JPS6110453A - Manufacture of laminated board for chemical plating - 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] [Industrial Application Field] This invention improves reliability by providing a smooth adhesive layer for chemical plating to improve printability, adhesion of the plating layer, and solder heat resistance. The present invention relates to a method of manufacturing a laminate for chemical plating, the purpose of which is to achieve the desired results.

[Conventional technology]

In manufacturing printed wiring boards, the substrative method of etching copper 7Pi has been widely used for a long time, but as the density of electronic devices has increased in recent years, demands for conductor width and conductor spacing have become even more important. As the technology became more stringent, the substrative method was unable to provide a satisfactory solution due to obstacles such as side edges, and the additive method, in which circuits are formed by chemical plating, has come into the spotlight. In order to improve the adhesion between the conductive metal to be formed and the laminate, the wiring manufacturing method involves providing an adhesive layer made of rubber and thermosetting 46I fat on the surface of the laminate, and chemically bonding the rubber. A conductive circuit is formed on the surface of the adhesive layer, which has been roughened by elution, by chemical plating or a combination of chemical plating and electroplating. It can also be manufactured using a small amount of copper,
This is a preferable method from the standpoint of resource saving. The following three methods can be cited as typical methods for producing a laminate suitable for such an additive method. That is, (1) A chemical plating varnish is applied to the surface of the laminate by dipping or o-rucoating (this method is followed by drying).

■ A desired number of prepregs impregnated with thermosetting resin are layered on a sheet of jil- (one side of the surface and separated from the other) to form an adhesive layer for chemical plating.
Release 1%Q Firno 4-Nakane 10, these 5
・Method that requires 11 steps to integrate without heating and pressurizing.

■ Place the mold release film J so that the frt layer, IN * if + i t, and # are on the inside of the adhesive layer for chemical mets, which has been shaded on one side of the mold film, and heat and press them together. This is a method of chemical molding.

[Problems to be solved by the invention] However, in the case of method (①), even though it has advantages such as being inexpensive and having less mixing of the adhesive with the resin of the laminate, The bonding force between the surface of the laminate and the adhesive layer may be insufficient, or the resin may aggregate during the drying process, resulting in wrinkles, mottling, etc., or even undesirable evaporation of the solvent may cause adhesion. Due to the serious drawback that surface roughness increases due to the occurrence of surface curvature (when printing with metsukiresist ink, bleeding occurs and printing accuracy decreases, additive In addition, in the method (2), it is inexpensive, a smooth adhesive layer surface can be easily obtained, and the adhesive layer and the 1st and 11th layer plates can be easily formed. It has the advantage of good bonding strength.However, the surface of the normal prepreg is exposed between the fibers, and during hot-pressure molding,
The adhesive with increased fluidity invades the filaments f (gap) on the surface of the prepreg, causing disturbances in the composition of the adhesive for chemical plating.As a result, the adhesive layer may become rough or not be applied uniformly over the entire surface. The thickness of the adhesive layer also becomes uneven, and the conductive circuit board formed by plating is difficult to coat and solder.
Reliability will be significantly reduced in terms of thermal properties. Sara(
Although this method has the characteristic that a smooth and uniform adhesive layer can be obtained, it has the disadvantage of reducing production efficiency due to the need to perform heating and pressure molding twice, so it is not preferred. I can't say that.

[Means for solving problems]

In order to determine the i4 point between the two legs, this invention is based on the prepreg forming the surface layer of the laminate to which the chemical plating layer is to be applied. Layer a prepreg that is flat and smooth with a resin content of 1 or 3 () to 70, and then layer this prepreg surface with IJIP + (1, The chemical plating layer 1 and the adhesive layer, which are 1 x 1 x 1 x 1 x 1 on one side of the 1 film, are in close contact with each other. The prepreg of this invention, which has an extremely smooth surface and a resin content of 30 to 70%, is a method of manufacturing a laminate for chemical plating. It is the same as conventional prepreg in that it is impregnated or coated, but at least the surface is made extremely smooth (by making the fiber gaps dense and exposed by the following methods (Method A, Method 8, Method C)). The fact that A
Method/Characteristics of the laminate to be obtained and the associated forming element fl
The resin content of the prepreg is usually 30~
70% (this will be adjusted, but it will not be possible to use a normal program like this)
/G 4- Pass through a heated hem roll 1 adjusted to the flow temperature of the containing resin and a suitable feeding speed 1 to smooth the surface.

Method 11: Depending on the characteristics of the laminate to be obtained and the associated molding conditions, it is adjusted to 30 to 70% as with the prepreg surface, but high density kraft base paper (density 0.5 to 0.9 g/C', Thickness 1~]om+1)
The resin varnish is applied and dried in the usual way. Here, the density of kraft paper (g/
If crn') exceeds 0.9, the impregnation of the resin varnish will become opaque, making it impossible to obtain the required properties for the laminate and 1-.On the other hand, if it is less than 0.9, the resin and fibers of the prepreg will not be absorbed into the adhesive layer. This causes confusion and the object of the invention cannot be achieved.

C method.

Adjusted to normal resin gold 11 + i 3 n ~ 70 pieces!
One sheet of prepreg is alternately layered with a heat-resistant release paper (there are no particular restrictions, but polyvinyl fluoride film is preferable) and 1 to 10 sheets of prepreg are placed between the hot plates.
Preforming is carried out by heating and pressing, for example, at 150 to 170° C. for 10 to 20 minutes.

This is a method such as

[Effect]

2. Prepregs with extremely smooth surfaces produced by methods A, B, and C are stacked on top of the outermost layer of a plurality of ordinary prepregs, and simultaneously heated and pressed together to form a unit. By molding and removing the release film after molding, a laminate consisting of a chemical plating adhesive layer with a uniform and smooth surface is completed.

[Examples and comparative examples]

Example 1 Carboxylated N ((Nippon Zeone 1: N1pol) was used as an adhesive cutting surface for chemical plating.
-1072)...50 Heavy epoxo resin (manufactured by Asahi Kasei Corporation: AER-661)...50
〃 Phenol resin (manufactured by Risho Kogyo Co., Ltd.)...l Q
LJ diaminodiphenylsulfone (DDS)
... 5 1L2-ethyl, 4-methylimidazole (2E4MZ)・0.3 silicon dioxide
・1011 solvent (MF, K)
...4507/ was prepared, and this was coated on a 50 μm thick stretched polypropylene film using a linomer coater, and dried at 100°C for 10 minutes to form a 40 μm thick adhesive layer for chemical plating. On the other hand, an oil-modified phenolic resin varnish adjusted to a solid content of 55% using methanol and toluene was applied to 10rnil kraft paper so that the resin content after drying was 60%. Afterwards, the solvent was removed by drying.Then, the material was passed through a heated smoothing roll at 120°C at a speed of 3 m/min to obtain a material with an extremely smooth surface and fluidity of the resin. A small (flow 3%) prepreg (this is called a special prepreg to distinguish it from the Congregation prepreg) was obtained.Therefore, five sheets of ordinary paper phenolic resin prepreg were combined, and the above special prepreg was applied to each of the front and back surfaces of the prepreg. The prepregs were stacked, and the above-mentioned release film prepared in advance was stacked so that the chemical plating adhesive layer was in contact with the special prepreg.
One piece was heated and pressurized under conditions of 1 minute to perform integral molding. After molding, the release film was peeled off from the surface of the laminate, and a printed wiring board was fabricated using the usual additive method.
, ttm >, tensile strength (kgf/cm ),
Various properties such as solder resistance (number of seconds at 260° C.) were investigated, and the results are summarized in the following table. The peel strength and solder resistance were measured in accordance with Method 1 of 715-C6481.

Example 2 The same oil-modified phenolic resin varnish as in Example 1 was used with a density of 0.
．． 82g/crr? It was applied to high-density kraft base paper with a thickness of 7 mi+ so that the resin content after drying was 50%, and then dried to remove the solvent. Furthermore, the special prepreg obtained in E7 was treated in the same manner as in Example 1 to produce a printed wiring board, and the various properties of this printed wiring board were investigated, and the results are listed together with the table number.

Example 3 The same oil-modified phenolic resin face as in Example 1 was used with a density of 0.
．． 11 or 50 pieces of dried oil on regular kraft paper of 50 g/C and 1Qmil. The prepreg was coated, dried, and then cut into 5 bond laminate sizes Lf, 'iQ, with a release film (polyvinyl fluoride film) interposed.1. On the top, combine 7 pieces of 11 preso I/re.
Jfl Bu1 Nosu C165℃, I (10kg/cn
? , 10 minute article fl! -Heated and pressurized. This, 1
Then, a printed wiring board was prepared using the special prepreg in exactly the same manner as in Example 1, and its properties were investigated in the same manner as in Example 1, and the results are also listed in Table 1.

Comparative Example 1 A product was prepared in exactly the same manner as in Example 1, except that ordinary paper phenol prepreg (base paper thickness was 10 ml, the same as the kraft base paper in Example 1) was used instead of the special prepreg prepared in Example 1. A printed wiring board was produced, and the same properties as in each of the above Examples were investigated and are also listed in the table. The interface between the adhesive layer for chemical plating and the normal prepreg was heavily mixed with each other, and the thickness varied greatly from 5 to 50 ttm. Although the surface was smooth, the uniformity was poor, and the Both peel strength and solder resistance were low.

Comparative Example 2 7 sheets of regular paper phenol prepreg stacked at 100k
g/ru? , 165°C, 10 minutes of heat and pressure to obtain a 31:Suni1()I~Nol('Jt laminate. This laminate was placed in the same chemical plating adhesive varnish solution used in Example 1 ( θυ(+,, 1 pull in the vertical direction at a speed of 6 m/hour [after pre-drying at 7,100°C for 10 minutes,
It was dried at 5°C for about 1 hour. A printed circuit board was fabricated from this laminate by the usual additive method, and the same properties as in Example 1-1 were investigated, and the results are shown in the table (also listed below).
The surface of the adhesive layer has undulations, the layer thickness varies greatly, the uniformity is very poor, and the surface roughness of the circuit board is between 4 and 1.
It was as large as 0 μm, and its peel strength and solder resistance were also smaller than any of the examples.

〔effect〕

The method of this invention (because the chemical plating laminate obtained by this process uses a special prepreg different from conventional prepreg, mixing of the chemical plating adhesive with the resin of the special prepreg is minimized) If it is possible to prevent disturbances in the thickness and composition of the adhesive layer for chemical plating, it is possible to obtain an adhesive layer with a uniform thickness even if the prepreg transfer method is used. By using this method, the bonding force between the adhesive layer and the laminate becomes significantly greater than when using the transfer method or the dipping method, and the surface smoothness of the adhesive layer is also excellent. The manufacturing cost is low, and a highly reliable chemical plating laminate with good printability, chemical plating adhesion, and solder heat resistance can be easily obtained.Moreover, by using the transfer method for prepreg, the laminate can be easily produced. Compared to when using the transfer method or the dipping method, the bonding force between the adhesive layer and the laminate is significantly greater, and the surface smoothness of the adhesive layer is also excellent.
Furthermore, manufacturing costs are low, printability is low,
A highly reliable chemical plating laminate with good chemical plating adhesion and solder heat resistance can be easily obtained. Therefore, it can be said that the significance of this invention is extremely significant.

Procedural amendment (voluntary) July 2711, 1985

Claims (1)

[Claims] (1) The prepreg that forms the surface layer of the laminate on which the adhesive layer for chemical plating is to be applied is prepared in advance so that the surface is extremely smooth and the resin content is 3.
0 to 70% prepreg is layered, and a release film is further layered so that the prepreg surface and a chemical plating adhesive layer of uniform thickness provided on one side of the release film are in close contact with each other. , a method for producing a laminate for chemical plating, characterized in that these are simultaneously heated and pressure molded.