JPH0720687B2 - Method for manufacturing copper clad laminate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a copper-clad laminate by continuously forming a copper foil layer by a continuous forming method.

[Conventional technology]

A predetermined number of long resin-impregnated base materials are sandwiched between a pair of upper and lower endless belts, and a copper clad laminate obtained by continuously press-molding is laminated by hot-pressing and heat-molding. It is known that it has less variation than copper-clad laminates and is superior in plate thickness accuracy, warpage, and dimensional stability.

In this continuous molding, a long prepreg coated and wound in advance is used, and the prepreg is supplied between upper and lower endless belts, that is, supplied to a double belt press machine and pressure-heat molded. Pressurization and heating include a method of pressurizing the belt with a roll, a method of pressurizing and heating the belt by hydraulic pressure, and a method of pressurizing and heating with air, each of which has its own characteristics.

There is a feature that the processing cost becomes low when continuous molding is performed, and in particular, glass epoxy copper clad laminate is often subjected to continuous molding not only for manufacturing cost but also for improving quality characteristics.

[Problems to be Solved by the Invention]

In the conventional continuous molding, the resin impregnation device and the pressure heating molding device are integrated, and the process from the base material to product cutting is performed continuously, but in terms of the cost of the copper clad laminate, only part of the processing cost is reduced. Absent. Further, in the conventional copper-clad method using these devices, a long copper foil is superposed on the outside of a plurality of long prepregs which are superposed and fed between the belts and simultaneously fed and heated under pressure.

However, when a very thin copper foil is stretched on a laminated plate, there is a problem that wrinkles and folds are generated in the copper foil due to the meandering of the base material and the meandering of the endless steel belt,
Continuous molding could be adopted only when the copper foil was thick.

In view of the above problems, the present invention provides a method capable of efficiently manufacturing a thin copper clad laminate.

[Means for Solving the Problems]

The present invention is a method of continuously forming a long laminated material sandwiched between a pair of endless steel belts, so that a copper foil is deposited on the upper surface of the belt through the electroless copper plating solution tank on the outer belt portion of the pulleys on both ends, Subsequently, the copper foil layer of the copper foil-clad belt is overlaid with the laminated material to be supplied and heated under pressure.

Next, the present invention will be described in detail. The explanatory view of FIG. 1 is a belt press including an upper steel belt 7, a lower steel belt, a lower drive pulley 13 and a heating / pressurizing container 9.
The four prepreg windings 4 together with the thin film 5 reach the supply port consisting of the upper drive pulley 12 and the lower drive pulley 13 via the guide rolls 6, are sandwiched by the upper and lower steel belts, and are continuously molded through the pressure heating container 9. Then, it is cut by the cutting machine 10.

The upper steel belt 7 is driven from the pressure heating container 9 to the drive pulley.
In the pretreatment tank 1 through 12 was treated with a solution of 0.1% sodium hydroxide aqueous solution and 1% sodium borohydride for 30 seconds, and then a solution of 1% PdCl ₂ dissolved in formamide was added to 0.3%. Dissolved in aqueous sodium hydroxide solution 0.05%
Swing the PdCl ₂ liquid of above onto the upper surface of the belt by spraying. Further, the liquid is drained and placed in the reduction tank 2, and a spray of a reducing solution in which 0.1% sodium borohydride is dissolved is shaken and sprayed. Subsequently, the electroless copper plating solution tank 3 is put in, and when the electroless copper plating solution is sprayed while the spray is swung, copper is thinly deposited over the entire width of the belt surface. In order to make this deposited copper foil thick, the tank 3 is lengthened and the tanks 1 and 2 are
3 to 4 times the length of. In this way, the upper belt 7 to which the copper is attached reaches the gap supply port of the pulleys 12 and 13, overlaps with the prepreg and the release film, is sandwiched between the upper and lower belts, reaches the pressure heating container 9, and is pressurized and heated. Are laminated and formed, and the copper foils are joined and integrated.

Since the electroless copper plating method used in the present invention is alkali plating, copper having a thickness of 0.1 to 0.5 μ is deposited on the belt without corroding the steel belt. Depending on the material of the laminated plate, an adhesive is applied to the laminated base material to supplement the adhesion with copper during the pressure and heat treatment.

The laminated molding material according to the present invention can be used not only as a single layer board but also as a constituent material of a multilayer wiring board. In particular, when the substrate is formed with through holes, the surface layer and the copper foil in the through holes have the same thickness, so that the reliability of the through holes is improved.

The pressurizing and heating vessel 9 used in the present invention may be an apparatus using a steel belt, but in particular, dirt and scratches on the belt appear as surface scratches on the deposited copper foil. is there.

Since the productivity of the present invention depends on the ability of copper foil deposition, the productivity is improved by lengthening the electroless copper plating bath. It also improves depending on high-speed plating conditions.

Also, by applying a plating resist to the belt,
The copper foil deposition width can be adjusted.

The base material used is paper, glass cloth, glass mat, glass non-woven fabric, etc., and the resin used is a resin developed for printing base materials, and phenol resin, epoxy resin, polyester resin, acrylic ester resin, polyimide resin, etc. are suitable. ,
In the case of continuous production from a substrate, a solventless type resin which is fast-curing is suitable.

[Action]

In the present invention, the upper surface of the steel belt is passed through the pretreatment tank and the reduction tank in the electroless copper plating solution tank until the endless steel belt is separated from the forming plate, moved, and laminated with the laminated material supplied again. Spray to deposit thin copper foil. This copper foil moves in a state of being weakly bonded to the steel belt, overlaps the laminated material to be supplied, is sandwiched by the lower steel belt, is moved to a pressure heating container, and is heated under pressure. Therefore, even if the ultra-thin copper foil is formed, no crease or wrinkle is caused.

In addition, in the present invention, there is a remarkable advantage in supplying the copper foil while forming the copper foil simultaneously with the continuous forming of the copper clad laminate.

〔Example〕

1. 0.18mm thickness, 1050mm width, 200g / m ² weight of glass cloth is treated with epoxysilane, and the epoxy resin / hardening agent / hardening accelerator compounded fast-curing liquid resin is applied to it using a coating device. Impregnation was performed so that the amount of resin was 50% by weight.

The steel belt was driven at a line speed of 50 cm / min, and the distance between the front and rear pulleys was set to 15 m. The pretreatment tank was sprayed with an aqueous solution of palladium chloride and sodium hydroxide for 5 minutes, and the reducing tank was sprayed with an aqueous solution of sodium borohydride for 5 minutes. The length of each tank was 3 m. Next, after spraying for 10 to 15 minutes in an electroless copper plating bath, washing with water and drying with hot air were performed.

The steel belt after the above treatment was overlapped with the above-mentioned seven resin-impregnated base materials at the supply port and molded in a pressure heating container to obtain an ultrathin copper-clad glass epoxy resin laminate having a thickness of 1.5 mm.

The resulting laminate was suitable for through hole plating.

2. Preliminary glass epoxy resin 0.2mm thick prepreg 4
The sheet was fed to a steel belt treated with an electroless copper plating solution as in Example 1. The belt was driven at a line speed of 20 cm / min, and the ultrathin copper clad laminate obtained by heating under pressure was excellent as a multilayer material and was suitable for through holes.

〔The invention's effect〕

According to the present invention, the cost is reduced because the copper foil is laminated while being simultaneously formed, and the energy consumption is low because it is produced without electrolysis, and the deposited ultrathin copper is bent while being adhered to the belt, so that it is bent. I don't have any problems.

The copper clad laminate manufactured according to the present invention has high through hole reliability.

[Brief description of drawings]

 FIG. 1 is a schematic explanatory view of the entire apparatus according to the present invention. Explanation of symbols 1 ... Pretreatment tank, 2 ... Reduction tank 3 ... Electroless copper plating solution tank 4 ... Prepreg winding, 5 ... Release film 6 ... Guide roll, 7 ... Upper steel belt 8 ... Lower steel belt 9 ... Pressurization Heating container, 10… Cutting machine 11… Copper clad laminate, 12… Upper drive pulley 13… Lower drive pulley

Claims (1)

[Claims] 1. A method of continuously molding a long laminated material sandwiched between a pair of endless steel belts, wherein an outer belt portion of a pulley on both ends is passed through an electroless copper plating bath to deposit copper on the upper surface of the belt to form a copper foil. A method for producing a copper-clad laminate, which comprises forming a belt with a copper foil, and further stacking the copper foil layer of the belt with a copper foil with a laminated material that is continuously supplied and heating under pressure.