JPS59175797A - Method of producing multilayer printed plate - 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] (a) Technical field of the invention The present invention relates to an improvement in the method for manufacturing multilayer printed boards.

(b) Background of the Technology J, L, and 72δ, which have a large number of laminated printed boards on which circuits are formed, are already well known as electronic circuits forming calculators and the like.

(C) Interference with the prior art Regarding the conventional manufacturing method of such a multilayer printed board, first, a resist film is applied to the surface of the L board, which is coated with copper on both sides. Thereafter, a film with a predetermined pattern in the form of 1fJ is pasted onto the resist III and exposed.

Next, the exposed portion of the resist e is developed and removed to form a resist film with a predetermined pattern. 2. Next, use the resist film as a masking mask to etch the copper foil on the substrate with unnecessary copper edges. Next, the resist i11x is removed to obtain an inner layer circuit pattern on the steel-clad substrate.

Next, like this inner layer IL! One or several guide bins are used to connect a board with one path formed on it/rζ sheet (
Prepreg). The face-contact substrate is bonded by thermocompression to form an integrated circuit board (IC4).

Next, through holes for connecting the inner layer circuits are formed using a drill bit.

Then, the substrate and the through holes were all coated with copper fr.
rc rM $pAfter depositing copper using the image, 78 PJf plating of copper was applied.After that, butter was applied to the surface of the laminated steel board using the same method as the inner layer circuit formation described in H1J. A circuit to be exposed at j' is pre-formed on a predetermined substrate surface using a resist film that can be etched. However, in the conventional multilayer printed board manufacturing method described above, when forming the through holes, the drill JJ+I process 11 (f) causes the tympanic membrane called smear to get stuck in the through holes. Therefore, even if you try to completely plate the inside of the through hole and the board in the process, the plating layer will not be connected to the inside MJ circuit in the through hole, and therefore it will not be connected to the board through the through hole. This has resulted in the inconvenience that prefabricated inner layer circuits are connected with low reliability.

Therefore, in order to prevent the occurrence of n-mark smear, the fit shape of the drill, the 1/11 rotation number of the drill, and the feed rate of the drill should be changed to a modified formula during drilling. f two but n11
There was no way to prevent the occurrence of solid proboscis.

In addition, in order to remove smear, it has been attempted to treat the smear using chemical mulberry products such as sulfuric acid or fluorocarbons. Therefore, there are 4 to 51 points that such methods cannot sufficiently remove OrJ memorized animal molds. 1 point is removed, and all the solid matter in the through-hole in J is completely evaporated, and the inner layer in the through-hole is removed. Electroless copper plating layer is formed on the lower surface of the circuit copper layer (+i
6) The purpose of this is to provide a novel multilayer printed circuit board method in which circuits can be connected with high reliability through the copper-plated through-holes. It is.

(e) Structure of the Invention In order to achieve the above object, the method for manufacturing a multilayer printed board of the present invention includes applying a resist film to the surface rhI of a copper-clad board, forming the resist film in a predetermined pattern, and performing the patterning. After forming the surface of the copper-clad board into a predetermined pattern using a resist film as a mask and forming all the inner layer circuits, the board on which the inner layer circuits have been formed is laminated with an adhesive sheet, and then through holes are formed on the board and the board is plated. In the method for manufacturing a multilayer printed board in which a circuit is formed on the surface of the board by forming a circuit on the surface of the board, after forming a through hole in the board on which the inner layer circuit has been formed, melting the resin eardrum and inner layer copper foil produced during the formation of the MU through hole. After soaking in the etching solution,
1: This is a warning to clean the J substrate using high-pressure cleaning water.

(f) Embodiment of the Invention An embodiment of the invention will be described in detail below. Figures 1 and 2 are one example of an uninvented multilayer printed board.
It is a sectional view showing an example.

As shown in the figure, a sheet-like thermosetting resin 2 is placed so as to sandwich a copper-clad substrate 1 having a predetermined pattern of inner layer circuits formed on the screen. Then, on the resin 2, 1iIII1
1 and 3 were laminated using a guide bin (not shown) and then thermocompression bonded.

Next, through holes 4 for connecting the inner layer circuits are formed by drilling.

The multilayer printed board that had been specially drilled was immersed in an aqueous solution of ammonium persulfate C (NH4) 28208), and the copper foil forming the inner layer circuit was exposed from the exposed surface by 3 to 10
μ〃Ensure that it is etched at 144 degrees. As a result, the inner copper foil of the solid V/J, called smear, made of the melted resin produced by the JJII drill is etched, and as a result, a gap is created between them and isolated.

Water M7. The pressure of mixed purified salumina (AAzO3) is 2-5 kQ/
13'l i by honing using crl high pressure water
+12 Motoyuki b. Increase the pressure by another 3~10k.
g/ (・Wash the base with gruel and pressurized water.

1. By doing this, the smear layer is etched with ammonium persulfate to create a gap between it and the smear.
As shown in FIG. 2, a recess 1) i5 is formed.

In this way, the li called the progenitor Sumya! ii
Since the molding can be completely removed, when the multilayer board is coated with solid copper in the subsequent process, the copper plating on the inner surface of the through hole 4 will be completely replaced by the inner layer copper foil J7+T+
Since j can be reduced to V, it becomes a blasphemy to reduce the contact between the inner layer circuits.

(g) Effects of the invention As stated above, 7 no'-Ucl! Expanding the multi-layer printed material by the IJ method is a reliable MJ method that does not cause connection failures between the IJ and FII members. Multi-layered pudding with high f・1 resistance) 4) X'lj
” 4;

4, Figure 1/] l's deep-frying explanation Figure 1, Saijyohi's funeral Figure 2 are the original prints of Ming's Tajiso prints! Qing Method Technique 4+! θ is the 1ift plan view
.

In the figure, 11 indicates the name board, 2 indicates the name of the tree, 3 indicates the printed board, 4 indicates the board, and I indicates the word of mouth.

Figure 1 Figure 2

Claims (1)

[Claims] After applying a resist film to the surface of the copper-clad substrate, the resist film is formed into a predetermined pattern, and the resist 1 is patterned.
After forming an inner layer circuit by forming a predetermined pattern on both sides of the metal-clad substrate using 4 as a mask, the substrates with the inner layer circuit formed thereon are laminated, and through holes are formed by blowing.
1 [In the method for manufacturing a multilayer printed board by plating the board described in 1 and forming a circuit on the board cover 11ij, after forming through holes in the board on which the inner layer circuit has been formed, n
A method for manufacturing a multilayer printed board, which comprises immersing the substrate in an entinda solution that dissolves the resin membrane produced during through-hole processing and the inner layer metal foil, and then washing and removing the substrate using washing water.