JPS5910308B2 - Double-sided copper clad laminate - Google Patents

Description

[Detailed description of the invention] The present invention relates to a double-sided copper-clad laminate.

Conventional double-sided copper-clad laminates are made by stacking the required number of resin-impregnated papers impregnated with a thermosetting resin varnish such as phenol formaldehyde resin and having approximately the same resin content, placing copper foil on both sides, and then heating them. Although it is manufactured by pressing, it has the disadvantage that warping and twisting that occur during and after the processing process are large regardless of the copper foil residual rate. The present invention solves the above-mentioned drawbacks, and its purpose is to impregnate paper of the same type and thickness with resin to prepare a main impregnated paper layer and a control impregnated paper layer with different resin contents. By providing adjustment impregnated paper layers with a lower resin content than the main impregnated paper layer on both the front and back sides of the main impregnated paper layer, it is possible to reduce warping and twisting that occur during and after processing. We offer tension laminates.

The present invention will be described in detail below.

As shown in Figure 1, the double-sided copper-clad laminate is made of a main impregnated paper layer 1, an upper adjustment impregnated paper layer 2, a lower adjustment impregnated paper layer 3, and a copper foil layer 4. The resin content of the main impregnated paper layer 1, which is made by laminating a plurality of sheets of impregnated paper impregnated with a synthetic resin, is 49 to 6096, and the resin content on both the front and back sides of the main impregnated paper layer 1 is lower than that of the main impregnated paper layer 1. Te44~4
An upper impregnated paper layer 2 for adjustment and a lower impregnated paper layer 3 for adjustment are each formed of a sheet of impregnated paper having a resin content of 9%. Here, the impregnated paper of the main impregnated paper layer 1 and the impregnated paper of the adjustment impregnated paper layers 2 and 3 are of the same type and thickness. A copper foil layer 4 is provided on the outer surface of each of the conditioning impregnated paper layers 2 and 3, and the copper foil layer 4 is etched with an etching solution such as ferric chloride. As described above, the adjusting impregnated paper layers 2 and 3 having a lower resin content than the main impregnated paper layer 1 are provided on both the front and back sides of the main impregnated paper layer 1, and the copper foil layer is formed on the outer surface of each adjusting impregnated paper layer 2 and 3. 4 to form a double-sided copper-clad laminate, the laminate may warp or twist due to the difference in thermal expansion coefficient between the copper foil layer 4 and the main impregnated paper layer 1 when the laminate is heat-treated. However, the tree is more dense than the main impregnated paper layer 1.
The impregnated paper layers 2 and 3 for adjustment, which have a low fat content, act to prevent warping and twisting, so that warping and twisting occurring in the laminate can be minimized. Since the present invention has the above configuration, it is possible to reduce warping and twisting that occur in the laminate during and after the processing process. Moreover, since the main impregnated paper layer and the adjustment impregnated paper layer are prepared by impregnating paper of the same type and thickness with resins at different resin contents, only one type of paper is used, and the resin-containing Warpage correction can be easily and precisely controlled by simply changing the rate, and manufacturing and quality control are also easy. The present invention will be explained in detail below using examples.

Examples 1 to 2 Methanol was added to a resol type phenol formaldehyde resin (reacted by adding 37% formalin to a mixture of carbolic acid and cresol) to obtain a varnish with a solid content of 60%.

Craft paper for laminates (10 mils) was impregnated with the above varnish and heated and dried at 130 to 155°C for 5 to 10 minutes to give resin contents of 45%, 48%, 51%, and 54%, respectively.
%, 60%, and resin flow of 7 to 9 (L) were obtained. Here, the resin-impregnated paper with a resin content of 45 (fl) was A, the one with a resin content of 48% was B, and the resin flow was 7 to 9 (L). thing C, 54
% is D and 60% is E. This impregnated paper A
-E as shown in Table 1, put one sheet of 35μ thick adhesive-coated copper foil on both sides, and apply a pressure of 120 to 130 kg/c! ! L2
, a thickness of 1.611 after being hot-pressed for 60 minutes at a temperature of 154-160°C! A double-sided copper-clad laminate was obtained. Table 2 A 200×200n circuit was formed on the resulting laminate using a conventional etching method, with a copper foil residual rate of 60% on one side and 30% on the opposite side.

After circuit formation, the laminate was heated at 130°C for 2 minutes, then at 140°C.
After heating and drying at 150℃ for 20 minutes,
It was heated at 5°C for 10 minutes and punched using an 80-ton power press. A punched laminate? Using a warp measuring machine with an n-dial gauge, measure the maximum warp at a fulcrum distance of 180n, and measure the maximum warp at a fulcrum distance of 250? The diagonal warpage of the laminated sheets was measured, and the difference between the absolute values was measured as the torsion. The results are shown in Table 2. As is clear from Table 2, Examples 1 and 2 had significantly less warp and twist than the comparative example. Example 3 Resol type phenol formaldehyde resin (37% carbonic acid formalin, a resin reacted with an ammonia catalyst, containing mono- to dinuclear methylolphenol as the main component), methanol and water in a weight ratio of By mixing, a varnish with a specific gravity of 0.92 to 0.95 and a solid content of 20 to 30% was obtained.

This varnish was used to impregnate 10 mils of kraft paper for laminates, and heat-dried at 130-155°C for 5-10 minutes.The resin content was 7-9% for A, 10-12% for B, and 10-12% for C. is 13 to 15%, and the volatile content of A, B, and C is 2.5 to 3.
．． 5% resin-impregnated papers A, B, and C were obtained.

Using this impregnated paper, we further prepared a resol-type formaldehyde resin (37% formalin was added to a carbonic acid cresol mixture and reacted with a 25$ ammonia catalyst, and a methanol solvent was added to make the solid content 55-57%). and the total resin content was 45%, 47%, as shown in Table 3.
Eight types of resin-impregnated papers with 50% and 55% were obtained.

The above resin-impregnated papers a1 to C are combined as shown in Table 4 to a thickness of 35
Place one piece of μ copper foil with adhesive on both sides and apply pressure to 120~13cm.
A double-sided laminate with a thickness of 1.6 nm was obtained by heat molding at a temperature of 154 to 160° C. for 60 minutes at a temperature of 01<9/Brain 2 and a temperature of 154 to 160°C.

The resulting laminate was 200×2001rg in size with a copper foil remaining rate of 60% on one side and a circuit of 30 (F6) on the other side by a normal etching method.

After forming the circuit, it was dried by heating at 130°C for 2 minutes, then at 140-150°C for 20 minutes, then further heated at 80-120°C for 10 minutes, and punched using an 80-ton power press. This laminate board i. . Distance between fulcrums is 1801 using a warp measuring machine with ml dial gauge! The maximum warpage is 250m1 between fulcrums.
The diagonal warpage of the laminate was measured, and the absolute value of the difference was defined as the torsion. As is clear from the table, ▲1 to Jf65 had much smaller warp and twist than ▲6 to Jf68.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an example of the present invention, FIG. 2 is an explanatory diagram of the same manufacturing process, and FIG. 3 is an explanatory diagram of a comparative example during manufacturing, in which 1 is the main impregnated paper layer, 2 The upper adjustment impregnated paper layer 3 is the lower adjustment impregnated paper layer, and 4 is the copper foil layer.

Claims (1)

[Claims] 1. Prepare a main impregnated paper layer and an adjustment impregnated paper layer by impregnating paper of the same type and thickness with resins at different resin contents. A double-sided copper-clad laminate comprising a small number of adjustment impregnated paper layers and a copper foil layer provided on the outer surface of each adjustment impregnated paper layer.