KR102066316B1 - Laminate and copper-clad laminate using same - Google Patents

Abstract

The surface-treated copper foil for copper clad laminated boards which adheres favorably to resin and is excellent in transparency of resin after copper foil is removed by etching is provided. In the surface-treated copper foil for copper clad laminates, roughened particles are formed on the copper foil surface by roughening, the average roughness Rz of the roughened surface is 0.5 to 1.3 µm, and the glossiness of the roughened surface is 0.5 to 68. The ratio A / B of the surface area A of a roughened particle | grain, and the area B obtained when the said roughened particle is planarly viewed from the said copper foil surface side is 2.00-2.45.

Description

Surface-treated copper foil and copper clad laminates using this, printed wiring boards, electronic devices {LAMINATE AND COPPER-CLAD LAMINATE USING SAME}

This invention relates to a surface-treated copper foil and the copper clad laminated board using the same, a printed wiring board, and an electronic device, The surface-treated copper foil which is especially suitable for the field where transparency of resin of the remainder after etching copper foil is calculated | required It relates to a copper clad laminated board, a printed wiring board, and an electronic device.

In small electronic devices such as smartphones and tablet PCs, flexible printed wiring boards (FPCs) have been adopted for ease of wiring and lightness. In recent years, as the electronic devices become more functional, signal transmission speeds have increased, and impedance matching has become an important factor even in FPC. As a measure of impedance matching with respect to an increase in signal capacity, a thickening of a resin insulating layer (for example, polyimide) serving as a base of an FPC is being progressed. On the other hand, the FPC is subjected to processing such as bonding to a liquid crystal substrate, mounting of an IC chip, and the like, in which the alignment is performed by passing through the resin insulating layer remaining after etching the copper foil of the copper clad laminate. Since it is implemented through, the visibility of the resin insulating layer becomes important.

Moreover, a copper clad laminated board can be manufactured even if it uses the rolled copper foil with which roughening plating was given to the surface. This rolled copper foil is usually made of tough pitch copper (oxygen content of 100 to 500 weight ppm) or oxygen free copper (oxygen content of 10 weight ppm or less) as a material, and after hot rolling these ingots, they are cold to a predetermined thickness. It is produced by repeating rolling and annealing. In patent document 1, using the low roughness electrolytic foil with high glossiness of the surface as a conductor layer is proposed.

On the other hand, in patent document 2, the rolled copper foil whose depth of the oil pit on the surface formed by the cold rolling process under conditions, such as oil film control, as copper foil excellent in flexibility is 2.0 micrometers or less is proposed.

Japanese Unexamined Patent Publication No. 2004-98659 Japanese Laid-Open Patent Publication 2001-58203

In patent document 1, the low roughness copper foil obtained by the adhesive improvement improvement process by the organic treatment agent after a blackening process or plating process may be disconnected by fatigue in the use which requires flexibility | flexibility to a copper clad laminated board, and resin transparency You may fall. Moreover, even if it uses the rolled copper foil which has the oil pit state of the grade described in patent document 2, sufficient transparency of resin is not obtained. Thus, in the prior art, the resin transparency after removing the rolled copper foil by etching was low, and the chip alignment could not be performed smoothly.

This invention provides the copper foil for copper clad laminated boards excellent in transparency of resin after adhere | attaching with resin favorably and removing copper foil by the etching.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching, the inventors discovered that surface average roughness Rz of the side adhering to the resin substrate of copper foil affects resin transparency after etching removal of copper foil. That is, it turned out that resin transparency after etching removal of copper foil becomes bad, so that surface average roughness Rz of the side adhering to the resin substrate of copper foil is large.

According to the present invention completed based on the above findings, in one aspect, roughened particles are formed on a copper foil surface by a roughening treatment, and the average roughness Rz of the roughened surface is 0.5 to 1.3 µm, and the roughened surface The surface treatment for copper clad laminated boards whose glossiness is 0.5-68 and ratio A / B of the area B obtained when the surface area A of the said roughening particle and the said roughening particle are planarly viewed from the said copper foil surface side are 2.00-2.45. Copper foil.

In one embodiment of the surface-treated copper foil for copper clad laminated board which concerns on this invention, the said average roughness Rz is 0.5-1.1 micrometers.

In another embodiment of the surface-treated copper foil for copper clad laminated boards which concerns on this invention, the said average roughness Rz is 0.6-0.9 micrometer.

In another embodiment of the surface-treated copper foil for copper clad laminated boards which concerns on this invention, the said glossiness is 1.0-40.

In another embodiment of the surface-treated copper foil for copper clad laminated boards which concerns on this invention, the said glossiness is 4.8-35.

In another embodiment of the surface-treated copper foil for copper clad laminated boards which concerns on this invention, said A / B is 2.00-2.30.

In another embodiment of the surface-treated copper foil for copper clad laminated boards which concerns on this invention, said A / B is 2.00-2.15.

When the said copper foil is bonded together on both surfaces of a 50-micrometer-thick resin substrate on the roughening process surface side, when the said copper foil is removed by etching, the light transmittance of the said resin substrate will be 30% or more.

This invention is the copper clad laminated board which laminated | stacked and comprised the said surface-treated copper foil and the resin substrate in another aspect.

ADVANTAGE OF THE INVENTION According to this invention, the surface-treated copper foil for copper clad laminated boards which adheres favorably with resin and is excellent in transparency of resin after copper foil is removed by etching can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is an observation photograph of the printed matter of (a) Comparative Example 1, (b) Example 1, (c) Reference Example 2, (d) Example 7, (e) Example 3 at the time of visibility evaluation.
2 is an SEM observation photograph of the copper foil surface of (a) Comparative Example 1, (b) Example 1, (c) Reference Example 2, (d) Example 7, (e) Example 3 at the time of Rz evaluation. .

[Form of surface-treated copper foil and manufacturing method]

The copper foil used in the present invention may be either an electrolytic copper foil or a rolled copper foil. Usually, the surface which adhere | attaches with the resin base material of copper foil, ie, a roughening surface, performs the roughening process which gives an uneven electrodeposition to the surface of copper foil after degreasing for the purpose of improving the peeling strength of copper foil after lamination. do. Electrolytic copper foil has unevenness | corrugation at the time of manufacture, but it raises the convex part of electrolytic copper foil by roughening process, and makes an unevenness | corrugation further larger. In this invention, this roughening process can be performed by copper-cobalt-nickel alloy plating. As a pretreatment before roughening, normal copper plating etc. may be performed, and in order to prevent the fall of an electrodeposition thing as a finishing process after roughening, normal copper plating etc. may be given. In rolled copper foil and electrolytic copper foil, a process content may differ to some extent. In this invention, the well-known process related to copper foil roughening including this pretreatment and finishing process is also included as needed, and it is collectively called a roughening process.

Copper-cobalt-nickel alloy plating as a roughening process in this invention is a copper-coated 100-100-3000 microgram / dm <2> cobalt-100-900 microgram / d of adhesion amount by 15-40 mg / dm <2> by electrolytic plating. It can be performed to form a ternary alloy layer of nickel of m 2. When Co adhesion amount is less than 100 microgram / dm <2>, heat resistance may deteriorate and etching property may worsen. When Co adhesion amount exceeds 3000 microgram / dm <2>, it is unpreferable when a magnetic influence should be considered, etching unevenness may occur, and acid resistance and chemical resistance may worsen. If Ni adhesion amount is less than 100 microgram / dm <2>, heat resistance may worsen. On the other hand, when Ni adhesion amount exceeds 900 microgram / dm <2>, etching residue will increase. Preferable Co adhesion amount is 1000-2000 microgram / dm <2>, and preferable nickel adhesion amount is 200-400 microgram / dm <2>. Here, the etching stain means that Co remains undissolved when etched with copper chloride, and the etching residue means that Ni remains undissolved when alkali etching with ammonium chloride.

Examples of general bath and plating conditions for forming such ternary copper-cobalt-nickel alloy plating are as follows:

Plating bath composition: Cu 10-20 g / l, Co 1-10 g / l, Ni 1-10 g / l

pH: 1-4

Temperature: 40-50 ℃

Current density D _k : 20 to 30 A / dm 2

Plating time: 1 to 5 seconds

After the roughening treatment, a cobalt-nickel alloy plating layer of nickel having cobalt -100 to 700 µg / dm 2 having an adhesion amount of 200 to 3000 µg / dm 2 can be formed on the roughened surface. This process can be regarded as a kind of antirust process in a broad sense. It is necessary to perform this cobalt- nickel alloy plating layer so that the adhesive strength of copper foil and a board | substrate may not substantially fall. When cobalt adhesion amount is less than 200 microgram / dm <2>, heat-resistant peeling strength may fall and oxidation resistance and chemical resistance may deteriorate. As another reason, a small amount of cobalt is not preferable because the treated surface becomes reddish. If the cobalt adhesion amount exceeds 3000 µg / dm 2, it is not preferable when the magnetic influence is to be considered, etching stains occur, and deterioration of acid resistance and chemical resistance is considered. Preferable cobalt adhesion amount is 500-3000 microgram / dm <2>. On the other hand, when nickel adhesion amount is less than 100 microgram / dm <2>, heat peeling strength falls and oxidation resistance and chemical-resistance deteriorate. When nickel exceeds 700 microgram / dm <2>, alkali-etchability will worsen. Preferable nickel adhesion amount is 200-600 microgram / dm <2>.

Moreover, an example of the conditions of cobalt- nickel alloy plating is as follows:

Plating bath composition: Co 1-20 g / ℓ, Ni 1-20 g / ℓ

pH: 1.5 ~ 3.5

Temperature: 30 to 80 ℃

Current density D _k : 1.0 to 20.0 A / dm 2

Plating time: 0.5-4 seconds

According to the present invention, a zinc plating layer having an adhesion amount of 10 to 80 µg / dm 2 is further formed on the cobalt-nickel alloy plating. If the zinc adhesion amount is less than 10 µg / dm 2, the effect of improving the heat resistance deterioration rate may be lost. On the other hand, when zinc adhesion amount exceeds 80 microgram / dm <2>, hydrochloric acid deterioration rate may become extremely bad. Preferably, zinc adhesion amount is 20-60 microgram / dm <2>, More preferably, it is 30-50 microgram / dm <2>.

An example of the conditions of the galvanizing is as follows:

Plating bath composition: Zn 100 ~ 300 g / ℓ

pH: 3-4

Temperature: 50-60 ℃

Current density D _k : 0.1 to 0.5 A / dm 2

Plating time: 1-3 seconds

In addition, a zinc alloy plating layer such as zinc-nickel alloy plating may be formed instead of the zinc plating layer, and an antirust layer may be formed on the outermost surface by chromate treatment, application of a silane coupling agent, or the like.

Moreover, the surface-treated copper foil of this invention is a roughening process, After forming the primary particle layer of copper on the surface of copper foil beforehand, The secondary which consists of ternary alloys which consist of copper, cobalt, and nickel on a primary particle layer. You may form a particle layer. In this case, an example of the plating conditions of the primary particles of copper is as follows:

Plating bath composition: Cu 10-25 g / l, Sulfuric acid 50-100 g / l

Temperature: 25-50 ℃

Current density D _k : 10 to 70 A / dm 2

Plating time: 5-25 seconds

Coulomb amount 50 to 500 As / dm

An example of the plating conditions of the secondary particles is as follows:

Plating bath composition: Cu 10-20 g / l, Nickel 5-15 g / l, Cobalt 5-15 g / l

pH: 2-3

Temperature: 30-50 ℃

Current density D _k : 20 to 60 A / dm 2

Plating time: 1 to 5 seconds

Coulomb amount 30 to 70 As / dm 2

(Surface roughness Rz)

In the surface-treated copper foil of this invention, a roughening particle is formed by the roughening process on the copper foil surface, and the average roughness Rz of the roughening process surface is 0.5-1.3 micrometer. By such a structure, peeling strength becomes high, it adheres favorably with resin, and the light transmittance of resin after removing copper foil by etching becomes favorable. As a result, positioning etc. at the time of IC chip mounting performed through the positioning pattern which permeate | transmits the said resin and is visualized becomes easy. If average roughness Rz is less than 0.5 micrometer, the roughening process of the copper foil surface is inadequate, and it cannot fully adhere | attach with resin. On the other hand, when average roughness Rz is more than 1.3 micrometers, the unevenness | corrugation of the resin surface after removing copper foil by etching becomes large, and as a result, the light transmittance of resin becomes bad. 0.5-1.1 micrometers is preferable and, as for the average roughness Rz of a roughening process surface, 0.6-0.9 micrometer is more preferable.

[Light transmittance]

Since the average roughness Rz of the roughening process surface of the surface-treated copper foil of this invention is controlled as mentioned above, after bonding to a resin substrate, the light transmittance of the resin substrate of the part which removed the copper foil becomes favorable. Specifically, after the surface-treated copper foil of the present invention is bonded to both surfaces of a resin substrate having a thickness of 50 μm on the roughened surface side, when the copper foil is removed by etching, the light transmittance of the resin substrate is 30% or more, Preferably 50% or more may be sufficient.

[Glossiness]

The glossiness of the roughening surface of surface-treated copper foil has big influence on the light transmittance of resin mentioned above. That is, the transmittance of resin mentioned above becomes favorable, so that the copper foil with a glossiness of a roughening surface is large. For this reason, the glossiness of a roughening surface is 0.5-68, it is preferable that it is 1.0-40, and, as for the surface-treated copper foil of this invention, it is more preferable that it is 4.8-35.

[Surface Area of Particles]

The surface area A of the roughened particle and the ratio A / B of the area B obtained when the roughened particle is viewed in a plan view from the copper foil surface side greatly influence the light transmittance of the resin described above. That is, when surface roughness Rz is the same, the transmittance | permeability of resin mentioned above will become so favorable that it is copper foil with a small ratio A / B. For this reason, it is preferable that the said ratio A / B is 2.00-2.45, it is 2.00-2.30, and, as for the surface-treated copper foil of this invention, it is more preferable that it is 2.00-2.15.

By controlling the current density and the plating time at the time of particle formation, the form and formation density of the particle are determined, and the surface roughness Rz, glossiness, and area ratio A / B of the particle can be controlled.

The surface-treated copper foil of this invention can be bonded to a resin substrate from the roughening process surface side, and a copper clad laminated body can be manufactured. The resin substrate is not particularly limited as long as it has properties applicable to printed wiring boards. For example, a paper-based phenolic resin, a paper-based epoxy resin, a synthetic fiber cloth-based epoxy resin, glass cloth, or paper for rigid PWB. Composite base material epoxy resin, glass cloth, glass nonwoven fabric Composite base material epoxy resin, glass cloth base material epoxy resin, etc. can be used, A polyester film, a polyimide film, etc. can be used for FPC.

In the bonding method, in the case of a rigid PWB, the base material, such as glass cloth, is impregnated with resin, and the prepreg which hardened resin to the semi-hardened state is prepared. It can carry out by heating and pressing copper foil overlapping a prepreg from the surface on the opposite side of a coating layer.

Although the copper clad laminated body of this invention can be used for various printed wiring boards (PWB), it does not restrict | limit especially, For example, single-sided PWB, double-sided PWB, multilayer PWB (three or more layers) from a viewpoint of the number of layers of a conductor pattern. It is applicable to rigid PWB, flexible PWB (FPC), and rigid flex PWB from a viewpoint of the kind of insulated substrate material.

Example

Copper foil is prepared as Examples 1, 3-5, 7-9, 13-15, Reference Examples 2, 6, 10-12, and Comparative Examples 1-8, and it shows in Table 1-4 as a roughening process to one surface. The plating treatment was performed under the conditions described. Here, as a copper foil of Examples 1, 3-5, 7-9, Reference Examples 2, 6, 10-12, and Comparative Examples 2-6, 8, tough pitch copper (JIS H 3100 C1100R manufactured by JX Nikko Niseki Metal Co., Ltd.) Rolled copper foil). In addition, electrolytic copper foil HLPLC foil manufactured by JX Nikko Niseki Metal Co., Ltd. was used as the copper foil of Examples 13 to 15 and Comparative Examples 1 and 7.

Various evaluation was performed about each sample of the Example and comparative example produced as mentioned above as follows.

(1) measurement of surface roughness Rz;

The 10-point average roughness was measured with respect to the roughening surface in accordance with JIS B0601-1994 using the contact roughness meter SP-11 manufactured by Kosaka Research Institute. The measurement position was changed 10 times in parallel with the rolling direction on the conditions of 0.8 mm of measurement lengths, 4 mm of evaluation lengths, 0.8 mm of cut-off values, and 0.1 mm / sec of feed rates, and the value in 10 measurements was calculated | required.

(2) the area ratio of the particles (A / B);

The surface area of a roughened particle used the measuring method by a laser microscope. Three-dimensional surface area A in 100 × 100 μm equivalent area (9924.4 μm ^{2 in} real data) of the roughened surface was measured using the laser microscope VK8500 manufactured by Keyence Co., Ltd., and three-dimensional surface area A ÷ two-dimensional surface area B = area ratio (A / The setting was performed by the method of B).

(3) glossiness;

Using Nippon Denshi Color Co., Ltd. glossimeter handy gloss meter PG-1 based on JIS Z 8741, it measured about the roughening surface of 60 degrees of incidence angles in the direction orthogonal to a rolling direction.

(4) light transmittance;

Copper foil was bonded to both surfaces of the polyimide film (50 micrometers in thickness) in which the thermosetting adhesive for lamination was formed, and copper foil was removed by the etching (ferric chloride aqueous solution), and the sample film was produced. About the obtained resin layer, the light transmittance was measured by setting the wavelength of 620 nm with a slit of 10 mm using the Nippon spectrophotometer V-660.

(5) visibility (resin transparency);

Copper foil was bonded to both surfaces of the polyimide film (50 micrometers in thickness) in which the thermosetting adhesive for lamination was formed, and copper foil was removed by the etching (ferric chloride aqueous solution), and the sample film was produced. The printed matter was affixed on one surface of the obtained resin layer, and the visibility of the printed matter was determined from the opposite surface over the resin layer. It was evaluated as "(circle)" (passed) that the outline of printed matter was clear, and "x" (failed) that the outline was disturbed.

(6) peel strength (adhesive strength);

Based on PC-TM-650, the state peeling strength was measured by the tensile tester Autograph 100, and it was assumed that the said state peeling strength can use 0.7 N / mm or more for copper clad laminated board applications.

Table 5 shows the conditions and evaluation of the above tests.

(Evaluation results)

Examples 1, 3 to 5, 7 to 9, 13 to 15, and Reference Examples 2, 6 and 10 to 12 all had good transmittance, visibility, and peel strength.

In Comparative Examples 1, 2 and 5, the average roughness Rz of the roughened surface was greater than 1.3 µm, so that the transmittance was poor.

Since the glossiness was more than 68, the comparative example 3 was poor in peeling strength.

In Comparative Example 4, the peel strength was poor because the area ratio A / B was less than 2.00.

In Comparative Example 6, since the average roughness Rz of the roughened surface was less than 0.5 µm, the peel strength was poor.

Since the glossiness was less than 0.5, the comparative example 7 was defective.

In Comparative Example 8, the area ratio A / B was more than 2.45, so the transmittance was poor.

The observation photograph of the printed matter of (a) Comparative Example 1, (b) Example 1, (c) Reference Example 2, (d) Example 7, (e) Example 3 at the time of the said visibility evaluation is shown, respectively in FIG. .

SEM observation photograph of the copper foil surface of (a) Comparative Example 1, (b) Example 1, (c) Reference Example 2, (d) Example 7, (e) Example 3 at the time of said Rz evaluation in FIG. Respectively.

Claims (16)

Roughening particle | grains are formed in a copper foil surface by a roughening process, the average roughness Rz of a roughening process surface is 0.5-1.3 micrometers, and the glossiness of a roughening process surface is 4.8-68,
The ratio A / B of the three-dimensional surface area A of the said roughening process surface and the two-dimensional surface area B obtained when the said roughening process surface is planarly viewed from the said copper foil surface side is 2.00-2.45, and the said copper foil is thickness in the roughening process surface side Surface bonding copper foil which the light transmittance of the said resin substrate will be 30% or more, after bonding to both surfaces of a 50 micrometers resin substrate, and removing the said copper foil by etching. Roughening particle | grains are formed in a copper foil surface by a roughening process, the average roughness Rz of a roughening process surface is 0.5-1.3 micrometers, and the glossiness of a roughening process surface is 7.1-68,
The ratio A / B of the three-dimensional surface area A of the said roughening process surface and the two-dimensional surface area B obtained when the said roughening process surface is planarly viewed from the said copper foil surface side is 2.00-2.45, and the said copper foil is in the roughening process surface side Surface bonding copper foil which the light transmittance of the said resin substrate will be 30% or more, after bonding to both surfaces of a 50-micrometer-thick resin substrate, and removing the said copper foil by etching. Roughening particle | grains are formed in a copper foil surface by a roughening process, the average roughness Rz of a roughening process surface is 0.5-0.9 micrometer, and the glossiness of a roughening process surface is 4.8-68,
The ratio A / B of the three-dimensional surface area A of the said roughening process surface and the two-dimensional surface area B obtained when the said roughening process surface is planarly viewed from the said copper foil surface side is 2.00-2.45, and the said copper foil is in the roughening process surface side Surface bonding copper foil which the light transmittance of the said resin substrate will be 30% or more, after bonding to both surfaces of a 50-micrometer-thick resin substrate, and removing the said copper foil by etching. The method of claim 1,
Surface-treated copper foil whose said average roughness Rz is 0.5-1.1 micrometers. The method of claim 2,
Surface-treated copper foil whose said average roughness Rz is 0.5-1.1 micrometers. The method of claim 3, wherein
Surface-treated copper foil whose said average roughness Rz is 0.6-0.9 micrometer. The method of claim 4, wherein
Surface-treated copper foil whose said average roughness Rz is 0.6-0.9 micrometer. The method of claim 5,
Surface-treated copper foil whose said average roughness Rz is 0.6-0.9 micrometer. The method according to any one of claims 1 to 8,
Surface-treated copper foil whose said glossiness is 1.0-40. The method according to any one of claims 1 to 8,
Surface-treated copper foil whose said glossiness is 4.8-35. The method according to any one of claims 1 to 8,
Surface-treated copper foil whose said A / B is 2.00-2.30. The method according to any one of claims 1 to 8,
Surface-treated copper foil whose said A / B is 2.00-2.15. delete The copper clad laminated board comprised by laminating | stacking the surface-treated copper foil and resin substrate of any one of Claims 1-8. The printed wiring board using the surface-treated copper foil in any one of Claims 1-8. The electronic device using the printed wiring board of Claim 15.

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