JPS6144637A - Manufacture of unsaturated polyester metallic-foil lined laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for manufacturing a metal foil laminate using unsaturated polyester resin for use as a printed circuit board.

1. The base material is paper, glass cloth, glass paper, etc., and multiple sheets of resin-impregnated base material impregnated with resin liquid are laminated,
A hardened laminate and a metal foil-covered laminate formed by laminating metal foil on one or both sides of the laminate are used as insulating plates and printed wiring boards.

Conventionally, these laminates were manufactured using a batch method in which the base material was impregnated with resin varnish and dried, then the resulting briple knobs were layered and formed by pressurizing and heating in a press, but recently, long base materials have been A continuous method in which resin impregnation, lamination, curing, etc. are carried out while continuously transporting the resin in one step has been developed and is attracting attention. .

The paper JJ5 material unsaturated polyester resin copper clad laminate manufactured by the continuous method is named "Fcelite" by the applicant.
It is commercially available under the trade name ``Paper Phenolic Copper Clad Laminates'' and is widely used primarily in consumer electronics products due to its many superior features compared to conventional paper phenolic resin copper clad laminates.

In recent years, the printed circuit boards used in these consumer electronic products are
With the spread of automation of the processing process and the automation of parts insertion into the board, the limits of the allowable value for warpage are becoming increasingly strict, and it is desired to supply products with even less warpage.

Under these circumstances, the present invention provides a product with improved warpage characteristics.

■The warpage of metal foil-clad laminates manufactured by the following continuous method is as follows:
It was found that there is a relationship with the water content of the uncured unsaturated polyester resin present in the base material layer after impregnation and before curing. That is, if the water content of the resin at this time is below a certain value, the amount of warpage of the product will increase, and if it is too excessive, other properties of the product, such as bending strength, will be reduced.

Therefore, the present invention impregnates a plurality of sheet-like substrates with a liquid unsaturated polyester resin while continuously conveying the substrates, combines the plurality of impregnated substrates, and at least In a continuous manufacturing method for metal foil-clad laminates, which includes a continuous process of laminating metal foil on one side and then curing the entire board, the water content of the unsaturated polyester resin in the base material layer after impregnation and before curing is reduced to 200 to 2000 ppm. It is characterized by being adjustable within a range.

The moisture range is more preferably 500 to 1000p.
The range is p+a.

The drawing is a schematic side view of an example of an apparatus for manufacturing a single-sided metal foil-clad laminate by carrying out the method of the present invention.

A base material 2, for example kraft paper 2 made of cellulose fiber, wound around a roll 1 is continuously conveyed to a pretreatment chamber 3.
to go into. In the drawing, three substrates are shown to be conveyed at the same time, but it goes without saying that the number of substrates can be increased or decreased as appropriate depending on the final thickness of the laminate. The base material 2 then enters the resin liquid impregnation chamber 4, where it is impregnated with resin liquid, and is placed between a pair of squeegees.
It passes between Growl 5.5 and is combined. At this time, the metal foil 8 fed out from the roll 7 is coated with adhesive and laminated on the top surface of the laminate of impregnated base materials, and the carrier sheet 10 fed out from the roll 9 is placed on the bottom surface of the laminate.
For example, polyester films are laminated together by rolls 5. The thus obtained uncured laminate enters the curing furnace 12, where it is heated and cured while traveling therein. The lower carrier sheet 10 is peeled off from the laminate 14 leaving the curing furnace 12 by a Ronil 13 and wound up as a roll 11. Next, the laminate 14
The ends of both ears are trimmed by a rotary cutter 18, and the cutter is cut to a required length by a guillotine cutter 19. The previous portions of this device are substantially the same as those disclosed in Japanese Patent Application Laid-Open Nos. 55-4838 and 56-98136, both of which were previously cited.

In the present invention, the term "substrate layer after impregnation and before curing" refers to the substrate layer 2 that is being transported from the impregnation chamber 4 to the rolls 5, 5 in the drawings. The moisture content of the resin in the base material layer between these layers is reduced to 200%.
from 2000 ppm, preferably from 500 to 110
In order to adjust the moisture content within the range of 0.00 pp, the impregnation chamber is humidified or dehumidified depending on the water content already contained in the resin liquid supplied to the impregnation chamber 4, and the moisture content is increased while the base material layer advances through the chamber. An equilibrium state may be established between the humidity in the room and the moisture content of the resin.

However, in general, the present applicant's Japanese Patent Application Laid-Open No. 56-131
As disclosed in No. 36, the resin liquid supplied to the impregnation chamber is degassed under reduced pressure to eliminate the generation of fine bubbles in the product, so dissolved gas is removed and moisture is removed at the same time. has also been removed. Therefore, the relative humidity in the impregnation chamber 4 may be adjusted so that the inside of the impregnation chamber 4 is humidified and the resin liquid in the base material layer immediately after impregnation absorbs moisture and reaches an equilibrium within the moisture range. As a result, the water content of the resin in the base layer is maintained substantially within the desired range during the progress from the impregnation chamber 4 to the rolls 5,5.

If the moisture content of the resin is too low, the warpage of the product will exceed the allowable value; on the other hand, if it is too high, the strength of the product will be adversely affected. It has been found that the moisture content must be within the range.

EXAMPLE An unsaturated polyester resin liquid was prepared consisting of 100 parts by weight of a commercially available unsaturated polyester (Polymer 3311, manufactured by Takeda Pharmaceutical Co., Ltd.), 1 part by weight of cumenohydronoxoxide, and 0.2 parts by weight of 6% cobalt naphthenate.

Using the apparatus shown in the drawing, five sheets of crust paper (Ryosumi Kokusaku Pulp Z13S-135, 10 mil), which had been pretreated with melamine resin in the pretreatment chamber 3, were impregnated with the resin liquid in the impregnation chamber 4. , a copper foil coated with an epoxy adhesive is laminated on the upper surface, a polyester film is laminated as a carrier sheet on the lower surface, and the mixture is heated in a curing furnace 12 at 110°C. The mixture was cured for 30 minutes at 150° C. and then for 15 minutes at 150° C. to obtain a single-sided copper foil-clad laminate having a thickness of 1.6111 mm.

At this time, the temperature inside the impregnation chamber 4 is maintained at 40°C and the relative humidity is 95%, and the moisture content of the resin liquid in the product base material layer is reduced to 800% immediately after leaving the impregnation chamber.
Adjusted to ppm.

The obtained laminate was cut into a length of 300 nm and a width of 240 m+*, and after being left in a constant temperature and humidity room at 40°C and 85% RH for 4 days, it was placed on a surface plate with the convex side facing down, and the height of the four corners was adjusted. measure,
The average value was taken as the amount of warpage.

When the moisture content of the resin in the base material layer after impregnation and before curing is within the above range, the amount of warpage is -1.5 mm (concave with the metal foil surface inside), whereas when the moisture content is 200 ppm or less, The amount of warpage of the product was -3.0 mm.

Further, the bending strength of the laminate according to the present invention is 17+r/
- However, when the water content exceeded 2 QOOppm, the bending strength decreased to 14 kg/-' and contained fine bubbles, which were thought to be caused by evaporation of water during curing.

[Brief explanation of drawings]

The drawing is a schematic diagram of an apparatus for implementing the invention. 2 is a base material, 4 is an impregnating chamber, 5 is a laminating roll, 8 is a metal foil, 10 is a carrier sheet, and 12 is a curing chamber.

Claims (4)

[Claims] (1) While continuously conveying multiple sheet-like base materials,
A metal foil comprising a continuous process of impregnating the substrate with a liquid unsaturated polyester resin, combining a plurality of impregnated substrates, laminating a metal foil on at least one side of the combined substrate, and then curing the whole. In the continuous manufacturing method of stretched laminates,
The method described above is characterized in that the moisture content of the unsaturated polyester resin in the base material layer after impregnation and before curing is adjusted to a range of 200 to 2000 ppm. (2) The method of item 1, wherein the moisture content of the unsaturated polyester resin is in the range of 500 to 1000 ppm. (3) The method of item 1, wherein the base material is paper. (4) The method of item 1, wherein the unsaturated polyester resin is subjected to reduced pressure treatment before impregnation.