat resistance required for manufacturing a printed circuit board.

For example, it is recommended that the resin film used in the present invention has oil repellency at high temperatures. The oil repellency of the resin film in a high temperature state greatly affects the releasability of the intermediate plate, and particularly, viscosity grade ISO VG46
This is because when the contact angle of a gear oil of 0 is measured at a steel sheet surface temperature of 180 ° C. and the contact angle of the gear oil is 15 ° or more, the oil repellency can be grasped with good reproducibility.

Here, the contact angle of the resin film is measured under the following conditions. The gear oil of viscosity grade ISO VG460 is used to make the droplets. It is considered that the viscosity of the gear oil affects the contact angle, and the higher the flash point, the better the safety. Therefore, gear oil of the above viscosity grade is used. For example, “Daphne Super Gear Oil 460” manufactured by Idemitsu Kosan Co., Ltd. can be used. This oil has a kinematic viscosity of 459.9 mm ² s at 40 ° C. and 30.85 at 100 ° C.
mm ² s, flash point 274 ° C, density (15 ° C) 0.902
8, the total acid value is 0.38 mgKOH / g. The contact angle measurement temperature is 180 ° C. That is, the measurement is performed in a state where the surface temperature of the surface-treated steel sheet indicates 180 ° C. Drops are formed on the resin film surface with gear oil, and the contact angle is measured with a contact angle meter (for example, “CD-DT · A type” manufactured by Kyowa Interface Chemical Co., Ltd.).

It is recommended that the contact angle of the gear oil is 15 ° or more. If the contact angle is less than 15 °, oil repellency is not exhibited, and the releasability is poor.

Further, the above resin film is formed by
It is preferable that a pencil scratch value (pencil hardness) obtained when a test machine method of a pencil scratch test specified in IS K 5400 is performed is 2H or more. If the pencil hardness is less than 2H, the resin film is likely to have a flaw, and the flaw may be transferred to a copper foil.

The arithmetic average surface roughness (Ra) of the resin film and the surface-treated steel sheet after application is preferably 0.3 μm or less, measured according to JIS-B0601. This is because if the resin film surface has irregularities, the irregularities are transferred to the copper foil, and it may not be possible to form an accurate printed circuit. In order to smooth the surface roughness of the resin film and the surface-treated steel sheet after coating, it is conceivable to increase the thickness of the resin film. However, in this case, the outermost surface is formed by a resin film that is softer than the steel sheet. And the pattern transfer of the inner layer circuit is promoted, which is not preferable.

The use of a hard film as the resin film is a preferable embodiment in consideration of preventing scratches during handling.

Here, it is recommended that the main component of the resin film is an organic resin. In the case where the surface-treated steel sheet of the present invention is used as an intermediate plate, it is recommended to use an organic resin having excellent heat resistance, in consideration of a high temperature environment during hot pressing. Specific examples include epoxy resins, phenol resins, polyimide resins, polyamide imides, ketone resins such as polyetheretherketone, wholly aromatic polyesters, unsaturated polyester resins, and the like. Further, a known crosslinking agent known to be combined with the resin may be added to these resins. This is because the addition of such a cross-linking agent causes the polymer chains in the resin to cross-link with each other and forms a more dense film, thereby increasing the film hardness.

In order to further enhance the releasability of the resin film, it is preferable to add a release agent as a component of the film. Examples of the release agent include a silicone resin and a fluorine resin. This is because these lower the surface energy of the resin film and improve the oil repellency. The amount of the release agent is preferably 0.5 to 10% by weight in the film. If the amount of the release agent is too small, the releasability is not exhibited. On the other hand, if the amount is too large, the release agent is transferred from the resin film to the copper foil side, causing inconvenience such as repelling ink at the time of circuit printing.

In order to further enhance the releasability of the resin film, it is preferable to include a surface roughening agent having a function of roughening the film surface in the film. The film surface is too rough and R
It is not preferable that a exceeds 0.5 μm, because the finer the film surface, the better the releasability. As the surface roughening agent, a particulate inorganic additive such as SiO ₂ , Al ₂ O ₃ , and MgO can be used.

The amount of the resin film deposited is 0.5 to 8.
It is preferably 0 g / m ² . If the amount of adhesion is small,
This is because the effect of smoothing the unevenness of the steel sheet base by the resin film is small, the unevenness may be transferred to the copper foil, and the release property and the corrosion resistance may be insufficient. Within the above range, since the resin film is formed on the hard steel plate with an appropriate amount of adhesion, the irregularities (about 15 to 80 μm) of the mold material located below the copper foil and the prepreg are interposed between the prepreg and the copper foil. There is no danger of transfer to the resin film of the release material. However, if the amount of the resin coating exceeds 8.0 g / m ² , the effect of the binding force of the steel sheet does not reach the coating surface, and the unevenness of the mold material is transferred to the resin coating, and the intermediate plate cannot be reused. There is.

The surface-treated steel sheet of the present invention is prepared by preparing a resin coating composition in which a resin coating component is blended with a Zn-plated steel sheet, and applying a known coating method such as a dipping method, a roll coater method, a knife coater method, and a spray method. It can be manufactured by applying by a method, and heating and solidifying the film.

The surface-treated steel sheet of the present invention is particularly useful as an intermediate sheet for producing a copper-clad laminate, and can be used in place of a conventionally used mirror-finished stainless steel sheet or release film. However, there is an advantage that it can be used repeatedly. In order to manufacture a laminate using the steel sheet of the present invention as an intermediate plate, a copper foil and a prepreg or a mold material are laminated, and a laminate between a mold and a copper foil or another laminate adjacent to one copper foil for a laminate. Pressing may be performed with the intermediate plate interposed between the copper foil for the plate.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples do not limit the present invention, and all modifications and alterations without departing from the spirit of the present invention are included in the present invention.

[0040]

EXAMPLE In this example, various steel sheets were cold-rolled, annealed, and temper-rolled steel sheets were used as original sheets (sheet thickness: 0.8 mm). The tensile strength and yield point of the original sheet
It was adjusted by changing the steel type and annealing method of the steel sheet. Further, the roughness Ra of the intermediate plate was adjusted by changing the roughness of the rolling roll during cold rolling and temper rolling.

The temper-rolled steel sheet thus obtained is degreased, electrogalvanized (Zn adhesion 20 g / m ² ), and then chromate-treated (Cr adhesion 20 mg / m ² ) on the surface.
² ) did.

On the surface of the chromate-treated electrogalvanized steel sheet, as a release coating treatment, a resin liquid containing 5 parts by weight of a solid content of a silicon resin with respect to 100 parts by weight of an epoxy resin is applied, and then baked and dried. A film of 3 μm was formed with the film. The hardness of the resin film was adjusted by changing the amount of melamine resin capable of crosslinking with the epoxy resin and the baking temperature.

The following test methods were performed on each of the above steel plates.

[Test Method] (1) Measurement of Tensile Properties The tensile strength and yield point of a steel sheet were measured in accordance with the tensile test test method for metal materials specified in JIS-Z2241.
It measured using the No. 5 test piece prescribed by IS-Z2201. In addition, about the test piece whose yield point is not clear,
The 0.2% proof stress was defined as the yield point of the test piece.

(2) Surface Roughness “Surfacecom 554A”, a surface profile measuring instrument manufactured by Tokyo Seimitsu Co., Ltd.
Was used to calculate the arithmetic average roughness Ra of the steel sheet in accordance with the method defined in JIS-B0601.

(3) Pencil hardness The hardness of the film after application of the resin is determined by measuring the pencil scratch value (pencil hardness) when the coating film is scratched in accordance with the pencil scratch tester method specified in JIS-K5400. did.

(4) Transfer Resistance to Copper Foil Intermediate plate / copper foil / prepreg / intermediate plate is laminated between the upper die and lower die of the hot press and pressurized at 40 kgf / cm ^2. After that, it was kept at 180 ° C. for 60 minutes. After cooling to room temperature and opening the mold, the laminate of the intermediate plate, the copper foil and the prepreg was peeled off. Whether or not the roughness of the intermediate plate was transferred to the copper foil surface was visually observed and evaluated according to the following criteria.

In this embodiment, as the prepreg,
0.1 mm thick, manufactured by Nitto Shinko Co., Ltd., standard curing conditions are temperature of 140 to 160 ° C., time of 60 to 90 minutes, pressure of 20 to 5
An epoxy resin impregnated glass cloth of 0 kgf / cm ² was used. Evaluation of transfer resistance: ：: No transfer to copper foil was observed, ○: Slight transfer to copper foil was observed, Δ: Transfer to copper foil was observed, ×: Transfer to copper foil was observed Prominently observed.

(5) Irregularities of prepreg After performing a press test in the same manner as in (4) above, the copper foil 5
The number of irregularities caused by the prepreg generated per 00 mm × 500 mm was visually observed and evaluated according to the following criteria: ◎: less than one, ： １: one or more and less than three, Δ: three or more and less than seven, ×: 7 or more.

(6) Repetitive mold release property The same operation as in the above (4) was repeated using the same intermediate plate as in the above (4), and the time when the intermediate plate and the prepreg with copper foil were not easily peeled off was repeated. The limit (the number of times) that it can be used was set.

(7) Scratch resistance After the repetition test of the above (6), the degree of surface flaws generated on the surface of the intermediate plate was visually observed and evaluated according to the following criteria: A: Surface flaws were recognized Not observed, ：: Almost no surface flaw is recognized, Δ: Surface flaw is recognized, ×: Surface flaw is remarkably recognized.

(8) Transfer Resistance of Inner Layer Circuit (Mold) to Intermediate Board Between the upper mold and lower mold of the hot press, an intermediate board / copper foil / prepreg / inner circuit (mold) / prepreg / copper Laminated in the order of foil / intermediate plate, pressurized at 40 kgf / cm ² , 180
C. for 60 minutes. After cooling to room temperature and opening the mold, the intermediate plate and the laminated plate were peeled off. Whether or not the unevenness of the inner layer circuit was transferred to the surface of the intermediate plate was visually observed and evaluated according to the following criteria.

As the inner layer circuit, a double-sided copper-clad laminate having a thickness of 0.3 mm was used, and a circuit on which a circuit having a height of 25 μm (thickness of copper foil) was formed was used. Also,
The same prepreg and copper foil as in (4) above were used.
Evaluation of transfer resistance of the inner layer circuit to the intermediate plate: ：: no transfer , ：: slight transfer observed, Δ: transfer observed, ×: remarkable transfer observed.

Table 1 shows the results.

[0055]

[Table 1]

As shown in Table 1, the tensile properties (yield point and tensile strength) and Ra of the steel sheet satisfy the requirements of the present invention. 1 to
No. 16 has excellent transfer resistance, and shows that there are few irregularities due to the prepreg and the surface appearance is good. Furthermore, by controlling the pencil hardness of the coating resin within a preferable range, the scratch resistance was also improved. The steel sheets used in this example all had a good releasability of the release film of 7 times.

On the other hand, in the case of No. 3 where the above tensile properties / Ra did not satisfy the requirements of the present invention. In Nos. 17 to 20, the transfer resistance was reduced, the unevenness due to the prepreg was increased, and the surface appearance was poor.

[0058]

As described above, the surface-treated steel sheet of the present invention is constructed as described above, so that it can be used repeatedly,
Excellent in all properties such as surface smoothness, heat resistance and mold release. Therefore, the steel sheet of the present invention is useful as an intermediate board when pressing a laminate such as a printed wiring board. In particular, the surface-treated steel sheet of the present invention is excellent in transfer resistance, heat resistance, releasability, etc.
Unlike a conventional intermediate plate such as an aluminum foil coated with a release agent, it can be used repeatedly without any special treatment, and is therefore a useful invention in terms of cost reduction and resource protection. The surface-treated steel sheet of the present invention can be applied to various fields as an oil-repellent steel sheet in addition to the intermediate sheet.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-94768 (JP, A) JP-A-7-90460 (JP, A) JP-A-9-51173 (JP, A) JP-A-4-94 9498 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 15/08

Claims (7)

(57) [Claims] 1. For hot pressing copper-clad laminates for printed wiring
A surface treated steel sheet used in the release plate, the surface treatment steel sheet, a release resin film is formed on the Zn-plated steel plate or a Zn alloy coated steel sheet, of the Zn-plated steel sheet or a Zn alloy plated steel sheet By controlling the surface roughness to 0.30 μm or less by the arithmetic average roughness Ra measured by the surface roughness test based on IS-B0601, it is confirmed that the transfer resistance to the copper foil is improved. Heat-release surface treated steel sheet with excellent transfer resistance. 2. For hot pressing copper-clad laminates for printed wiring.
A surface treated steel sheet used for the intermediate plate, the surface treatment steel sheet, a release resin film is formed on the Zn-plated steel plate or a Zn alloy plated steel sheet, the yield of the Zn-plated steel sheet or a Zn alloy plated steel sheet The point was 200 N / mm ² or more and / or the tensile strength was 300 N /
By controlling the mm ² or more, the heat release surface-treated steel sheet excellent in耐転copy of which is characterized in that those耐転shooting property is increased to said intermediate plate. 3. For hot pressing copper-clad laminates for printed wiring.
Surface treatment used for release plate and / or intermediate plate for hot press
A surface-treated steel sheet , wherein a release resin film is formed on a Zn-plated steel sheet or a Zn-alloy-plated steel sheet, and the surface roughness of the Zn-plated steel sheet or the Zn-alloy-plated steel sheet
Measured by a surface roughness test according to IS-B0601.
The arithmetic mean roughness Ra is controlled to 0.30 μm or less.
Rutotomoni, by controlling the 200 N / mm ² or more and / or tensile strength yield point of the Zn-plated steel sheet or a Zn alloy plated steel sheet to 300N / mm ² or more, Oyo copper foil
A heat-treated release surface-treated steel sheet with excellent transfer resistance, characterized in that the transfer resistance to the intermediate plate and the intermediate plate is enhanced. 4. The release resin film has a viscosity grade of IS.
OVG460 gear oil in contact with steel plate surface temperature of 180 ° C
When the angle is measured, the contact angle of the gear oil is 15 ° or more
The heat-resistant release surface-treated steel sheet according to claim 1 . 5. The release resin film according to claim 1, wherein the release resin film comprises an epoxy resin,
Enol resin, polyimide resin, polyamide imide,
Ton-based resin, wholly aromatic polyester, unsaturated polyester
The resin film according to claim 4, which is a resin film of any of the tellurium resins.
The heat-resistant release surface-treated steel sheet as described . 6. The release resin film according to JIS K
Testing machine for pencil scratch test specified in 5400
The pencil scratch value obtained by performing the method is 2H or more
The heat-resistant release surface-treated steel sheet according to claim 4 . 7. The surface roughness of the release resin film is measured according to JIS.
Arithmetic flatness measured by a test according to B0601
7. The method according to claim 4, wherein the average roughness a is 0.3 μm or less.
Heat releasing surface treated steel sheet according to either.