TWI479958B - Copper foil for printed wiring board and manufacturing method thereof - Google Patents

Description

Copper foil for printed wiring board and method of manufacturing same

The present invention relates to a copper foil for a printed wiring board which is excellent in chemical resistance and adhesion, and a method for producing the same. In particular, a substrate for packaging represented by a BT (double-maleimide triazine) resin impregnated substrate provides a strong peel strength for chemical treatment during fine pattern formation, and can be finely etched. Copper foil and its manufacturing method. Further, in the method of forming a copper pattern by electroless plating after the copper foil is completely etched, a copper foil for a printed wiring board which can greatly improve the peel strength and a method for producing the same are provided.

The copper foil for a semiconductor package substrate is also generally referred to as a copper foil for a printed wiring board, and is usually produced by the following procedure. First, a copper foil is laminated on a substrate such as a synthetic resin under high temperature and high pressure. Next, in order to form a target conductive circuit on a substrate, a circuit equivalent to a circuit is printed on a copper foil using a material such as an etching resistant resin.

Then, the unnecessary portion of the exposed copper foil is removed by etching. After the etching, the printed portion made of a material such as a resin is removed, and a conductive circuit is formed on the substrate. On the formed conductive circuit, the predetermined components are finally soldered to form various printed circuit boards for electronic devices. Finally, it is bonded to a resist or a build up resin substrate. In general, the quality of the copper foil for a printed wiring board is different between the adhesion surface to the resin substrate (so-called rough surface) and the non-adhesive surface (so-called glossy surface), and both must be satisfied.

As a requirement for a glossy surface, it is required to have: (1) good appearance and no oxidative discoloration during storage, (2) good solder wettability, (3) no oxidative discoloration when heated at high temperature, and (4) dense with resist Good sex and so on.

On the other hand, the roughened surface mainly includes (1) no oxidative discoloration during storage, (2) peel strength with the substrate, and high temperature heating, wet processing, welding, chemical treatment, etc., 3) There is no so-called build-up stain or the like which is formed after lamination and etching with the substrate.

Further, in recent years, as the pattern is refined, a low profile of the copper foil is required. Therefore, it is necessary to increase the peel strength of the roughened surface of the copper foil.

In addition, in the electronic devices such as computers and mobile communications, as the speed of communication increases and the capacity increases, the high frequency of electrical signals is progressing, and printed wiring boards and copper foils corresponding thereto are required. When the frequency of the electric signal is more than 1 GHz, the influence of the skin effect of the current flowing only on the surface of the conductor becomes remarkable, and the influence of the current transmission path change and the impedance increase due to the unevenness of the surface cannot be ignored. In this regard, it is also desirable that the surface roughness of the copper foil is small.

In order to cope with the above requirements, a large number of treatment methods are advocated for copper foil for printed wiring boards.

In general, a copper foil for printed wiring board is treated by using a rolled copper foil or an electrolytic copper foil. First, in order to improve the adhesion between the copper foil and the resin (peeling strength), copper and copper oxide are usually applied to the surface of the copper foil. The roughening treatment of the formed fine particles. Then, in order to have heat-resistant and rust-proof properties, a heat-resistant treatment layer (barrier layer) such as brass or zinc is formed. Then, in order to prevent oxidation of the surface during transportation or storage, a rust-preventing treatment such as immersion or electrolytic chromate treatment or electrolytic chromium-zinc treatment is performed to obtain a product.

Among them, in particular, the roughening treatment layer plays a large role in improving the adhesion (peeling strength) between the copper foil and the resin. Conventionally, the roughening treatment is preferably a round (spherical) projection. The rounded protrusions are achieved by inhibiting the development of dendrites. However, the rounded projections are peeled off during etching to cause "falling powder". This phenomenon can be taken for granted. The reason for this is that the contact area between the spherical projections and the copper foil is very small compared to the diameter of the circular (spherical) projections.

In order to avoid this "falling powder" phenomenon, a thin copper plating layer is formed on the projections after the roughening treatment to prevent peeling of the projections (see Patent Document 1). This has the effect of preventing "falling powder", but there is a problem in that the step is increased, and the effect of preventing the "falling powder" from being different depending on the thin copper plating layer.

Further, a technique of forming a needle-shaped tuberculous coating layer composed of an alloy of copper and nickel on a copper foil is known (Patent Document 2). Since the tuberculous coating layer has a needle shape, it is considered that the adhesion strength to the resin is increased as compared with the circular (spherical) protrusion disclosed in Patent Document 1, but the composition is different from the copper foil serving as the base. Copper-nickel alloys have different etching velocities when etching copper circuits. Therefore, there is a problem that is not suitable for stable circuit design.

When a copper foil for a printed wiring board is formed, a heat-resistant rust-preventing treatment layer is usually formed. As an example of a metal or an alloy forming a heat-resistant layer, a plurality of copper foils having a coating layer of Zn, Cu-Ni, Cu-Co, and Cu-Zn have been put into practical use (for example, see Patent Document 3).

Among these, a copper foil having a heat-resistant treatment layer made of Cu-Zn (brass) is formed, and when it is laminated on a printed circuit board made of an epoxy resin or the like, there is no spot of the resin layer, and It has excellent characteristics such as low deterioration of peel strength after high-temperature heating, and therefore is widely used industrially.

A method of forming the heat-resistant treatment layer made of brass is described in detail in Patent Document 4 and Patent Document 5.

A copper foil having such a heat-resistant treatment layer made of brass is formed, and then an etching process is performed to form a printed circuit. Recently, a large amount of hydrochloric acid-based etching liquid has been used in the formation of a printed circuit.

However, if a printed circuit board using a copper foil formed with a heat-resistant treatment layer made of brass is etched with a hydrochloric acid-based etching liquid (for example, CuCl ₂ or FeCl ₃ ), copper other than the printed circuit portion is used. When the foil is not partially removed to form a conductive circuit, the phenomenon of erosion (circuit erosion) at the end of the circuit (edge portion) occurs on both sides of the circuit pattern, thereby causing a problem that the peel strength with the resin substrate is deteriorated.

The phenomenon of the circuit erosion refers to a phenomenon in which an adhesion boundary layer of a copper foil and a resin substrate adhered to the circuit formed by the etching treatment, that is, a heat-resistant rust-preventing treatment layer made of brass, is exposed. After being etched by the above etching liquid, and subsequent water washing is insufficient, the sides which are usually yellow (since formed of brass) are red by etching, and the peeling strength of the portion is remarkably deteriorated. Moreover, if this phenomenon occurs on the entire surface of the circuit pattern, the circuit pattern is peeled off from the substrate and becomes a problem.

According to the above situation, after roughening the surface of the copper foil, rust-preventing treatment of zinc or zinc alloy, and chromate treatment, the decane coupling agent containing a small amount of chromium ions is adsorbed on the surface after the chromate treatment. The hydrochloric acid resistance is improved (refer to Patent Document 7).

Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. Hei 8-236930

Patent Document 2: Japanese Patent No. 3459964

Patent Document 3: Japanese Patent Publication No. 51-35711

Patent Document 4: Japanese Patent Publication No. 54-6701

Patent Document 5: Japanese Patent No. 3306404

Patent Document 6: Japanese Patent Application No. 2002-170827

Patent Document 7: Japanese Patent Laid-Open No. Hei 3-122298

An object of the present invention is to develop a copper foil for a semiconductor package substrate which does not deteriorate other characteristics of the copper foil and avoids the above-described circuit erosion phenomenon. In particular, it is an object of the present invention to provide a copper foil for a printed wiring board which can improve the roughening treatment layer of the copper foil and which can improve the adhesion strength between the copper foil and the resin, and a method for producing the same.

In order to solve the above problems, the inventors of the present invention conducted intensive studies, and as a result, provided the following copper foil for printed wiring boards and a method for producing the same.

1) A copper foil for a printed wiring board, characterized in that it has a thickness of 0.1 to 2.0 μm on at least one side of the copper foil and has a needle-like fine copper roughening particle having a longitudinal to transverse ratio of 1.5 or more. Processing layer.

2) A copper foil for a printed wiring board, which is characterized in that it has a thickness of 0.1 to 2.0 μm on at least one side of the copper foil and has a needle-like fine copper roughened particle having a longitudinal to transverse ratio of 3.0 or more. Processing layer.

(3) The copper foil for a printed wiring board according to the above 1) or 2), wherein the number of the needle-like roughened particles is five or more in a circuit width of 10 μm.

(4) The copper foil for a printed wiring board according to the above 1) or 2), wherein the number of the needle-like roughened particles is 10 or more in a circuit width of 10 μm.

(5) The copper foil for a printed wiring board according to any one of the present invention, wherein the roughened layer has a heat-resistant rust-proof layer containing at least one element selected from the group consisting of zinc, nickel, copper, and phosphorus. A chromate coating layer is provided on the heat-resistant rust-preventing layer, and a decane coupling agent layer is provided on the chromate coating layer.

6) A method for producing a copper foil for a printed wiring board, comprising: using an electrolytic bath comprising at least one of sulfuric acid/copper sulfate containing at least one selected from the group consisting of an alkyl sulfate salt, a tungsten ion, and an arsenic ion; A roughened layer composed of needle-shaped fine copper roughened particles having a diameter of 0.1 to 2.0 μm and a longitudinal and lateral ratio of 1.5 or more is formed on at least one surface of the copper foil.

(7) The method for producing a copper foil for a printed wiring board according to 6), wherein a heat-resistant rust-preventing layer containing at least one element selected from the group consisting of zinc, nickel, copper, and phosphorus is formed on the roughened layer, and then the heat-resistant layer is formed A chromate coating layer is formed on the rust layer, and a decane coupling agent layer is formed on the chromate coating layer.

[Effects of the Invention]

As described above, the copper foil for a printed wiring board of the present invention is not a rounded (spherical) protrusion which is conventionally considered to be a good roughening treatment, and has a needle-like fine roughened particle on at least one side of the copper foil. By. Thereby, the following effects are obtained: the adhesion strength of the copper foil itself to the resin can be improved, and the substrate for packaging can be provided with a chemical treatment for fine pattern formation, which can also increase the peel strength, and the copper foil which can be finely etched and Production method.

In recent years, in the process of fine patterning and high-frequency printing of printed circuits, copper foil for printed circuit (copper foil for semiconductor package substrate) and copper foil for semiconductor package substrate are bonded to resin for semiconductor packaging. The substrate for semiconductor packaging is extremely effective.

Next, the present invention will be specifically and specifically described in order to facilitate the understanding of the present invention. The copper foil used in the present invention may be either an electrolytic copper foil or a rolled copper foil.

As described above, the copper foil for a printed wiring board of the present invention is not a rounded (spherical) projection which is conventionally considered to be excellent in roughening treatment, and is formed into a needle-like fine copper roughening on at least one side of the copper foil. Particles. The shape is a roughened layer having a diameter of 0.1 to 2.0 μm and a ratio of the longitudinal (length) to the transverse (diameter) of 1.5 or more.

Further, it is preferably needle-shaped fine copper roughened particles having a diameter of 0.1 to 2.0 μm and a longitudinal to transverse ratio of 3.0 or more, that is, long roughened particles.

The shape of the copper roughened particles has a shape of a horsetail, and as shown in a microscope photograph to be described later, it is often a bulge. The ratio of the minimum diameter to the maximum diameter is about 1:1 to 1:1.2. This ratio is a factor for further improving the adhesion, and the needle of the above numerical value can sufficiently achieve the object of the present invention.

Further, in the needle-shaped fine copper roughened particles, the diameter is not deviated by 0.1 to 2.0 μm, and the ratio of the longitudinal (length) to the transverse (diameter) is deviated from 1.5 or more, for example, a shorter length or a differently shaped particle. In the case of the resin, if the amount is within 5% of the whole, the adhesion strength between the copper foil itself and the resin is not affected.

In the case where the circuit is formed by etching a copper foil for a printed wiring board, it is preferable that the number of the needle-like roughened particles of the copper is five or more in a circuit width of 10 μm. Thereby, the adhesion strength between the copper foil and the resin can be greatly improved. More preferably, the number of needle-like roughened particles of copper is 10 or more in a circuit width of 10 μm. An electrolytic bath composed of at least one of sulfuric acid/copper sulfate containing at least one selected from the group consisting of an alkyl sulfate salt, a tungsten ion, and an arsenic ion can be used as the roughened layer composed of the acicular fine copper roughened particles. And manufacturing.

In order to prevent falling powder and to improve peeling strength, the roughened layer composed of acicular fine copper roughened particles is preferably subjected to cladding plating using an electrolytic bath composed of sulfuric acid/copper sulfate.

The specific processing conditions are as follows.

(liquid composition 1)

CuSO ₄ ‧5H ₂ O: 39.3 to 118 g/L

Cu: 10 to 30 g/L

H ₂ SO ₄ : 10 to 150 g/L

Na ₂ WO ₄ ‧2H ₂ O: 0 to 90 mg/L

W: 0 to 50 mg/L

Sodium lauryl sulfate: 0-50 mg

H ₃ AsO ₃ (60% aqueous solution): 0 to 6315 mg/L

As: 0 to 2000 mg/L

(plating condition 1)

Temperature: 30 ~ 70 ° C

(current condition 1)

Current density: 25 ~ 110 A / dm ²

Coarse coulomb amount: 50 ~ 500 As / dm ²

Plating time: 0.5 to 20 seconds

(liquid composition 2)

CuSO ₄ ‧5H ₂ O: 78～314 g/L

Cu: 20 to 80 g/L

H ₂ SO ₄ : 50 to 200 g/L

(plating condition 2)

Temperature: 30 ~ 70 ° C

(current condition 2)

Current density: 5 to 50 A/dm ²

Coarse coulomb amount: 50 to 300 As/dm ²

Plating time: 1 to 60 seconds

Further, a heat-resistant rust-preventing layer containing at least one element selected from the group consisting of zinc, nickel, copper, and phosphorus is further formed on the roughened layer, and a chromate film layer is formed on the heat-resistant rust-preventing layer, and the chromium is formed on the rust-resistant layer. A layer of a decane coupling agent is formed on the acid salt film layer to form a copper foil for a printed wiring board.

The heat-resistant rust-preventing layer is not particularly limited, and a conventional heat-resistant rust-proof layer can be used. For example, as the copper foil for a semiconductor package substrate, a conventionally used brass coating layer can be used.

Further, a chromate coating layer and a decane coupling agent layer are formed on the heat-resistant rust-preventing layer to form at least an adhesion surface of the copper foil to the resin. A copper foil layer having a coating layer composed of the chromate coating layer and the decane coupling agent layer is adhered to the resin, and an etching resistive printed circuit is formed on the copper foil, and then the printing is performed by etching. The copper foil other than the circuit portion is not partially removed, thereby forming a conductive circuit.

As the heat-resistant rust-preventing layer, an existing treatment can be used, and specifically, for example, the following can be used.

(liquid composition)

NaOH: 40 ~ 200 g / L

NaCN: 70～250 g/L

CuCN: 50 ~ 200 g / L

Zn(CN) ₂ : 2 to 100 g/L

As ₂ O ₃ : 0.01 to 1 g/L

(liquid temperature)

40～90°C

(current condition)

Current density: 1 to 50 A/dm ²

Plating time: 1 to 20 seconds

The chromate coating layer may be an electrolytic chromate coating layer or an impregnated chromate coating layer. The chromate coating layer preferably has a Cr content of 25 to 150 μg/dm ² .

If the amount of Cr is less than 25 μg/dm ² , there is no rust-proof layer effect. Further, when the amount of Cr exceeds 150 μg/dm ² , the effect is saturated, which is wasteful. Therefore, the amount of Cr should be set to 25 to 150 μg/dm ² .

An example of the conditions for forming the chromate coating layer described below is described below. However, as described above, it is not necessarily limited to this condition, and any of the known chromate treatments can be used. The rust-preventing treatment is one of the factors affecting the acid resistance, and the acid resistance is further improved by the chromate treatment.

(a) impregnated chromate treatment

K ₂ Cr ₂ O ₇ : 1 to 5 g / L, pH: 2.5 to 4.5, temperature: 40 to 60 ° C, time: 0.5 to 8 seconds

(b) electrolytic chromate treatment (chromium zinc treatment (alkaline bath))

K ₂ Cr ₂ O ₇ : 0.2 to 20 g/L, acid: phosphoric acid, sulfuric acid, organic acid, pH: 1.0 to 3.5, temperature: 20 to 40 ° C, current density: 0.1 to 5 A/dm ² , time: 0.5 ~8 seconds

(c) Electrolytic chromium and zinc treatment (alkaline bath)

K ₂ Cr ₂ O ₇ (Na ₂ Cr ₂ O ₇ or CrO ₃ ): 2 to 10 g/L, NaOH or KOH: 10 to 50 g/L, ZnOH or ZnSO ₄ ‧7H ₂ O: 0.05 to 10 g/ L, pH: 7 to 13, bath temperature: 20 to 80 ° C, current density: 0.05 to 5 A / dm ² , time: 5 to 30 seconds

(d) electrolytic chromate treatment (chromium zinc treatment (acid bath))

K ₂ Cr ₂ O ₇ : 2 to 10 g / L, Zn: 0 to 0.5 g / L, Na ₂ SO ₄ : 5 to 20 g / L, pH: 3.5 to 5.0, bath temperature: 20 to 40 ° C, current Density: 0.1 ~ 3.0 A / dm ² , time: 1 ~ 30 seconds

The decane coupling agent layer used in the copper foil for a semiconductor package substrate of the present invention can be a decane coupling agent which is usually used for a copper foil, and is not particularly limited. For example, if the specific conditions of the decane treatment are shown, the following is shown.

0.2% epoxy decane / 0.4% TEOS, pH 5

A tetraalkoxy decane or an alkoxy decane containing one or more functional groups having reactivity with a resin can also be used. The selection of the decane coupling agent layer is also arbitrary, but it can be said that it is preferable to consider the adhesion to the resin.

Example

Next, examples and comparative examples will be described. Furthermore, the present embodiment is a preferred embodiment, and the present invention is not limited to the embodiments. Therefore, variations, other embodiments, or aspects included in the technical idea of the present invention are included in the present invention.

Further, a comparative example is disclosed in comparison with the present invention.

(Example 1)

The rough surface (rough surface: M surface) of the copper foil was subjected to rough plating as described below using an electrolytic copper foil having a thickness of 12 μm. The processing conditions are shown below.

(liquid composition 1)

CuSO ₄ ‧5H ₂ O: 58.9 g/L

Cu: 15 g/L

H ₂ SO ₄ : 100 g/L

As addition amount: 1000 ppm: using H ₃ AsO ₃ (60% aqueous solution)

(plating temperature 1) 50 ° C

(current condition 1)

Current density: 90 A/dm ²

Coarse coulomb amount: 200 As/dm ²

After the roughening treatment, normal plating as shown below was performed. The processing conditions are shown below.

(liquid composition 2)

CuSO ₄ ‧5H ₂ O: 156 g/L

Cu: 40 g/L

H ₂ SO ₄ : 100 g/L

(plating temperature 1) 40 ° C

(current condition 1)

Current density: 30 A/dm ²

Coarse coulomb amount: 150 As/dm ²

The SEM photograph of the roughened layer of Example 1 is shown in Fig. 1. The magnification of the scanning electron microscope (SEM) photograph on the left side shown in Fig. 1 is (×3000), and the magnification of the SEM photograph on the right side is (×30000). As shown in FIG. 1, it is understood that the shape of the particles is formed into a needle shape. The average particle diameter was 0.57 μm, the length of the particles was 1.56 μm, and the ratio of the longitudinal to the transverse direction was 2.7, which satisfied the conditions of the present invention.

Next, a heat-resistant rust-preventing layer is formed on the copper roughened surface. As the condition, a known heat-resistant rust-preventing layer can be used, and in the present embodiment, it is carried out under the following conditions.

(liquid composition)

NaOH: 72 g / L

NaCN: 112 g/L

CuCN: 91.6 g/L (Cu: 65 g/L)

Zn(CN) ₂ : 8.1 g/L (Zn: 4.5 g/L)

As ₂ O ₃ : 0.125 g/L (As: 95 ppm)

(liquid temperature) 76.5 ° C

(current condition)

Current density: 6.7 A/dm ²

Current: 4.0 A

Plating time: 5 seconds

Next, electrolytic chromate treatment is performed on the heat-resistant rustproof layer.

Electrolytic chromate treatment (chromium zinc treatment (acid bath))

Cr ₂ O ₃ : 0.73 g/L

ZnSO ₄ ‧7H ₂ O: 2.46 g/L

Na ₂ SO ₄ : 18 g/L

H ₃ PO ₃ : 0.53 g/L

pH: 4.6, bath temperature: 37 ° C

Current density: 2.06 A/dm ²

Time: 1 to 30 seconds

(pH adjustment is carried out with sulfuric acid or potassium hydroxide)

Next, a decane treatment (by coating) is performed on the chromate coating layer.

The conditions for the treatment of decane are as follows.

0.2% epoxy decane / 0.4% TEOS, pH 5

The copper foil layer produced in the above manner was adhered to a glass cloth substrate BT (bis-butylene diamine ‧ triazine) resin plate, and the following items were measured or analyzed.

(1) Observation of falling powder

No powder was confirmed. The results are shown in Table 1.

(2) Normal peel strength

The normal peel strength is 0.79 kg/cm and has good peel strength. The results are shown in Table 1.

(3) Hydrochloric acid resistance test

Regarding hydrochloric acid resistance, the amount of loss (Loss) in a 0.4 mm circuit after immersion for 90 minutes at 60 ° C using 12 wt% hydrochloric acid is expressed in %. The same is true below. The amount of loss (Loss) was 5%, and the amount of loss (Loss) was small as compared with the comparative example described later, and exhibited good properties. The results are shown in Table 1.

(4) Test results of sulfuric acid-resistant hydrogen peroxide (sulfuric acid 10%, hydrogen peroxide 2%, room temperature: 30 ° C)

Implemented in a 0.4 mm circuit. At this time, the case of etching 2 μm was investigated. The amount of loss (Loss) is expressed in %. The same is true below. The results are shown in Table 1.

As shown in Table 1, the amount of Loss was as small as 6.6%, and the sulfuric acid-resistant hydrogen peroxide was good.

(Example 2)

The rough surface (rough surface: M surface) of the copper foil was subjected to rough plating as shown below and normal plating similar to that of Example 1 using an electrolytic copper foil having a thickness of 12 μm. The roughening plating treatment conditions are shown below.

(liquid composition 1)

CuSO ₄ ‧5H ₂ O: 58.9 g/L

Cu: 15 g/L

H ₂ SO ₄ : 100 g/L

Na ₂ WO ₄ ‧2H ₂ O: 5.4 mg/L

W addition amount: 3 ppm

(plating temperature 1) 50 ° C

(current condition 1)

Current density: 40 A/dm ²

Coarse coulomb amount: 300 As/dm ²

The SEM photograph of the roughened layer of Example 2 is shown in Fig. 2. The magnification of the SEM photograph on the left side shown in Fig. 2 is (×3000), and the magnification of the SEM photograph on the right side is (×30000). As shown in FIG. 2, it is understood that the shape of the particles is formed into a needle shape. The average particle diameter was 0.67 μm, the length of the particles was 1.78 μm, and the ratio of the longitudinal to the transverse direction was 2.7, which satisfied the conditions of the present invention.

Next, a heat-resistant rust-preventing layer similar to that of the first embodiment is formed on the roughened surface of the copper, an electrolytic chromate treatment is performed on the heat-resistant rust-preventing layer, and decane treatment is performed on the chromate coating layer ( By coating).

The copper foil layer produced in the above manner was adhered to a glass cloth substrate BT (Bismaleimide Triazine) resin plate, and the following items were measured or analyzed.

(1) Observation of falling powder

No powder was confirmed. The results are shown in Table 1.

(2) Normal peel strength

The normal peel strength is 0.83 kg/cm and has good peel strength. The results are shown in Table 1.

(3) Hydrochloric acid resistance test

Regarding hydrochloric acid resistance, the amount of loss (Loss) in a 0.4 mm circuit after immersion for 90 minutes at 60 ° C using 12 wt% hydrochloric acid is expressed in %. The same is true below. The amount of loss (Loss) was 2.3%, and the amount of loss (Loss) was small as compared with the comparative example described later, and exhibited good properties. The results are shown in Table 1.

(4) Test results of sulfuric acid-resistant hydrogen peroxide (sulfuric acid 10%, hydrogen peroxide 2%, room temperature: 30 ° C)

Implemented in a 0.4 mm circuit. At this time, the case of etching 2 μm was investigated. The amount of loss (Loss) is expressed in %. The same is true below. The results are shown in Table 1.

As shown in Table 1, the amount of Loss was as low as 4.4%, and the sulfuric acid resistant to sulfuric acid was good.

(Example 3)

The rough surface (rough surface: M surface) of the copper foil was subjected to rough plating as shown below and normal plating similar to that of Example 1 using an electrolytic copper foil having a thickness of 12 μm. The roughening plating treatment conditions are shown below.

(liquid composition 1)

CuSO ₄ ‧5H ₂ O: 58.9 g/L

Cu: 15 g/L

H ₂ SO ₄ : 100 g/L

Sodium lauryl sulfate addition: 10 ppm

(plating temperature 1) 50 ° C

(current condition 1)

Current density: 100 A/dm ²

Coarse coulomb amount: 200 As/dm ²

The SEM photograph of the roughened layer of Example 3 is shown in Fig. 3. The magnification of the SEM photograph on the left side shown in Fig. 3 is (×3000), and the magnification of the SEM photograph on the right side is (×30000). As shown in Fig. 3, it is understood that although the shape is slightly closer to the spherical shape, the shape of the needle-like particles is maintained. The average particle diameter was 0.6 μm, the length of the particles was 1.5 μm, and the ratio of the longitudinal to the transverse was 2.5, which satisfied the conditions of the present invention.

Next, a heat-resistant rust-preventing layer similar to that of the first embodiment is formed on the roughened surface of the copper, an electrolytic chromate treatment is performed on the heat-resistant rust-preventing layer, and decane treatment is performed on the chromate coating layer ( By coating).

The copper foil layer produced in the above manner was adhered to a glass cloth substrate BT (Bismaleimide Triazine) resin plate, and the following items were measured or analyzed.

(1) Observation of falling powder

No powder was confirmed. The results are shown in Table 1.

(2) Normal peel strength

The normal peel strength is 0.75 kg/cm and has good peel strength. The results are shown in Table 1.

(3) Hydrochloric acid resistance test

Regarding hydrochloric acid resistance, the amount of loss (Loss) in a 0.4 mm circuit after immersion for 90 minutes at 60 ° C using 12 wt% hydrochloric acid is expressed in %. The same is true below. The amount of loss (Loss) was 7.8%, and the amount of loss (Loss) was small as compared with the comparative example described later, and exhibited good properties. The results are shown in Table 1.

(4) Test results of sulfuric acid-resistant hydrogen peroxide (sulfuric acid 10%, hydrogen peroxide 2%, room temperature: 30 ° C)

Implemented in a 0.4 mm circuit. At this time, the case of etching 2 μm was investigated. The amount of loss (Loss) is expressed in %. The same is true below. The results are shown in Table 1.

As shown in Table 1, the amount of Loss was as small as 8.7%, and the sulfuric acid-resistant hydrogen peroxide was good.

(Example 4)

The rough surface (rough surface: M surface) of the copper foil was subjected to rough plating as shown below and normal plating similar to that of Example 1 using an electrolytic copper foil having a thickness of 12 μm. The roughening plating treatment conditions are shown below.

(liquid composition 1)

CuSO ₄ ‧5H ₂ O: 58.9 g/L

Cu: 15 g/L

H ₂ SO ₄ : 100 g/L

Na ₂ WO ₄ ‧2H ₂ O: 5.4 mg/L

W: 3 ppm

As: 150 ppm (using H ₃ AsO ₃ (60% in water))

(plating temperature 1) 50 ° C

(current condition 1)

Current density: 90 A/dm ²

Coarse coulomb amount: 200 As/dm ²

The SEM photograph of the roughened layer of Example 4 is shown in Fig. 4. The magnification of the SEM photograph on the left side shown in Fig. 4 is (×3000), and the magnification of the SEM photograph on the right side is (×30000). As shown in FIG. 4, it is understood that the shape of the particles is formed into a needle shape. The average particle diameter was 0.59 μm, the length of the particles was 1.9 μm, and the ratio of the longitudinal to the transverse direction was 3.2, which satisfied the conditions of the present invention.

Next, a heat-resistant rust-preventing layer similar to that of the first embodiment is formed on the roughened surface of the copper, an electrolytic chromate treatment is performed on the heat-resistant rust-preventing layer, and decane treatment is performed on the chromate coating layer ( By coating).

The copper foil layer produced in the above manner was adhered to a glass cloth substrate BT (Bismaleimide Triazine) resin plate, and the following items were measured or analyzed.

(1) Observation of falling powder

No powder was confirmed. The results are shown in Table 1.

(2) Normal peel strength

The normal peel strength is 0.82 kg/cm and has good peel strength. The results are shown in Table 1.

(3) Hydrochloric acid resistance test

Regarding hydrochloric acid resistance, the amount of loss (Loss) in a 0.4 mm circuit after immersion for 90 minutes at 60 ° C using 12 wt% hydrochloric acid is expressed in %. The same is true below. The amount of loss (Loss) was 4.3%, and the amount of loss (Loss) was small as compared with the comparative example described later, and exhibited good properties. The results are shown in Table 1.

(4) Test results of sulfuric acid-resistant hydrogen peroxide (sulfuric acid 10%, hydrogen peroxide 2%, room temperature: 30 ° C)

Implemented in a 0.4 mm circuit. At this time, the case of etching 2 μm was investigated. The amount of loss (Loss) is expressed in %. The same is true below. The results are shown in Table 1.

As shown in Table 1, the amount of Loss was as small as 6.8%, and the sulfuric acid-resistant hydrogen peroxide was good.

(Example 5)

The rough surface (rough surface: M surface) of the copper foil was subjected to rough plating as shown below and normal plating similar to that of Example 1 using an electrolytic copper foil having a thickness of 12 μm. The roughening plating treatment conditions are shown below.

(liquid composition)

CuSO ₄ ‧5H ₂ O: 58.9 g/L

Cu: 15 g/L

H ₂ SO ₄ : 100 g/L

Sodium lauryl sulfate addition: 10 ppm

As addition amount: 1000 ppm: using H ₃ AsO ₄ (60% aqueous solution)

(plating temperature) 50 ° C

(current condition)

Current density: 40 A/dm ²

Coarse coulomb amount: 240 As/dm ²

The SEM photograph of the roughened layer of Example 5 is shown in Fig. 5. The magnification of the SEM photograph on the left side shown in Fig. 5 is (×3000), and the magnification of the SEM photograph on the right side is (×30000). As shown in FIG. 5, it is understood that the shape of the particles is formed into a needle shape. The average particle diameter was 0.72 μm, the length of the particles was 1.93 μm, and the ratio of the longitudinal to the transverse direction was 2.7, which satisfied the conditions of the present invention.

Next, a heat-resistant rust-preventing layer similar to that of the first embodiment is formed on the roughened surface of the copper, an electrolytic chromate treatment is performed on the heat-resistant rust-preventing layer, and decane treatment is performed on the chromate coating layer ( By coating).

The copper foil layer produced in the above manner was adhered to a glass cloth substrate BT (Bismaleimide Triazine) resin plate, and the following items were measured or analyzed.

(1) Observation of falling powder

No powder was confirmed. The results are shown in Table 1.

(2) Normal peel strength

The normal peel strength is 0.83 kg/cm and has good peel strength. The results are shown in Table 1.

(3) Hydrochloric acid resistance test

Regarding hydrochloric acid resistance, the amount of loss (Loss) in a 0.4 mm circuit after immersion for 90 minutes at 60 ° C using 12 wt% hydrochloric acid is expressed in %. The same is true below. The amount of loss (Loss) was 4.6%, and the amount of loss (Loss) was small as compared with the comparative example described later, and exhibited good properties. The results are shown in Table 1.

(4) Test results of sulfuric acid-resistant hydrogen peroxide (sulfuric acid 10%, hydrogen peroxide 2%, room temperature: 30 ° C)

Implemented in a 0.4 mm circuit. At this time, the case of etching 2 μm was investigated. The amount of loss (Loss) is expressed in %. The same is true below. The results are shown in Table 1.

As shown in Table 1, the amount of Loss was as small as 7.5%, and the sulfuric acid-resistant hydrogen peroxide was good.

(Example 6)

The rough surface (rough surface: M surface) of the copper foil was subjected to rough plating as shown below and normal plating similar to that of Example 1 using an electrolytic copper foil having a thickness of 12 μm. The roughening plating treatment conditions are shown below.

(liquid composition 1)

CuSO ₄ ‧5H ₂ O: 58.9 g/L

Cu: 15 g/L

H ₂ SO ₄ : 100 g/L

Na ₂ WO ₄ ‧2H ₂ O: 5.4 mg/L

W: 3 ppm

Sodium lauryl sulfate addition: 10 ppm

(plating temperature 1) 50 ° C

(current condition 1)

Current density: 100 A/dm ²

Coarse coulomb amount: 200 As/dm ²

The SEM photograph of the roughened layer of Example 6 is shown in Fig. 6. The magnification of the SEM photograph on the left side shown in Fig. 6 is (×3000), and the magnification of the SEM photograph on the right side is (×30000). As shown in FIG. 6, it is understood that the shape of the particles is formed into a needle shape. The average particle diameter was 0.48 μm, the length of the particles was 1.6 μm, and the ratio of vertical to horizontal was 3.3, which satisfied the conditions of the present invention.

Next, a heat-resistant rust-preventing layer similar to that of the first embodiment is formed on the roughened surface of the copper, an electrolytic chromate treatment is performed on the heat-resistant rust-preventing layer, and decane treatment is performed on the chromate coating layer ( By coating).

The copper foil layer produced in the above manner was adhered to a glass cloth substrate BT (Bismaleimide Triazine) resin plate, and the following items were measured or analyzed.

(1) Observation of falling powder

No powder was confirmed. The results are shown in Table 1.

(2) Normal peel strength

The normal peel strength is 0.83 kg/cm and has good peel strength. The results are shown in Table 1.

(3) Hydrochloric acid resistance test

Regarding hydrochloric acid resistance, the amount of loss (Loss) in a 0.4 mm circuit after immersion for 90 minutes at 60 ° C using 12 wt% hydrochloric acid is expressed in %. The same is true below. The amount of loss (Loss) was 3.9%, and the amount of loss (Loss) was small as compared with the comparative example described later, and exhibited good properties. The results are shown in Table 1.

(4) Test results of sulfuric acid-resistant hydrogen peroxide (sulfuric acid 10%, hydrogen peroxide 2%, room temperature: 30 ° C)

Implemented in a 0.4 mm circuit. At this time, the case of etching 2 μm was investigated. The amount of loss (Loss) is expressed in %. The same is true below. The results are shown in Table 1.

As shown in Table 1, the amount of Loss was 5.2%, and the sulfuric acid-resistant hydrogen peroxide was good.

(Example 7)

The rough surface (rough surface: M surface) of the copper foil was subjected to rough plating as shown below and normal plating similar to that of Example 1 using an electrolytic copper foil having a thickness of 12 μm. The roughening plating treatment conditions are shown below.

(liquid composition 1)

CuSO ₄ ‧5H ₂ O: 58.9 g/L

Cu: 15 g/L

H ₂ SO ₄ : 100 g/L

Na ₂ WO ₄ ‧2H ₂ O: 5.4 mg/L

W: 3 ppm

Sodium lauryl sulfate addition: 10 ppm

As addition amount: 150 ppm: using H ₃ AsO ₃ (60% aqueous solution)

(plating temperature 1) 50 ° C

(current condition 1)

Current density: 80 A/dm ²

Coarse coulomb amount: 280 As/dm ²

The SEM photograph of the roughened layer of Example 7 is shown in Fig. 7. The magnification of the SEM photograph on the left side shown in Fig. 7 is (×3000), and the magnification of the SEM photograph on the right side is (×30000). As shown in FIG. 7, it is understood that the shape of the particles is formed into a needle shape. The average particle diameter was 0.55 μm, the length of the particles was 1.7 μm, and the ratio of the longitudinal to the transverse direction was 3.1, which satisfied the conditions of the present invention.

Next, a heat-resistant rust-preventing layer similar to that of the first embodiment is formed on the roughened surface of the copper, an electrolytic chromate treatment is performed on the heat-resistant rust-preventing layer, and decane treatment is performed on the chromate coating layer ( By coating).

The copper foil layer produced in the above manner was adhered to a glass cloth substrate BT (Bismaleimide Triazine) resin plate, and the following items were measured or analyzed.

(1) Observation of falling powder

No powder was confirmed. The results are shown in Table 1.

(2) Normal peel strength

The normal peel strength is 0.85 kg/cm and has good peel strength. The results are shown in Table 1.

(3) Hydrochloric acid resistance test

Regarding hydrochloric acid resistance, the amount of loss (Loss) in a 0.4 mm circuit after immersion for 90 minutes at 60 ° C using 12 wt% hydrochloric acid is expressed in %. The same is true below. The amount of loss (Loss) was 1.6%, and the amount of loss (Loss) was small as compared with the comparative example described later, and exhibited good properties. The results are shown in Table 1.

(4) Test results of sulfuric acid-resistant hydrogen peroxide (sulfuric acid 10%, hydrogen peroxide 2%, room temperature: 30 ° C)

Implemented in a 0.4 mm circuit. At this time, the case of etching 2 μm was investigated. The amount of loss (Loss) is expressed in %. The same is true below. The results are shown in Table 1.

As shown in Table 1, the amount of Loss was as low as 4.5%, and the sulfuric acid-resistant hydrogen peroxide was good.

(Comparative Example 1)

The rough surface (rough surface: M surface) of the copper foil was subjected to rough plating as shown below and normal plating similar to that of Example 1 using an electrolytic copper foil having a thickness of 12 μm. The roughening plating treatment conditions are shown below. At this time, the additive of the present invention is not used.

(liquid composition)

CuSO ₄ ‧5H ₂ O: 58.9 g/L

Cu: 15 g/L

H ₂ SO ₄ : 100 g/L

(plating temperature) 50 ° C

(current condition)

Current density: 90 A/dm ²

Coarse coulomb amount: 200 As/dm ²

The SEM photograph of the roughened layer of Comparative Example 1 is shown in Fig. 8. The magnification of the SEM photograph on the left side shown in Fig. 8 is (×3000), and the magnification of the SEM photograph on the right side is (×30000). As shown in FIG. 8, it is understood that the shape of the particles is formed into a dendritic crystal. The average particle diameter was 5 μm, the length of the particles was 25 μm, and the ratio of the longitudinal to the transverse direction was 5.0, which satisfied the conditions of the present invention.

Next, a heat-resistant rust-preventing layer similar to that of the first embodiment is formed on the roughened surface of the copper, an electrolytic chromate treatment is performed on the heat-resistant rust-preventing layer, and decane treatment is performed on the chromate coating layer ( By coating).

The copper foil layer produced in the above manner was adhered to a glass cloth substrate BT (Bismaleimide Triazine) resin plate, and the following items were measured or analyzed.

(1) Observation of falling powder

In Comparative Example 1, it was confirmed that the powder was dropped. The results are shown in Table 1.

(2) Normal peel strength

The normal peel strength was 0.58 kg/cm, and the peel strength was low. The results are shown in Table 1.

(3) Hydrochloric acid resistance test

Regarding hydrochloric acid resistance, the amount of loss (Loss) in a 4 mm circuit after immersion for 90 minutes at 60 ° C using 12 wt% hydrochloric acid is expressed in %. The same is true below. The amount of loss (Loss) was 32.4%, and the amount of loss (Loss) was small as compared with the comparative example described later, and exhibited good properties. The results are shown in Table 1.

(4) Test results of sulfuric acid-resistant hydrogen peroxide (sulfuric acid 10%, hydrogen peroxide 2%, room temperature: 30 ° C)

Implemented in a 0.4 mm circuit. At this time, the case of etching 2 μm was investigated. The amount of loss (Loss) is expressed in %. The results are shown in Table 1.

As shown in Table 1, the amount of Loss is as much as 31%, and the resistance to sulfuric acid hydrogen peroxide is poor.

(Comparative Example 2)

The rough surface (rough surface: M surface) of the copper foil was subjected to rough plating as shown below and normal plating similar to that of Example 1 using an electrolytic copper foil having a thickness of 12 μm. The roughening plating treatment conditions are shown below.

(liquid composition)

CuSO ₄ ‧5H ₂ O: 58.9 g/L

Cu: 15 g/L

H ₂ SO ₄ : 100 g/L

As addition amount: 150 ppm: using H ₃ AsO ₃ (60% aqueous solution)

(plating temperature) 50 ° C

(current condition)

Current density: 40 A/dm ²

Coarse coulomb amount: 240 As/dm ²

The SEM photograph of the roughened layer of Comparative Example 2 is shown in Fig. 8. The magnification of the SEM photograph on the left side shown in Fig. 8 is (×3000), and the magnification of the SEM photograph on the right side is (×30000). As shown in FIG. 8, it is understood that the shape of the particles is formed into a spherical shape. The average particle diameter was 1.3 μm, the length of the particles was 1.8 μm, and the ratio of the longitudinal to the transverse direction was 1.4, which did not satisfy the conditions of the present invention.

Next, a heat-resistant rust-preventing layer similar to that of the first embodiment is formed on the roughened surface of the copper, an electrolytic chromate treatment is performed on the heat-resistant rust-preventing layer, and decane treatment is performed on the chromate coating layer ( By coating).

The copper foil layer produced in the above manner was adhered to a glass cloth substrate BT (Bismaleimide Triazine) resin plate, and the following items were measured or analyzed.

(1) Observation of falling powder

No powder was confirmed. The results are shown in Table 1.

(2) Normal peel strength

The normal peel strength is 0.82 kg/cm and has good peel strength. The results are shown in Table 1.

(3) Hydrochloric acid resistance test

Regarding hydrochloric acid resistance, the amount of loss (Loss) after immersion for 90 minutes at 60 ° C using 12 wt% hydrochloric acid is expressed in %. The same is true below. The amount of loss (Loss) was 20%, and the amount of loss (Loss) was small as compared with the comparative example described later, and exhibited good properties. The results are shown in Table 1.

(4) Test results of sulfuric acid-resistant hydrogen peroxide (sulfuric acid 10%, hydrogen peroxide 2%, room temperature: 30 ° C)

Implemented in a 0.4 mm circuit. At this time, the case of etching 2 μm was investigated. The amount of loss (Loss) is expressed in %. The same is true below. The results are shown in Table 1.

As shown in Table 1, the amount of Loss is as much as 15%, and the resistance to sulfuric acid hydrogen peroxide is poor.

As described above, the copper foil for a printed wiring board of the present invention is not a rough (spherical) protrusion or a dendritic crystal grain size which is conventionally considered to be excellent in roughening treatment, and is used in copper foil. Since the needle-shaped fine roughened particles are formed on at least one side, the adhesive film has the excellent effect of improving the adhesion strength between the copper foil itself and the resin, and the chemical treatment for forming the fine pattern on the substrate for packaging can also increase the peel strength. And a copper foil which can be finely etched and a method of manufacturing the same.

As described above, the present invention has an excellent effect of forming the needle-like fine roughened particles on at least one side of the copper foil, thereby improving the adhesion strength between the copper foil itself and the resin, and providing the package substrate with a fine pattern formation. The chemical treatment can also increase the peel strength, and can perform fine etching of the copper foil and a method of manufacturing the same.

In recent years, in the process of fine patterning and high-frequency development of printed circuits, copper foil for printed circuit (copper foil for semiconductor package substrate) and copper foil for semiconductor package substrate are bonded to resin for semiconductor packaging. The substrate for semiconductor packaging is extremely effective.

Figure 1 is a SEM photograph of the roughened layer of Example 1.

2 is a SEM photograph of the roughened layer of Example 2.

Figure 3 is a SEM photograph of the roughened layer of Example 3.

Figure 4 is a SEM photograph of Example 4.

Figure 5 is a SEM photograph of the roughened layer of Example 5.

Figure 6 is a SEM photograph of Example 6.

Figure 7 is a SEM photograph of the roughened layer of Example 7.

Fig. 8 is a SEM photograph of the roughened layer of Comparative Example 1.

Figure 9 is a SEM photograph of the roughened layer of Comparative Example 2.

Claims (13)

A copper foil for a printed wiring board, characterized in that it has a roughening treatment of at least one surface of a copper foil, which is composed of needle-shaped fine copper roughened particles having a diameter of 0.1 to 2.0 μm and a vertical to horizontal ratio of 1.5 or more. Floor. A copper foil for a printed wiring board, characterized in that the copper foil has a roughening treatment composed of needle-shaped fine copper roughened particles having a diameter of 0.1 to 2.0 μm and a vertical to horizontal ratio of 3.0 or more on at least one side of the copper foil. Floor. The copper foil for a printed wiring board according to the first aspect of the invention, wherein the number of the needle-like roughened particles is five or more in a circuit width of 10 μm. The copper foil for a printed wiring board according to the second aspect of the invention, wherein the number of the needle-like roughened particles is five or more in a circuit width of 10 μm. The copper foil for a printed wiring board according to the first aspect of the invention, wherein the number of the needle-like roughened particles is 10 or more in a circuit width of 10 μm. The copper foil for a printed wiring board according to the second aspect of the invention, wherein the number of the needle-like roughened particles is 10 or more in a circuit width of 10 μm. The copper foil for a printed wiring board according to any one of claims 1 to 6, wherein the roughened layer has heat-resistant rust containing at least one element selected from the group consisting of zinc, nickel, copper, and phosphorus. The layer has a chromate coating layer on the heat-resistant rust-preventing layer, and a decane coupling agent layer is provided on the chromate coating layer. A method for producing a copper foil for a printed wiring board, comprising: using an electrolytic bath comprising at least one of sulfuric acid/copper sulfate containing at least one selected from the group consisting of alkyl sulfate salts, tungsten ions, and arsenic ions; At least one side of the copper foil is formed to have a diameter of 0.1 to 2.0 μm and a vertical to horizontal ratio of 1.5 or more. A roughened layer composed of acicular fine copper roughened particles. The method for producing a copper foil for a printed wiring board according to the eighth aspect of the invention, wherein the heat-treated rust-preventing layer containing at least one element selected from the group consisting of zinc, nickel, copper, and phosphorus is formed on the roughened layer, and then A chromate coating layer is formed on the heat-resistant rust-preventing layer, and a decane coupling agent layer is formed on the chromate coating layer. A copper clad laminate is produced by using a copper foil for a printed wiring board according to any one of claims 1 to 5. A printed wiring board produced by using a copper foil for a printed wiring board according to any one of claims 1 to 5. A substrate for packaging is produced by using a copper foil for a printed wiring board according to any one of claims 1 to 5. An electronic machine using the printed wiring board of claim 11 of the patent application.