JPH0964544A - Multilayer printed wiring board and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: A multilayer printed wiring board having a high-definition pattern and a manufacturing method capable of manufacturing such a multilayer printed wiring board by a transfer lamination method onto a substrate without including a photolithography process. And how to provide. SOLUTION: A conductive pattern and an insulating electrolytic polymer film are formed by sequentially performing an operation of transferring a wiring pattern layer provided on a wiring pattern layer transfer plate onto a substrate, for a plurality of wiring pattern layer transfer plates. The wiring pattern layer which it has is formed on a board | substrate, and it is set as a multilayer printed wiring board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer printed wiring board and a method for manufacturing the same, and more particularly to a multilayer printed wiring board having a high-definition pattern, and such a multilayer printed wiring board can be manufactured at low cost. Manufacturing method

[0002]

2. Description of the Related Art Due to the rapid development of semiconductor technology, downsizing of semiconductor packages, increase in pin count, fine pitch,
The miniaturization of electronic components has rapidly progressed, and the era of so-called high-density mounting has entered. Along with that, printed wiring boards are being further multilayered and thinned from single-sided wiring to double-sided wiring.

At present, a subtractive method and an additive method are mainly used for forming a copper pattern on a printed wiring board.

The subtractive method is a method in which a hole is formed in a copper-clad laminate, copper is plated on the inside and the surface of the hole, and a pattern is formed by photoetching. Although this subtractive method is technically highly complete and inexpensive, it is difficult to form a fine pattern due to restrictions such as the thickness of the copper foil.

On the other hand, in the additive method, a resist is formed on a portion other than a circuit pattern forming portion on a laminated plate containing a catalyst for electroless plating, and a circuit is formed on the exposed portion of the laminated plate by electroless copper plating or the like. This is a method of forming a pattern. Although the additive method can form a fine pattern, it is difficult in terms of cost and reliability.

In the case of a multi-layer substrate, a method of pressure laminating a single-sided or double-sided printed wiring board produced by the above method or the like together with a semi-cured prepreg obtained by impregnating glass cloth with an epoxy resin or the like is preferred. It is used. In this case, the prepreg plays a role of an adhesive for each layer, and the connection between layers is made by forming a through hole and applying electroless plating or the like inside.

Further, due to the progress of high-density mounting, thin and lightweight multi-layer boards are required, and on the other hand, high wiring capability per unit area is required.
Ingenuity has been made in the connection between layers and the mounting method of parts.

[0008]

However, the production of a multilayer substrate using the double-sided printed wiring board produced by the subtractive method described above requires the precision of drilling for forming holes in the double-sided printed wiring board and the There is a limit to the densification from the viewpoint of the limit of materialization, and it was difficult to reduce the manufacturing cost.

On the other hand, in recent years, a multilayer wiring board manufactured by sequentially laminating a conductor pattern layer and an insulating layer on a base material has been developed to satisfy the above-mentioned requirements. Since this multilayer wiring board is manufactured by alternately performing photoetching of the copper plating layer and patterning of the photosensitive resin, high-definition wiring and interlayer connection at arbitrary positions are possible.

However, in this method, copper plating and photo-etching are performed alternately a plurality of times, which complicates the process. In addition, if a trouble occurs in an intermediate process due to a series process of stacking one layer on a substrate, Reproduction becomes difficult, which hinders reduction in manufacturing cost.

Further, in the conventional multilayer wiring board, since the connection between the layers is made by forming via holes, a complicated photolithography step is required, which hinders a reduction in manufacturing cost.

The present invention has been made in view of the above circumstances, and a multilayer printed wiring board having a high-definition pattern and such a multilayer printed wiring board on a substrate without including a photolithography process. An object of the present invention is to provide a manufacturing method that can be manufactured by a transfer stacking method.

[0013]

In order to achieve such an object, a multilayer printed wiring board according to the present invention comprises a substrate and a plurality of wiring pattern layers sequentially transferred onto the substrate. Has a conductive layer and an insulating electrolytic polymerized film formed under the conductive layer.

Further, the multilayer printed wiring board of the present invention has a portion where the wiring pattern layers intersect with each other and / or a portion where the wiring pattern layers are adjacent to each other, and at the intersection, insulation between upper and lower wiring pattern layers is an upper wiring pattern. It is configured to be retained by an insulating electrolytic polymerized film that constitutes a layer, and further, to be configured such that the wiring pattern layers are connected to each other at a necessary portion of the intersecting portion and / or the adjacent portion. .

According to the method for manufacturing a multilayer printed wiring board of the present invention, a pattern made of an insulating material is formed on a transfer substrate having at least a conductive surface, and then a conductive method is applied to a portion where the pattern is not formed by a plating method. Pattern layer having a conductive layer and a wiring pattern layer having the conductive layer and the electrolytic polymerization film by further forming an insulating electrolytic polymerization film on the conductive layer by an electrolytic polymerization method A plurality of transfer plates are produced, and then the wiring pattern layer transfer plate is pressure-bonded to one surface of the substrate for a multilayer printed wiring board via an adhesive layer, and the transfer substrate is peeled off to form the wiring pattern layer. The transfer operation was sequentially repeated to form a plurality of the wiring pattern layers on the substrate.

Further, in the method for manufacturing a multilayer printed wiring board according to the present invention, each wiring pattern layer is formed at a necessary portion of a portion where the wiring pattern layers intersect with each other and / or a portion where the wiring pattern layers are close to each other. By forming a bonding portion so as to extend between the conductive layers, the wiring pattern layers are connected to each other.

In such a multilayer printed wiring board of the present invention, the wiring pattern layer laminated on the substrate has a so-called overprint type structure including a conductive layer and an insulating electrolytic polymerized film, and each wiring pattern is The conductive layer of the layer is partially exposed at all times, and the wiring pattern is formed by sequentially transferring the wiring pattern layers on the wiring pattern layer transfer plate onto the substrate. Moreover, the photoetching process is not required, and the manufacturing process of the multilayer wiring board can be simplified.

[0018]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view showing an example of the multilayer printed wiring board of the present invention. In FIG. 1, a multilayer printed wiring board 1 includes an insulating substrate 2 having an adhesive layer (not shown) on its surface, a first wiring pattern layer 3 provided on the substrate 2, and a wiring layer of this wiring. Second formed on the pattern layer 3
A multilayer printed wiring board having a three-layer structure, which includes a wiring pattern layer 4 of a layer and a wiring pattern layer 5 of a third layer formed on the wiring pattern layer 4.

The wiring pattern layers 3, 4 and 5 constituting the multilayer printed wiring board 1 are made of conductive layers 3a and 4 respectively.
a, 5a and insulating electropolymerized films 3b, 4b, 5b formed under the conductive layer, and the wiring pattern layers 4, 5 are further formed under the electropolymerized films 4b, 5b. The adhesive layers 4c and 5c are formed. The multilayer printed wiring board 1 has an overprint type structure in which the wiring pattern layer 3 is sequentially transferred onto the substrate 2 and the wiring pattern layers 4 and 5 are sequentially transferred onto the lower wiring pattern layer. In the portion where the pattern layers intersect with each other (intersection), the insulation between the upper and lower wiring pattern layers is maintained by the electrolytic polymerized film forming the upper wiring pattern layer.

Therefore, the multilayer printed wiring board 1 of the present invention is
Does not have a wiring pattern covering with an insulating layer as seen in a conventional multilayer printed wiring board, and the conductive layers 3a, 4a, 5a of the respective wiring pattern layers 3, 4, 5 are always partially exposed. Therefore, as will be described later, the wiring pattern layers can be easily connected to each other at the intersections of the wiring pattern layers or the portions (proximity portions) where the wiring pattern layers are close to each other.

The substrate 2 constituting the multilayer printed wiring board 1 of the present invention is a substrate known as a substrate for a multilayer printed wiring board, such as a glass epoxy substrate, a polyimide substrate, an alumina ceramic substrate, a glass epoxy / polyimide composite substrate or the like. Can be used. The thickness of the substrate 2 is 5 to 1
It is preferably in the range of 000 μm. Examples of the adhesive layer formed on such a substrate include epoxy resin, polyimide, silicone resin, phenol resin, acrylic resin,
A thermosetting resin such as a urea resin or a melamine resin is preferable, and the thickness of the adhesive layer can be about 1 to 50 μm. Further, as the substrate 2, a semi-cured prepreg substrate obtained by impregnating glass cloth with epoxy resin may be used, and in this case, it is not necessary to form the above-mentioned adhesive layer on the substrate.

The thickness of each of the wiring pattern layers 3, 4 and 5 is set to 100 μm or less, preferably 10 to 60 μm so that the wiring pattern layer as an underlying layer can be overcome without defects in the later-described layer transfer. The thickness of the conductive layers 3a, 4a, 5a constituting each of the wiring pattern layers 3, 4, 5 is 1 μm in order to keep the electric resistance of the wiring pattern layers low.
As described above, the thickness is preferably in the range of 5 to 40 μm. further,
The thickness of the insulative electropolymerized films 3b, 4b, 5b is at least 1 μm or more, preferably 5 to 30 μm in order to maintain insulation between upper and lower wiring pattern layers at intersections. The thickness of the adhesive layers 4c and 5c is 5 to 30 μm.
The degree is preferred. Such wiring pattern layers 3, 4, 5
The line width can be arbitrarily set up to a minimum width of about 10 μm.

The material of the conductive layers 3a, 4a and 5a is not particularly limited as long as it can form a thin film by a plating method as described later, and for example, copper, silver, gold, nickel, chromium, zinc, Tin, platinum or the like can be used.

The insulating electrolytic polymerized films 3b, 4b and 5b are
It is a thin film formed by an electrolytic polymerization method using an electrolytic polymerization liquid as described below. This electrolytic polymerized film 3b, 4b, 5
The electrolytic polymerization method for forming b may be electrolytic reduction polymerization or electrolytic oxidation polymerization.

Further, as the material of the adhesive layers 4c and 5c,
Acrylic resin, polybutadiene, phenol resin, polyimide, urea resin, melamine resin, epoxy resin, B
An adhesive such as T-resin can be used.

Next, the manufacturing method of the multilayer printed wiring board of the present invention will be described with reference to FIGS. 2 to 5 by taking the manufacturing of the multilayer printed wiring board 1 as an example.

First, a photoresist is applied on a conductive substrate 11 as a transfer substrate to form a photoresist layer 12 (FIG. 2A). Then, the photoresist layer 12 is closely exposed and developed using a predetermined photomask to expose the wiring pattern portion 11a of the conductive substrate 11 (FIG. 2B). Next, the conductive layer 14 is formed on the wiring pattern portion 11a of the conductive substrate 11 by a plating method (FIG. 2C).

After that, the transfer substrate 11 is immersed in an electrolytic polymerization solution to form an insulating electrolytic polymerization film 15 on the conductive layer 14 by an electrolytic polymerization method (FIG. 2 (D)). This electrolytic polymerization film 15 is formed by using the following electrolytic polymerization solution for electrolytic reduction polymerization for performing electrolytic polymerization on the cathode or the following electrolytic polymerization solution for electrolytic oxidation polymerization for performing electrolytic polymerization on the anode. It can be formed by a legal method, and the thickness of the electrolytically polymerized film can be controlled by adjusting the applied voltage, the energization time, and the like. (Electrolytic Polymerization Solution for Electrolytic Reduction Polymerization) At least one of the following monomers alone, one obtained by adding a polymerizable functional group to the following monomers, and at least one copolymer of the following monomers is described below. Which is dissolved in the solvent or the mixture thereof, and the following additives can be added if necessary.

Monomer -Acrylonitrile or its derivative-Acrolein or its derivative-Acrylic acid or its derivative-Acrylamide or its derivative-Maleic anhydride-Styrene or its derivative-Vinylpyridine or its derivative-Vinylimidazole or its derivative- Xylene derivatives such as xylene or halogenated xylenes ・ Divinylbenzene or its derivative solvents・ Alcohols such as methanol, ethanol, propanol, isopropyl alcohol ・ Methyl cellosolve, cellosolve, butyl cellosolve,
Cellosolve-based solvents such as cellosolve acetate-Glycols such as ethylene glycol, propylene glycol, trimethylene glycol, and 1,5-pentadiol-Dimethylformamide-Dimethylacetamide-Acetone-Acetonitrile-Dichloromethane-Ion exchange water additive -Allylamine, ethylenediamine, Amine derivatives such as propylamine ・ Polyoxyethylene, surfactants such as Triton X-100 (made by Rohm and Haas) ・ Bases such as potassium hydroxide and sodium hydroxide ・ Acids such as oxalic acid ・ Sodium silicate, sulfite Salts of sodium, ammonium perchlorate, etc. (electrolytic polymerization solution for electrolytic oxidative polymerization) The following monomers alone, those obtained by adding a polymerizable functional group to the following monomers, and the following monomers At least one of the polymers is a solvent Others are obtained by dissolving the mixture, it can be added the following additives as required.

Monomers / phenols or their derivatives: diphenylphenol, dimethylphenol, hydroxybenzaldehyde, hydroxypropiophenone, 4- (P-hydroxyphenyl) -2-butanone, hydroxyacetophenone, hydroxybenzophenone, allylphenol, hydroxysilicon. Cinnamic acid, halogenated phenols, etc.-Aniline or its derivative: aminocinnamic acid, phenylenediamine, dicarboxyaniline, etc.-Thiophene or its derivative-Thiophenol or its derivative-Pyrrole or its derivative-Quinolinol or its derivative: Aminoquinolinol, etc. -Quinone or its derivative: Solvent such as 1,4-naphthoquinone-Alcohol such as methanol, ethanol, propanol, isopropyl alcohol-Methyl Lucersolve, Cellsolve, Butylcellsolve,
Cellosolve-based solvents such as cellosolve acetate-Glycols such as ethylene glycol, propylene glycol, trimethylene glycol, and 1,5-pentadiol-Dimethylformamide-Dimethylacetamide-Acetone-Acetonitrile-Dichloromethane-Ion exchange water additive -Allylamine, ethylenediamine, Amine derivatives such as propylamine ・ Polyoxyethylene, surfactants such as Triton X-100 (made by Rohm and Haas) ・ Bases such as potassium hydroxide and sodium hydroxide ・ Acids such as oxalic acid ・ Sodium silicate, sulfite Salt such as sodium As a result, the wiring pattern layer transfer plate 10 provided with the wiring pattern layer 13 for the first layer having the conductive layer 14 and the electrolytic polymerization film 15 is obtained.

Similarly, as shown in FIGS. 3 and 4, conductive layers 24 and 34 and insulating electrolytic polymerized films 25 and 35 are formed on the conductive substrates 21 and 31, respectively. The adhesive layer 2 is formed by screen printing or dipping on the top.
6 and 36 are formed to produce the wiring pattern layer transfer plate 20 for the second layer and the wiring pattern layer transfer plate 30 for the third layer, which have the wiring pattern layers 23 and 33.

Next, the wiring pattern layer transfer plate 1 is formed on the insulating substrate 2 on which an adhesive layer (not shown) is formed in advance.
0 is pressure-bonded so that the insulating electrolytic polymerized film 15 contacts the substrate 2. This pressure bonding may be performed by any method such as roller pressure bonding, plate pressure bonding, and vacuum pressure bonding. Further, when the above-mentioned pressure-sensitive adhesive layer exhibits tackiness or adhesiveness by heating, thermocompression bonding can be performed. Thereafter, the conductive substrate 11 is peeled off and the wiring pattern layer 13 is transferred onto the substrate 2, whereby the first wiring pattern layer 3 having the conductive layer 3a and the electrolytic polymerized film 3b having an insulating property is formed on the substrate 2. It is formed on top (FIG. 5 (A)). After that, the wiring pattern layer transfer plate 20 for the second layer is used to perform alignment with the first wiring pattern layer on the substrate 2 on which the first wiring pattern layer 3 has been transferred and formed. Similarly, the wiring pattern layer is transferred to form the second wiring pattern layer 4 having the conductive layer 4a, the insulating electrolytic polymerized film 4b and the adhesive layer 4c (FIG. 5 (B)). Further, on the substrate 2 on which the first wiring pattern layer 3 and the second wiring pattern layer 4 have been transferred and formed, alignment is similarly performed using the wiring pattern layer transfer plate 30 for the third layer. Then, the wiring pattern layer is transferred to form the third wiring pattern layer 5 having the conductive layer 5a, the insulating electrolytic polymerized film 5b and the adhesive layer 5c (FIG. 5C).

As described above, each wiring pattern layer 3, 4,
5 is formed by sequentially transferring the wiring pattern layers 13, 23, 33 of the wiring pattern layer transfer plates 10, 20, 30 onto the substrate, so that the multilayer printed wiring board 1 can form the wiring pattern layers 3, 4 , 5 is a so-called overprint type structure. FIG. 6 is a perspective view showing an intersection of the wiring pattern layer 3 and the wiring pattern layer 4 which constitute the multilayer printed wiring board 1. As shown in FIG. 6, the conductive layers 3a and 4a of the wiring pattern layers 3 and 4 are always partially exposed, and at the intersection, between the wiring pattern layer 3 and the wiring pattern layer 4. The insulation is maintained by the insulating electrolytic polymerized film 4b that constitutes the upper wiring pattern layer 4. Also, the intersection of the wiring pattern layers, or FIG.
As shown in FIG. 3, the wiring pattern layers are easily connected to each other at a portion where the wiring pattern layers are close to each other (proximity portion, the wiring pattern layer 3 and the wiring pattern layer 4 are close to each other in the illustrated example). be able to.

The multilayer printed wiring board 1 of the present invention described above is
The wiring pattern layer 13 for the first layer is transferred through the adhesive layer formed in advance on the surface of the substrate 2, and the wiring pattern layer 23 for the second layer and the wiring pattern layer 33 for the third layer are transferred. Similarly, the wiring pattern layer 13 for the first layer also has an adhesive layer on the insulative electropolymerized film 15, and is transferred to a substrate not provided with an adhesive layer via this adhesive layer to form a first adhesive layer. The first wiring pattern layer 3 may be formed.

Next, the connection at the intersection or the proximity of each wiring pattern layer of the multilayer printed wiring board 1 of the present invention will be described.

8 to 12 show a multilayer printed wiring board 1
FIG. 6 is a perspective view showing a connection state of intersections of the wiring pattern layers of FIG. In FIG. 8, a joint portion 41 is formed and connected to the through hole formed in the upper wiring pattern layer 4. Further, in FIG. 9, a joint portion 42 is formed at a part of the intersection to connect the conductive layer 3a of the wiring pattern layer 3 and the conductive layer 4a of the wiring pattern layer 4. Further, in FIG. 10, a joint portion 43 is formed so as to cover the intersection of the wiring pattern layer 3 and the wiring pattern layer 4. Further, FIG. 11 shows a connection portion 44 formed so as to extend over a part of the proximity portion to connect the wiring pattern layer 3 and the wiring pattern layer 4, and FIG. 12 shows the wiring pattern layer 3 and the wiring pattern. The connection part 45 is formed and connected so as to cover the vicinity of the layer 4.

As a connection by forming a joint at the intersection or the proximity of each wiring pattern layer,
(1) printing method, (2) dispensing method, (3) ultra fine particle spraying method, (4) laser drawing method, (5) selective electroless plating method,
(6) Selective vapor deposition method, (7) Welding joining method and the like.

The connection at the intersection or the proximity of the wiring pattern layers of the multilayer printed wiring board 1 by the printing method of the above (1) is so made as to extend between the conductive layers constituting each wiring pattern layer by printing. This is performed by fixing a conductive paste or solder to form a joint. The printing method used is not particularly limited, but screen printing, which is generally suitable for thick film printing and widely used in the electronic industry, is preferable. When performing screen printing, create a screen printing plate that has openings in the areas corresponding to the connections between wires in advance, place it in position on the multilayer wiring board, and place a conductive paste such as silver paste. Just print the ink.

Further, the connection at the intersection or the proximity of the wiring pattern layers of the multilayer printed wiring board 1 by the dispensing method of the above (2) is similar to the above-mentioned printing method, but the conductive ink is finely divided. This is performed by ejecting from a nozzle and directly drawing and forming a joint between wirings. Specifically, a dispenser having a needle-shaped ejection port, which is generally used for attaching a small amount of an adhesive or the like to a required place, can be used. Further, depending on the viscosity of the conductive ink used, an inkjet method used in an output device such as a computer can also be used.

In the method (3) of spraying ultrafine particles, the ultrafine particles are carried by being carried on a high-speed air stream, and sprayed onto the multilayer printed wiring board from a fine nozzle provided close to the multilayer printed wiring board. A method of forming a film by sintering the ultrafine particles and the multilayer printed wiring board with each other by collision energy, and a method called a gas deposition method can be used. The apparatus used in this method is basically composed of two vacuum tanks of high vacuum and low vacuum, and a connecting pipe connecting each vacuum tank. The ultrafine particles are formed by a vacuum evaporation method in a low vacuum tank into which argon gas or the like is introduced, and the substrate is placed in a high vacuum tank. The connection pipe has an opening in the vicinity of the ultra-fine particles generated in the low vacuum tank and in the vicinity of the multilayer printed wiring board in the high vacuum tank and in a direction orthogonal to the wiring board. There is. Since each vacuum tank is kept at a constant pressure by the vacuum exhaust system, a high-speed air flow (gas flow) from the low vacuum tank to the high vacuum tank in the connecting pipe due to the pressure difference between the vacuum tanks. The ultrafine particles generated and generated in the low vacuum tank are carried on this air stream and conveyed to the high vacuum tank side, and collide with the wiring pattern layer of the multilayer printed wiring board to be sintered to form a film. By using this method with a metal such as gold, silver, copper or nickel as a base material, it is possible to selectively form a conductor (joint portion) at a place where a connection between wirings is required.

In the laser drawing method of the above (4), a solution in which conductive fine particles are dispersed is applied to a multilayer printed wiring board, and a desired portion of this coating film is heated by a laser to decompose or decompose the resin binder. It is vaporized and removed, and conductive fine particles are deposited and aggregated at the heated portions to selectively form a conductor. As the solution, a conductive resin fine particle such as gold or silver dispersed in a polyester resin, an acrylic resin, or the like is used, and a fine line of about several tens of μm can be drawn by irradiating with squeezing an argon laser or the like.

As the selective electroless plating method (5) above, a selective electroless plating technique generally known as a photoforming method can be used. This technique is capable of reducing and forming a photosensitizer layer containing a metal in an oxidized state serving as a catalyst for electroless plating on a multilayer printed wiring board, and selectively exposing the photosensitizer layer, In the electroless plating, metal particles serving as a catalyst are deposited and then immersed in an electroless plating solution to selectively plate only the exposed portion.

The selective vapor deposition method (6) uses a selective film deposition technique which is one of thin film forming techniques. That is, a metal, an organometallic gas containing a conductive element such as carbon, or an organic substance vapor containing a conductive element is introduced into the vacuum chamber, and the above gas or the above gas is applied to the surface of the multilayer printed wiring board installed in the vacuum chamber. The vapor is adsorbed, and then the laser or ion beam is condensed or converged to irradiate the substrate, and the gas or vapor adsorbed on the portion is decomposed by heat or collision energy to generate metal,
A conductive material such as carbon is deposited on the multilayer printed wiring board. Such a selective vapor deposition method has been put to practical use as a wiring correction technique for LSI. Specifically, with a focused argon laser, chromium, cobalt, platinum,
A technique for decomposing an organometallic gas containing tungsten and depositing these metals at a desired correction position, or a technique for decomposing a vapor of an organic material such as pyrene by an ion beam of gallium to deposit a carbon film is proposed. Can be used.

Further, in the welding joining method of the above (7), the crossing portion of the wiring pattern layers is selectively heated by a laser, and the insulating resin layer (upper layer is formed between the conductive layers of the upper and lower wiring pattern layers is formed. Insulating resin layer) is melted and evaporated, and
By heating the conductive layer itself to a high temperature, the conductive layers forming the respective wiring pattern layers are fused to each other to form a joint portion and connect them.

Further, the wiring pattern layers constituting the multilayer printed wiring board of the present invention are connected to each other by (8) wire bonding method and (9) wire bonding apparatus.
Shot method, (10) laser plating method, (11) batch transfer method of laminated body of conductor and solder plating, (12) metal lump insertion method, (13) electroless plating method and the like can be performed.
The wire bonding method of (8) above is performed, for example, by using the method shown in FIG.
As shown in (4), the adjacent portions where the wiring pattern layers 3 and 4 are not electrically connected (the same can be dealt with at intersections).
Is wire-bonded using a wire-bonding device, and the conductive layers 3a and 4a are connected by a wire bridge 46.

The one-shot method using the wire bonding apparatus of the above (9) is, for example, as shown in FIG. 14, the non-conducting proximity portions of the wiring pattern layers 3 and 4 (the same can be dealt with at the intersection portion). Is bonded for one shot (one time) using a wire bonding device, and the conductive layers 3a and 4a are formed without a bridge.
And a bonding block (pad) 47 is used to connect them.

In the laser plating method of the above (10), for example, a predetermined spot diameter, power on the irradiation surface, etc. were adjusted in a state where the multilayer printed wiring board before the connection operation was immersed in a palladium plating solution. This is a method of irradiating a laser (for example, an argon laser) at a proximity portion or a crossing portion to be conducted for a predetermined time, and depositing a Pd film at a predetermined thickness on the irradiation portion and connecting the same. It is preferable to irradiate the laser while circulating the palladium plating solution. Further, the plating liquid is removed by washing with water, and the plating liquid shown in FIG.
The conductive layer 3a and 4a are connected by the plated film 48 deposited as shown in FIG.

The batch transfer method of the laminated body of the conductor and the solder plating of the above (11) is performed as shown in FIGS. 16 (A) and 16 (B). First, as shown in FIG. 16 (B), a laminated body 50 of a conductor layer 51 and a solder plating layer 52 is manufactured by the following procedure. That is, on the conductive substrate 55,
A conductive layer 51 is formed, for example, by electroplating on a transfer substrate which is developed using a resist method to form a desired pattern (conductive pattern), and a predetermined solder plating bath composition is formed on the conductive layer. Solder plating is performed using an object to form the solder plating layer 52. The solder plating layer 52 can be formed in the same manner by solder printing, screen printing of solder paste, or dipping. The laminated body 50 laminated in this way is collectively thermally transferred to a non-conducting proximity portion of the wiring pattern layers 3 and 4 (which can also be dealt with at an intersection portion) as shown in FIG. 16A. , The conductive layers 3a and 4a are connected. At this time, the thermal transfer temperature is a temperature at which the solder plating layer 52 can be melted and deformed from 200 to
It is performed in a temperature range of about 300 ° C.

The method (12) for inserting a metal block is shown in FIG.
As shown in (A), for example, a diameter of 30 to 1 is set in the wiring gap in the non-conducting proximity portion of the wiring pattern layers 3 and 4.
A method of arranging a metal ball 61 of about 00 μm, and thereafter, as shown in FIG. 17B, pressure-bonding a sheet 62 coated with a pressure-sensitive adhesive to connect the conductive layers 3a and 4a. Is. The use of metal balls is a more preferable mode of use, but metal balls (lumps) that are not spherical can also be used. Further, such a metal ball (lump) can also be used to further improve the reliability of the connection portion in the printing method and the dispensing method. That is, the above-mentioned printing or dispensing is performed after the metal balls are installed.

FIG. 18 shows the electroless plating method of (13) above.
A description will be given based on (A) to (F). First of all,
An electroless plating catalyst is applied to the entire surface of a multilayer printed wiring board having wiring pattern layers 3 and 4 as shown in FIG. 8A to form a catalyst layer 71 (FIG. 18B). Next, a photoresist is applied on this to form a resist layer 73.
After forming, the resist layer 73 is contact-exposed and developed using a predetermined photomask to expose the portion H corresponding to the position where the wiring pattern should be connected (FIG. 18C).
Then, after activating the exposed portion H, electroless plating is performed to form a connecting portion 75 and connect the conductive layers 3a and 4a (FIG. 18D). Then, the remaining unnecessary resist and the catalyst layer are sequentially removed to leave only the connecting portion 75 (catalyst layer 71a) (FIGS. 18E and 18F).

The multilayer printed wiring board of the present invention has been described above.
By using the connection method such as (2) to (13), it is possible to connect between the wiring pattern layers at any place without being restricted by the place where the through hole is formed. The degree of freedom in changing the circuit design is greater than that of the conventional multilayer printed wiring board.

In the above example, the multilayer printed wiring board 1 has a three-layer structure, but in the method for manufacturing a multilayer printed wiring board of the present invention, a desired number of wiring pattern layers can be obtained by repeating the same layer transfer. It is possible to manufacture a multilayer printed wiring board provided with.

Further, the multilayer printed wiring board of the present invention having a two-layer structure has a problem in the conventional double-sided printed wiring board, that is, high densification due to the precision of the drilling process for forming holes in the double-sided printed wiring board. Can solve the problem. This is because, as described above, in the multilayer printed wiring board of the present invention, the conductive layer of each wiring pattern layer is always partially exposed, and the intersection of the wiring pattern layers without forming a through hole, or This is because it is possible to easily connect the wiring pattern layers to each other in the proximity portion.

[0055]

Next, the present invention will be described in more detail with reference to examples. (Example 1) (1) Formation of Conductive Layer in Wiring Pattern Layer Transfer Plate As a conductive transfer substrate, the surface was polished to a thickness of 0.2 m.
m stainless steel plate is prepared, and a commercially available photoresist for plating (PM made by Tokyo Ohka Kogyo Co., Ltd.
ER P-AR900) is applied to a thickness of 8 μm and dried, and contact exposure is performed using each of the three types of photomasks on which wiring patterns are formed, followed by development, washing with water, drying, and further heat curing. A transfer substrate (3 types) in which the wiring pattern portion was exposed was prepared.

A copper pyrophosphate plating bath (pH = 8, liquid temperature = 55) having the following composition was prepared with the above-mentioned transfer substrate and the platinum electrode facing each other.
℃), connect the platinum electrode to the anode of the DC power supply,
The above transfer substrate is connected to the cathode, and the current density is 10 A / d.
A current was supplied at m ² for 5 minutes to form a 10 μm-thick copper plating film on the exposed portion of the transfer substrate which was not covered with the photoresist to form a conductive layer. This conductive layer formation was performed on three types of transfer substrates.

(Composition of copper pyrophosphate plating bath) Copper pyrophosphate: 94 g / l Copper potassium pyrophosphate: 340 g / l Ammonia water: 3 g / l (2) Preparation of electrolytic polymerization solution Acrolein (manufactured by Wako Pure Chemical Industries, Ltd.) 5.6 g of special grade and 1.185 g of ammonium perchlorate were dissolved in a solvent (1000 g of ion-exchanged water or a mixed solution of 900 g of ion-exchanged water and 100 g of methanol) to prepare an electrolytic polymerization solution. (3) Formation of Insulating Electrolytic Polymerization Film in Wiring Pattern Layer Transfer Plate The three types of transfer substrates having the conductive layer formed in (1) above are dipped in the electrolytic polymerization solution prepared in (2) above, The transfer substrate was connected to the cathode of the DC power source and the stainless plate electrode was connected to the anode, respectively, and electrolytic polymerization (electrolytic reduction polymerization) was performed at a voltage of 5 V for about 1 hour. Next, the transfer substrate is washed with ion-exchanged water and dried under reduced pressure (8 hours), and further 120 ° C., 3
After drying for 0 minutes, an electropolymerized film (thickness of about 5μ is formed on the conductive layer.
m) to form three wiring pattern layer transfer plates A1 and A
2, A3 was obtained.

Of the above three types of wiring pattern layer transfer plates, the other two except the wiring pattern layer transfer plate A1 for the first layer are used.
For the wiring pattern layer transfer plates A2 and A3 of the seeds, an adhesive (KE34 manufactured by Shin-Etsu Chemical Co., Ltd.) was used by silk printing.
79) is applied onto the electrolytic polymerized film to form an adhesive layer (thickness 10 μm
m) was formed. (4) Preparation of multilayer printed wiring board 1 Wiring pattern layer transfer plate A prepared in (3) above
1 was thermocompression-bonded under the following conditions so that the electrolytic polymerized film was in contact with a prepreg substrate (TLP-551 manufactured by Toshiba Chemical Co., Ltd.) having a thickness of 50 μm, and was composed of a conductive layer and an insulating electrolytic polymerized film. The first wiring pattern layer was transferred onto the substrate.

(Pressure bonding conditions) Pressure: 10 kgf / cm ² Temperature: 170 ° C. Next, the wiring pattern layer transfer plates A2 and A3 prepared in (3) above were formed on the substrate on which the first layer was formed. Thermocompression bonding was sequentially performed under pressure bonding conditions, and the second and third wiring pattern layers were transferred onto the substrate to produce a multilayer printed wiring board. (5) Preparation of multilayer printed wiring board 2 Wiring pattern layer transfer plate A prepared in (3) above
1 was coated with an adhesive (Japan Carbide Co. PE-118) to a thickness of about 3 μm and dried to form an adhesive layer 25 μm
The first wiring pattern layer composed of a conductive layer and an insulating electrolytic polymer film was transferred onto the substrate by pressure bonding under the following conditions so that the electrolytic polymer film was in contact with the polyimide film of m.

(Pressing condition) Pressure: 10 kgf / cm ² Temperature: Room temperature Next, the wiring pattern layer transfer plates A2 and A prepared in (3) were formed on the polyimide film on which the first layer was formed.
3 are sequentially crimped under the above crimping conditions, and the second layer and the third
The wiring pattern layer of the layer was transferred onto the film to produce a multilayer printed wiring board. (Example 2) (1) Formation of conductive layer in wiring pattern layer transfer plate A conductive layer was formed in the same manner as in (1) of Example 1 to prepare three types of transfer substrates. (2) Preparation of electropolymerization liquid 14.3 parts by weight of 2-6 diphenylphenol, Tri
Ton X-100 (manufactured by Rohm and Haas Co.) was used.
An electrolytic polymerization solution was prepared by mixing 291 parts by weight and 500 parts by weight of a 0.01 molar sodium hydroxide aqueous solution with stirring. (3) Formation of Insulating Electrolytic Polymerization Film in Wiring Pattern Layer Transfer Plate The three types of transfer substrates having the conductive layer formed in (1) above are dipped in the electrolytic polymerization solution prepared in (2) above, The transfer substrate was connected to the anode of the DC power source and the stainless plate electrode was connected to the cathode, respectively, and electrolytic polymerization (electrolytic oxidation polymerization) was performed at a voltage of 5 V for about 1 hour. Next, the connection between the cathode and the anode was reversed and a voltage of 5 V was applied for about 1 hour. Thereafter, the transfer substrate was washed with ion-exchanged water, dried under reduced pressure (8 hours), and further dried at 120 ° C. for 30 minutes to form an electropolymerized film (thickness of about 5 μm) on the conductive layer, and three types were prepared. Wiring pattern layer transfer plates B1, B2 and B3 were obtained.

Of the above three types of wiring pattern layer transfer plates, the other two except the wiring pattern layer transfer plate B1 for the first layer are used.
For the wiring pattern layer transfer plates B2 and B3 of the seeds, an adhesive (KE34 manufactured by Shin-Etsu Chemical Co., Ltd.) was used by silk printing.
79) is applied onto the electrolytic polymerized film to form an adhesive layer (thickness 10 μm
m) was formed. (4) Preparation of multilayer printed wiring board 1 Wiring pattern layer transfer plate B prepared in (3) above
1 was thermocompression-bonded under the following conditions so that the electrolytic polymerized film was in contact with a prepreg substrate (TLP-551 manufactured by Toshiba Chemical Co., Ltd.) having a thickness of 50 μm, and was composed of a conductive layer and an insulating electrolytic polymerized film. The first wiring pattern layer was transferred onto the substrate.

(Pressure bonding conditions) Pressure: 10 kgf / cm ² Temperature: 170 ° C. Next, the wiring pattern layer transfer plates B2 and B3 prepared in (3) above were formed on the substrate on which the first layer was formed. Thermocompression bonding was sequentially performed under pressure bonding conditions, and the second and third wiring pattern layers were transferred onto the substrate to produce a multilayer printed wiring board. (5) Preparation of multilayer printed wiring board 2 Wiring pattern layer transfer plate B prepared in (3) above
1 was coated with an adhesive (Japan Carbide Co. PE-118) to a thickness of about 3 μm and dried to form an adhesive layer 25 μm
The first wiring pattern layer composed of a conductive layer and an insulating electrolytic polymer film was transferred onto the substrate by pressure bonding under the following conditions so that the electrolytic polymer film was in contact with the polyimide film of m.

(Pressure bonding conditions) Pressure: 10 kgf / cm ² Temperature: Room temperature Next, the wiring pattern layer transfer plates B2, B prepared in (3) on the polyimide film on which the first layer was formed.
3 are sequentially crimped under the above crimping conditions, and the second layer and the third
The wiring pattern layer of the layer was transferred onto the film to produce a multilayer printed wiring board.

[0064]

As described above in detail, according to the present invention, the wiring pattern layer provided on the transfer substrate is transferred onto the substrate to thereby form the conductive layer on the upper side and the insulating electrolytic polymer film on the lower side. The provided wiring pattern layers can be formed in multiple layers on the substrate. In this multilayer formation, a plurality of transfer substrates having predetermined wiring pattern layers are prepared in parallel and the transfer substrates are sequentially transferred. Since it is a parallel series process, defective products can be eliminated by inspection before transfer, manufacturing yield is improved, throughput is high, and wiring layer formation and patterning that were conventionally performed on the substrate The plating process and the photo-etching process are not required, and the manufacturing process can be simplified. In addition, the multilayer printed wiring board does not have a wiring pattern covering with an insulating layer as seen in the conventional multilayer printed wiring board, and the conductive layers constituting each wiring pattern layer are always partially exposed. Therefore, the wiring pattern layers can be easily connected to each other at the intersections of the wiring pattern layers or the portions where the wiring pattern layers are close to each other, and a multi-layer printed wiring board having extremely high versatility can be realized.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a multilayer printed wiring board according to the present invention.

FIG. 2 is a diagram illustrating a method for manufacturing a multilayer printed wiring board according to the present invention.

FIG. 3 is a schematic cross-sectional view showing an example of a wiring pattern layer transfer plate used in the method for manufacturing a multilayer printed wiring board according to the present invention.

FIG. 4 is a schematic cross-sectional view showing an example of a wiring pattern layer transfer plate used in the method for manufacturing a multilayer printed wiring board according to the present invention.

FIG. 5 is a diagram illustrating a method for manufacturing a multilayer printed wiring board according to the present invention.

FIG. 6 is a perspective view showing an intersection of wiring pattern layers of the multilayer printed wiring board according to the present invention.

FIG. 7 is a perspective view showing the vicinity of the wiring pattern layer of the multilayer printed wiring board according to the present invention.

FIG. 8 is a perspective view showing a connection state at an intersection of wiring pattern layers of the multilayer printed wiring board according to the present invention.

FIG. 9 is a perspective view showing a connection state at an intersection of wiring pattern layers of the multilayer printed wiring board according to the present invention.

FIG. 10 is a perspective view showing a connection state at an intersection of wiring pattern layers of the multilayer printed wiring board according to the present invention.

FIG. 11 is a perspective view showing a connection state in the vicinity of the wiring pattern layer of the multilayer printed wiring board according to the present invention.

FIG. 12 is a perspective view showing a connection state in the vicinity of the wiring pattern layer of the multilayer printed wiring board according to the present invention.

FIG. 13 is a perspective view showing a connection state in the vicinity of the wiring pattern layer of the multilayer printed wiring board according to the present invention.

FIG. 14 is a perspective view showing a connection state in the vicinity of the wiring pattern layer of the multilayer printed wiring board according to the present invention.

FIG. 15 is a perspective view showing a connection state in the vicinity of the wiring pattern layer of the multilayer printed wiring board according to the present invention.

FIG. 16 is a diagram for explaining a connection state in the vicinity of the wiring pattern layer of the multilayer printed wiring board according to the present invention.

FIG. 17 is a perspective view showing a state in which connections are sequentially formed in the vicinity of the wiring pattern layer of the multilayer printed wiring board according to the present invention.

FIG. 18 is a diagram for explaining a connection state in the vicinity of the wiring pattern layer of the multilayer printed wiring board according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Multilayer printed wiring board 2 ... Substrate 3,4,5 5 ... Wiring pattern layer 3a, 4a, 5a ... Conductive layer 3b, 4b, 5b ... Insulating electrolytic polymerized film 4c, 5c ... Adhesive layer 10, 20, 30 ... Wiring pattern layer transfer plate 11 ... Conductive substrate 13, 23, 33 ... Wiring pattern layer 41, 42, 43, 44, 45, 46, 47, 48, 5
0, 61, 71 ... Joint

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H05K 3/20 6921-4E H05K 3/20 A

Claims (5)

[Claims] 1. A substrate, a plurality of wiring pattern layers sequentially transferred onto the substrate, the wiring pattern layer having a conductive layer and an insulating electrolytic polymer film formed under the conductive layer. A multilayer printed wiring board characterized by the above. 2. The wiring pattern layer has a portion where the wiring pattern layers intersect and / or a portion where the wiring pattern layers are close to each other, and at the intersection, insulation between upper and lower wiring pattern layers is an insulating electrolytic polymerization forming an upper wiring pattern layer. The multilayer printed wiring board according to claim 1, which is held by a film. 3. The multilayer printed wiring board according to claim 2, wherein wiring pattern layers are connected to each other at required portions of the intersecting portion and / or the adjacent portion. 4. A pattern made of an insulating material is formed on a transfer substrate having a conductive surface at least, and then a conductive layer is formed by a plating method on a portion where the pattern is not formed. By forming an insulating electrolytic polymerization film on the layer by an electrolytic polymerization method, to produce a plurality of wiring pattern layer transfer plate provided with a wiring pattern layer having the conductive layer and the electrolytic polymerization film, then, The operation of pressure-bonding the wiring pattern layer transfer plate to one surface of the substrate for a multilayer printed wiring board via an adhesive layer and peeling the transfer substrate to transfer the wiring pattern layer is repeated in sequence. A method for manufacturing a multilayer printed wiring board, comprising forming a plurality of the wiring pattern layers on a substrate. 5. A junction is formed at a required portion of a portion where the wiring pattern layers intersect with each other and / or a portion where the wiring pattern layers are close to each other so as to extend between the conductive layers forming each wiring pattern layer. The method for manufacturing a multilayer printed wiring board according to claim 4, wherein the wiring pattern layers are connected to each other by forming portions.