JP2002344135A - Insulation layer transfer sheet in manufacturing wiring board, built-up printed wiring board, and manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high density of wiring pattern and improve electrical characteristics in a built-up printed wiring board, by improving evenness of the surface of the insulating layer, and improving surface evenness of the wiring pattern layer and peel strength of the wring pattern layer formed on the surface of the layer. SOLUTION: In the insulation layer transfer sheet, a catalyst nucleus layer 12 for electroless plating is previously absorbed in a supporting member 11, and insulating resin is applied on the supporting member 11 and dried to form the insulating resin layer 13. Then, the insulating resin layer 13 can be peeled from the supporting member 11 easily. The transfer sheet is overlapped on the wiring board 14, heated under pressure and exposed. The supporting member 11 is peeled so that the insulating resin layer with the surface, on which catalyst nucleus is absorbed, is transferred to the wiring board to form an electroless plating layer on the insulating resin layer through the catalyst nucleus layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating layer transfer sheet for manufacturing a wiring board for realizing a high-density wiring pattern in a wiring board as a semiconductor device substrate, and a build-up printed wiring board. It relates to a manufacturing method.

[0002]

2. Description of the Related Art In recent years, as represented by an electronic organizer and a mobile phone, electronic devices tend to be smaller and more portable.
Along with this, semiconductor device substrates such as printed wiring boards for mounting LSIs and the like are also disclosed in, for example, Japanese Patent Application Laid-Open No. 7-162.
As disclosed in JP-A-154-154, further densification has been achieved.

FIG. 11 schematically shows a cross-sectional view of a conventional wiring board for a semiconductor device. For example, copper foil 2 on both sides
1 is stuck and a hole 24 is drilled in a core substrate 22 containing a glass cloth (glass epoxy part) using a 0.3 mm drill, and a plating layer 29 is applied in the hole 24 to form a conductive through hole. A hole is formed.

Subsequently, the copper foils 21 on both sides of the core substrate 22 are etched, and the copper foils 21 are formed on the wiring pattern layer 21 having a predetermined wiring pattern. In addition, the wiring pattern layer 21 is subjected to a blackening process for improving the adhesion to an insulating layer formed on the surface layer.

Next, an insulating resin layer 25 is formed on both surfaces of the core substrate 22. In the insulating resin layer 25, a via hole 26 for establishing electrical conductivity with the lower wiring layer is formed by, for example, exposure and development. Further, the copper layer is formed by roughening the insulating resin layer 25, providing the catalyst core layer 23 for electroless plating, electroless plating, and electrolytic plating, and selectively removing the copper layer by applying a resist, exposing, developing, and etching. Thus, an upper wiring pattern layer 27 having a predetermined wiring pattern is formed.

Subsequently, a solder resist 28 is formed on both sides of the core substrate 22 to complete a semiconductor device substrate.

However, the above semiconductor device substrate has a step of roughening the insulating resin layer before performing electroless plating on the insulating resin layer 25 for a build-up wiring board. ) To (3).

(1) Since the roughness of the surface of the build-up insulating resin layer 25 increases due to the roughening, the line / space = 20 μm /
There is a problem that it is difficult to form a fine build-up pattern wiring of 20 μm or less. Also, (2) when exchanging signals at a speed of terahertz, in the currently widely used processes of roughening, providing a catalyst core layer 23 for electroless plating, and plating, the roughness of the surface of the build-up insulating resin layer 25 is increased. And cannot cope with high-speed signals.
(3) Since the surface of the material of the interlayer insulating resin layer 25 for the build-up wiring board deteriorates and becomes brittle at the time of roughening, the peel strength of the build-up wiring pattern layer 27 of the conductor provided on the interlayer insulating resin material does not increase. There is a problem.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been made in order to achieve a higher density of the wiring pattern and an improvement in electrical characteristics in a build-up printed wiring board. It is an object of the present invention to (1) improve the smoothness of the surface of the insulating resin layer 25 as the insulating material, and (2) to form a conductive build-up formed on the surface of the insulating resin layer 25. Up wiring pattern layer 2
7) and (3) the insulating resin layer 25
A wiring board for a semiconductor device or the like that can realize a high density of the build-up wiring wiring pattern layer 27 by improving the peel strength (adhesive strength) of the conductive build-up wiring pattern layer 27 formed on the surface of the semiconductor device. The purpose is to provide.

[0010]

According to the first aspect of the present invention, there is provided an insulating resin layer in which an insulating resin is applied and dried on a support on which a catalyst core layer for electroless plating is previously adsorbed on the surface. An insulating layer transfer sheet for manufacturing a wiring board, which is formed so as to be easily peelable from a support.

According to a second aspect of the present invention, there is provided an insulating resin layer having a catalyst nucleus adsorbed on a surface of a wiring substrate transferred and formed using the insulating layer transfer sheet according to the first aspect of the present invention. A build-up printed wiring board comprising: a via hole in a layer; and a wiring pattern formed on the insulating resin layer by electroless plating via the catalyst core layer and subsequent electrolytic plating.

According to a third aspect of the present invention, the insulating layer transfer sheet according to the first aspect is superposed on a wiring board with the insulating resin layer inside, and heated and pressed and exposed, and then the support is peeled off. Transferring the insulating resin layer having the catalyst nuclei adsorbed on the surface thereof to the wiring board, forming a via hole in the insulating resin layer, and forming the catalyst nucleus on the insulating resin layer. A conductive layer forming step of forming a conductive layer by electroless plating through the layer and subsequent electrolytic plating, and a wiring pattern forming step of pattern-etching the conductive layer to form a wiring pattern. This is a method for manufacturing a build printed wiring board.

According to a fourth aspect of the present invention, there is provided a via-hole forming step of forming a via-hole in the insulating layer transfer sheet according to the first aspect, and a wiring board having the insulating resin layer of the insulating layer transfer sheet inside. An insulating resin layer transferring step of transferring the insulating resin layer having the catalyst nuclei adsorbed on the surface thereof to a wiring substrate after heating and pressurizing and exposing to a wiring substrate, and the catalyst nuclei layer on the insulating resin. A conductive layer forming step of forming a conductive layer by electroless plating and subsequent electrolytic plating via a step of forming a wiring pattern, and a wiring pattern forming step of pattern-etching the conductive layer to form a wiring pattern. This is a method for manufacturing a printed wiring board.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The gist of the present invention is to use an interlayer insulating sheet for a build-up substrate having a catalyst nucleus provided on the surface in advance, so that the surface roughness of the material of the interlayer insulating resin layer 13 for the build-up substrate can be kept small. Electroplating can be performed. Thus, the density of the build-up wiring wiring pattern layer 27 is increased.

FIG. 1 is a side sectional view of an insulating layer transfer sheet according to claim 1 of the present invention, and a support of a known catalyst chemical in which a catalyst core layer 12 for electroless plating is adsorbed on the surface. An insulating resin layer 13 formed by applying and drying an insulating resin on a body 11 is formed so as to be easily peelable from a support.

As the support 11, the build-up substrate 1
When the insulating resin used as the insulating resin layer 13 for 4 is applied on the support, it is desirable that the insulating resin layer 13 has good releasability. As the material of the support 11, Teflon (registered trademark), polyimide, PET (polyethylene terephthalate), PE (polyethylene), and a composite thereof can be used. The shape of the support 11 may be any of a film shape and a plate shape.

As the insulating resin, the support 11 according to claim 1 is used.
One that is peeled into a film by being dried after being applied on the top is used. For example, an epoxy resin, a polyimide resin, an acrylic resin, and a mixed resin containing these are used. Glass cloth may be contained in the resin. Insulating resin is photosensitive
(Light-curing type), but may be a heat-sensitive thermosetting type.

As the catalyst core, palladium chloride, a mixture of palladium chloride and tin chloride, and a palladium colloid are used. By immersing the support 11 in a solution containing palladium chloride, a mixture of palladium chloride / tin chloride, and a palladium colloid, the catalyst nuclei can be adsorbed on the support 11.

FIG. 2 is an example of a build-up printed circuit board for a semiconductor device according to a second aspect of the present invention, and is a view schematically showing a side cross section thereof. A specified hole 24 is formed in a wiring board substrate (core substrate) including a glass cloth (glass epoxy portion) 22 with a copper foil 21 adhered to both sides thereof by a drill bit or pressing with a mold jig. The plating layer 29 is formed in the hole 24 to form a conductive through hole. The copper foil 21 and the conductive plating layer 29 of the conductive through hole are formed as wiring pattern layers 21 and 29 having a predetermined wiring pattern, and the printed wiring board 14 serving as a core is completed.

An insulating resin layer 13 formed by transfer using the insulating layer transfer sheet according to claim 1 is formed on both sides of the printed wiring board 14 serving as the core. The insulating resin layer 13 has catalyst nuclei adsorbed on its surface in advance. Via holes 16 are formed in the insulating resin layer 13 for electrical conduction with the lower wiring pattern layers 21 and 29. The conductive wiring pattern layer 17 is formed by electroless plating and electrolytic plating of the insulating resin layer 13. The conductive layer 17 is formed in a predetermined wiring pattern by resist coating, exposure, development, etching and the like.
A solder resist layer 28 is formed on the conductive wiring pattern layer 17 on the entire outermost surface on both sides of the build-up printed wiring board serving as a core.

FIGS. 3 to 7 are side views schematically illustrating a method for manufacturing a build-up printed wiring board according to a third aspect of the present invention. The method of manufacturing the build-up printed wiring board is sequentially performed from FIG. 3 to FIG.

FIGS. 3 and 4 are sectional views showing the structure of the method for manufacturing an insulating resin layer transfer sheet for manufacturing a wiring board according to the first aspect. A film-shaped or plate-shaped support 11 such as a plastic is immersed in a solution containing a catalyst core for electroless plating, heated and dried. As a result, a catalyst nucleus layer 12 having the catalyst nucleus as a component and having the catalyst nucleus attached to the surface of the support 11 is formed. As shown in FIG. 4, the insulating resin layer 13 is formed by applying (coating) an insulating resin to the support 11 by an appropriate coating means. The thickness of the insulating resin layer 13 is suitably 70 μm or less.

Further, as shown in FIG. 5 (a), the insulating resin layer 13 is placed on the inside and the back of the substrate 14 for manufacturing a build-up printed wiring board by an appropriate method, for example, (pin system in a conventional process) or the like. Fix by a predetermined method. This is heated by an appropriate method, such as (hot pressing in the conventional process),
Pressurization and exposure are performed. Thereby, the catalyst core layer 12 attached to the support 11 is taken into the insulating resin layer 13. Thereafter, as shown in FIG. 5B, the support 11 is peeled off, and the insulating resin layer 13 is heated and cured by a curing device such as a heating oven.

Next, as shown in FIG. 6, the via hole 16 is formed by an appropriate drilling method, for example (drill bit, laser in a conventional process) or the like. Next, as shown in FIG. 7, a conductive build-up wiring pattern forming layer is formed on the surface of the wiring board 14 and the entire surface of the insulating resin layer 13 via the catalyst core layer 12 by electroless plating, electrolytic plating, or the like. Applying a photosensitive resist to the pattern forming layer, pattern exposure, development,
A predetermined wiring pattern 17 is formed by etching the wiring pattern forming layer.

FIGS. 8 to 10 are schematic cross-sectional views illustrating a method for manufacturing a build-up printed wiring board according to a fourth aspect. The method of manufacturing the build-up printed wiring board is sequentially performed from FIG. 8 to FIG. Support 11
The insulating transfer sheet for manufacturing a wiring board, comprising the insulating resin layer 13 and the insulating resin layer 13, is manufactured in the same manner as the transfer sheet according to the first aspect. As shown in FIG. 8, a specified via hole 16 is formed in the support 11 and the insulating resin layer 13 in the insulating transfer sheet by a drill bit, a laser, a press with a mold jig, or the like.

Further, as shown in FIG. 9A, the transfer sheet is placed on the front and back of the printed wiring board 14 with the insulating resin layer 13 inside, for example, (pin system of the conventional process).
Fix with, for example. This is subjected to heating, pressing, and exposure by an appropriate method, for example (hot pressing in a conventional process). As a result, the catalyst core layer 12 attached (adsorbed) to the support 11 is taken into the insulating resin layer 13. Thereafter, as shown in FIG. 9B, the support 11 is peeled off, and the insulating resin layer 13 is heated and cured.

Next, as shown in FIG. 10, a conductive build-up wiring pattern forming layer is formed on the surface of the wiring board 14 and the entire surface of the insulating resin layer 13 by electroless plating, electrolytic plating, etc. via the catalyst core layer 12. . Next, a predetermined resist pattern 1 is formed on the wiring pattern forming layer by applying a photosensitive resist, pattern exposure, development, and etching of the wiring pattern forming layer.
7 is formed.

[0028]

<Example 1> A specific example of an insulating layer transfer sheet used for manufacturing a build-up printed wiring board according to claim 1 of the present invention will be described with reference to FIG.
The support 11 made of a PET (polyethylene terephthalate) film having a thickness of 5 μm is immersed in a tin / palladium colloid solution for electroless plating for 10 seconds, and dried at 80 ° C. for 10 minutes. Thus, a catalyst core layer 12 of palladium is formed on the support 11.

Further, as shown in FIG. 4, a (acrylic resin) photosensitive resin ink (sun ink; P
SR-4000) by screen printing,
An m-thick insulating resin layer 13 is formed. Thus, an insulating layer transfer sheet is formed.

Next, a specific method of manufacturing a build-up printed wiring board according to a third aspect of the present invention will be described with reference to FIG.
The support 11 on which the insulating resin layer 13 having a thickness of μm is formed is placed on the printed circuit board 1 such that the resin layer 13 is on the inside.
At the four corners of 4, the four corners are fixed to the adhesive tape by attaching, for example, (Kapton tape). This is pressed with a vacuum laminator at 90 ° C. for 10 seconds.

The printed wiring board 14 having the insulating resin layer 13 and the support 11 attached to the surface is exposed to 450 mJ. Thereby, a part of the tin / palladium catalyst attached to the support 11 (PET film) is taken into the resin layer 13. After the exposure, the support 11 is peeled off as shown in FIG. 5B, baked in an oven at 150 ° C. for 1 hour, and the insulating resin layer 13 is thermally cured.

Subsequently, as shown in FIG.
A via hole 16 having a diameter of 50 μm is processed by a CO2 laser.

Further, as shown in FIG. 7, the printed wiring board 14 having the via holes 16 formed in the insulating resin layer 13 is immersed in permanganic acid for 10 minutes, immersed in a tin-palladium catalyst solution for 30 seconds, and subsequently Immerse in a 5% sulfuric acid solution for 30 seconds. Electroless plating is applied to a thickness of 0.2 μm on the surfaces of the insulating resin layer 13 and the printed wiring board via the catalyst core layer 12, and electrolytic copper plating is applied to a thickness of 10 μm to form a conductive wiring pattern forming layer. Thereafter, a photosensitive etching resist is coated on the entire surface of the wiring pattern forming layer, a desired pattern is exposed and developed, and then a wiring pattern 17 is formed by etching. Thereby, the build-up printed wiring board according to claim 2 is formed.

<Embodiment 2> Next, a specific method of manufacturing the build-up printed wiring board according to the fourth embodiment is the same as that of the above-mentioned Embodiment 1, as shown in FIG. 11 is immersed in a tin-palladium colloid solution for electroless plating for 10 seconds, and dried at 80 ° C. for 10 minutes. Thus, a catalyst core layer 12 of palladium is formed on the support 11.

Further, as shown in FIG. 4, a photosensitive (acrylic resin) resin ink (solar ink; PSR
-4000) by screen printing to form an insulating resin layer 13 having a thickness of 40 μm, thereby forming an insulating layer transfer sheet.

Subsequently, as shown in FIG. 8, via holes 16 having a diameter of 50 μm are formed at desired positions in the support 11 and the insulating resin layer 13 of the insulating transfer sheet by using a CO 2 laser.

Further, as shown in FIG. 9A, the support 11 on which the insulating resin layer 13 having a thickness of
Are fixed to the inside and outside of the printed wiring board 14 by attaching an adhesive tape, for example (Kapton tape), to the four corners. This is pressed with a vacuum laminator at 90 ° C. for 10 seconds.

Further, the printed wiring board 14 having the insulating resin layer 13 and the support adhered to the surface is exposed to 450 mJ. Thereby, a part of the catalyst core layer 12 made of tin / palladium adhered to the support 11 is taken into the insulating resin layer 13. Next, after exposure, the support 11 is peeled off as shown in FIG. 9B, the insulating resin layer 13 is baked in an oven at 150 ° C. for 1 hour, and the resin layer is thermally cured.

Further, as shown in FIG.
6 is immersed in permanganic acid for 10 minutes, immersed in a tin-palladium catalyst solution for 30 seconds, and then immersed in a 5% sulfuric acid solution for 30 seconds. Thereafter, 0.2 μm of electroless plating 17 was applied, and 10 μm of electrolytic copper plating 29 was further applied.
3 and conductive wiring pattern forming layers 17 and 29 are formed on the surface of the wiring board 14. Thereafter, a photosensitive etching resist is coated on the surface of the copper (conductive plating layer) 29 of the wiring pattern forming layers 17 and 29, and a desired pattern is exposed and exposed.
After the development, the wiring pattern 17 is formed by etching.

[0040]

As described above, according to the present invention, the roughness of the surface of the build-up resin can be reduced, and therefore, the uniformity of the thickness of the copper pattern can be improved, and etching can be performed. A fine pattern can be formed because it becomes easier. This makes it possible to provide a build-up printed wiring board used for a semiconductor device or the like which can realize a higher density wiring pattern and improved electrical characteristics as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an insulating layer transfer sheet for manufacturing a wiring board according to the present invention.

FIG. 2 is a side sectional view of a build-up printed wiring board according to the present invention.

FIG. 3 is a side sectional view for explaining an example of a method (method) of manufacturing a build-up printed wiring board according to the present invention.

FIG. 4 is a sectional side view for explaining an example of a method (method) of manufacturing a build-up printed wiring board according to the present invention.

FIG. 5 is a sectional side view for explaining an example of a method (method) of manufacturing a build-up printed wiring board according to the present invention.

FIG. 6 is a cross-sectional side view illustrating an example of a method (method) of manufacturing a build-up printed wiring board according to the present invention.

FIG. 7 is a side sectional view for explaining an example of the method (method) of manufacturing a build-up printed wiring board according to the present invention.

FIG. 8 is a sectional side view for explaining another example of the method (method) of manufacturing a build-up printed wiring board according to the present invention.

FIG. 9 is a sectional side view for explaining another example of the method (method) for manufacturing a build-up printed wiring board according to the present invention.

FIG. 10 is a sectional side view for explaining another example of the method (method) for manufacturing a build-up printed wiring board according to the present invention.

FIG. 11 is a side sectional view of a conventional build-up printed wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Support 12 ... Palladium catalyst core layer for electroless plating 13 ... Insulating resin layer for build-up printed circuit board 14 ... Core printed wiring board 16 ... Via hole 17 ... Wiring pattern 21 ... Copper foil (wiring pattern layer) 22 ... glass cloth (glass epoxy part) 23 ... palladium catalyst core layer for electroless plating 24 ... through hole 25 ... insulating resin layer 26 ... via hole 27 ... build-up wiring pattern layer 28 ... solder resist layer 29 ... conductive plating layer

Continued on front page F-term (reference) 5E343 AA02 AA15 AA17 AA18 BB24 CC62 CC73 CC76 DD33 DD43 ER02 ER12 ER18 GG06 GG08 5E346 AA16 AA43 CC02 CC04 CC09 CC10 CC32 CC55 CC57 CC58 CC60 DD02 DD25 DD32 DD44 EE33 GG18 GG13 GG17 GG17 HH11 HH26

Claims (4)

[Claims] An insulating resin layer coated with an insulating resin and dried on a support having catalyst nuclei for electroless plating adsorbed on the surface in advance is formed so as to be easily peelable from the support. Characteristic insulation layer transfer sheet for wiring board production. 2. An insulating resin layer in which a catalyst nucleus is adsorbed on a surface transferred and formed using the insulating layer transfer sheet according to claim 1 on a wiring board, and a via hole is provided in the insulating resin layer. A build-up printed wiring board, wherein a wiring pattern is formed on a resin layer by electroless plating via the catalyst core and subsequent electrolytic plating. 3. An insulating layer transfer sheet according to claim 1, wherein said insulating resin layer is placed inside on a wiring board and heated and pressed or heated and exposed, and then the support is peeled off to form a catalyst core on the surface. An insulating resin layer transferring step of transferring the insulating resin layer onto which the substrate has been adsorbed to a wiring board, a via hole forming step of forming a via hole in the insulating resin layer, and electroless plating via the catalyst nucleus on the insulating resin layer. And a conductive layer forming step of forming a conductive layer by electrolytic plating thereafter. 4. A via hole forming step of forming a via hole in the insulating layer transfer sheet according to claim 1, wherein the insulating layer transfer sheet is superposed on a wiring board with the insulating resin layer being on the inside, and heated and pressurized or heated. Pressure and exposure, an insulating resin layer transfer step of transferring the insulating resin layer having the catalyst nuclei adsorbed on the surface thereof to the wiring board by peeling the support and electroless plating through the catalyst nuclei on the insulating resin; A method for manufacturing a build-up printed wiring board, comprising a conductive layer forming step of forming a conductive layer for electrolytic plating thereafter.