JPH062369B2 - Surface roughening film and sheet made of poly-4-methyl-1-pentene for manufacturing multilayer printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to poly-4-methyl-
1-Pentene surface roughening film and sheet, especially multilayer printed wiring board (hereinafter PWB)
The said surface roughening film used for the surface roughening of the surface not covered with the metal foil of the single-sided metal-clad laminate.

[Conventional technology]

Due to the rapid demand for high precision, high density, and high reliability of electronic devices, mounting methods using a multilayer PWB have been rapidly increasing in recent years.

This multilayer PWB has a pair of single-sided copper-clad laminates 21a, 21b or double-sided copper-clad laminates 31a, 3 as shown in FIGS. 7a and 7b.
1b is a double-sided outer layer, and one or two or more inner layer circuit boards 23 or 33 are alternately stacked on the inside via prepregs 22 or 32, and these are sandwiched by jigs 24 or 34 and cushion materials 25 or 35 are interposed. Hot pressing with a hot plate 26 or 36 to cure the prepreg 22 or 32 to form a strongly integrated laminate.
It is formed by etching the surface after performing drilling and through-hole plating.

[Problems to be solved by the invention]

By the way, a single-sided copper-clad laminate that constitutes such a multilayer PWB
21a, 21b, double-sided copper clad laminates 31a, 31b, and inner layer circuit boards 23, 3
3 is a semi-cured state where copper foil and prepreg, that is, glass cloth or paper base material, is impregnated with phenol resin, epoxy resin, polyester resin, etc., and volatile components such as solvents are removed in a drying process at 120 to 180 ° C. The sheet can be obtained by stacking the sheet and the sheet, followed by hot pressing to completely cure the prepreg and firmly laminating it with the copper foil.

A single-sided copper-clad laminate (including a single-sided inner layer circuit board) often has a surface not coated with copper foil, that is, a resin surface, in order to strengthen the adhesive force with the prepreg 22 when forming a multilayer PWB. A method of increasing the surface area by roughening the resin surface by applying a roughened steel press pan or pressing a paper or a film or sheet whose surface is roughened against the resin surface is adopted. . Then, usually a single-sided copper-clad laminate is manufactured several sheets in a single press by stacking a plurality of layers of copper foil and prepreg, the surface roughening film is also used as a release film of the copper foil and prepreg Often.

As a surface-roughened film that can be used for such means, TEDRA (TEDLAR: a biaxially stretched film made of a 1-vinyl fluoride polymer containing 5% CaCO ₃ and a trade name of DuPont, USA) is However, this tedra has a large content of low molecular weight substances, and the film is biaxially stretched, so that CaCO _{3 of the} filler is exposed on the surface of the film, and therefore a plurality of copper foils and prepregs are used. When manufacturing a single-sided copper clad laminate by stacking layers, low molecular weight substances and CaCO ₃ migrate to the opposing copper foil surface, resulting in poor adhesion and etching failure between the copper foil and the resist, especially in fine circuits. Problems can occur when forming the.

In addition, although a film obtained by roughening the surface of the triacetyl cellulose film by sandblasting is also used,
In this case, fine particles of sand and triacetyl cellulose fall off,
The problem is similar to the above.

An object of the present invention is to provide a surface roughened film and sheet made of poly-4-methyl-1-pentene for producing a multilayer printed wiring board capable of improving the adhesiveness between a resin substrate and its prepreg without impairing the releasability. To provide.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention takes the following technical means.

That is, as a material suitable for achieving such an object, although PMP can easily transfer a roughened pattern at a temperature below its melting point, it has a high melting point (235 ° C), so that the temperature is sufficient for prepreg curing. Focusing on the ability to endure, a film or sheet is formed by PMP, and the surface of the film and sheet made of PMP is subjected to a roughening process with an average roughness of 0.5 to 10μ by means of a surface roughened roll to manufacture a multilayer printed wiring board. The surface roughened film and sheet made of poly-4-methyl-1-pentene were used.

[Action]

Such a surface-roughened PMP film or sheet is P
It has excellent hardness, impact resistance, and heat resistance inherent to MP, and is hard to break because it does not contain a large amount of inorganic filler.

Here, the degree of surface roughening of the film or sheet is 0.5 to 10 μ in average roughness. If it is 0.5 μ or less, there is no effect of enlarging the surface area, and there is no effect of improving the adhesion strength between the resin and prepreg after curing, while if it exceeds 10 μ, the resin and PMP film after curing become This is because the adhesive strength becomes too strong and the PMP film may be broken during peeling or may remain partially on the cured resin surface.

The PMP used for the production of this film or sheet may contain a small amount of CaCO ₃ , silica, mica, BaSO ₄ talc or the like filler (about 30 wt% or less) as long as the tear strength is not lowered. When such a filler is added, unevenness due to the filler is formed on the surface of the film, and the adhesive strength is further increased.

Furthermore, since the PMP film of the present invention is roughened on the surface, stretching is inevitably avoided. That is, when the film surface is roughened and then stretched, the roughened surface extends and becomes a smooth flat surface, and even when the stretched film surface is roughened, it becomes a roughened surface. Because it is difficult. Therefore, since the PMP film of the present invention is not stretched, even if a small amount of the filler is added, the filler is not exposed on the surface of the PMP film, and the strength is not significantly reduced.

In addition, if the film does not exude to the cured resin surface and migrates to the cured resin surface, and the adhesive strength between the cured resin surface of the single-sided metal-clad laminate and the prepreg during molding of the multi-layer PWB is not deteriorated, the film contains silicon oil. May be (about 6 wt%
Less than). When silicone oil is added, the releasability between the film and the cured resin surface is further improved, and the molding operation of the single-sided metal-clad laminate is facilitated.

Next, an apparatus for manufacturing the surface-roughened film and sheet will be described.

As the manufacturing apparatus, at least three kinds or more can be considered as shown in FIGS.

First, as shown in FIG. 1, the first type is provided with a pair of rolls 2a and 2b in the vicinity of a molten resin extrusion port of a T die 1 for molding a film or the like, and at least one of the rolls 2a.
The peripheral surface is a roughened surface having an average roughness of 0.5 to 10μ, and the molten resin of PMP heated and melted by an extruder is extruded from the T die 1 to form a film, which is in a heated state. Hold it with a pair of rolls 2a, 2b and pick it up,
At that time, the film surface is roughened by the roughened surface of one roll 2a. If both the rolls 2a and 2b are roughened surfaces, both surfaces of the film are roughened surfaces.

Next, as shown in FIG. 2, the second type is a roll 2c closest to the molten resin extrusion port of the T die 1 among the rolls used in the film take-up machine of the film forming machine. A surface-roughened film 4 having an average roughness of 0.5 to 10 μ is wound around and stuck to the surface of the T-die 1. The molten resin film extruded from the T die 1 in a heated state is taken up by a roll 2c and the surface of the peripheral surface is roughened. The film is pressed against the surface of the film 4 for roughening.

The surface-roughened film 4 is a film formed from a resin having a softening temperature higher than the softening temperature of PMP. Specific examples of the resin include 4-fluoroethylene resin and polyvinylidene fluoride. , Polysulfone, polyether ether ketone, and the like.

As shown in FIG. 3, the third type is provided with a surface treatment machine 5 next to the film take-up machine 3, and a roughening process is performed by the surface treatment machine 5 as a step after the take-up step by the take-up machine 3. The surface treatment machine 5 receives a film from the take-up machine 3 and heats the film, and a pair of roughening rolls 2d for sandwiching the film from the heating roll 6 and performing a roughening process. , 2e, and the pair of roughening rolls 2d, 2e has an average roughness on the circumferential surface of at least one roll 2d.
Roughening processing of 0.5 to 10μ is performed. In the case of using the surface treatment machine 5, as in the case of FIG. 2, it is also possible to perform the roughening process on only one surface of the film with only one roll without providing the pair of roughening rolls 2d and 2e.

What is common to the above-mentioned devices is that the film is roughened in a heated state, and those shown in FIGS. 1 and 2 are when extruded from the T die 1 and not yet cooled. In FIG. 3, roughening is performed, and after once being taken up by the cooling roll of the take-up machine 3, it is reheated by the heating roll 6 of the surface treatment machine 5 and then subjected to surface roughening.

Further, although the surface of the roughening roll 2 may be directly used as the roughening surface for the roughening processing, as in the case of FIG. 2, the surface roughening film 4 previously roughened is wound around the roll. It is more economical to use the conventional film forming apparatus as it is, to easily manufacture the apparatus used in the method for manufacturing the film or sheet of the present invention.

Poly-4-methyl-1-pentene (PM used in the present invention
P) is a homopolymer of 4-methyl-1-pentene or 4-methyl-1-pentene and other α-olefins such as ethylene, propylene, 1-butene, 1-hexene,
A copolymer of 1-octene, 1-decene, 1-tetradecene, 1-octadecene and the like with an α-olefin having 2 to 20 carbon atoms, usually 4-methyl-1-pentene containing 85 mol% or more of 4-methyl -1-A polymer mainly composed of pentene. The melt flow rate of poly-4-methyl-1-pentene (load: 5 kg, temperature: 260 ° C) is preferably 0.5.
To 250 g / 10 min. If the melt flow rate is less than 0.5 g / 10 min, the molten clay is high and the moldability is poor, and if the melt flow rate exceeds 200 g / 10 min, the melt viscosity is low and the moldability is poor, and the mechanical strength is low.

In addition, PMP is blended with various additives such as heat resistance stabilizer, weather resistance stabilizer, anti-casting agent, copper damage resistance stabilizer, and antistatic agent, which are used in addition to polyolefin within a range not impairing the object of the present invention. You can leave it.

〔The invention's effect〕

The surface-roughened film made of poly-4-methyl-1-pentene of the present invention has an appropriate surface roughness, and has excellent hardness, impact resistance, and heat resistance inherent to PMP, and the filling material is a film. Since it is not exposed on the surface, when used as a film or sheet for surface roughening of the resin surface when creating a single-sided metal-clad laminate, it does not soften or deteriorate during heat curing of the prepreg, and after curing The resin has excellent releasability from the resin, and also has an excellent effect of improving the adhesiveness between the surface-roughened resin and the prepreg. In addition, foreign matter does not remain on the metal foil to cause defective etching or the like.

〔Example〕

 Hereinafter, examples of the present invention will be described in comparison with comparative examples.

<Example 1> Using the apparatus shown in FIG. 3, a melt flow rate of 26 g / 10 min
PMP (trade name ... TPX-MX002, manufactured by Mitsui Petrochemical Co., Ltd.) with a 65 mmφ extruder 7 at a set temperature of 280 °
After being melted at C, it was extruded by a manifold type T die 1 and cooled by a cooling roll at 60 ° C. to form a film having a thickness of 50 μm.

Next, this film was heated by passing it through heating rolls 6 at 200 ° C, and then passed through a pair of rolls 2d, 2e whose peripheral surfaces were processed to have an average roughness of 5μ to obtain a surface-roughened film.

Then, as shown in FIG. 4, using the surface roughening film, a copper foil 11a having a thickness of 40 μ, a glass-reinforced epoxy prepreg 12a having a thickness of 500 μ, a surface roughening film 13a, an epoxy prepreg 12b, and a copper foil 11b are arranged in this order. Overlap and press both sides with jigs 15 and 15, and preheat for 3 minutes at a pressure of 5 kg / cm ² · G at 180 ° C heat with pressing hot plates 17 and 17 via cushioning materials 16 and 16.
Then, it was pressed at a pressure of 30 kg / cm ² · G for 3 minutes to cure the epoxy prepreg to form a pair of single-sided copper-clad laminates.

Next, as shown in FIG. 5, after peeling the one-sided copper-clad laminate and the surface-roughened film 13a, the cured epoxy resin surfaces of the pair of one-sided copper-clad laminates are laminated via the epoxy prepreg 12c. Then, press molding was performed under the same conditions as above to form a multilayer laminated plate.

In addition, this was manufactured on a trial basis.
B is an inner layer circuit board having a cured layer of epoxy prepreg surface-roughened by peeling the surface-roughened film on both sides, similar to that shown in FIGS.
Epoxy prepreg is laminated between a pair of single-sided copper clad laminates formed as shown in the figure, and pressed in the same manner as described above to obtain a multilayer PWB.

Then, the peel strength (kg / 15 mm) between the one-sided copper-clad laminate and the surface-roughened film and the cured epoxy resin layer 12a or 12b of the one-sided copper-clad laminate and the cured resin layer 12c of the epoxy prepreg in the multilayer laminate. Peel strength between (kg / 15
mm) Instron type tensile tester (Instron)
Was measured under the condition of a tensile speed of 200 mm / min.

The physical properties of the surface-roughened film are evaluated by the following methods.

(1) Gloss: ASTM-D2457 (60 degree angle) (2) Surface roughness: Surface roughness meter (SE-3A type, Kosaka Laboratory) (3) Tear strength: ASTM-D1922 The results are shown in Table 1.

Example 2 The same as Example 1 except that a roll having an average roughness of 2 μ was used. The results are shown in Table 1.

Example 3 The same as Example 1 except that a roll having an average roughness of 7 μ was used. The results are shown in Table 1.

<Example 4> A roughening roll having an average roughness of 5 [mu] is wound around and attached to the cooling roll of Example 1 as in the case of FIG. 2, thereby forming a surface roughened film. Other conditions are the same as those in the first embodiment. The results are shown in Table 1.

Example 5 Under the same conditions as in Example 1, PMP and CaCO ₃ were mixed at a ratio of 95: 5 wt% and melt-extruded.

The results are shown in Table 1.

Comparative Example 1 A film extruded from a T die under the conditions of Example 1 was used for molding a multilayer PWB without surface roughening.
The results are shown in Table 1.

Comparative Example 2 The same as Example 1 except that a surface-roughened film having an average roughness of 20 μ is used. The results are shown in Table 1.

<Comparative Example 3> The same as Example 5 except that PMP and CaCO ₃ were mixed at a ratio of 60:40 wt%. The results are shown in Table 1.

As is clear from Table 1, the peel strength between the cured epoxy resin layer and the surface-roughened film in each example was 0.03.
It is as low as ~ 0.1kg / 15mm and has excellent releasability, and the peel strength between the cured epoxy resin layer whose surface is roughened and the prepreg is 2.8-4.0kg / 15mm, which is excellent in adhesion. .

On the other hand, a film having a smooth surface as in Comparative Example 1 has excellent releasability, but the adhesiveness with the prepreg is 0.8 k.
Not improved at all with g / 15mm.

Further, a film having a surface roughness of 25μ and more than 10μ as in Comparative Example 2 has a poor releasability of 1.1kg / 15mm, and a film containing a large amount of filler as in Comparative Example 3 has a peel strength of 1.2kg /
It is inferior in releasability with 15 mm and tear strength of 3-5 kg / cm.

[Brief description of drawings]

FIG. 1 is a perspective view showing an apparatus for producing a surface-roughened film and a sheet of the present invention, FIG. 2 is a perspective view showing another apparatus, and FIG.
FIG. 7 is a schematic view showing another device, FIGS. 4 to 6 are diagrams showing a manufacturing process of a multilayer printed wiring board, and FIGS. 7a and 7b are general manufacturing methods of a conventional multilayer printed wiring board. It is a figure. 1 ... die, 2a, 2b, 2c, 2d, 2e ... rolls for surface roughening,
13a, ... Surface roughening film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-58-128846 (JP, A) JP-A-56-111637 (JP, A) JP-A-57-70654 (JP, A) JP-A-53- 121070 (JP, A) JP 48-31257 (JP, A) JP 50-140859 (JP, A) JP 50-76565 (JP, A) JP 50-133455 (JP, A)

Claims (1)

[Claims] 1. A poly-4-methyl-1 for producing a multilayer printed wiring board, characterized in that the surface is roughened by a surface-roughened roll to an average roughness of 0.5 to 10 μm.
-Penten surface roughening films and sheets.