KR20120084784A - Copper foil including resistive film layer - Google Patents

Abstract

A copper-zinc alloy layer having a zinc content of 1000 to 9000 µg / dm ² per unit area on the rough surface or gloss surface of the copper foil, and on the copper-zinc alloy layer at least The copper foil with an electrical resistance film layer which forms the stabilization layer which has a thickness between 5 GPa and 100 GPa which consists of one component, and is provided with the film layer which consists of an electrical resistance material on the said stabilization layer. This invention provides the copper foil which has a resistive film layer which made the board | substrate embedding of resistance possible by further providing an electrical resistive film layer in copper foil, and improved the adhesiveness.

Description

Copper foil with a resistive layer {COPPER FOIL INCLUDING RESISTIVE FILM LAYER}

This invention is excellent in the adhesiveness of a film | membrane, and relates to the copper foil provided with the resistive film layer with high peeling strength.

Copper foil is generally used as a wiring material of a printed circuit board. This copper foil is divided into electrolytic copper foil and rolled copper foil by the manufacturing method. This copper foil can arbitrarily adjust the range from the very thin copper foil of 5 micrometers to the thick copper foil of about 140 micrometers.

These copper foils are bonded to the board | substrate which consists of resins, such as epoxy and a polyimide, and are used as a board | substrate for printed circuits. The copper foil is required to sufficiently secure the adhesive strength with the resin serving as the substrate. For this reason, the electrolytic copper foil uses a rough surface called a mat surface generally formed at the time of milling, and further The surface roughening process is used on it. Moreover, a rolled copper foil is also used by giving a roughening process to the surface similarly.

In recent years, forming the thin film layer which consists of an electrical resistance material further on copper foil which is wiring material is proposed (refer patent document 1, 2). Although an electrical resistance element is indispensable for an electronic circuit board, when copper foil provided with a resistance layer is used, you may only expose a resistance element to the electrical resistance film layer formed in copper foil using etching solution, such as a cupric chloride.

Therefore, the substrate embedding of the resistance enables effective use of the limited surface area of the substrate as compared with the conventional method of surface mounting the chip resistance element on the substrate using the solder bonding method as in the prior art.

In addition, design constraints by forming a resistance element inside the multilayer substrate are reduced, and the circuit length can be shortened, thereby improving the electrical characteristics. Therefore, when the copper foil provided with the resistance layer is used, solder bonding becomes unnecessary or greatly reduced, and weight reduction and reliability improvement are attained. Thus, the board | substrate with which an electric resistance film was built | formed has many advantages.

The copper foil used as the base used for these resistive materials is surface-treated on the premise that a resistive layer is further formed thereon, and is usually different from that for general printed circuit board wiring. The point of securing the adhesive strength of is the same.

In evaluating the adhesive strength of the resistive material, it is necessary to examine both the strength between the copper foil and the resistive film and the strength between the resistive film and the resin. Happens. In any case, the larger the surface roughness, the higher the adhesive strength. Adhesive strength can be considered to be influenced by factors such as surface roughness and other surface chemical species (element species).

On the other hand, it is required to suppress the surface roughness of the resistive material due to the formation of a better microresistance circuit and the improvement of the high frequency characteristics, which are required as a printed circuit board which is continuously improved in performance. In order to realize this, improvement of the adhesive strength which does not depend on surface roughness becomes indispensable.

Patent Document 1 Japanese Patent No. 3311338 Patent Document 2 Japanese Patent No. 352557

This invention provides the copper foil which has a resistance film layer which made the board | substrate embedding of resistance possible, and improved the adhesiveness by providing an electrical resistance film layer further on copper foil.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, the present inventors acquired the knowledge that it is effective to form the layer which raises the adhesive force between copper foil and an electrical resistance film layer.

On the basis of this finding,

1) A copper-zinc alloy layer having a zinc content of 1000 to 9000 µg / dm ² per unit area on the rough surface or gloss surface of the copper foil, comprising zinc oxide, chromium oxide, and nickel oxide on the copper-zinc alloy layer It provides the copper foil provided with the electrical resistance film layer which forms the stabilization layer which has a thickness between 5 kPa and 100 kPa which consists of at least 1 selected component, and is provided with the film layer which consists of an electrical resistance material on the said stabilization layer.

When using the copper foil provided with an electrical resistance film layer as a film for circuit boards, the copper foil is provided with the stabilization layer which consists of at least 1 component selected from zinc oxide, chromium oxide, and nickel oxide, and further an electrical resistance layer is formed on it. When formed, it is thought that sufficient adhesive strength with copper foil is obtained. However, when the roughness copper foil which lowered the roughening level was used for the copper foil used as a base, the problem that adhesive force may not be enough arises.

In order to improve this, it was found that forming a copper-zinc alloy layer having a zinc content of 1000 to 9000 µg / dm ² per unit area before forming the stabilization layer is effective. The improvement of the adhesive force between the copper foil and the copper-zinc alloy layer and the stabilization layer, and the electrical resistance film layer can be evaluated by the peel strength.

If necessary, a copper-zinc alloy layer having a zinc content of 1000 to 9000 µg / dm ² per unit area is formed on the surface of the copper foil subjected to such surface treatment. This process is an important process for improving adhesive strength. In the copper-zinc alloy layer whose zinc content per unit area is less than 1000 µg / dm ² , the adhesive strength does not improve. In addition, in the copper-zinc alloy layer whose zinc content per unit area exceeds 9000 µg / dm ² , since chemical resistance (corrosion by etching solution) is poor, it is not preferable. This is because the inclusion of a large amount of zinc causes a problem of lowering the corrosion resistance.

This copper-zinc alloy layer can be formed by electroplating. The zinc content of the copper-zinc alloy in electroplating is arbitrary. That is, after electroplating, zinc contains the layer which spread | diffused in copper foil. What is necessary is just to become a copper-zinc alloy layer whose zinc content per unit area is 1000-9000 microgram / dm <^2> . As a result, the thickness of a copper- zinc alloy layer corresponds to the range of about 100-1200 GPa.

On the copper-zinc alloy layer thus formed, a stabilization layer having a thickness between 5 Pa and 100 Pa consisting of at least one component selected from zinc oxide, chromium oxide and nickel oxide is formed.

As mentioned above, this stabilization layer has the effect, although it has a limit to the effect, and also improves adhesiveness with copper foil.

Zinc oxide, chromium oxide, and nickel oxide are all effective as stabilizing layers, and they can also be used in combination. This stabilization layer prevents oxidative corrosion of copper foil, prevents decomposition of the dielectric substrate by copper, and has a function of maintaining stable peel strength. The thickness is usually between 5 kPa and 100 kPa, but may be set to a thickness of 100 kPa or more, that is, 200 to 300 kPa, as necessary. However, if it is less than 5 GPa, since it cannot play a role as a stabilization layer, and also adhesive force falls, it is not preferable.

An electrical resistive film layer is formed on the stabilization layer thus formed. The electrical resistive film layer is arbitrarily determined according to the circuit design. That is, the selection of the type and film thickness of the electrical resistance material is determined in consideration of the function of the resistance element, and there is no particular limitation.

As an example used as a material of an electrical resistance element, materials, such as vanadium, tungsten, zirconium, molybdenum, tantalum, nickel, chromium, are mentioned, for example. Thus, as long as it is a metal with a comparatively high electrical resistance, it can use as an independent film | membrane or an alloy film with another element, respectively.

Moreover, even if it is a material with comparatively low electrical resistances, such as aluminum, silicon, copper, iron, indium, zinc, and tin, as long as it is a material which becomes high in electrical resistance by alloying it with another element, it can be used naturally.

For example, electric resistance elements, such as NiCr alloy and NiCrAlSi alloy, are attracting attention. Further, material oxides, nitrides, and silicides selected from the group of oxides, nitrides, and silicides of the above elements can also be used. As mentioned above, it will be understood that the selection of these materials is arbitrarily selected according to the circuit design, and is not limited to these materials.

At the time of formation of this electrical resistive film layer, physical surface treatment methods such as sputtering, vacuum deposition, ion beam plating, etc., chemical surface treatments such as pyrolysis and gas phase reaction, or wet surface treatments such as electroplating and electroless plating It can form using.

In general, there is an advantage that the electroplating method can be produced at low cost.

In addition, the sputtering method has an advantage that a resistive element of high quality can be obtained because the thickness of the film is uniform and isotropic.

Formation of this electrical resistive film layer is formed according to the use of a film | membrane, and it can be said that it is preferable to select suitably the adhesion method or plating method in that case according to the property of the electrical resistive film layer.

Copper foil provided with the resistive film layer of this invention,

2) Copper foil whose thickness is 5-70 micrometers, especially 5-35 micrometer copper foil can be used. Although the thickness of this copper foil can be arbitrarily selected according to a use, there exists a restriction which comes from manufacturing conditions, and it is efficient to manufacture in said range.

3) Moreover, this invention provides the copper foil which provided the electrical resistance layer on the mat surface (rough surface) of electrolytic copper foil or the surface which performed the roughening process of rolled copper foil.

The roughening process which attaches a grainy bump-shaped particle further to the mat surface of electrolytic copper foil can also be performed. Moreover, the roughening process with respect to a rolled copper foil can also be given as needed. By the said roughening process, roughening surfaces, such as low profile copper foil of Rz 0.3-10.0 micrometers or a standard profile, can be obtained.

By using the copper foil incorporating the electrical resistance film layer of the present invention, it is not necessary to newly form an electrical resistance element alone in the circuit design, and the etching solution such as cupric chloride is used for the electrical resistance film layer formed on the copper foil. In this case, since the resistive element may be exposed only, the solder joint becomes unnecessary or greatly reduced, and the mounting process is considerably simplified.

Moreover, as a result of reducing the number of mounting parts and solders, there is an advantage that the space can be expanded and the weight becomes small and light. This can improve the degree of freedom in circuit design. Moreover, since a resistor is built into a copper foil in this way, the signal characteristic in a high frequency range is improved.

Moreover, this invention can improve the fall of the adhesive force which is a fault with the copper foil incorporating such an electrical resistance film layer, and has the outstanding effect that it is equipped with favorable heat resistance and acid resistance.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the outline | summary of the electrolytic copper foil manufacturing apparatus.
2 is a diagram illustrating an outline of a surface treatment apparatus.

Carrying out the invention  Best form for

The outline | summary of the manufacturing apparatus of an electrolytic copper foil is shown in FIG. In this apparatus, a negative electrode drum is provided in an electrolytic cell containing an electrolyte solution. This cathode drum 1 is made to rotate in the state partially immersed in electrolyte solution (almost half of lower part).

An insoluble anode (anode) 2 is formed so as to surround half of the outer circumferential lower portion of the negative electrode drum 1. There is a constant gap 3 between the cathode drum 1 and the anode 2, and the electrolyte solution flows therebetween. Two anode plates are arranged in this apparatus.

In this apparatus, an electrolyte is supplied from below, and this electrolyte flows through the gap 3 between the cathode drum 1 and the anode 2, overflows from the upper edge of the anode 2, and the electrolyte is circulated. Consists of. A predetermined voltage can be maintained between the cathode drum 1 and the anode 2 via a rectifier.

As the negative electrode drum 1 rotates, the copper electrodeposited from the electrolytic solution increases its thickness, and when the thickness becomes more than a predetermined thickness, the raw foil 4 is peeled off and wound continuously. The raw foil produced in this way adjusts thickness according to the distance between the negative electrode drum 1 and the anode 2, the flow rate of the supplied electrolyte solution, or the amount of electricity to be supplied.

As for the copper foil manufactured by such a copper foil manufacturing apparatus, the surface which contacts a cathode drum becomes a mirror surface (glossy surface), but the surface on the opposite side becomes a rough surface (matt surface) with an unevenness | corrugation. The thickness of this electrolytic copper foil can be selected arbitrarily. Usually, 9 micrometers-35 micrometers thick copper foil can be used.

The copper foil produced in this way is next subjected to the cleaning process of removing the oxide film of a surface, and also performs the washing process with water. In a cleaning process, 10-80 g / l sulfuric acid aqueous solution is used normally.

In the above, although manufacture of electrolytic copper foil was demonstrated, about rolled copper foil, the melted and cast ingot can be annealed, hot-rolled, cold-rolled, and can be manufactured as copper foil of a required thickness. Since all the rolled copper foil is a gloss surface, a roughening process is performed as needed. This roughening process can use the well-known roughening process.

An example of the roughening process is as follows. Moreover, this roughening process is applicable also to the gloss surface and mat surface (rough surface) of electrolytic copper foil.

Cu ion concentration: 10 to 30 g / l

Sulfuric acid concentration: 20 to 100 g / l

Electrolytic solution temperature: 20-60 degreeC

Current density: 5 to 80 A / dm ²

Treatment time: 0.5 to 30 seconds

The zinc-copper alloy plating treatment is performed on the electrolytic copper foil or the rolled copper foil thus produced. This zinc-copper alloy plating process bath composition and electroplating conditions are as follows.

(Zinc-copper alloy plating bath performance and processing conditions)

Bathtub

CuCN: 60 to 120 g / ℓ

Zn (CN) ₂ : 1-10 g / l

NaOH: 40-100 g / l

Na (CN): 10 to 30 g / l

pH: 10 to 13

Bath temperature: 60 to 80 ℃

Current density: 100 to 10000 A / dm ²

Processing time: 2 to 60 seconds

Thereby, the copper- zinc alloy layer whose zinc content per unit area is 1000-9000 microgram / dm <^2> can be formed. The electroplating is preferable zinc-copper alloy plating conditions. If the copper-zinc alloy layer whose zinc content per unit area is 1000-9000 microgram / dm <^2> can be formed, it does not need to be limited to the above.

Therefore, you may zinc-plat on copper and heat-diffuse it to form a copper- zinc alloy layer. Moreover, in general, since heat is applied in the pressing step, if a zinc plating is formed, a copper-zinc alloy layer is formed by heat diffusion, and thus may be used. Examples of preferred zinc plating are shown below.

(Galvanized bath and plating conditions)

Bathtub

ZnSO ₄ · 7H ₂ O: 50 to 350 g / l

pH: 2.5-4.5

Bath temperature: 40-60 ℃

Current density: 0.05 to 0.4 A / dm 2

Processing time: 1 to 30 seconds

Next, on the zinc-copper alloy layer, a stabilization layer having a thickness between 5 Pa and 100 Pa consisting of at least one component selected from zinc oxide, chromium oxide and nickel oxide is formed.

As one embodiment, the coating layer can be formed using an electrolytic solution containing zinc ions and chromium ions. As the electrolytic zinc ion source in the solution, for example, it can be used, such as _{ZnSO 4, ZnCO 3, ZnCrO 4} . As the chromium ion source in the electrolytic solution, salts or compounds of hexavalent chromium such as ZnCrO ₄ , CrO ₃ , and the like can be used.

The concentration of zinc ions in the electrolytic solution is in the range of 0.1 to 2 g / l, preferably 0.3 to 0.6 g / l, more preferably 0.4 to 0.5 g / l. The concentration of chromium ions in the electrolytic solution is preferably 0.3 to 5 g / l, preferably 0.5 to about 3 g / l, more preferably 0.5 to 1.0 g / l. In addition, these conditions are conditions for performing efficient plating to the last, and can also be out of the range of this condition as needed.

As another embodiment, to form the stabilizing layer, nickel oxide and nickel metal, zinc oxide or chromium oxide, or these may be coated together. As the nickel ion source of the electrolytic solution, any of Ni ₂ SO ₄ , NiCO ₃ , or the like, or a combination thereof may be used.

It is preferable that the density | concentration in the electrolytic solution of nickel ion shall be 0.2 g / L-1.2 g / L. It is also possible to use a stabilizing layer containing phosphorus described in US Pat. No. 5,908,544. In addition, these conditions are conditions for efficiently forming the stabilization layer which has a thickness between 5 GPa and 100 GPa which consists of at least 1 component chosen from zinc oxide, chromium oxide, and nickel oxide to the last, and the range of the said conditions as needed. You can do it alone.

The electrolytic solution may contain other conventional additives such as Na ₂ SO _{4 at} a concentration in the range of 1 to 50 g / l, preferably 10 to 20 g / l, more preferably 12 to 18 g / l. . The pH of the electrolytic solution is generally 3 to 6, preferably 4 to 5, and more preferably 4.8 to 5.0.

The temperature of the electrolytic solution is 20 ° C to 100 ° C, preferably 25 ° C to 45 ° C, more preferably 26 ° C to 44 ° C.

As shown in FIG. 2, in order to provide a current density to the copper foil 12, the anode 48 is disposed adjacent to each side of the copper foil 12. The guide roller 46 is a cathode roller, and when voltage is applied to the anode 48 by a power supply (not shown), the stabilizing layer 49 made of, for example, zinc oxide and chromium oxide is exposed to the copper foil 12. On the polished side 14 and the mat face 16.

The current density ranges from 1 to 100 A / ft ² (about 0.108 to about 10.8 A / dm 2), preferably from 25 to 50 A / ft ² (about 2.7 to about 5.4 A / dm 2), more preferably Is 30 A / ft ² (about 3.2 A / dm 2). When forming a plurality of anodes, the current density can be changed between the anodes.

Preferable plating time is 1-30 second, Preferably it is 5-20 second, More preferably, it is about 15 second. In some embodiments, the total treatment time is about 3 to about 10 seconds on the glossy side, or smooth side, and about 1 to about 5 seconds on the non-gloss side.

As a preferable example, the molar ratio of chromium ions to zinc ions in the electrolytic solution is preferably 0.2 to 10, preferably 1 to 5, and more preferably about 1.4. According to this invention, it is good that the thickness of the stabilization layer applied to copper foil shall be 5 kPa-100 kPa. Preferably it is 20 kPa-50 kPa.

In the above-mentioned embodiment, although the stabilization layer is comprised from chromium oxide and zinc oxide, you may comprise a stabilization layer only with chromium oxide.

Preferable conditions of the bath for applying a chromium oxide stabilization layer are as follows.

1-10 g / l CrO ₃ solution

5 g / l CrO ₃ is preferred.

pH-2

Bath temperature: 25 ℃

10-30 A / ft ² (1.08-3.2 A / dm 2) in 5-10 seconds

Immersion treatment: 10 seconds

Cleaning is performed following the process of forming a stabilization layer. In the washing | cleaning process, water spray is sprayed on the surface of the spray apparatus copper foil (having stabilization layer) arrange | positioned above and below copper foil, for example, it is rinsed and cleaned and the residual electrolytic solution is removed from it. The washed solution can be recovered in a vessel placed under the spray nozzle.

Copper foil which has a stabilization layer in an upper surface further dries. As shown in embodiment, a forced air dryer is arrange | positioned above and below copper foil, air is blown out from it, and the surface of copper foil is dried.

The layer which consists of an electrical resistance material is further formed in the copper foil which provided the stabilization layer. As an example of this electrical resistance layer, electrical resistance elements, such as a NiCr alloy and a NiCrAlSi alloy, are mentioned, for example. The layer made of this electrically resistive material is a requirement from the circuit board design, which can be arbitrarily selected. Thus, there is no need to be limited to a particular material.

Moreover, in order to improve adhesiveness with a base material (base material), you may perform various silane treatment on a resistance layer as needed. However, this silane treatment is arbitrary and this invention is not limited to this.

Example

Next, an Example is described. In addition, the following Example is for ease of understanding of this invention, It is not limited to this. That is, modifications, embodiments, and other examples based on the technical spirit of the present invention are included in the present invention.

(Example 1)

In the present Example, 18 micrometers electrodeposited copper foil was used. The copper-zinc alloy layer was formed in the rough surface (mat surface) side of this electrolytic copper foil.

This copper-zinc alloy layer was performed on the following process conditions, and formed the copper- zinc alloy layer whose zinc content per unit area is about 3500 micrograms / dm <^2> (the last two digits rounded off). The coating amount was adjusted by the treatment time.

(Bath and Plating Conditions of Copper-Zinc Alloy Plating)

Bathtub

CuCN: 90 g / ℓ

Zn (CN) ₂ : 5 g / l

* NaOH: 70 g / ℓ

Na (CN): 20 g / ℓ

Bath temperature: 70 ℃

Current density: 500 A / dm ²

Processing time: 5-20 seconds

Next, on the copper-zinc alloy layer, the stabilizing layer which consists of about 50 Pa of zinc oxide-chromium oxide was formed on the following process conditions.

(Bath property and processing condition of stabilization treatment)

Bathtub

0.53 g / l zinc as ZnSO ₄

0.6 g / l chromium as CrO ₃

Na ₂ SO ₄ 11g / ℓ

PH of bath: 5.0

Bath temperature: 42 ℃

Current Density: 0.85-1.6 A / dm

Plating time: 3-4 seconds

Next, the electrical resistance material of the alloy which consists of 80% nickel (Ni) and 20% chromium (Cr) was made to adhere on the said stabilization layer on condition of the following.

Ni / Cr Alloy Sputtering:

14 inch sputtering device

Power: 5-8 kw

Line speed: 1.4-2.2 ft / min (0.43-0.67 m / min)

Ni / Cr alloy thickness: about 100 μs,

In addition, the sheet resistivity of this resistive material was about 160 ohm / square.

The peeling value (heat resistance) after the soldering process, the peeling value (hydrochloric acid resistance) after hydrochloric acid treatment was investigated about the coating layer with respect to the above copper foil.

In addition, about the peeling value after a soldering process, the peeling value was measured after being immersed in the 260 degreeC molten solder bath for 20 second (that is, the state heat-processed), ie, the peeling value after a soldering process is this process (heat It shows the peeling value after the affected). This is for evaluating heat resistance.

In addition, about the peeling value after hydrochloric acid treatment, 18 wt% hydrochloric acid is used and the peeling value after immersion at room temperature for 1 hour is shown. That is, hydrochloric acid resistance is evaluated. The same applies to the following.

From the above results, the state peeling value is 0.81 kg / cm, the peeling value (heat resistance) after the soldering treatment is 0.77 kg / cm, and the peeling value (hydrochloric acid resistance) after the hydrochloric acid treatment is 0.70 kg / cm, and the solder Even after treatment and hydrochloric acid treatment, there was little deterioration, and both showed good properties.

In addition, the last two digits of zinc content round off.

After solder bath immersion: The peeling strength after 260 degreeC melt solder bath immersion is shown.

After hydrochloric acid dipping: Peel strength after 18 wt% hydrochloric acid dipping is shown.

(Examples 2-11) [Zinc Content]

Next, based on the conditions of Example 1 which showed favorable characteristics, when the zinc content per unit area was changed, the copper- zinc alloy layer of (1000-9000 microgram / dm <^2> ) was formed. Similarly, two digits or less rounded off. Treatment conditions other than the zinc content of the copper-zinc alloy layer are the same as in Example 1. The coating amount was adjusted according to the treatment time. This result is shown in Table 1. In addition, what formed the copper- zinc alloy layer of zinc content other than the conditions of this invention as a comparison was shown as the comparative example 1 and the comparative example 2.

As apparent from Table 1, when the zinc content in the copper-zinc alloy layer was about 3500 µg / dm ² (2 digits rounded off) (Example 1), the state peel strength, heat resistance, and hydrochloric acid resistance were good. And good balance.

On the other hand, as zinc content per unit area increases, peeling strength and heat resistance improved, but the hydrochloric acid resistance tended to fall on the contrary. On the contrary, hydrochloric acid resistance improved as zinc content per unit area decreased, but the state peeling strength and heat resistance tended to decrease.

In Comparative Example 1, since the zinc content is small, the state peel strength, heat resistance, and hydrochloric acid resistance are all low, and in Comparative Example 2, since the zinc content is too large, the state peel strength and heat resistance are high, but the hydrochloric acid resistance is poor, and both are acceptable. We exceeded limit that there was and knew that it was not suitable for practical use. Thus, it turns out that presence of a copper- zinc alloy layer is very effective in order to improve state peeling strength, heat resistance, and hydrochloric acid resistance.

(Example 1-Example 1-4) [Thickness of Copper Foil]

Next, based on the conditions of Example 1 which showed the favorable characteristic, the state peeling strength, heat resistance, and hydrochloric acid resistance when the thickness of copper foil was changed was investigated. It is the same as that of Example 1 except having changed the thickness of copper foil. The coating amount was adjusted according to the treatment time. This result is shown in Table 2.

In the case of Example 1, although it implemented by the thickness of 18 micrometers of electrolytic copper foil, when peeling was carried out in the range of 9 micrometers-35 micrometers, state peeling changed large according to thin thickness. That is, the peeling strength increased as the thickness of the copper foil increased.

However, the deterioration rate of the peeling value after the soldering process and the peeling deterioration rate after the hydrochloric acid treatment did not change so much. Therefore, it was found that the peeling strength after soldering and the peeling strength after hydrochloric acid treatment are not significantly affected by the thickness of the copper foil from the viewpoint of the deterioration rate after the treatment. The results are shown in Table 2. Generally, it can be said that peeling strength increases by increasing the thickness of copper foil.

All zinc content is 3500 ㎍ / dm ²

Deterioration rate: (peel strength before treatment-peel strength after treatment) / peel strength before treatment × 100 (%)

Example 12 [silane treatment]

In this embodiment, the electrodeposited copper foil having a thickness of 18 µm and 35 µm is used, and when the rough surface of the electrolytic copper foil is used as it is and the roughened surface, the same conditions as in Example 1, that is, copper-zinc alloy plating Using a bath, a copper-zinc alloy plating layer was formed under the same plating conditions as in Example 1.

In addition, the conditions of the said roughening process are as follows.

Cu ion concentration: 20 g / ℓ

Sulfuric acid concentration: 60 g / ℓ

Electrolytic solution temperature: 40 ℃

Current Density: 30 A / dm ²

Processing time: 5 seconds

As a result, a copper-zinc alloy layer having a zinc content of about 3500 mg / m 2 (the last two digits were rounded off) was formed. Next, the stabilizing layer of Cr-Zn oxide was formed like this Example 1 on this copper- zinc alloy layer.

Moreover, the electrical resistance material of the alloy which consists of 80% nickel (Ni) and 20% chromium (Cr) was formed on the stabilization layer of this Cr-Zn oxide by sputtering. This condition is also the same as in Example 1.

Next, a silane treatment (TEOS: Tetraethoxysilane) was performed on the resistive layer. The results are shown in Table 3. As shown in this Table 3, it turns out that a state peeling strength improves and a silane treatment is effective.

All zinc content is 3500 ㎍ / dm ²

Silane treatment on resistive layer (TEOS)

Example 13 [Cr Resistance Film]

Under the conditions of Example 1, a copper-zinc alloy layer having a zinc content of about 3500 µg / dm ² (lower two digits rounded off) was formed, and a Cr-Zn oxide was formed on the Cu-Zn alloy layer. The stabilization layer of was formed.

Next, a chromium resistive film was formed on the Cr-Zn oxide stabilized layer by sputtering.

The conditions of chrome sputtering are as follows.

A 14 inch sputtering device was used.

Power: 5-8 kw

Line Speed: 1.8-2.8 ft / min (0.55-0.85 m / min)

Chrome thickness: 6 types of 100 100, 1000Å, 1200Å, 2000Å, 3000Å, 4000Å

Although the state peeling strength, heat resistance, and hydrochloric acid resistance were examined about this Example 13, it was the same as Example 1, and although not shown in a table, all showed the favorable property. As mentioned above, it turned out that formation of a copper- zinc alloy layer is effective irrespective of the kind and thickness of a resistance layer.

(Example 14- Example 14-4) [Ni / Cr / Al / Si alloy resistive film]

Under the conditions of Example 1, a copper-zinc alloy layer having a zinc content of about 3500 µg / dm ² (the last two digits rounded off) was formed, and on the copper-zinc alloy layer, chromium-zinc oxide The stabilization layer of was formed.

Subsequently, on the stabilization layer of this chromium-zinc oxide, an alloy consisting of 56% nickel (Ni), 38% chromium (Cr) and 4% aluminum (Al) and 2% silicon (Si) as a dopant was subjected to the following conditions. Attached.

Ni / Cr / Al / Si Alloy Sputtering:

14 inch sputtering device

Power: 0.85-2.3 kw

Line speed: 0.49 ft / min (0.15 m / min)

Sheet resistivity: about 90 to 300 Ω / square

About this Example 14-Example 14-4, the film | membrane of the sheet resistance shown in Table 4 was formed. Although the state peeling strength, heat resistance, and hydrochloric acid resistance at this time were investigated, it was the same as Example 1, and showed all the favorable properties as shown in Table 4. As mentioned above, it turned out that formation of a copper- zinc alloy layer is effective irrespective of a Ni / Cr / Al / Si alloy resistance layer.

All zinc content is 3500 ㎍ / dm ²

The thickness of all copper foil is 18 ㎛

(Examples 15-15-15) [Rolled Copper Foil]

In the present Example, rolled copper foil of 9 micrometers, 12 micrometers, 18 micrometers, and 35 micrometers was used. The roughening process was given to this rolled copper foil on condition of the following.

Cu ion concentration: 20 g / ℓ

Sulfuric acid concentration: 60 g / ℓ

Electrolytic solution temperature: 40 ℃

Current Density: 30 A / dm ²

Processing time: 5 seconds

Next, the Zn plating layer of 3500 micrograms / dm <^2> was formed in the rolled copper foil which performed this roughening process on condition of the following. The thickness of the zinc plating was adjusted by the treatment time.

Galvanized Bathtub

ZnSO ₄ · 7H ₂ O: 50 to 350 g / l

pH: 3

Bath temperature: 50 ℃

Current density: 0.2 A / dm

Processing time: 2-3 seconds

The copper foil which formed this process layer was heat-processed at 300 degreeC, and the copper- zinc alloy layer was formed. The zinc content per unit area of the copper-zinc alloy layer thus formed was about 3500 µg / dm ² (the last two digits rounded off).

Next, on the copper-zinc alloy layer, the stabilization layer which consists of about 50 Pa of zinc oxide-chromium oxide was formed on the following process conditions.

Stabilization treatment:

0.53 g / l zinc as ZnSO ₄

0.6 g / l chromium as CrO ₃

Na ₂ SO ₄ 11g / ℓ

PH of bath: 5.0

Bath temperature: 42 ℃

Current Density: 0.85-1.6 A / dm

Plating time: 3-4 seconds

Next, the electrical resistance material of the alloy which consists of 80% nickel (Ni) and 20% chromium (Cr) was made to adhere on the said stabilization layer on condition of the following.

Ni / Cr Alloy Sputtering:

14 inch sputtering device

Power: 5-8 kw

Line speed: 1.4-2.2 ft / min (0.43-0.67 m / min)

Ni / Cr alloy thickness: about 100 μs,

In addition, the sheet resistivity of this resistive material was about 160 ohm / square.

The state peeling strength, heat resistance (peel strength after solder processing), and hydrochloric acid resistance (peel strength after hydrochloric acid treatment) were examined about the coating layer with respect to the above copper foil. This result is shown in Table 5. As shown in this Table 5, the state peel strength is 0.64 to 1.22 kg / cm, the peel strength after solder immersion is 0.60 to 1.16 kg / cm, and the peel strength after 18 wt% hydrochloric acid immersion is 0.53 to 1.09 kg. It became / cm, and all showed the favorable property.

Moreover, when the thickness of the Cu-Zn alloy layer was changed similarly to the said Example 2-11, the same result was obtained. Therefore, both the electrolytic copper foil and the rolled copper foil show that forming a copper-zinc alloy layer having a zinc content of 1000 to 9000 µg / dm ² per unit area is effective for improving adhesion (increase in state peel strength), heat resistance, and acid resistance. Could.

All zinc content is 3500 ㎍ / dm ²

The present invention eliminates the need to newly form an electric resistance element alone in circuit design by using a copper foil having a built-in electric resistance film layer, and uses an etching solution such as cupric chloride as the electric resistance film layer formed on the copper foil. It is only necessary to expose the resistive element, which eliminates the need for solder bonding or greatly reduces the mounting process. This greatly reduces the circuit design and manufacturing process and significantly reduces the circuit design and manufacturing process. The signal characteristic in the region is improved. Moreover, this invention is useful as a printed circuit board because it can improve the fall of the adhesive force which is a fault with the copper foil in which such an electrical resistance film layer was built, and has the outstanding effect that it has favorable heat resistance and acid resistance. .

1: cathode drum
2: insoluble anode (anode)
3: gap
4: raw foil
11: raw material copper foil (raw foil)
12: copper foil
14: copper foil glossy surface
20: pretreatment process
22: pretreatment tank
24: lower guide roller
26: guide roller
30: washing tank
32: flush nozzle
34: washing tank
40: stabilization process
42: electrolytic cell
44: lower guide roller
46: guide roller (cathode roller)
48: anode
60: dryer
62: heater
72: sputter device
76: target
77 gas introduction pipe
100: copper-zinc process

Claims (3)

On the rough surface or gloss surface of copper foil, a zinc-copper-zinc alloy layer having a zinc content of 1000 to 9000 µg / dm ² per unit area is provided, and the copper-zinc alloy layer is selected from zinc oxide, chromium oxide, and nickel oxide. The copper foil provided with the electrical resistance film layer which forms the stabilization layer which has a thickness between 5 kPa and 100 kPa which consists of at least 1 component, and is provided with the film layer which consists of an electrical resistance material on the said stabilization layer. The method of claim 1,
The foil thickness of copper foil is 5-35 micrometers, Copper foil with an electrical resistance film layer characterized by the above-mentioned. The method according to claim 1 or 2,
An electrical resistance film layer is formed in the mat side of electrolytic copper foil or the surface side which carried out the roughening process of rolled copper foil, The copper foil with an electrical resistance film layer characterized by the above-mentioned.

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