JPH0587386B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for manufacturing a metal-based copper-clad laminate with excellent adhesion. [Conventional technology] In recent years, electric devices have become lighter, thinner, and more dense, and the electronic components used in these devices have become more densely packaged. As a result, the amount of heat generated per unit surface area has increased significantly. The wiring boards on which electronic components are mounted are also required to have excellent heat resistance and heat dissipation. In recent years, aluminum,
Printed circuit boards based on metal plates such as copper or iron have come into use. Especially for printed circuit boards that incorporate small electronic motors or rotation speed and position detection circuits.
Cold-rolled steel plates and silicon steel plates with better electromagnetic properties are usually used for the base. However, these steel plates have poor corrosion resistance and are prone to rust, especially in summer or when it is humid. Therefore, the surface is usually plated with zinc, etc., and then treated with chromate or phosphate to further improve corrosion resistance. is commercially available. [Problems to be solved by the invention] Copper-clad laminates in which copper foil is laminated via an adhesive insulating layer using such galvanized steel sheets have poor adhesion between the steel sheet and the insulating layer, and, for example, have a long lifespan. When performing a high temperature humidification test to confirm this, the insulating layer tends to peel off. Furthermore, there is a problem in that if the drying after etching or cleaning is even slightly insufficient during the production of a printed circuit board, blisters are likely to occur during solder reflow. The present invention was made in view of the above situation, and it is an object of the present invention to provide a method for manufacturing a steel plate-based copper-clad laminate in which the adhesion between the galvanized steel plate and the insulating layer is improved. [Means for Solving the Problems] According to the present invention, the purpose is to form a thin film of thermosetting resin on the surface of a galvanized steel sheet that has been treated with chromate or phosphate, and to apply an adhesive layer thereon. This is achieved by laminating copper foil through an insulating layer. The galvanized steel sheets used in the present invention include ordinary steel sheets such as cold-rolled steel sheets and hot-rolled steel sheets, as well as silicon steel sheets with excellent electromagnetic properties, which are coated with zinc or a base metal or composite plating mainly composed of zinc, and further laminated plating. It is a steel plate that has been treated with The amount of zinc deposited is 5 to 70
g/m ² is desirable; if it is less than 5 g/m ² , there will be no corrosion resistance effect, and if it exceeds 70 g/m ² , peeling will occur more easily than the galvanized layer during punching with a press.
Further, the chromate treatment applied thereto forms a film of hydrated chromium oxide, etc., and the phosphate treatment forms a film mainly composed of zinc phosphate or the like. These treatments increase corrosion resistance and improve adhesion to resin. The amount of chromium deposited in chromate treatment is 10~
200 mg/m ² is suitable, and in the case of phosphate treatment, 1 to 5 g/m ² is desirable. Thermosetting resins applied over this chromate or phosphate treatment include alkyd resins, phenolic alkyd resins, amino alkyd resins, acrylic resins,
These are water-soluble polymer compounds such as epoxy ester resins, or water-insoluble resins such as epoxy resins, phenolic resins, and unsaturated polyester resins. Furthermore, inorganic substances such as silicon, titanium, or aluminum may be added to prevent the chromate film from deteriorating over time and improve corrosion resistance. The coating amount of these thermosetting resins is 0.1 to 3
g/m ² is desirable. Adhesion is less than 0.1g/ ^m2 ;
The effect of improving corrosion resistance is small, and if it exceeds 3 g/m ² , the adhesion with the insulating layer decreases. The adhesive insulating layer used in the present invention is made of epoxy resin, phenolic resin, unsaturated polyester resin, polyimide resin, etc., and various hardening agents, pigments, inorganic fillers, etc. may be added thereto. This insulating layer can be formed by applying these resins to copper foil or the above-mentioned galvanized steel sheet, or by making these resins into adhesive prepreg sheets reinforced with a base material such as glass fiber or polyester fiber paper, and applying these resins through the resin. A laminate is produced by laminating copper foil and applying heat and pressure. As the heating and pressing method, a laminated press is usually used, but a continuous pressing steel belt or a roll press may also be used. The present invention will be explained in more detail below based on examples. Example 1 Electrolytic galvanized steel sheet (SECC) made of SPCC with a thickness of 1 mm and galvanized with a zinc coating amount of 20 g/m ²
Then, CrO ₃ /10g/, H ₃ BO ₃ 5g/, were used as a base liquid, silicate was added as a reducing agent, and a chromate solution at a bath temperature of 50°C was sprayed to reduce Cr.
The hydrated oxide was subjected to chromate treatment of 50 m ² /m ² and dried. An aqueous solution of a water-soluble polymer compound prepared by dispersing silica sol in an acrylic modified alkyd resin was applied to the chromate-treated surface using a roll coater, and dried to form a film of 500 mg/m ² . A galvanized steel plate was created. In addition, epoxy resin liquid of 35μ copper foil was applied and dried to create a copper foil with an 80μ insulating layer.
Overlaid on the above galvanized steel plate, 30Kg/cm ² , 160
A single-sided copper-clad laminate was obtained by heat-pressing molding at ℃ for 2 hours. Example 2 An electrogalvanized silicon steel plate (JIS C2552-S18) with a thickness of 0.5 mm and galvanized at 20 g/m ² was used in the same manner as in Example 1, but chromate treatment was applied at 50 mg/m ² and acrylic was applied. Modified alkyd resin coating
A single-sided copper-clad laminate was obtained using a steel plate formed at 600 mg/m ² . Example 3 Galvanizing amount 20g/mm on SPCC plate thickness/mm
m ² , the same epoxy resin solution as the insulating layer was applied with a roll coater to a commercially available electrogalvanized steel sheet that had been subjected to subsalt phosphate treatment at 3 g/m ² and dried to form a layer of 800 mg/m ² . A single-sided copper-clad laminate was obtained in the same manner as in 1. Comparative example 1 Galvanizing amount 20g/1mm plate thickness SPCC
A single ^- sided copper-clad laminate was obtained directly in the same manner as in Example 1 without providing an organic polymer coating on a commercially available electrogalvanized steel sheet that had been subjected to a chromate treatment of 25 mg/m ² . Comparative Example 2 A single-sided copper-clad laminate was obtained in the same manner as in Example 1 using a galvanized steel sheet coated with the same epoxy resin as the insulating layer at 5 g/m ² in the galvanized steel sheet of Example 3. Comparative Example 3 The galvanized steel sheet of Example 1 was treated in the same manner as in Example 1, using a galvanized steel sheet in which 800 mg/m ² of acrylic modified alkyd resin was directly formed on the galvanized surface without chromate or zinc phosphate treatment. A single-sided copper-clad laminate was obtained. Comparative Example 4 One side of the commercially available electrogalvanized steel sheet of Comparative Example 1 was surface roughened with #180 sandpaper, and copper foil was laminated thereon via an insulating layer in the same manner as in Example 1, resulting in single-sided copper clad lamination. Got the board. The following tests were conducted on the copper-clad laminates obtained in Examples 1 to 3 and Comparative Examples 1 to 4, and the results are shown in Table 1. 1. Withstanding voltage: According to JIS C2110 (DC) 2. Soldering heat resistance: 300℃ - 1 minute (according to JIS C6481): ○: No abnormality, ×: Blistering 3. PCT (pressure vacuum test): 121 ℃, in a steam atmosphere at 2 atm ○: No peeling of the insulation layer, ×: Peeling of the insulation layer 4. Boiling for 2 hours: Immersed in boiling water for 2 hours ○: No peeling of the insulation layer, ×: Peeling of the insulation layer 5. Fingerprint resistance: ○: Steel plate Fingerprint marks are not noticeable even when you touch the steel plate part with your finger ×: Fingerprint marks remain when you touch the steel plate part with your finger. 6. Salt water spray: 35℃, 5% concentration salt water spray test for 48 hours ○: No rust, ×: Rust occurred Note) Solder heat resistance, PCT, and boiling tests were performed by etching the copper foil of a single-sided copper-clad laminate. Tests were conducted after removal.

〔Effect of the invention〕

As is clear from the results shown in Table 1, according to the present invention, it has become possible to provide a steel plate-based copper-clad laminate with excellent voltage resistance, solder heat resistance, and insulating layer adhesion.

Claims (1)

[Claims] 1 By applying a thermosetting resin at a rate of 0.1 to 3 g/ ^m2 to the surface of a chromate or phosphate treated galvanized steel sheet, the thickness is reduced to 0.1 to 3 g/m2.
A method for producing a steel sheet-based copper-clad laminate, which is characterized by forming a thin film of 2.5 μm and laminating copper foil on top of the thin film through an adhesive insulating layer.