JPH1174640A - Manufacture of printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which an inexpensive printed wiring board which can be used for a variety of electronic equipment can be formed easily in various thicknesses and on which parts can be mounted at a high packing density. SOLUTION: A double-sided printed wiring board 9 is formed in such a way that a through hole 4 is formed through a substrate 1 carrying copper foil 2 on both surfaces after a mold-releasable film 3 is stuck to at least one surface of the substrate 1 and the hole 4 is filled up with conductive paste 5. Then, after the film 3 is removed and heat-resistant films 6 placed on both surfaces of the substrate 1 are heated and pressurized, a prescribed wiring pattern 7 is formed of the copper foil 2 by etching, etc. Therefore, the thickness of the wiring board 9 can be set with a high degree of freedom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing double-sided and multilayer printed wiring boards used for various electronic devices.

[0002]

2. Description of the Related Art In recent years, various electronic devices have been reduced in size and weight.
Furthermore, there is a tendency toward multifunctionality, and a higher density is required for a printed wiring board used for the same. As a printed wiring board for such a demand, for example, a printed wiring board disclosed in JP-A-6-268345 is disclosed. It has been known.

FIGS. 7 (a) to 7 (i) are cross-sectional views showing a main part of a method of manufacturing this conventional printed wiring board. First, as shown in FIG. 7 (a), an aramid epoxy sheet or the like is used. A film material 101 such as a polyethylene terephthalate material is attached to both surfaces of the prepreg 102 to form a laminate 103.

[0004] Next, as shown in FIG. 7 (b), a through hole 104 is formed in the laminated body 103 by laser processing or the like, and a conductive paste 105 is formed in the through hole 104 as shown in FIG. 7 (c). Is filled by an operation such as a squeegee.

Subsequently, after the film material 101 is peeled off as shown in FIG. 7D, a copper foil 106 as a conductive layer is bonded to both surfaces as shown in FIG. f)
The via hole 107 is heated and pressurized as shown in FIG.
To form

Further, as shown in FIG. 7 (g), by forming a predetermined wiring pattern 108 on one or both surfaces of the copper foil 106 by etching or the like, the wiring patterns 108 on both surfaces are electrically connected by via holes 107. Thus, a double-sided printed wiring board 109 is obtained.

[0007] Next, as shown in FIG. 7 (h), the through holes 1 shown in FIG.
Prepreg 1 filled with conductive paste 105 in 04
02 and the upper and lower copper foils 106, respectively, and after heating and pressing, the copper foils 106 on one or both sides are formed on a predetermined outer layer wiring pattern 110 by etching or the like, thereby forming a multilayer as shown in FIG. Printed wiring board 1
11 was to be obtained.

[0008]

Generally, the printed wiring board is required to have various thicknesses depending on its use. However, in the above-mentioned conventional configuration, the thickness is limited to the thickness of a prepreg such as an aramid epoxy sheet, and the thickness is increased. For this purpose, there is no other choice but to stack multiple layers of aramid epoxy sheets, and furthermore, the aramid epoxy sheets have a problem that the amount of distribution is small and that they are relatively expensive as compared with general glass epoxy substrates.

It is an object of the present invention to provide a method of manufacturing a printed wiring board which can easily realize various thicknesses and can obtain a printed wiring board capable of increasing the density at a low cost. .

[0010]

In order to solve the above-mentioned problems, the present invention provides a method of forming a printed wiring board having copper foil on both sides by attaching a release film to at least one surface of the substrate. After that, a through-hole is provided, and after the conductive paste is filled in the through-hole, the release film is peeled off, and then the conductive paste is heated and pressurized on the base material filled in the through-hole, thereby conducting the conductive paste. After curing the conductive paste and electrically connecting the conductive paste and the copper foil provided on both surfaces of the base material, the copper foil provided on both surfaces of the base material is formed into a predetermined wiring pattern It is.

According to the present invention, it is possible to easily form a double-sided printed wiring board having various plate thicknesses and capable of high density.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The invention described in claim 1 of the present invention is to provide a printed wiring board having copper foils on both sides and a release film attached to at least one surface of a substrate constituting the printed wiring board. A through-hole is provided, and after the conductive paste is filled into the through-hole, the release film is peeled off, and then the conductive paste is heated and pressurized to fill the through-hole with the conductive paste. A printed wiring in which the paste is cured and the copper foil provided on both sides of the base material is electrically connected to the conductive paste, and then the copper foil provided on both sides of the base material is formed into a predetermined wiring pattern. This is a method for manufacturing a substrate, and has an effect that a double-sided printed wiring board having various plate thicknesses and capable of high density can be easily formed.

According to a second aspect of the present invention, a through hole is provided in a base material having a copper foil on both sides and constituting a printed wiring board,
A mask having a through-hole corresponding to the through-hole is brought into close contact with the base material, and the conductive paste is filled into the through-hole of the base material through the through-hole of the mask. The conductive paste is cured by heating and pressurizing the base material filled in, and after electrically connecting the conductive paste and the copper foil provided on both surfaces of the base material, the copper provided on both surfaces of the base material This is a method of manufacturing a printed wiring board in which the foil is formed into a predetermined wiring pattern, the filling of the conductive paste into the through holes is reliable, and it can be used multiple times, and various thicknesses can be obtained. This has the effect of easily forming a double-sided printed wiring board having high density.

According to a third aspect of the present invention, after a through hole and a predetermined wiring pattern are formed on the surface of a substrate constituting a printed wiring board having copper foil on both sides, the through hole corresponding to the through hole is formed. A mask having holes is brought into close contact with the base material, the conductive paste is filled into the through holes of the base material through the through holes of the mask, and then the base material filled with the conductive paste is heated. 3. A method for manufacturing a printed wiring board, wherein a conductive paste is cured by applying pressure and a copper foil provided on both surfaces of a base material and the conductive paste are electrically connected to each other. In addition to the effect of the invention, the conductive paste has no effect of etching or the like.

According to a fourth aspect of the present invention, in the first aspect of the present invention, there is provided a printed wiring board having a copper foil on both sides and filling the inside of a through hole of a substrate. This is a method of manufacturing a printed wiring board in which the amount of conductive paste to be used is larger than the volume of this through-hole. Even if the filling rate of the conductive paste varies, the resistance value of the via hole of the printed wiring board is stabilized. It has the effect that it can be done.

According to a fifth aspect of the present invention, in the second or third aspect, the diameter of the through hole of the mask on the surface in contact with the substrate is equal to or smaller than the diameter of the through hole of the substrate. It is a method of manufacturing a printed wiring board that has a variation in the elongation of the mask and the positioning of the mask and the base material, but the penetration of the base material does not protrude from the through hole of the base material. This has the effect that the conductive paste can be filled only in the holes.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the conductive paste is formed by heating and pressurizing the base material filled in the through-hole with the conductive paste. Is a method of manufacturing a printed wiring board in which a heat-resistant film having elasticity is placed on both surfaces of a base material when curing the conductive paste. It has the effect of being able to be confined in the hole and cured while being reliably pressurized, thereby stabilizing the resistance value of the formed via hole.

According to a seventh aspect of the present invention, there is provided a printed wiring board, wherein wiring patterns formed on both sides of a base material constituting a printed wiring board are connected to both sides of an inner layer substrate connected by through holes or via holes, or when a plurality of inner layer substrates are provided. Alternately, prepregs made of an aramid epoxy sheet filled with a conductive paste are placed in the through holes, and a conductive layer is disposed on the outermost layer of the prepreg, and the prepregs are laminated by heating and pressing. Is a method for manufacturing a printed wiring board in which the outermost conductive layer is formed in a predetermined wiring pattern, and a multilayer printed wiring board capable of increasing the density of various thicknesses can be easily formed. It has the action of:

According to an eighth aspect of the present invention, in the seventh aspect of the invention, a printed wiring board manufactured by the method for manufacturing a printed wiring board according to any one of the first to sixth aspects is used as an inner layer board. This is a method of manufacturing a printed wiring board to be used, and has an effect that it is possible to provide a multilayer printed wiring board having excellent connection performance and capable of increasing the density of various thicknesses at low cost.

According to a ninth aspect of the present invention, a printed wiring board manufactured by the method for manufacturing a printed wiring board according to any one of the first to sixth aspects is used as an inner layer board, and both sides of the inner layer board are provided. Alternatively, when there are a plurality of inner layer substrates, prepregs are alternately arranged, and a conductive layer is disposed on the outermost layer of the prepreg, and the prepregs are laminated by applying heat and pressure. A method of manufacturing a printed wiring board in which a conductive layer on the surface is formed in a predetermined wiring pattern after forming a through hole by copper plating on the printed wiring board. This has the effect that the substrate can be easily formed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a manufacturing process diagram showing a method of manufacturing a double-sided printed wiring board according to a first embodiment of the present invention in a cross section of a main part. In FIG. A base material constituting a printed wiring board made of epoxy, polyamide, paper phenol, or the like. A copper foil 2 is attached to both sides, and a base material 1 having the copper foil 2
Is generally marketed as a copper-clad laminate, and various thicknesses are available.

Next, as shown in FIG.
A releasable film 3 such as a polyester film coated with an adhesive (not shown) is adhered to both sides of the substrate, and a through hole 4 is provided by a hole making means using a drill or laser processing as shown in FIG. 1 (c). .

Next, as shown in FIG. 1D, a conductive paste 5 made of a metal powder, an epoxy resin, a curing agent, or the like is filled in the through hole 4 by a filling means such as a squeegee operation. As shown in (e), the release film 3
Is peeled off and separated.

At this time, the amount of the conductive paste 5 is
The filling conditions for the thickness of the release film 3 and the amount of the conductive paste 5 are determined so as to be larger than the volume of the conductive paste 5.

Further, as shown in FIG. 1 (f), a heat press is performed while an elastic heat resistant film 6 such as polyimide, polyphenylene sulfide or polyether ether ketone is placed on both surfaces of the substrate 1. For example, the conductive paste 5 is cured by heating and pressing at 160 to 200 ° C. under the conditions of 20 to 60 kg / cm ² for 30 to 180 minutes, and the copper foil 2 provided on both surfaces of the base material 1 The conductive paste 5 is electrically connected.

Thereafter, the heat-resistant film 6 is removed, and the outermost copper foil 2 is formed into a predetermined wiring pattern 7 by etching or the like, whereby the wiring patterns 7 on both sides are formed as shown in FIG. The double-sided printed wiring board 9 electrically connected by the via hole 8 is formed.

(Embodiment 2) FIG. 2 is a manufacturing process diagram showing a method for manufacturing a double-sided printed wiring board according to a second embodiment of the present invention in a cross section of a main part. First, in FIG. As in the first embodiment, reference numeral 1 denotes a base material, and reference numeral 2 denotes a copper foil. As shown in FIG. 2B, through holes 4 are formed in the base material by a hole forming means such as a drill or laser processing.

Next, as shown in FIG. 2C, a mask 11 made of a metal material or a resin material provided with a through-hole 10 corresponding to the through-hole 4 is brought into close contact with the base material 1, and
As shown in (d), the conductive paste 5 is filled into the through hole 4 by a filling means such as a squeegee operation through the through hole 10 of the mask 11.

At this time, even if the elongation of the mask 11 or the positioning of the mask 11 and the base material 1 vary, the base of the through-hole 10 of the mask 11 is prevented so that the conductive paste 5 does not adhere to other than the through-hole 4. The hole diameter of the surface in contact with the material 1 is set to be equal to or smaller than the hole diameter of the through hole 4 of the base material 1.

At this time, the filling condition of the thickness of the mask 11 and the amount of the conductive paste 5 is set so that the amount of the conductive paste 5 is larger than the volume of the through hole 4.

Next, as shown in FIG.
Then, as shown in FIG. 2 (f), heating is carried out in a state where an elastic heat-resistant film 6 such as polyimide, polyphenylene sulfide or polyether ether ketone is placed on both upper and lower surfaces of the base material 1. By pressing etc.
The conductive paste 5 is cured by heating and pressing at 160 to 200 ° C. under the conditions of 20 to 60 kg / cm ² for 30 to 180 minutes, and the copper foil 2 and the conductive paste 5 provided on both surfaces of the base material 1 are hardened. Are electrically connected.

Thereafter, the heat-resistant film 6 is removed, and the outermost copper foil 2 is formed into a predetermined wiring pattern 7 by etching or the like, whereby the wiring patterns 7 on both surfaces are formed as shown in FIG. The double-sided printed wiring board 9 electrically connected by the via hole 8 is formed.

(Embodiment 3) FIG. 3 is a manufacturing process diagram showing a method for manufacturing a double-sided printed wiring board according to a third embodiment of the present invention in cross section of a main part. First, in FIG. As in the first embodiment, reference numeral 1 denotes a base material, and 2 denotes a copper foil. On the base material 1, copper foils 2 on both sides are formed into a predetermined wiring pattern 7 by etching or the like as shown in FIG. I do.

Subsequently, as shown in FIG. 3C, a through hole 4 is provided by a hole forming means such as a drill or laser processing.
In this case, the wiring pattern 7 may be formed after the through holes 4 are provided.

Next, as shown in FIG. 3D, a mask 11 made of a metal material or a resin material provided with a through hole 10 corresponding to the through hole 4 is brought into close contact with the base material 1, and
As shown in (e), the conductive paste 5 is filled into the through hole 4 by a filling means such as a squeegee operation through the through hole 10 of the mask 11.

At this time, even if the elongation of the mask 11 and the positioning of the mask 11 and the base material 1 vary as described above,
In order to prevent the conductive paste 5 from attaching to other than the through holes 4,
The diameter of the through hole 10 of the mask 11 that is in contact with the substrate 1 is set to be equal to or smaller than the diameter of the through hole 4 of the substrate 1.

At this time, the filling condition of the thickness of the mask 11 and the amount of the conductive paste 5 is set so that the amount of the conductive paste 5 is larger than the volume of the through hole 4.

Next, as shown in FIG.
After the removal, as shown in FIG. 3 (g), an elastic heat-resistant film 6 such as polyimide, polyphenylene sulfide or polyether ether ketone is placed on both surfaces of the base material 1 and is heated and pressed. , 160-20
30 to 180 under the condition of 20 to 60 kg / cm ² at 0 ° C.
By removing the heat-resistant film 6 after heating and pressurizing for minutes, a double-sided printed wiring board 9 in which the wiring patterns 7 on both sides are electrically connected by via holes 8 as shown in FIG. It was made.

(Embodiment 4) FIG. 4 is a manufacturing process diagram showing a method of manufacturing a multilayer printed wiring board according to a fourth embodiment of the present invention in a sectional view of a main part. First, FIG. As described above, the double-sided printed wiring board 12 is generally provided as a copper-clad laminate. After a through-hole is formed in a base material having copper foil on both sides by means of drilling or laser processing, a through-hole is formed by copper plating. 28 and a wiring pattern 7 formed by etching or the like, and various thicknesses can be manufactured.

Next, as shown in FIG. 4B, the through hole 28 of the double-sided printed wiring board 12 is filled with a hole filling resin 13 such as an epoxy resin to form the inner layer substrate 1.
4 is formed.

Next, as shown in FIG.
4 or the inner substrate 1 as shown in FIG.
When there are a plurality of sheets 4, a prepreg 16 made of an aramid epoxy sheet filled with a conductive paste 15 is disposed in the through hole alternately with the inner layer substrate 14, and a copper foil 17 as a conductive layer is disposed on the outermost layer. I do.

Subsequently, 160-
30 to 1 under the condition of 20 to 60 kg / cm ² at 200 ° C.
By heating and pressing for 80 minutes, the prepreg 16 and the conductive paste 15 are hardened, and the wiring pattern 7
And the copper foil 17 are electrically connected by the conductive paste 15.

Thereafter, the outermost layer copper foil 17 is formed into a predetermined wiring pattern 18 by etching or the like, so that the outermost layer wiring pattern 18 and the inner layer substrate are formed as shown in FIGS. 4 (d) and 4 (f). 14 or a multilayer printed wiring board 20 in which the inner substrates 14 are electrically connected to each other by via holes 19.

(Embodiment 5) FIG. 5 is a manufacturing process diagram showing a method of manufacturing a multilayer printed wiring board according to a fifth embodiment of the present invention in a sectional view of a main part. In FIG. A double-sided printed wiring board 9 of various thicknesses manufactured by the method of manufacturing a printed wiring board according to the first to third embodiments. First, as shown in FIG. As shown in FIG. 5C, when there are a plurality of inner layer substrates 21,
A prepreg 16 made of an aramid epoxy sheet filled with a conductive paste 15 is disposed in the through hole, and a copper foil 17 as a conductive layer is disposed on the outermost layer.

Subsequently, by a hot press or the like,
30 to 1 under the condition of 20 to 60 kg / cm ² at 200 ° C.
The prepreg 16 and the conductive paste 15 are cured by heating and pressing for 80 minutes,
Alternatively, the via hole 8 of the inner layer substrate 21 and the copper foil 17 are electrically connected by the conductive paste 15, respectively.

Thereafter, an outermost copper foil 17 is formed in a predetermined wiring pattern 18 by etching or the like, so that the outermost wiring pattern 18 and the inner layer substrate are formed as shown in FIGS. 5 (b) and 5 (d). 21 or a multilayer printed wiring board 22 in which the inner layer boards 21 are electrically connected to each other through the via holes 19.

(Embodiment 6) FIG. 6 is a manufacturing process diagram showing a method of manufacturing a multilayer printed wiring board according to a sixth embodiment of the present invention in a sectional view of a main part. In FIG. A double-sided printed wiring board 9 of various thicknesses manufactured by the method for manufacturing a printed wiring board according to the first to third embodiments. First, as shown in FIG. As shown in FIG. 6E, when there are a plurality of inner layer substrates 21, prepregs 23 such as glass epoxy are alternately arranged with the inner layer substrates 21, and copper foil 17 as a conductive layer is disposed on the outermost layer. Then, at 160-200 ° C., 20
The prepreg 23 is hardened as shown in FIG. 6B and FIG. 6F by heating and pressing under a condition of の 60 kg / cm ² for 30 to 180 minutes.

Next, as shown in FIGS. 6 (c) and 6 (g), through holes 24 are provided in each of these by drilling or laser processing, and the inner wall of these through holes 24 and the surface of the copper foil 17 are formed. After the copper plating is performed to form the through-hole 25, the outermost copper foil 17 is formed on the predetermined wiring pattern 26 by etching or the like, thereby forming a multilayer as shown in FIGS. 6 (d) and 6 (h). The printed wiring boards 27 are formed respectively.

[0049]

As described above, according to the present invention, there is an effect that it is possible to easily form a double-sided printed circuit board having various plate thicknesses and capable of high density.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram showing a method for manufacturing a double-sided printed wiring board according to a first embodiment of the present invention in a cross section of a main part.

FIG. 2 is a manufacturing process diagram showing a method for manufacturing a double-sided printed wiring board according to the second embodiment in a cross section of a main part.

FIG. 3 is a manufacturing process diagram showing a method for manufacturing a double-sided printed wiring board according to the third embodiment in a cross section of a main part.

FIG. 4 is a manufacturing process diagram showing a method for manufacturing a multilayer printed wiring board according to the fourth embodiment in a cross section of a main part.

FIG. 5 is a manufacturing process diagram showing a method for manufacturing a multilayer printed wiring board according to the fifth embodiment in a cross section of a main part.

FIG. 6 is a manufacturing process diagram showing a method for manufacturing a multilayer printed wiring board according to the sixth embodiment in a cross section of a main part.

FIG. 7 is a manufacturing process diagram showing a conventional method for manufacturing a double-sided printed wiring board in a cross section of a main part.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 base material 2 copper foil 3 release film 4 through hole 5 conductive paste 6 heat resistant film 7 wiring pattern 8 via hole 9 double-sided printed wiring board 10 through hole 11 mask 12 double-sided printed wiring board 13 hole filling resin 14 inner layer substrate 15 Conductive paste 16 Prepreg 17 Copper foil 18 Wiring pattern 19 Via hole 20 Multilayer printed wiring board 21 Inner layer board 22 Multilayer printed wiring board 23 Prepreg 24 Through hole 25, 28 Through hole 26 Wiring pattern 27 Multilayer printed wiring board

Claims (9)

[Claims] 1. A through hole is provided after a release film is attached to at least one surface of a substrate having a copper foil on both sides and constituting a printed wiring board, and a conductive paste is provided in the through hole. After the filling, the release film is peeled off, and then the conductive paste is cured by heating and pressing the base material filled in the through holes, and the copper provided on both surfaces of the base material is cured. A method for manufacturing a printed wiring board, wherein a copper foil provided on both surfaces of a base material is formed into a predetermined wiring pattern after electrically connecting the foil and the conductive paste. 2. A through-hole is provided in a base material having a copper foil on both sides and constituting a printed wiring board, and a mask having a through-hole corresponding to the through-hole is brought into close contact with the base material. The conductive paste is filled into the through-holes of the base material through the holes, and then the conductive paste is cured by heating and pressing the base material filled in the through-holes, and the conductive paste is hardened and the both sides of the base material are cured. A method for manufacturing a printed wiring board, wherein the copper foil provided on the substrate is electrically connected to the conductive paste, and then the copper foil provided on both surfaces of the base material is formed into a predetermined wiring pattern. 3. After forming a through hole and a predetermined wiring pattern on the surface of a base material constituting a printed wiring board having copper foil on both sides, a mask having a through hole corresponding to the through hole is used as the base. The conductive paste is filled into the through holes of the base material through the through holes of the mask, and then the base material filled in the through holes is heated and pressurized to form the conductive paste. A method for manufacturing a printed wiring board, wherein a paste is cured and a conductive paste is electrically connected to a copper foil provided on both surfaces of a base material. 4. The printed circuit board according to claim 1, wherein the amount of the conductive paste to be filled in the through hole of the base material having the copper foil on both sides and constituting the printed wiring board is larger than the volume of the through hole. A method for manufacturing a printed wiring board according to any one of the above. 5. The method for manufacturing a printed wiring board according to claim 2, wherein the diameter of the through hole of the mask on the surface in contact with the substrate is equal to or smaller than the diameter of the through hole of the substrate. 6. When the conductive paste is cured by heating and pressurizing the base material filled with the conductive paste in the through-hole, the heat-resistant film having elasticity is placed on both surfaces of the base material. The method for manufacturing a printed wiring board according to claim 1. 7. A wiring pattern formed on both sides of a base material constituting a printed wiring board is connected to both sides of an inner layer substrate connected by through holes or via holes, or alternately when a plurality of inner layer substrates are provided, the through holes are formed in the through holes. A prepreg made of an aramid epoxy sheet filled with a conductive paste is arranged, and a conductive layer is arranged on the outermost layer of the prepreg and laminated by heating and pressing,
A method of manufacturing a printed wiring board, wherein an outermost conductive layer of the prepreg is formed in a predetermined wiring pattern. 8. The method for manufacturing a printed wiring board according to claim 7, wherein the printed wiring board manufactured by the method for manufacturing a printed wiring board according to claim 1 is used as an inner layer substrate. . 9. A printed wiring board manufactured by the method for manufacturing a printed wiring board according to any one of claims 1 to 6, wherein the printed wiring board is used as an inner layer board, and a plurality of inner layer boards are provided on both sides of the inner layer board. When the prepreg is alternately arranged, a conductive layer is disposed on the outermost layer of the prepreg, and the layers are laminated by heating and pressing.Then, a through-hole is formed, and a through-hole is formed in the through-hole by copper plating. A method for manufacturing a printed wiring board, wherein a conductive layer on the surface is formed into a predetermined wiring pattern after formation.