JPH05317807A - Production of resin coated copper-based material - Google Patents

Abstract

PURPOSE:To produce a resin coated copper-based material excellent in adhesion and not causing tarnish under easy plate thickness control without requiring surface roughening treatment such as etching or heating. CONSTITUTION:A copper or copper alloy material 1 as a base material is anodically oxidized in an alkali soln. to form a copper oxide film 5 on the surface of the base material and the film 5 is coated with a photosetting resin 6. This resin 6 is cured by irradiation with light to form a resin coating film 3 on the surface of the base material and the objective resin coated copper-based material is produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a copper-based material coated with a resin, and to a material applicable to electronic parts and others.

[0002]

2. Description of the Related Art Copper and copper alloys represented by phosphor bronze, nickel silver and beryllium copper are widely used as materials for connectors, switches, relays and other electronic parts. Generally, these copper alloy materials are electrical contacts,
Alternatively, for soldering, gold, silver, tin, solder, nickel or the like is plated and processed into terminals or contact pieces of each electronic component before use. In any case, these copper-based materials are used as conductive members, and the terminals made of the copper-based material and the terminals and the insulation between the contact pieces may be housed in an insulating container or sealed. It was taken.

By the way, recently, a material in which an insulating member is preliminarily compounded with a copper-based material has appeared. For example, in a copper alloy material used for a connector, a resin which is an insulating member is coated on the strip surface of the copper alloy, and after pressing into a terminal shape,
By stacking them, it is intended to realize a higher density connector. FIG. 5 is a process diagram showing a conventional method for producing a copper-based material coated with such a resin, and (a) to (e) schematically show changes in cross section in each production process.

In FIG. 5, reference numeral 1 denotes a copper-based material made of phosphor bronze or other copper alloy. The copper-based material 1 is subjected to a roughening treatment such as etching from the state of (a),
As shown in (b), the roughened surface 1a is formed. This roughening treatment is for improving the adhesion between the resin and the copper alloy to be coated in the subsequent step, as disclosed in, for example, JP-A-2-12714. The required surface roughness is a center line average roughness (Ra) of 0.3 μm or more, and a maximum surface roughness (Rmax) of more than 3 μm. After this roughening treatment, as shown in (c), a liquid material 2 of a resin such as epoxy, polyimide, or polyamide-imide is applied onto the roughened surface 1a of the copper-based material 1 and solidified by heat treatment. , (D), the resin coating film 3 is formed. The heating conditions at this time vary depending on the resin to be applied, but it is said that it is preferable to select it at 130 to 420 ° C. for 5 to 20 minutes. A resin coating method is called a die coating method, and a method in which a coated portion and a non-coated portion can be formed by using a dedicated tool so that the resin can be continuously coated in a predetermined width is adopted.
After the resin coating film 3 is formed on the surface of the copper-based material 1 in this way, a predetermined metal plating layer 4 is applied to the surface of the remaining material 1 on which the resin coating film 3 is not formed, as shown in (e). ..

[0005]

When a copper-based material is coated with a resin, the adhesion between the copper-based material and the resin is poor, so that it is necessary to carry out a roughening treatment such as the above-mentioned etching. An uneven surface considerably larger than that of the base material is formed on the surface. The surface roughness of the material is deeply involved in the condensation of moisture in the atmosphere, and the larger the unevenness, the higher the vapor pressure near the material interface and the easier the moisture condenses. There is. In addition, due to the exposed new surface of the copper-based material due to etching, etc., indoor corrosion, so-called discoloration of the copper-based material, is more likely to proceed. It is necessary to take measures against discoloration including proper management.

When the above-mentioned applied resin is heat-cured, the surface of the copper-based material in the non-applied portion is oxidized by heating to form an oxide scale, and pickling is performed to remove the oxide scale. Will be needed. In this pickling, in addition to the removal of oxide scale, from the viewpoint of imparting smoothness to the plated surface and plating cost, it is stronger than ordinary pickling, which reduces the roughness of the surface that has been roughened previously. A new light etching process is required. At this time, the amount of light etching is naturally affected by the difference in the degree of generation of oxide scale, which is an obstacle to finishing the plate to an appropriate thickness.

The present invention has been made to solve the above problems, and can easily form a resin coating film having excellent adhesiveness without requiring a roughening treatment such as etching. Another object of the present invention is to obtain a method for producing a resin-coated copper-based material that does not require heating and solidification of the resin, thereby preventing discoloration of the copper-based material and cost increase of plating, and easily controlling the plate thickness.

[0008]

The present invention is the following method for producing a resin-coated copper-based material. (1) A base material made of copper or a copper alloy is anodized in an alkaline solution to form a copper oxide film on the surface of the base material, and a photocurable resin is further applied on the base oxide film, and irradiated with light. A method for producing a resin-coated copper-based material, which is cured by forming a resin coating film on the surface of the base material. (2) A base material made of copper or a copper alloy is anodized in an alkaline solution to form a copper oxide film on the surface of the base material, and a photocurable resin is further applied on the base material to form the base material. By irradiating light through a partial light-shielding means, the irradiated portion is cured to partially form a resin coating film, and the uncured resin film is dissolved and removed in a solvent to remove the base material. A method for producing a resin-coated copper-based material, wherein a resin coating film is partially formed on the surface. (3) A base material made of copper or a copper alloy is anodized in an alkaline solution to form a copper oxide film on the surface of the base material, and a photocurable resin is further applied onto the base material to form the base material. By irradiating light through a partial light-shielding means to the resin, the irradiated portion is cured to partially form a resin coating film, and the uncured resin film is dissolved and removed in a solvent to remove the exposed copper. A method for producing a resin-coated copper-based material, wherein a resin coating film is partially formed on the surface of the base material without dissolving the copper oxide film on the outermost surface by dissolving and removing the oxide film with an acidic solution. (4) A base material made of copper or a copper alloy is anodized in an alkaline solution to form a copper oxide film on the surface of the base material, and a photocurable resin is further applied onto the base material to form a base material. By irradiating light through a partial light-shielding means to the resin, the irradiated portion is cured to partially form a resin coating film, and the uncured resin film is dissolved and removed in a solvent to remove the exposed copper. A method for producing a resin-coated copper-based material, which comprises dissolving and removing an oxide film with an acidic solution, and further forming one or more metal plating layers on the exposed base material surface.

[0009]

In the manufacturing method according to claim 1 of the present invention, the copper oxide film formed by anodizing in an alkaline solution has a very fine villous surface with a length of several hundred to several thousand Å. I am configuring. Since this fine villi-shaped copper oxide film has an extremely good affinity with the resin, it has excellent resin wettability, and since the liquid resin enters the gaps between the villi and solidifies, it exerts an anchor effect, so it is sufficient. Good adhesion is obtained. The thickness of this anodic oxide film has a controllability according to Faraday's law, and a film thickness of about 1 μm is sufficient to obtain adhesion, and does not increase the surface roughness. Therefore, a certain amount of pickling can be removed, and the plating cost does not increase and the plate thickness is not difficult to control. Since the anodic oxide film has a dense surface structure, it has low susceptibility to oxidation in the atmosphere, and there is no risk of discoloration until it is removed by pickling. Further, the photo-curable resin applied on the copper oxide film is cured by irradiating light, so there is no need for heating,
No oxide scale is formed during curing.

In the method of the second aspect, since the light irradiation is performed by using the partial light shielding means, the cured portion and the uncured portion are formed in the photocurable resin coating film. Then, by removing the uncured portion by dissolution, the light-irradiated portion remains as a partial resin coating film, and the copper oxide film is exposed at the non-irradiated portion.

In the method of the third aspect, the surface of the base material is exposed by further removing the copper oxide film, but the removal of the copper oxide film is easily performed with an acidic solution.

In the method of the fourth aspect, the metal plating layer is formed on the surface of the exposed base material, but since the exposed base material has fine irregularities, plating is easily performed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are process diagrams showing a method for producing a resin-coated copper-based material of Examples 1 to 4, and (a) to (h) are schematic representations of changes in cross section in each process. In the figure, the same reference numerals as those in FIG. 5 indicate the same or corresponding portions.

Example 1 In FIG. 1, the manufacturing method of Example 1 is as follows. First, as shown in (b), a copper-based material 1 is prepared by anodizing the copper-based material 1 shown in (a) in an alkaline solution. A copper oxide film 5 is formed on the surface of 1. The copper oxide film 5 is brown to black,
It has a very fine villous surface structure. Subsequently, a liquid material of a photocurable resin is applied, and as shown in (c),
The uncured resin film 6 is formed. Next, as shown in (d),
The uncured resin film 6 is irradiated with light 7 to cure the photocurable resin, and the resin coating film 3 is formed as shown in (e). The resin-coated copper-based material 10 thus obtained has an insulating film with a blackish tone, and is therefore suitable as a spring material for optoelectronic components.

The above-mentioned photocurable resin may be those commercially available, and has a composition in which an acrylic resin, an epoxy resin or the like is used as a base resin, and a photoinitiator, a sensitizer or the like is mixed in a solvent. .. In addition, the method of applying the photocurable resin is
A roll coating method or a constant speed pulling method is suitable. Such a photo-curable resin does not have sufficient adhesion to a copper-based material, or has poor wettability to a copper-based material, and thus a uniform thin coating film is often not obtained, resulting in severe bending. Although not applied to materials for electronic parts that require workability and plate thickness accuracy, the wettability is improved and a uniform thin coating film is obtained by forming a copper anodic oxide film.

In FIG. 2, the manufacturing method of the second embodiment is the same as that of the first embodiment up to the step (c) of forming the uncured resin film 6 by applying the liquid material of the photocurable resin. In the second embodiment, when irradiating the uncured resin film 6 with light 7, as shown in (d), a light shielding means 8 such as a metal mask is provided between the copper-based material 1 and the light source (not shown). To place. As a result, as shown in (e), the portion irradiated with the light 7 that has passed through the opening 8a of the light shielding unit 8 is cured to become the resin coating film 3, and the portion shielded by the light shielding unit 8 is the uncured resin film. Remain as 6. Then, the material in this state is washed with a solvent composed of the same solvent as the solvent of the photocurable resin, and the remaining uncured resin film 6 is dissolved in the solvent and removed from the surface. Thus, as shown in (f),
The resin-coated copper-based material 10 on which the resin coating film 3 is partially formed is completed. The surface of the material 10 other than the resin coating film 3 is the copper oxide film 5 having good resin adhesion, and thus is suitable as a material for electronic parts that is resin-sealed during assembly.

In FIG. 3, the manufacturing method of the third embodiment is the same as that of the second embodiment up to the step (f) of partially forming the resin coating film 3. In the third embodiment, the copper oxide film 5 that has reappeared due to the removal of the uncured resin film 6 is washed with an acidic solution to be dissolved and removed from the surface. The acidic solution at this time is preferably a solution of an inorganic acid such as sulfuric acid, hydrochloric acid or nitric acid, a mixed solution thereof, a solution obtained by adding hydrogen peroxide to an inorganic acid, or the like. Good. In this way, as shown in (g), the resin coating film 3 is partially formed, and the resin coating copper-based material 10 having the copper-based material 1 on the other surface is completed. This material 10 is suitable as a material for a high-density mounting connector, which requires plating after punching in order to use the material cross section as a contact.

In FIG. 4, the manufacturing method of the fourth embodiment is the same as that of the third embodiment up to the step (g) of removing the copper oxide film 5. In the fourth embodiment, gold, silver, tin, solder, and the like are formed on the surface of the copper-based material 1 that has reappeared by removing the copper oxide film 5.
One or more metals selected from nickel, copper, palladium and the like are plated to form a metal plating layer 9 as shown in (h). Two or more kinds of plating means two or more layers of plating and / or two or more platings applied separately. In this way, the resin coating copper-based material 10 in which the resin coating film 3 is partially formed and the metal plating layer is formed on the other surface is completed. This material 10 is suitable for a connector material that requires low cost in that plating is performed before punching.

Next, in order to confirm the effect of the present invention,
Test examples conducted on the examples and comparative examples will be described. In this comparative test, the adhesiveness of the resin coating film and the roughness of the surface not coated with the resin were examined for the two samples manufactured according to the above-mentioned examples and the sample of Comparative Example 2.

Test Example 1 Phosphor bronze C5210R plate thickness specified by JIS 0.15 m
Using the strip material of m as a base material, after electrolytic degreasing and pickling, anodic oxidation was performed under the following conditions to form a copper oxide film. <Anodic oxidation conditions> Bath composition: 3% NaOH Bath temperature: 50 ° C. Anode current density: 0.15 A / dm ² Next, a photocurable resin containing a modified acrylate as a main component (manufactured by ThreeBond, TB3041N) at a constant speed. It was applied by the pull-up method, a part of the material was shielded from light by a metal mask, and was cured with a light amount of 3800 mJ / cm ² using a high pressure mercury lamp to form a resin coating film having a film thickness of 20 μm.
Subsequently, this sample was washed with toluene to remove the uncured resin from the surface. Further, this sample having a partially exposed copper oxide film was washed with 5% sulfuric acid to remove the oxide film from the surface.

Test Example 2 A copper alloy (M: 2% Sn, 0.2% Ni, balance Cu)
F202) strip material having a plate thickness of 0.15 mm was used as a base material, after electrolytic degreasing and pickling, anodization was performed under the same conditions as in Example 1 to form a copper oxide film. Next, a photocurable resin containing modified acrylate as a main component (manufactured by ThreeBond, TB30
52F) was applied by a constant speed pulling method, and a resin coating film having a film thickness of 20 μm was formed in the same manner as in Example 1. Further, the uncured resin and the oxide film were removed from the surface by the same method.

Comparative Example 1 The same copper-based material as in Test Example 1 was subjected to a surface roughening treatment by etching with a ferric chloride solution at 40 ° Be, and a polyimide varnish (TVB2703 manufactured by Toshiba Chemical Co.) was partially used. Apply and hold in a drying oven at 200 ° C for 5 hours to cure, then
A resin coating film having a film thickness of 0 μm was formed. At this stage, an oxide film has been formed by heating on the surface of the material not coated with resin.
Washed with% sulfuric acid.

Comparative Example 2 A resin having a film thickness of 20 μm was formed in the same manner as in Example 2 except that the copper-based material of Test Example 2 was not subjected to anodic oxidation to form a copper oxide film and the final pickling. A coating film was formed.

With respect to the resin-coated copper-based materials of Test Examples 1 and 2 and Comparative Examples 1 and 2 manufactured in this way, after scribing 2 mm squares on the resin coating film with a cutter knife, the bending radius was set to 0. It was bent at 2 mm by 90 ° and examined for resin peeling. Further, the surface roughness of the surface not coated with the resin was measured with a surface roughness meter. The results are shown in Table 1.

[0025]

[Table 1]

As shown in Table 1, the resin-coated copper-based materials of Test Examples 1 and 2 have good resin adhesion and small surface roughness. On the other hand, in Comparative Example 1 in which the surface-roughening treatment and the resin are heat-cured, the surface roughness is large, and it can be easily imagined that the above-mentioned problems such as an increase in plating cost may occur. Further, it was shown that in Comparative Example 2 in which the photoeffect resin was applied without performing the anodizing treatment, sufficient resin adhesion could not be obtained.

In the above embodiments, the base material, anodizing conditions, etc. are not limited to the above, and other combinations can be selected. It goes without saying that the material of the present invention can be applied not only to electronic parts but also to other uses such as ornaments.

[0028]

According to the manufacturing method of claim 1 of the present invention, a copper oxide film is formed on a copper-based material, a photocurable resin is applied on the copper oxide film, and cured by light irradiation to form a resin coating film. Therefore, a resin-coated copper-based material having excellent adhesion and easy control of the plate thickness can be easily manufactured at low cost without etching and heating, and the copper-based material does not discolor.

According to a second aspect of the present invention, in order to partially cure the resin film and remove the uncured resin film, a resin-coated copper-based material in which a resin coating film and a copper oxide film coexist. Can be easily manufactured.

According to the manufacturing method of claim 3 of the present invention, since the copper oxide film exposed by the removal of the uncured film is dissolved and removed, the copper oxide film can be easily removed by an acidic solution and there is no discoloration. The copper-based material can be exposed.

According to the manufacturing method of claim 4 of the present invention, since the metal plating layer is formed on the copper-based material exposed as described above, the plating process is easy and the metal plating layer having high adhesion can be formed. ..

[Brief description of drawings]

FIG. 1 is a process chart showing the manufacturing method of Example 1,
(A)-(e) shows each process.

FIG. 2 is a process chart showing the manufacturing method of Example 2,
(A)-(f) shows each process.

FIG. 3 is a process chart showing the manufacturing method of Example 3;
(A)-(g) shows each process.

FIG. 4 is a process chart showing the manufacturing method of Example 4;
(A)-(h) shows each process.

FIG. 5 is a process chart showing a conventional manufacturing method, including (a) to
(E) shows each process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copper-based material 3 Resin coating film 5 Copper oxide film 6 Unhardened resin film 7 Light 8 Light-shielding means 9 Metal plating layer 10 Resin-coated copper-based material

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area // B32B 15/08 G

Claims (4)

[Claims] 1. A base material made of copper or a copper alloy is anodized in an alkaline solution to form a copper oxide film on the surface of the base material, and a photocurable resin is applied on the base material to form a photocurable resin. A method for producing a resin-coated copper-based material, which comprises curing the resin coating film on the surface of the base material by irradiating the resin material. 2. A base material made of copper or a copper alloy is anodized in an alkaline solution to form a copper oxide film on the surface of the base material, and a photocurable resin is applied on the copper oxide film. By irradiating light through the partial light shielding means to the base material to cure the irradiated portion to partially form a resin coating film, and removing the uncured resin film by dissolving it in a solvent, A method for producing a resin-coated copper-based material, which comprises partially forming a resin coating film on a surface of a base material. 3. A base material made of copper or a copper alloy is anodized in an alkaline solution to form a copper oxide film on the surface of the base material, and a photocurable resin is further applied onto the base material to form a copper oxide film. By irradiating light through the partial light shielding means to the base material, the irradiated portion is cured to partially form the resin coating film, and the uncured resin film is dissolved and removed in the solvent to expose it. The resin-coated copper is characterized in that a resin coating film is partially formed on the surface of the base material without dissolving the copper oxide film on the outermost surface by dissolving and removing the copper oxide film to be removed. Method of manufacturing base material. 4. A base material made of copper or a copper alloy is anodized in an alkaline solution to form a copper oxide film on the surface of the base material, and a photocurable resin is further applied thereon to form a copper oxide film. By irradiating light through the partial light shielding means to the base material, the irradiated portion is cured to partially form the resin coating film, and the uncured resin film is dissolved and removed in the solvent to expose it. The method for producing a resin-coated copper-based material, characterized in that the copper oxide film is dissolved and removed with an acidic solution, and one or more metal plating layers are formed on the exposed surface of the base material.