CN104812945A - Surface-treated electrolytic copper foil, laminates, and printed wiring boards - Google Patents

Abstract

The invention provides a surface-treated electrolytic copper foil, a laminate and a printed wiring board, wherein the surface-treated electrolytic copper foil can realize fine pitch and has excellent adhesion reliability with resin. The surface-treated electrolytic copper foil has a roughness Rz of a rough surface of the copper foil measured by a stylus roughness meter of 2.0 [ mu ] m or less and a roughness curve of the rough surface having a kurtosis number Sku of 2 to 4.

Description

Surface-treated electrolytic copper foil, laminates, and printed wiring boards

technical field

The present invention relates to a surface-treated electrolytic copper foil, a laminate, and a printed wiring board.

Background technique

Printed wiring boards have developed considerably over the past half century, and are now even used in almost all electronic devices. With the increasing demand for miniaturization and high performance of electronic equipment in recent years, high-density mounting of mounted parts or high-frequency signals have developed, and printed wiring boards are required to miniaturize (fine-pitch) or respond to conductor patterns. high frequency etc.

The lower the roughness of the copper foil roughened surface, the better the fine pitch of the conductor pattern with respect to the printed wiring board is formed. Therefore, with the finer pitch of conductor patterns in recent years, there is an increasing demand for low roughness of the roughened surface of copper foil.

On the other hand, the copper foil is bonded to the resin to form a laminate, but in terms of the reliability of adhesion to the resin at this time, the greater the roughness of the rough surface of the copper foil, the higher the fixing effect on the rough surface. Therefore, the better the bonding reliability is. This adhesion reliability is an important management item in the formation of fine pitches, and it is only necessary that the 90° peel strength be a fixed value (0.6 kg/cm) or more. In addition, as another evaluation method of adhesion reliability, there is a method of immersing a laminate with a resin substrate in a high-temperature bath at 260° C., and measuring the number of protrusions generated on the surface, and the number of protrusions is 0 to 1 per m ² is set as a standard of adhesion reliability.

Various technologies have been developed for copper foil that can realize finer pitches and improve the reliability of adhesion to resins. For example, Patent Document 1 discloses a surface-treated copper foil characterized by having an adhesive surface with an insulating resin base material, the surface roughness (Rzjis) of the adhesive surface is 2.5 μm or less, and the surface area is measured by a laser method. The value of the surface area ratio (B) calculated from the ratio of the surface area (three-dimensional area: Aμm ² ) to the area of the two-dimensional region [(A)/(6550)] when it is a two-dimensional region ^of 6550 μm 2 is 1.25 to 2.50, and the two-dimensional The amount of chromium per unit area of the region is 2.0 mg/m ² or more.

Patent Document 1: Japanese Unexamined Patent Publication No. 2009-105286.

Contents of the invention

The problem to be solved by the invention

As disclosed in Patent Document 1, the background art mainly focuses on Rz of the roughened surface of copper foil and controls it in order to improve the adhesion reliability with resin. However, according to the studies of the inventors, it was found that even if Rz of the roughened surface of the copper foil is controlled to have the same value and other conditions are the same, the above-mentioned bonding interface with the resin substrate The number of protrusions is also different. Therefore, it became clear that only the copper foil which controls Rz of the roughened surface of copper foil is not enough to acquire favorable adhesion reliability.

The present invention provides a surface-treated electrolytic copper foil, a laminate, and a printed wiring board. The surface-treated electrolytic copper foil can achieve finer pitches and has excellent adhesion reliability with resin.

Technical means to solve the problem

When the Rz of the roughened surface is reduced to finer the pitch of the conductor pattern of the copper foil, air accumulates in the fine unevenness formed on the surface of the copper foil at the bonding interface between the surface of the copper foil and the resin substrate. Since it is difficult to remove the air, if the temperature is high, the air accumulated in the fine unevenness expands to form protrusions. Therefore, the inventors of the present invention have made intensive studies and found that by providing the surface of the copper foil with a structure such that air does not easily accumulate on the surface of the copper foil even if a low-roughened copper foil for fine-pitching is used, it is possible to suppress all The generation of the above-mentioned protrusions can be prevented, thereby achieving good adhesion reliability with the resin substrate.

One aspect of the present invention made based on the above knowledge is a surface-treated electrodeposited copper foil whose roughness Rz of the rough surface of the copper foil measured using a stylus type roughness meter is 2.0 μm or less, and the rough surface The number of kurtosis (kurtosis) Sku of the roughness curve is 2-4.

In one Embodiment of the surface-treated electrolytic copper foil of this invention, the said roughness Rz is 0.8-1.8 micrometers.

In another embodiment of the surface-treated electrolytic copper foil of the present invention, the number of kurtosis Sku is 2.5 to 3.5.

In still another embodiment of the surface-treated electrodeposited copper foil of the present invention, the ratio A/B of the surface area A of the rough surface to the area B obtained when the rough surface is planarly viewed is 1.2 to 2.0.

In still another embodiment of the surface-treated electrodeposited copper foil of this invention, the said ratio A/B is 1.3-1.9.

In yet another embodiment of the surface-treated electrodeposited copper foil of the present invention, the normal-state peel strength is 0.8 kg/cm or more.

Another aspect of the present invention is a laminate formed by laminating the surface-treated electrolytic copper foil of the present invention and a resin substrate.

Still another aspect of the present invention is a printed wiring board made of the laminate of the present invention.

The effect of the invention

According to the present invention, it is possible to provide a surface-treated electrodeposited copper foil, a laminate board, and a printed wiring board, which can realize finer pitches and has excellent adhesion reliability with resin.

Description of drawings

FIG. 1 is an SEM observation photograph of the roughened surface of the sample of Example 1. FIG.

FIG. 2 is an SEM observation photograph of the roughened surface of the sample of Comparative Example 1. FIG.

Detailed ways

The electrodeposited copper foil used in the present invention is useful as an electrodeposited copper foil that is used by bonding to a resin substrate to form a laminate and removing it by etching.

The purpose of the electrolytic copper foil used in the present invention is to improve the peel strength (adhesion reliability) of the laminated copper foil on the surface of the copper foil that is bonded to the resin substrate, that is, the roughened surface, and the pretreated The surface of the copper foil is subjected to a roughening treatment of bump-like plating. Although the electrodeposited copper foil has irregularities at the time of manufacture, the convexities of the electrodeposited copper foil are reinforced by the roughening treatment to make the irregularities larger.

[Roughness Rz]

The surface-treated electrolytic copper foil of the present invention conforms to JIS B0601-1994, and the roughness Rz of the rough surface of the copper foil measured using a stylus roughness meter is 2.0 μm or less. When the roughness Rz exceeds 2.0 μm, air tends to accumulate in fine unevenness formed on the copper foil surface at the bonding interface between the copper foil surface and the resin substrate, and it becomes difficult to remove the air. Therefore, in a high-temperature state, the air deposited on the fine unevenness expands to generate protrusions. The roughness Rz of the roughened surface measured using a stylus-type roughness meter is preferably from 0.8 to 1.8 μm, more preferably from 1.0 to 1.7 μm. This roughness Rz can be controlled by optimizing the glossy surface (S surface) processing conditions of copper foil and using both-surface smooth raw foil.

[Kurtosis Sku]

The kurtosis Sku of the roughness curve of the rough surface is controlled from the viewpoint that the "kurtosis" of the unevenness existing on the rough surface of the surface-treated electrodeposited copper foil of the present invention affects the adhesion reliability with the resin substrate. 2 to 4. The kurtosis Sku of the roughness curve indicates the sharpness (smoothness) of the unevenness on the rough surface of the copper foil. The smaller the kurtosis Sku, the more curved the unevenness becomes, and the larger the kurtosis Sku, the sharper the unevenness becomes. curve. The kurtosis number Sku of the roughness curve is an index of the sharpness of the unevenness in the three-dimensional surface roughness measurement using the non-contact roughness meter drawn in accordance with ISO25178, and is represented by the following formula as the unevenness in the Z-axis direction of the three-dimensional surface roughness The (protrusion) height obtained by dividing the following fourth power of the height Z(x) of the protrusion at the reference length lr by the fourth power of the following root mean square roughness Rq.

The fourth root of the height of the protrusion at the reference length lr:

{(1/lr)×∫Z ⁴ (x)dx (where the integral is the accumulated value from 0 to lr)}

Root mean square roughness Rq:

Rq: √{(1/lr)×∫Z ² (x)dx (wherein, the integral is the cumulative value from 0 to lr)}

The number of kurtosis Sku of the roughness curve:

Sku=(1/Rq ⁴ )×{(1/lr)×∫Z ⁴ (x)dx (where the integral is the accumulated value from 0 to lr)}

As described above, the sharper the degree of sharpness and the steeper the shape of the unevenness on the rough surface of the copper foil, the greater the kurtosis Sku of the roughness curve. In addition, the steeper the degree of sharpness and the sharper form of the unevenness, the greater the variation in the magnitude of the unevenness existing on the rough surface of the copper foil. Therefore, if the number of kurtosis Sku of the roughness curve indicating the control of the uneven shape is controlled, the larger variation in the size of the unevenness existing on the rough surface of the copper foil can be further controlled. By suppressing the variation in the size of the irregularities present on the rough surface of the copper foil in this way, air is less likely to accumulate on the surface of the copper foil even if the pitch is made finer. Therefore, the occurrence of protrusions due to the expansion of the air accumulated in the unevenness in a high-temperature state is suppressed, thereby achieving good adhesion reliability with the resin substrate. When the kurtosis Sku of the roughness curve of the rough surface is less than 2, sufficient adhesive force with the resin cannot be maintained, and if it exceeds 4, as described above, there is a problem that protrusions are generated after heating. In addition, the kurtosis Sku of the roughness curve is preferably from 2.5 to 3.7, more preferably from 2.5 to 3.5, even more preferably from 2.4 to 3.4. The number of kurtosis Sku can be controlled by optimizing the roughening treatment conditions of copper foil.

[Surface area ratio A/B]

In the surface-treated electrolytic copper foil of the present invention, it is preferable that the ratio A/B of the surface area A of the rough surface (roughened surface) to the area B obtained when the rough surface is viewed from above is 1.2 to 2.0. Here, the surface area A is the surface area (three-dimensional area) when a two-dimensional region of a predetermined range is measured by the laser method, and the area B obtained when the rough surface is viewed from above represents the area of the two-dimensional region. These surface area ratios A/B are a proxy for the contact area between the surface-treated electrodeposited copper foil and the resin substrate. If the surface area ratio A/B is less than 1.2, sufficient adhesion with the resin may not be ensured. If it exceeds 2.0, Then, as described above, there is a possibility that the problem of protrusions after heating may occur. The surface area ratio A/B is more preferably 1.3 to 1.9. Surface area ratio A/B can be controlled by optimizing the roughening process conditions of copper foil. For example, when W is added to the copper roughening treatment liquid, the surface area ratio A/B increases. In addition, when the current density is increased in the copper roughening treatment, the surface area ratio A/B is increased, and when the current density is decreased, the surface area ratio is decreased. The surface area ratio A/B can be controlled to be 1.2 to 2.0 in this way.

[Normal Peel Strength]

The surface-treated electrodeposited copper foil of the present invention has good normal-state peel strength as described above. Specifically, the surface-treated electrodeposited copper foil of the present invention preferably has a normal-state peel strength measured in accordance with JIS C5016 of 0.8 kg/cm or more. In addition, the normal-state peel strength is more preferably 0.9 kg/cm or more.

[high temperature bath protrusion]

The surface-treated electrodeposited copper foil of the present invention can suppress high-temperature bath protrusion favorably as described above. Specifically, after the surface-treated electrolytic copper foil of the present invention is preferably formed with a fine-pitch circuit as a conductor pattern, when the roughened surface is bonded to a resin substrate, the number of protrusions after immersion in a high-temperature bath at 260° C. for 1 minute is: 0 to 1 piece/m ² .

As a method of manufacturing the surface-treated electrodeposited copper foil of the present invention, first, an electrodeposited copper foil (green foil) is produced. The electrodeposited copper foil used in the present invention is an electrodeposited copper foil having high high-temperature elongation that suppresses pinholes, which is a relatively useful characteristic of green foil.

The electrolytic copper foil used in the present invention can be produced by electrolysis using a sulfuric acid copper sulfate electrolytic solution. The concentration of the glue solution in the electrolyte can be adjusted to be below 0.5ppm, preferably adjusted to 0.01 to less than 0.2ppm, and preferably by adding an adjusted amount of chloride ions, and also adjusted together Other electrolytic conditions such as electrolyte temperature and sulfuric acid concentration can be used to manufacture electrolytic copper foil with no pinholes and high elongation at high temperature. Reducing the amount of glue added to the electrodeposited copper foil manufactured using this electrolytic solution promotes annealing (recrystallization) of crystals during high-temperature treatment, and as a result, increases the elongation at high temperature.

The composition and electrolysis conditions of the electrolytic solution used in the present invention when chlorine ions are added are as follows.

(A) Electrolyte composition:

Cu: 50～120g/l

H ₂ SO ₄ : 20-200g/l, preferably 40-120g/l

Chloride ion (Cl ^- ): 20～100ppm(mg/l)

Glue: less than 0.5ppm (mg/l), preferably 0.01 to less than 0.2ppm (mg/l)

(B) Electrolysis conditions:

Electrolyte temperature: 20-70°C, preferably 40-60°C

Current density: 20～150A/ ^dm2

Anode: Pb

When the glue concentration exceeds 0.5 ppm, the elongation at high temperature hardly increases. Also, a minimum amount of glue must be added to prevent pinholes and the like. Preferably, the glue solution is added in an amount of 0.01 to less than 0.2 ppm (mg/l).

Ideally, the sulfuric acid concentration is set to 20-200 g/l, preferably 40-120 g/l. If it is less than 20 g/l, the electrical conductivity of the electrolytic solution will decrease, and the voltage of the electrolytic cell will increase. If it exceeds 200 g/l, it will become more and more difficult to manufacture the copper foil with high high-temperature elongation, and corrosion of a facility will become easy to generate|occur|produce.

Preferably, it is added in an amount of 20 to 100 ppm (mg/l) of chloride ions. Outside this range, the basic properties (tensile strength, roughness, etc.) of the electrolytic copper foil cannot be fixed. Chloride ions are added in the form of hydrochloric acid, salt, potassium chloride, etc.

Ideally, the temperature of the electrolyte solution is set at 20-70°C, more preferably at 40-60°C. If the electrolyte temperature is lowered, copper foil with high elongation at high temperature can be produced even if the glue concentration is high. If it is less than 20°C, the electrical conductivity of the electrolytic solution will decrease, and the voltage of the electrolytic cell will increase. When it exceeds 70 degreeC, it will become difficult to manufacture the copper foil with high high temperature elongation, and energy cost will also increase.

In order to manufacture electrolytic copper foil stably and within a practically allowable time, the current density ranges from 20 to 150 A/dm ² .

The following shows an example of the method of controlling the kurtosis Sku in raw foil manufacturing:

＜Conditions for Raw Foil Manufacturing＞

In the electrolyte solution when raw foil is made of foil, the glue concentration is set to 1-10ppm, SPS [polydithiodipropanesulfonate sodium] is set to 1-50ppm, and the amine compound [tertiary amine compound] is set to 1 ~50ppm, thereby smoothing the surface of the green foil (the unevenness becomes less sharp). Thereby, in the subsequent roughening treatment, the shape of the roughened particles on the surface after the copper clad plating becomes round. In this way, the number of kurtosis Sku can be made smaller than that of ordinary electrolytic copper foil (for example, the case of producing raw foil by using an electrolyte solution added with copper, sulfuric acid, Cl, and glue).

In addition, the following compounds were used as the tertiary amine compound.

(In the above chemical formula, _R1 and _R2 are selected from the group consisting of hydroxyalkyl groups, ether groups, aryl groups, substituted aromatic alkyl groups, unsaturated hydrocarbon groups, and alkyl groups; in the following examples, R ₁ and R ₂ are both set to methyl)

In addition, the above-mentioned compounds used in the following examples can be obtained by mixing predetermined amounts of, for example, Denacol Ex-314 manufactured by NagasechemteX Co., Ltd. and dimethylamine, and reacting at 60° C. for 3 hours.

Next, roughen the surface of the electrolytic copper foil. As the roughening treatment, for example, the conditions shown below can be employed. In this invention, the surface of the electrolytic copper foil by the roughening process side is made into a rough surface.

When the raw foil is ordinary electrolytic copper foil (for example, when the raw foil is produced by using an electrolyte solution added with copper, sulfuric acid, Cl, and glue)

[Copper roughening treatment conditions]

Cu: 5～50g/l

H ₂ SO ₄ : 10～100g/l

・Other added elements (any one of conditions 1 to 4)

(Condition 1)

As: 0.01～20mg/l(ppm) and

W: 0.01～10mg/l (ppm)

(Condition 2)

Mo: 0.01～5mg/l(ppm)

(Condition 3)

Mo: 0.01～5mg/l(ppm)

and

As: 0.01～5mg/l(ppm) and/or W: 0.01～5mg/l(ppm) and/or Co: 0.01～0.5mg/l(ppm)

(Condition 4)

As: 0.01～20mg/l(ppm) and

W: 0.01～10mg/l(ppm) and

Co: 0.01～0.5mg/l (ppm)

Liquid temperature: room temperature (20°C) ~ 50°C

Current density: 5～120A/ ^dm2

Time: 1~30 seconds

When the raw foil is double-sided smooth (flat) foil (a foil whose copper deposition surface is smoother than ordinary electrolytic copper foil due to the addition of a leveling agent to the electrolyte) (for example, by adding copper, sulfuric acid, Cl, Glue, SPS, electrolyte solution of amine compound when manufacturing raw foil)

[Copper roughening treatment conditions]

Cu: 5～50g/l

H ₂ SO ₄ : 10～100g/l

・Other added elements (any one of conditions 1 to 4)

(Condition 1)

As: 0.01～5mg/l(ppm) and

W: 0.01～5mg/l (ppm)

(Condition 2)

Mo: 0.01～3mg/l(ppm)

(Condition 3)

Mo: 0.01～3mg/l(ppm)

and

As: 0.01～5mg/l(ppm) and/or W: 0.01～5mg/l(ppm) and/or Co: 0.01～1mg/l(ppm)

(Condition 4)

W: 0.01～5mg/l(ppm) and/or Co: 0.01～1mg/l(ppm)

Liquid temperature: room temperature (20°C) ~ 50°C

Current density: 5～130A/ ^dm2

Time: 1~30 seconds

An example of a method of controlling the number of kurtosis Sku in the copper roughening treatment is shown below:

＜Copper roughening treatment conditions＞

By adding both As and W, or adding Mo to the copper roughening treatment liquid, the shape of the roughened particles is rounded. In this way, the number of kurtosis Sku can be made small.

Moreover, by adding Co to the copper roughening treatment liquid, or adding W alone (no As), the shape of the roughened particles can be sharpened (the tip of the particle is sharp). In this way, the number of kurtosis Sku can be increased.

Furthermore, by lowering the liquid temperature (for example, 20° C. or higher and lower than 25° C.), the shape of the roughened particles can be sharpened (the tip of the particle is sharpened). In this way, the number of kurtosis Sku can be increased.

After the roughening treatment, a thinner copper plating is performed as a coating for preventing particle drop-off. For example, the following conditions can be adopted.

[Copper clad thin layer plating conditions]

Cu: 30～100g/l

H ₂ SO ₄ : 10～200g/l

Liquid temperature: room temperature to 75°C

Current density: 5～65A/ ^dm2

Time: 1~30 seconds

An example of a method of controlling the number of kurtosis Sku in the copper clad plating process is shown below:

＜Copper Plating Conditions＞

By increasing the current density (for example, setting it higher than 60 A/dm ² ), the shape of the roughened particles can be sharpened (the tip of the particle is sharp). In this way, the number of kurtosis Sku can be increased.

Preferably, the roughened surface is processed to form a single metal layer or an alloy layer of one or more selected from Cu, Cr, Ni, Fe, Co, and Zn. Examples of alloy plating include Cu—Ni, Cu—Co, Cu—Ni—Co, Cu—Zn, and others. Such processing plays a role of determining the final characteristics of the copper foil and also a role of a barrier.

In addition, nickel, cobalt, copper, and zinc monomers or alloys can be used to form a heat-resistant layer or an anti-rust layer on the roughened surface, and further treatments such as chromate treatment and silane coupling treatment can also be performed on the surface. Alternatively, without roughening treatment, a heat-resistant layer or an anti-rust layer may be formed with nickel, cobalt, copper, or zinc monomers or alloys, and then the surface may be subjected to chromate treatment, silane coupling treatment, and other treatments. That is, one or more layers selected from the group consisting of a heat-resistant layer, an antirust layer, a chromate-treated layer, and a silane coupling-treated layer may be formed on the surface (roughened surface) of the roughened layer, or One or more layers selected from the group consisting of a heat-resistant layer, a rust-proof layer, a chromate-treated layer, and a silane coupling-treated layer are formed on the surface of the electrolytic copper foil. Furthermore, the above-mentioned heat-resistant layer, rust-proof layer, chromate-treated layer, and silane-coupling-treated layer may each be formed in multiple layers (for example, two or more layers, three or more layers, etc.).

A laminate can be produced by bonding the surface-treated electrolytic copper foil of the present invention to a resin substrate from the roughened surface side. The resin substrate is not particularly limited as long as it has properties applicable to printed wiring boards, etc. For example, paper-based phenolic resin, paper-based epoxy resin, synthetic Fiber cloth base epoxy resin, glass cloth-paper composite base epoxy resin, glass cloth-glass non-woven composite base epoxy resin and glass cloth base epoxy resin, etc., used in FPC (flexible wiring board) A polyester film or polyimide film, a liquid crystal polymer (LCP) film, or the like is used.

Regarding the bonding method, in the case of a rigid PWB, a prepreg in which a base material such as glass cloth is impregnated with a resin and cured to a semi-cured state is prepared. Bonding can be performed by laminating the copper foil on the prepreg from the surface on the opposite side of the coating layer, and heating and pressing. In the case of FPC, substrates such as polyimide film can be laminated on copper foil under high temperature and pressure without adhesive or without adhesive, or coated, dried, and hardened polyimide precursor and so on to manufacture laminates.

The laminate of the present invention can be used for various printed wiring boards (PWB) without particular limitation, for example, from the viewpoint of the number of layers of the conductor pattern, it can be applied to single-sided PWB, double-sided PWB, and multilayer PWB (3 or more layers), from the viewpoint of the type of insulating substrate material, it can be used for rigid PWB, flexible PWB (FPC), and rigid-flexible PWB.

[Example]

As Examples 1 to 6 and Comparative Examples 1 to 5, green foils were manufactured under the manufacturing conditions shown in Table 1, then roughened under the manufacturing conditions shown in Table 2, and then roughened by the manufacturing conditions shown in Table 3. Copper plating is performed on the roughened surface according to the manufacturing conditions to form a rough surface respectively. In Tables 1-3, the processing surface M shows a matte surface (copper precipitation surface), and the processing surface S shows a glossy surface.

[Table 1]

[Table 2]

[table 3]

Various evaluations were performed as described below about each sample of the examples and comparative examples produced as described above.

stylus roughness;

The measurement was performed using a contact roughness meter Surfcorder SE-3C stylus roughness meter manufactured by Kosaka Laboratories Co., Ltd.

Surface area ratio (A/B);

The surface area of the rough surface is measured using a laser microscope. Using LEXT OLS 4000 manufactured by Olympus, the three-dimensional surface area A corresponding to the area B of 257.9×257.9 μm (66524 μm ² in the actual data) of the roughened surface was measured, and the three-dimensional surface area A÷two-dimensional surface area B=area ratio Set in the form of (A/B). The measurement ambient temperature was set at 23 to 25°C.

Kurtosis Sku;

Using the LEXT OLS 4000 three-dimensional surface profile measuring device manufactured by Olympus, the area of 257.9×257.9 μm on the roughened surface of the test material was measured at a resolution of 0.12 μm in plane and 0.01 μm in height. The measurement environment temperature was set at 23 to 25°C.

normal peel strength;

In accordance with JIS C5016 (8.1.6 Measurement (1) method A (90° direction peeling method)), the normal peel strength was measured using a tensile tester Autograph 100.

High temperature bath protrusion;

Copper foil was laminated on a glass-cloth-based epoxy resin plate, and fine-pitch circuits were formed on the copper foil by etching (aqueous ferric chloride solution) to obtain a laminate. Next, this laminate was immersed in a high-temperature bath at 260° C. for 1 minute, and the number of protrusions formed on the surface was measured and converted into the number per 1 m ² .

The evaluation results are shown in Table 4.

[Table 4]

(Evaluation results)

All of Examples 1 to 6 had good adhesion reliability, and no protrusions occurred even when immersed in a high-temperature bath.

In Comparative Examples 1 to 4, although the roughness Rz was all 2.0 μm or less, since the kurtosis Sku of the roughness curve of the rough surface was outside the range of 2 to 4, the adhesion reliability was poor, or a large protrusion.

FIG. 1 shows a SEM observation photograph of the roughened surface of the sample of Example 1. As shown in FIG. FIG. 2 shows a SEM observation photograph of the roughened surface of the sample of Comparative Example 1. As shown in FIG.

Claims (8)

1. a surface-treated electro-deposited copper foil, the roughness Rz of the uneven surface of its Copper Foil using contact pin type roughmeter to determine is less than 2.0 μm, and the kurtosis number Sku of the roughness curve of described uneven surface is 2 ~ 4.

2. surface-treated electro-deposited copper foil as claimed in claim 1, wherein, described roughness Rz is 0.8 ~ 1.8 μm.

3. surface-treated electro-deposited copper foil as claimed in claim 1 or 2, wherein, described kurtosis number Sku is 2.5 ~ 3.5.

4. as claimed any one in claims 1 to 3 surface-treated electro-deposited copper foil wherein, the surface-area A of described uneven surface, is 1.2 ~ 2.0 with the ratio A/B of the area B of gained when overlooking described uneven surface.

5. surface-treated electro-deposited copper foil as claimed in claim 4, wherein, described is 1.3 ~ 1.9 than A/B.

6. the surface-treated electro-deposited copper foil according to any one of claim 1 to 5, its normality stripping strength is more than 0.8kg/cm.

7. a laminated plates, it is surface-treated electro-deposited copper foil according to any one of lamination claim 1 to 6 and resin substrate and forms.

8. a printing distributing board, it is for material with laminated plates according to claim 7.