JP3070599B2 - Surface-roughened copper foil and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for roughening the surface of copper, and more particularly, to a method of mixing a carbon and a polyethylene and curing the same to produce a polymer PTC characteristic electrode for an overcurrent protection element and a copper for a multilayer printed circuit board. The present invention relates to a method for producing a surface roughened copper foil which requires bonding with a resin such as a foil.

[0002]

2. Description of the Related Art In recent years, polymer PTCs have been developed for the purpose of protecting lithium batteries and circuits of personal computers.
Characteristic overcurrent protection elements are being actively used. In addition, as electronic circuits have become smaller and faster, a large number of multilayer printed circuit boards have been used.

As a PTC characteristic overcurrent protection element made of a polymer, a resin type resin filled with carbon is known. In this type of overcurrent protection element, since the thermal expansion of the resin is used, a strong bonding force is required between the resin and the copper foil serving as an electrode. Similarly, as a method for increasing the bonding strength between a copper foil and a resin insulating film in a multilayer printed circuit board, the surface of the copper foil has been conventionally roughened to have irregularities.

In a conventional method for producing a roughened copper foil, first, roughening plating is performed on only one side at a relatively low current density using a negative electrode as a roll and a positive electrode as copper. Thus, it was usual to perform roughening plating in the same manner.

[0005]

In the above conventional method,
Since plating is carried out at a low current density, the time required for the treatment is long, the cost is high, and it is difficult to control the plating solution.

In view of these problems, the present invention provides a roughened copper foil capable of maintaining the same adhesiveness to a resin as a copper foil prepared by roughening plating by a simple and inexpensive method. It is intended to do so.

[0007]

In order to solve the above-mentioned problems, a surface roughening method of the present invention is characterized in that a copper foil or a copper plate is subjected to AC etching in an electrolytic solution.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described.
This will be described with reference to the drawings. FIG. 1 is a schematic view of an etching tank according to the present invention. In FIG. 1, 1 is an electrode, 2 is another electrode (sample), and 3 is a mixed solution of an electrolytic solution and an additive.

The principle of AC etching using the above-described apparatus will be described in detail below.

Normally, electrolytic etching is performed to smooth the surface of a metal like electrolytic polishing. The reason is,
This is because, when a metal plate and a counter electrode plate are placed in an electrolytic solution in parallel and electrochemical etching is performed using the metal plate as an anode, if there is unevenness in the metal, the current concentrates on the protrusion near the counter electrode.

For this reason, it is difficult to make the surface uneven by etching, except for metals such as aluminum which form an oxide when it becomes an anode.

According to the present invention, by adding an anion which forms a salt which is hardly soluble with copper ions in an aqueous solution,
A compound is generated in a portion of the protrusion where the copper ions increase during electrolytic etching, and a concave portion where anions do not easily reach is easily etched, thereby realizing a roughened surface by etching.

In order to form fine irregularities uniformly, AC etching is more preferable than DC etching because it has more opportunities to generate etch pits.

In general, when the frequency of the AC etching is reduced, the interval between the etch pits is increased, and irregularities with a wide interval can be obtained. For example, when the frequency is about 1 Hz, unevenness with a considerably large interval is obtained. On the other hand, when the etching frequency is increased, the interval between the etch pits is reduced, and fine irregularities are obtained. When the etching frequency is higher than 50 Hz, the progress of the etching is substantially stopped.

Further, copper ions are acidic and are easily dissolved, and particularly, halogen ions are liable to form a complex with copper ions. Therefore, halogen acid is effective as an acid for etching on the acidic side. Among them, hydrochloric acid is a particularly preferred acid from the viewpoint of cost and handling.

An acid concentration of 0.001 mol / L or more is required. If the concentration is less than 0.001 mol / L, there is a problem that a change in current density and an etching solution is large and stable etching cannot be performed.

When a neutral salt is used, a salt having a halogen ion which easily forms a complex with a copper ion such as a hydrochloric acid ion is preferable. In addition, since a precipitate such as copper oxide is often formed on the surface in a combination that forms a compound insoluble with a neutral salt and copper ions, it is preferable to remove the precipitate by acid treatment or etching in an acid.

Further, the roughened surface formed by this etching can control the irregularities quite freely by the liquid composition, frequency and current density, so that the surface roughness suitable for the purpose can be obtained.

For this reason, when used for a copper electrode requiring a particularly strong bonding strength, such as an electrode of a polymer PTC characteristic overcurrent protection element used by utilizing the thermal expansion of a resin, the resistance value which does not change with time is stable. A current protection element is obtained. Further, it has become possible to provide the multilayer printed circuit board copper foil at low cost.

[0020]

The present invention will be specifically described below with reference to examples.

Example 1 A copper foil was used as an electrode in an electrolytic solution obtained by dissolving 3 mol / L of sodium chloride and 0.2 wt% of ammonium carbonate or ammonium hydrogen carbonate in water.
When a sample of 60 * 60 mm was etched at a current density of 170 mA / cm 2 for 5 minutes using an alternating current of 1 Hz using carbon as the other electrode, the surface roughness Rmax was 10 μm.
It became.

When a tensile test was performed using a 3 * 3 mm, 0.1 mm thick copper foil using an α-cyanoacrylate instant adhesive, the weight was 2.5 kg before etching, but was 2.5 kg before etching. It became 14.7 kg. A similar tendency was observed with epoxy and rubber adhesives. Almost the same strength was observed in both ammonium carbonate and hydrogencarbonate ammonium.

When the frequency was 50 Hz or more, the etching did not proceed. The current density tended to have a higher surface roughness as the current density increased, but no remarkable difference was observed. Desirably, the voltage of the overcurrent protection device electrode is set to 0.
An alternating current of 3 to 5 Hz and 1 to 10 Hz is preferable for a copper foil for multilayer printing.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate instant adhesive, the weight was 2.5 kg before etching, but 12. It became 5 kg. A similar tendency was observed with epoxy and rubber adhesives.

The electrolytic solution is made of a halogen salt of an alkali metal or an alkaline earth metal, and soluble sulfates such as sodium chloride, potassium chloride, sodium nitrate, potassium nitrate,
No significant difference was found when changing to a salt containing sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate. When the amount of ammonium carbonate or ammonium hydrogen carbonate added was 0.001 wt% or less, no remarkable effect was observed. In addition, the same effect was obtained with an alkali salt of hydrogen carbonate.

The pH was adjusted to pH 4 with hydrochloric acid and etching was performed.
The weight was 7 kg, but it was 3.5 kg at PH1 and 10.2 kg when the pH was adjusted to 11 with sodium hydroxide. Thus, it was confirmed that the tensile strength could be controlled by PH.

(Example 2) In an electrolytic solution obtained by dissolving 3 mol / L sodium chloride and 0.2 wt% ammonium fluoride in water, copper foil was used as an electrode and carbon was used as another electrode. * A 60 mm sample was etched for 5 minutes at a current density of 170 mA / cm2 with an alternating current of 1 Hz for use as a polymer PTC overcurrent protection device, and the surface roughness Rmax was 10 µm. When etching was performed for 5 minutes at a current density of 85 mA / cm 2 at an alternating current of 5 Hz as a copper foil for a multilayer printed board, the surface roughness Rmax
μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 0.1 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, it was 2.5 kg before etching, but Rmax 10 μm after etching. It became 13.7 kg. With Rmax2μ, the weight was 3.7 kg. A similar tendency was observed with epoxy and rubber adhesives.

Example 3 In an electrolytic solution in which 3 mol / L of sodium chloride and 0.2 wt% of ammonium phosphate were dissolved in water, copper foil was used as an electrode and carbon was used as another electrode. 170mA at 1Hz AC with 60mm sample
When etching was performed at a current density of / cm 2 for 5 minutes, the surface roughness became Rmax 9 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, the weight was 2.5 kg before the etching, but 12 kg after the etching. It became 8 kg. A similar tendency was observed with epoxy and rubber adhesives. A similar tendency was observed for phosphoric acid and other phosphates.

Example 4 In an electrolytic solution obtained by dissolving 3 mol / L sodium chloride and 0.2 wt% ammonium pyrophosphate in water, copper foil was used for the electrode and carbon was used for the other electrode.
170 mA / cm2 at 1 Hz AC with a sample of 0 * 60 mm
When etching was performed at a current density of 5 minutes, the surface roughness became Rmax 8 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 0.1 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, the weight was 2.5 kg before the etching, but 11.11 after the etching. It became 8 kg. A similar tendency was observed with epoxy and rubber adhesives. A similar tendency was observed for pyrophosphate and other pyrophosphates.

(Example 5) In an electrolytic solution obtained by dissolving 3 mol / L sodium chloride and 0.2 wt% ammonium iodide in water, a copper foil was used as an electrode and carbon was used as another electrode. , 170 * at 1 Hz alternating current with 60 * 60 mm sample
When etching was performed at a current density of mA / cm 2 for 5 minutes, the surface roughness became Rmax 7 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 0.1 mm and a thickness of 0.1 mm using an α-cyanoacrylate instant adhesive, the weight was 2.5 kg before etching, but was 10.10 kg after etching. It became 2 kg. A similar tendency was observed with epoxy and rubber adhesives.

(Example 6) In an electrolytic solution in which 3 mol / L of sodium chloride and 0.2 wt% of ammonium oxalate were dissolved in water, copper foil was used as an electrode and carbon was used as another electrode. 170mA at 1Hz AC with 60mm sample
When etching was performed at a current density of 5 cm / cm 2 for 5 minutes, the surface roughness became Rmax 8 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate instant adhesive, the weight was 2.5 kg before etching, but was 11.1 kg after etching. It became 5 kg. A similar tendency was observed with epoxy and rubber adhesives. A similar tendency was observed for oxalic acid and other oxalates.

Example 7 In an electrolytic solution obtained by dissolving 3 mol / L of sodium chloride and 0.2 wt% of ammonium formate in water, a copper foil was used as an electrode and carbon was used as another electrode. 170mA at 1Hz AC with 60mm sample
When etching was performed at a current density of / cm 2 for 5 minutes, the surface roughness became Rmax 9 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, the weight was 2.5 kg before etching, but 11.11 after etching. It became 9 kg. A similar tendency was observed with epoxy and rubber adhesives. A similar tendency was observed with formic acid and other formate salts.

(Example 8) In an electrolytic solution obtained by dissolving 3 mol / L of sodium chloride and 0.2 wt% of ammonium metaphosphate in water, copper was used as an electrode, and carbon was used as an electrode. 170mA at 1Hz AC with 60mm sample
When etching was performed at a current density of 5 cm / cm 2 for 5 minutes, the surface roughness became Rmax 8 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, the weight was 2.5 kg before etching, but was 11.1 kg after etching. It became 8 kg. A similar tendency was observed with epoxy and rubber adhesives. A similar tendency was observed in metaphosphoric acid and other metaphosphates.

Example 9 In an electrolytic solution in which 3 mol / L of potassium chloride and 0.2 wt% of ammonium formate were dissolved in water, copper foil was used as an electrode and carbon was used as another electrode. 170mA at 1Hz AC with 60mm sample
When etching was performed at a current density of / cm 2 for 5 minutes, the surface roughness became Rmax 9 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 0.1 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, the weight was 2.5 kg before the etching, but 12 kg after the etching. It became 2 kg. A similar tendency was observed with epoxy and rubber adhesives. A similar tendency was observed with formic acid and other formate salts.

In Examples 1 to 9, the electrolytic solution was replaced with an alkali metal or alkaline earth metal halide, soluble sulfates such as sodium chloride, potassium chloride and sodium nitrate.
No significant difference was found even when a salt containing potassium nitrate, sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate was used.

Example 10 In an electrolytic solution in which 3 mol / L of lithium chloride and 0.2 wt% of ammonium metaphosphate were dissolved in water, copper foil was used as an electrode and carbon was used as another electrode. * 170m for 1mm alternating current with 60mm sample
When etching was performed at a current density of A / cm 2 for 5 minutes, the surface roughness became Rmax 8 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 0.1 mm and a thickness of 0.1 mm using an α-cyanoacrylate instant adhesive, the weight was 2.5 kg before etching, but was 10.10 kg after etching. It became 2 kg. A similar tendency was observed with epoxy and rubber adhesives. A similar tendency was observed in metaphosphoric acid and other metaphosphates.

The electrolytic solution is treated with an alkali metal or alkaline earth metal halide, soluble sulfates such as sodium chloride, potassium chloride, sodium nitrate and potassium nitrate.
No significant difference was found when changing to a salt containing sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate.

As an additive, it is preferable to form a hardly soluble salt or an insoluble salt with copper. It goes without saying that the same effect can be expected with various additives.

Example 11 In an electrolytic solution obtained by dissolving 3 mol / L potassium bromide and 0.2 wt% ammonium formate in water, copper foil was used as an electrode and carbon was used as another electrode. * 170mA at 1Hz AC for 60mm sample
When etching was performed at a current density of / cm 2 for 5 minutes, the surface roughness became Rmax 9 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate instant adhesive, the weight was 2.5 kg before etching, but 12. It became 2 kg. A similar tendency was observed with epoxy and rubber adhesives. A similar tendency was observed with formic acid and other formate salts.

The electrolytic solution is treated with an alkali metal or alkaline earth metal halide, soluble sulfates such as sodium chloride, potassium chloride, sodium nitrate, potassium nitrate,
No significant difference was found when changing to a salt containing sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate.

Example 12 In an electrolytic solution in which 3 mol / L of potassium bromide and 0.001 wt% of ammonium formate were dissolved in water, copper foil was used as an electrode and carbon was used as another electrode. * 170m for 1mm alternating current with 60mm sample
When etching was performed at a current density of A / cm 2 for 5 minutes, the surface roughness became Rmax 6 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate instantaneous adhesive, the weight was 2.5 kg before etching, but was 6. It became 8 kg. Epoxy,
A similar tendency was observed for the rubber-based adhesive. A similar tendency was observed with formic acid and other formate salts.

The electrolytic solution is treated with an alkali metal or alkaline earth metal halide, soluble sulfates such as sodium chloride, potassium chloride, sodium nitrate and potassium nitrate.
No significant difference was found when changing to a salt containing sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate.

Example 13 In an electrolytic solution in which 3 mol / L of potassium bromide and 0.0001 wt% of ammonium formate were dissolved in water, a copper foil was used as an electrode and carbon was used as another electrode. * 170 at 1 Hz AC for 60 mm sample
When etching was performed at a current density of mA / cm 2 for 5 minutes, the surface roughness became Rmax 2 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate instant adhesive, the weight was 2.5 kg before etching, but was 8. It became 5 kg. Epoxy,
A similar tendency was observed for the rubber-based adhesive. A similar tendency was observed with formic acid and other formate salts.

The electrolytic solution was treated with an alkali metal or alkaline earth metal halide, soluble sulfates such as sodium chloride, potassium chloride, sodium nitrate and potassium nitrate.
No significant difference was found when changing to a salt containing sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate.

It is desirable that the concentration of both the electrolytic solution and the additive is not a saturated solution, but there is no problem even if there is a precipitate.

(Example 14) In an electrolytic solution in which 0.001 mol / L of potassium bromide and 0.05 wt% of ammonium formate were dissolved in water, a copper foil was used as an electrode, and a carfoil was used as another electrode.
Using a Bonn, a sample of 60 * 60 mm is
When etching was performed for 5 minutes at a current density of 0 mA / cm 2, the surface roughness became Rmax 5 μm.

When a tensile test was performed using a 3 * 3 mm thick 0.1 mmt copper foil using an α-cyanoacrylate instant adhesive, the weight was 2.5 kg before etching, but was 5.5 kg after etching. It became 9 kg. Epoxy,
A similar tendency was observed for the rubber-based adhesive. A similar tendency was observed with formic acid and other formate salts.

The electrolytic solution is treated with an alkali metal or alkaline earth metal halide, soluble sulfates such as sodium chloride, potassium chloride, sodium nitrate and potassium nitrate.
No significant difference was found when changing to a salt containing sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate.

Example 15 In an electrolytic solution in which 0.0001 mol / L of potassium bromide and 0.05 wt% of ammonium formate were dissolved in water, a copper foil was used as an electrode and carbon was used as another electrode. , 60 * 60mm sample and 1Hz AC
When etching was performed at a current density of 30 mA / cm 2 for 5 minutes, the surface roughness became Rmax 3 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, the weight was 2.5 kg before etching, but was 2. There was no big effect at 9 kg. A similar tendency was observed with epoxy and rubber adhesives. A similar tendency was observed with formic acid and other formate salts.

The electrolytic solution was treated with a salt of an alkali metal or an alkaline earth metal, or a soluble sulfate such as sodium chloride, potassium chloride, sodium nitrate, potassium nitrate, or the like.
No significant difference was found when changing to a salt containing sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate.

It goes without saying that either one side or both sides of the copper foil is possible. Changing the bath temperature had no significant effect. A similar effect was obtained by DC etching, but process control was difficult.

Using the roughened copper foil obtained in the above example, a polymer PTC characteristic overcurrent protection element was prepared, mounted on a printed circuit board, and checked for characteristics.

It is connected to a DC power supply of 12 V, an overcurrent of 40 A is applied to operate the PTC characteristic overcurrent protection element made of polymer, and the current is supplied for 1 minute.
The cycle was 500 cycles.

Example 1 did not ignite, and there was no problem of peelability between the conductive polymer and the roughened copper foil. The rate of change of the resistance was within ± 20%. In Example 15, no ignition occurred, and a problem of peelability occurred between the conductive polymer and the roughened copper foil. 1 out of 10 samples
Peeling occurred in all 0 cases. The rate of change of the resistance value is 90
0% or more.

(Example 16) In an electrolytic solution obtained by bubbling carbon dioxide gas into 3 mol / L potassium chloride or adding a small piece of dry ice, a copper foil was used as an electrode and a carfoil was used as another electrode.
With a 60 * 60 mm sample and 1 Hz alternating current
When etching was performed at a current density of 70 mA / cm 2 for 5 minutes, the surface roughness became Rmax 10.5 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, the weight was 2.5 kg before etching, but 12. It became 9 kg. A similar tendency was observed with epoxy and rubber adhesives.

The electrolytic solution is prepared by using a salt of an alkali metal or an alkaline earth metal, or a soluble sulfate such as sodium chloride, potassium chloride, sodium nitrate, potassium nitrate, or the like.
No significant difference was found when changing to a salt containing sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate.

Example 17 0.3 mol% of aqueous ammonia was added to 3 mol / L of potassium chloride, and copper foil was used as an electrode and carbon was used as another electrode in an electrolytic solution.
mm sample was etched at an alternating current of 1 Hz at a current density of 170 mA / cm 2 for 5 minutes to obtain a surface roughness Rma.
x12 μm. Further, bubbling of carbon dioxide gas or addition of small pieces of dry ice increased the liquid life ten times.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, the weight was 2.5 kg before etching, but 12. It became 5 kg. A similar tendency was observed with epoxy and rubber adhesives.

The electrolytic solution is treated with an alkali metal or alkaline earth metal halide, soluble sulfates such as sodium chloride, potassium chloride, sodium nitrate and potassium nitrate.
No significant difference was found when changing to a salt containing sodium bromide, potassium iodide, potassium fluoride, lithium chloride, sodium sulfate, or magnesium sulfate. When the amount of added ammonia water was 0.001 wt% or less, no remarkable effect was observed.

(Example 18) In an electrolytic solution containing 3 mol / L hydrochloric acid, a copper foil was used as an electrode and carbon was used as another electrode.
When etching was performed at a current density of mA / cm 2 for 5 minutes, the surface roughness became Rmax 6.5 μm.

When a tensile test was performed on a copper foil having a thickness of 3 mm × 3 mm and a thickness of 0.1 mm using an α-cyanoacrylate-based instant adhesive, it was 2.5 kg before etching, but 6.5 kg after etching. Became. A similar tendency was observed with epoxy and rubber adhesives.

Even if the electrolytic solution was changed to sulfuric acid, phosphoric acid, nitric acid, organic sulfonic acid, hydrofluoric acid or halogen oxide, no significant difference was observed. Addition of ammonia water, ammonium chloride, ammonium sulfate, or ammonium persulfate also had an effect, but no significant effect was observed when the addition amount was 0.001 wt% or less.

[0077]

As described above, by performing electrolytic etching in an electrolytic solution in order to produce a copper foil having a roughened surface, a roughened surface having a high Rmax can be obtained.
This makes it possible to obtain a roughened copper foil at low cost,
It has become possible to manufacture a multilayer printed circuit board and a polymer PTC characteristic overcurrent protection element at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an etching tank.

[Explanation of symbols]

 1 electrode 2 other electrode (sample) 3 electrolyte and additive

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Koichi Morimoto 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-8-118852 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C25F 3/02 H05K 1/09 H05K 3/38

Claims (12)

(57) [Claims] 1. A copper foil or a copper plate is prepared in an amount of 0.001 mol / L.
A method for alternating or direct current etching in an electrolyte containing more salts, salts of alkali metals or alkaline earth metal halide salts, soluble sulfates or nitrates der
Easy to make a compound that is hardly soluble in copper ion and water in the electrolyte
A method for producing surface-roughened copper to which anions have been added . 2. The method according to claim 1, wherein the anion is carbonate ion or fluorine ion.
, Phosphate ion, pyrophosphate ion, iodate ion, oxalate
Acid ion, formate ion, bicarbonate ion, hydroxyl ion
Or at least one selected from metaphosphate ions
The method for producing a roughened copper according to claim 2. 3. The method according to claim 1, wherein the frequency of the AC etching is 50 Hz or less. 4. After etching using a solution containing a salt of not less than 0.001 mol / L as an electrolyte, 0.001 mol / L
Claim 1, 2 or 3 surface roughening method for producing copper according performing an acid treatment or an etching acidic solution as an electrolyte solution containing L or more acids. 5. nitrate, sodium chloride, potassium chloride, a manufacturing method of the surface roughening copper according to any one of claims 1 to 4, sodium nitrate, potassium nitrate or magnesium sulfate. 6. An electrolyte according to claim 1, wherein said electrolyte is added with ammonium carbonate or ammonium hydrogencarbonate.
6. The method for producing a surface roughened copper according to any one of claims 5 to 5 . 7. The electrolytic solution, the manufacturing method of the surface roughening copper according to any one of claims 1 to 5, characterized in that the addition of aqueous ammonia. 8. The method according to claim 1, wherein an additive whose cation is ammonium ion is added to the electrolytic solution.
6. The method for producing a surface roughened copper according to any one of claims 5 to 5 . 9. The method of surface roughening copper according to any one of claims 1-8, characterized by bubbling carbon dioxide gas into the electrolytic solution. 10. A surface Arakado prepared by the method according to any one of claims 1-9. 11. A PT obtained by curing a carbon and a polymer.
A PTC characteristic overcurrent protection device made of a conductive polymer having C characteristics, wherein the PTC characteristic overcurrent protection device has a roughened copper electrode prepared by the method according to any one of claims 1 to 9 as an electrode. 12. A multi-layer printed circuit board to a copper foil surface roughening copper produced by the method according to any one of claims 1-9.