JP3787178B2 - Manufacturing method of multilayer printed wiring board - Google Patents

Description

（５） 配線パターン層転写版における樹脂層の形成（図２（Ｅ）対応））
上記（３）において導電性層上に絶縁層を形成した透明転写基板（３種）の導電性層と絶縁層の形成面側に、上記の（４）で作製したフィルムを粘着感光性樹脂層が絶縁層に接するように重ね、下記の条件で熱圧着し、その後、導電性層をマスクとして透明転写基板の裏面から下記の条件で露光（背面露光）を行い、次いで、剥離現像を行い絶縁層上に粘着性の樹脂層（厚み約５μｍ）を形成して、３種の配線パターン層転写版Ａ１、Ａ２、Ａ３を得た。
【００８７】
（熱圧着条件）
圧 力 ： ０．４５ｋｇｆ／ｃｍ²
温 度 ： １００℃
（露光条件）
密着露光機：大日本スクリーン製造（株）製 Ｐ−２０２−Ｇ
真空引き ：６０秒
露光時間 ：３０カウント
（６） 多層プリント配線板の作製（図５対応）
厚さ２５μｍのポリイミドフィルム基板上に、上記の（５）において作製した配線パターン層用の転写用原版Ａ１を下記の条件で熱圧着して導電性層、絶縁層および粘着性の樹脂層からなる第１層目の配線パターン層を転写した。
【００８８】
（熱圧着条件）
圧 力 ： １０ｋｇｆ／ｃｍ²
温 度 ： １００℃
次に、第１層目の配線パターン層が形成されたフィルム基板上に、上記の（５）において作製した配線パターン層用の転写用原版Ａ２を上記と同様の条件で熱圧着して導電性層、絶縁層および粘着性の樹脂層からなる第２層目の配線パターン層を転写した。
【００８９】
同様に、第２層目の配線パターン層が形成されたフィルム基板上に、上記の（５）において作製した配線パターン層用の転写用原版Ａ３を上記と同様の条件で熱圧着して導電性層、絶縁層および粘着性の樹脂層からなる第３層目の配線パターン層を転写した。
【００９０】
次いで、１８０℃、３０分の条件で粘着性の樹脂層を硬化させて、図１に示されるような３層の配線パターン層を備えた本発明の多層プリント配線板を作製した。
【００９１】
【発明の効果】
以上詳述したように、本発明によれば透明転写基板上に設けた配線パターン層を基板上に転写することにより、上部に導電性層を下部に絶縁層と樹脂層を備えた配線パターン層、あるいは、上部に導電性層を下部に絶縁樹脂層を備えた配線パターン層を、基板上に多層に形成することができ、この多層形成は、所定の配線パターン層を形成した転写基板を並行して複数作製し、これらの転写基板を用いて順次転写する並直列プロセスであるため、転写前の検査により不良品を排除することができ、製造歩留が向上するとともに、スループットが高く、さらに、従来基板上で行っていた配線層の形成やパターニングのためのメッキ、およびフォトエッチング工程は不要となり、製造工程の簡略化が可能となる。
【００９２】
また、透明転写基板上に上記の配線パターン層を形成して配線パターン層転写版を作製する際に、透明転写基板上に形成した粘着感光性樹脂層あるいは粘着絶縁感光性樹脂層を、透明転写基板の裏面から光を照射して導電性層をマスクとして露光を行うので、従来の転写基板の上側からの露光におけるマスクアライメントが不要となり、装置および工程の簡略化が可能となる。さらに、製造工程において、粘着感光性樹脂層を備えるフィルムあるいは粘着絶縁感光性樹脂層を備えるフィルムを使用するので、いわゆるドライ処理が可能となり、製造工程の大幅な効率化が実現できる。
【００９３】
また、多層プリント配線板には、従来の多層プリント配線板に見られたような絶縁層による配線パターンの被覆がなく、各配線パターン層を構成する導電性層は部分的に常に裸出されており、各配線パターン層の交差部あるいは各配線パターン層が相互に近接する部位における各配線パターン層相互の接続を容易に行うことができ、汎用性の極めて高い多層プリント配線板が可能となる。
【図面の簡単な説明】
【図１】本発明の多層プリント配線板の一例を示す概略断面図である。
【図２】本発明の多層プリント配線板の製造方法を説明するための図面である。
【図３】本発明の多層プリント配線板の製造方法に使用する配線パターン層転写版の一例を示す概略断面図である。
【図４】本発明の多層プリント配線板の製造方法に使用する配線パターン層転写版の一例を示す概略断面図である。
【図５】本発明の多層プリント配線板の製造方法を説明するための図面である。
【図６】本発明の多層プリント配線板の配線パターン層の交差部を示す斜視図である。
【図７】本発明の多層プリント配線板の配線パターン層の近接部を示す斜視図である。
【図８】本発明の多層プリント配線板の他の例を示す概略断面図である。
【図９】本発明の多層プリント配線板の製造方法の他の例を説明するための図面である。
【図１０】本発明の多層プリント配線板の配線パターン層の交差部における接続状態を示す斜視図である。
【図１１】本発明の多層プリント配線板の配線パターン層の交差部における接続状態を示す斜視図である。
【図１２】本発明の多層プリント配線板の配線パターン層の交差部における接続状態を示す斜視図である。
【図１３】本発明の多層プリント配線板の配線パターン層の近接部における接続状態を示す斜視図である。
【図１４】本発明の多層プリント配線板の配線パターン層の近接部における接続状態を示す斜視図である。
【図１５】本発明の多層プリント配線板の配線パターン層の近接部における接続状態を示す斜視図である。
【図１６】本発明の多層プリント配線板の配線パターン層の近接部における接続状態を示す斜視図である。
【図１７】本発明の多層プリント配線板の配線パターン層の近接部における接続状態を示す斜視図である。
【図１８】本発明の多層プリント配線板の配線パターン層の近接部における接続状態を説明するための図である。
【図１９】本発明の多層プリント配線板の配線パターン層の近接部における接続を順次形成する状態を示す斜視図である。
【図２０】本発明の多層プリント配線板の配線パターン層の近接部における接続状態を説明するための図である。
【符号の説明】
１，４０…多層プリント配線板
２，４２…基板
３，４，５，４３，４４，４５…配線パターン層
３ａ，４ａ，５ａ，４３ａ，４４ａ，４５ａ…導電性層
３ｂ，４ｂ，５ｂ…絶縁層
３ｃ，４ｃ，５ｃ…樹脂層
４３ｂ，４４ｂ，４５ｂ…絶縁樹脂層
１０，２０，３０，５０…配線パターン層転写版
１１，５１…透明転写基板
１１ａ，５１ａ…透明導電膜
１３，２３，３３，５３…配線パターン層
１６，５６…フィルム
１７，５７…支持体
１８…粘着感光性樹脂層
５８…粘着絶縁感光性樹脂層
１９…樹脂層
５９…絶縁樹脂層
６１，６２，６３，６４，６５，６６，６７，６８，７０，８１，９１…接合部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multilayer printed wiring board and a manufacturing method thereof, and more particularly to a multilayer printed wiring board having a high-definition pattern and a manufacturing method capable of manufacturing such a multilayer printed wiring board at a low cost.
[0002]
[Prior art]
Due to the dramatic development of semiconductor technology, semiconductor packages have rapidly become smaller, more pins, fine pitch, and miniaturized electronic components, and entered the era of so-called high-density packaging. Along with this, printed wiring boards are also being made thinner and thinner from single-sided wiring to double-sided wiring.
[0003]
Currently, a subtractive method and an additive method are mainly used for forming a copper pattern on a printed wiring board.
[0004]
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. This subtractive method is technically highly complete and low in cost, but it is difficult to form a fine pattern due to restrictions such as the thickness of the copper foil.
[0005]
On the other hand, in the additive method, a resist is formed on a part other than the circuit pattern forming part on the laminated board containing the electroless plating catalyst, and a circuit pattern is formed on the exposed part of the laminated board by electroless copper plating or the like. It is a method to do. Although this additive method can form a fine pattern, it is difficult in terms of cost and reliability.
[0006]
In the case of a multilayer substrate, a method is used in which a single-sided or double-sided printed wiring board produced by the above-described method is pressure-laminated together with a semi-cured prepreg in which a glass cloth is impregnated with an epoxy resin or the like. . In this case, the prepreg functions as an adhesive for each layer, and the connection between the layers is performed by creating a through hole and applying electroless plating or the like to the inside.
[0007]
In addition, with the progress of high-density packaging, multilayer boards are required to be thinner and lighter, while high wiring capacity per unit area is required, board thickness per layer, interlayer connection and component mounting methods, etc. Has been devised.
[0008]
[Problems to be solved by the invention]
However, the production of multi-layer boards using double-sided printed wiring boards produced by the subtractive method described above will increase the density due to the precision of drilling for hole formation in double-sided printed wiring boards and the limit of miniaturization. There was a limit and it was difficult to reduce the manufacturing cost.
[0009]
On the other hand, in recent years, a multilayer wiring board produced by sequentially laminating a conductor pattern layer and an insulating layer on a substrate has been developed to satisfy the above requirements. Since this multilayer wiring board is produced by alternately performing photo-etching of the copper plating layer and patterning of the photosensitive resin, high-definition wiring and interlayer connection at an arbitrary position are possible.
[0010]
However, in this method, copper plating and photoetching are alternately performed a plurality of times, which makes the process complicated. In addition, because of the serial process of stacking one layer on the substrate, it is difficult to regenerate the product if trouble occurs in the intermediate process. This has hindered the reduction of manufacturing costs.
[0011]
Further, in the conventional multilayer wiring board, since the connection between the layers is made by creating a via hole, a complicated photolithography process is required, which hinders the reduction of the manufacturing cost.
[0012]
The present invention has been made in view of such circumstances, and a multilayer printed wiring board having a high-definition pattern, and a method for transferring such a multilayer printed wiring board to a substrate without including a photolithography process. It aims at providing the manufacturing method which can be manufactured by this.
[0013]
[Means for Solving the Problems]
  In order to achieve such an object, the multilayer printed wiring board of the present inventionManufacturing methodIsA pattern made of an insulating material is formed on a transparent transfer substrate having at least a surface conductive, a conductive layer is formed by plating on a portion where the pattern is not formed, and an insulating layer is formed on the conductive layer. After that, a film having a negative-type adhesive photosensitive resin layer on a support is superimposed on the surface of the transparent transfer substrate, and the adhesive photosensitive resin layer is stacked and pressure-bonded so as to be in contact with the insulating layer. The back surface of the transfer substrate is irradiated with light to expose the adhesive photosensitive resin layer using the conductive layer as a mask, and then the support is peeled off to form a resin layer on the insulating layer. A plurality of wiring pattern layer transfer plates provided with a wiring pattern layer having a layer, the insulating layer, and the resin layer, and then the wiring on one surface of a substrate for a multilayer printed wiring board via the resin layer Pattern layer Crimp the copy version, the transparent transfer substrate sequentially repeated operation of transferring the wiring pattern layer by peeling were configured so as to form a plurality of said wiring pattern layer on the substrate.
  Further, the insulating layer is formed by any one of an electrodeposition method, an electrolytic polymerization method, and a photolithography method.The configuration is as follows.
[0017]
In the method for producing a multilayer printed wiring board of the present invention, a pattern made of an insulating material is formed on at least a surface of a conductive transparent transfer substrate, and a conductive layer is formed by plating on a portion where the pattern is not formed. On the surface of the transparent transfer substrate, and a pressure-sensitive adhesive insulating resin layer having a negative adhesive layer on the support is stacked and pressure-bonded so that the adhesive insulating photosensitive resin layer is in contact with the conductive layer. Then, after irradiating light from the back surface of the transparent transfer substrate and exposing the adhesive insulating photosensitive resin layer using the conductive layer as a mask, an insulating resin layer is formed on the conductive layer by peeling the support. A plurality of wiring pattern layer transfer plates provided with a wiring pattern layer having the conductive layer and the insulating resin layer, and then the insulating resin layer on one surface of a substrate for a multilayer printed wiring board Before Crimp the wiring pattern layer transfer plate, wherein the transparent transfer substrate sequentially repeated operation of transferring the wiring pattern layer by peeling were configured so as to form a plurality of said wiring pattern layer on the substrate.
[0018]
Furthermore, in the method for producing a multilayer printed wiring board according to the present invention, the conductive layer constituting each wiring pattern layer is formed at a necessary portion of a portion where the wiring pattern layers intersect each other and / or a portion where the wiring pattern layer is adjacent. It was set as the structure which connects between wiring pattern layers by forming a junction part so that it may straddle between each other.
[0019]
In such a multilayer printed wiring board of the present invention, the wiring pattern layer formed on the substrate is a laminate comprising a conductive layer, an insulating layer and a resin layer formed by curing an adhesive photosensitive resin, or a conductive layer. And a so-called overprint type structure comprising a laminate composed of an insulating resin layer formed by curing an adhesive insulating photosensitive resin, and the conductive layer of each wiring pattern layer is always partially exposed. In addition, since the wiring pattern is formed by sequentially transferring the wiring pattern layer on the wiring pattern layer transfer plate onto the substrate, the plating and photoetching steps on the substrate are unnecessary, and the production of the multilayer wiring board is performed. The process can be simplified. In addition, since a film having an adhesive photosensitive resin layer on a support or a film having an adhesive insulating photosensitive resin layer on a support is used in the production process, so-called dry processing can be performed.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to the drawings.
[0021]
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, a first wiring pattern layer 3 provided on the substrate 2, and a second layer formed on the wiring pattern layer 3. This is a multilayer printed wiring board having a three-layer structure including the wiring pattern layer 4 and a third wiring pattern layer 5 formed on the wiring pattern layer 4.
[0022]
Each of the wiring pattern layers 3, 4 and 5 constituting the multilayer printed wiring board 1 includes conductive layers 3a, 4a and 5a, insulating layers 3b, 4b and 5b formed under the conductive layer, and an adhesive layer. It has resin layers 3c, 4c, and 5c formed by curing a photosensitive resin. The multilayer printed wiring board 1 has an overprint structure in which the wiring pattern layer 3 is transferred onto the substrate 2 and the wiring pattern layers 4 and 5 are sequentially transferred onto the lower wiring pattern layer. In portions (intersections) where the pattern layers intersect each other, the insulation between the upper and lower wiring pattern layers is maintained by the insulating layer constituting the upper wiring pattern layer.
[0023]
For this reason, the multilayer printed wiring board 1 of the present invention is not covered with the wiring pattern by the insulating layer as found in the conventional multilayer printed wiring board, and the conductive layers 3a, 4a and 5a are partly bare at all times, and as will be described later, it is easy to connect the wiring pattern layers to each other at an intersection of the wiring pattern layers or a portion where the wiring pattern layers are close to each other (proximity portion). Can be done.
[0024]
The substrate 2 constituting the multilayer printed wiring board 1 of the present invention uses a known substrate 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 and polyimide composite substrate. Can do. The thickness of the substrate 2 is preferably in the range of 5 to 1000 μm. Further, as the substrate 2, a semi-cured prepreg substrate in which a glass cloth is impregnated with an epoxy resin can also be used.
[0025]
The thickness of each wiring pattern layer 3, 4, 5 is set to a range of 100 μm or less, preferably 10 to 60 μm in order to overcome the wiring pattern layer in the lower layer in the layer transfer described later without any defects. The thickness of the conductive layers 3a, 4a, 5a constituting each wiring pattern layer 3, 4, 5 is set to 1 μm or more, preferably 5 to 40 μm in order to keep the electric resistance of the wiring pattern layer low. Furthermore, the thickness of the insulating layers 3b, 4b, and 5b is at least 1 μm or more, preferably 5 to 50 μm, in order to maintain insulation between the upper and lower wiring pattern layers at the intersection. Further, the thickness of the resin layers 3c, 4c, 5c is preferably about 1 to 100 μm. The line widths of such wiring pattern layers 3, 4 and 5 can be arbitrarily set up to a minimum width of about 10 μm.
[0026]
The material of the conductive layers 3a, 4a and 5a is not particularly limited as long as it can be formed into a thin film by a plating method as will be described later. For example, copper, silver, gold, nickel, chromium, zinc, tin, platinum Etc. can be used.
[0027]
The insulating layers 3b, 4b and 5b can be formed of a conventionally known electrically insulating material.
[0028]
The resin layers 3c, 4c, and 5c are obtained by curing a negative-type adhesive photosensitive resin. As the adhesive photosensitive resin for forming the resin layers 3c, 4c, and 5c, a resin such as rosin, terpene, and petroleum resin is added as a tackifier to the conventionally known negative photosensitive resin. Things can be used.
[0029]
Next, a method for manufacturing a multilayer printed wiring board according to the present invention will be described with reference to FIGS. 2 to 5 taking the multilayer printed wiring board 1 as an example.
[0030]
First, a photoresist layer 12 is formed by applying a photoresist on a transparent transfer substrate 11 having a transparent conductive film 11a such as indium tin oxide (ITO) on the surface. Then, using a predetermined photomask, the photoresist layer 12 is closely exposed and developed to expose the wiring pattern portion 11b of the transparent transfer substrate 11 (FIG. 2A). Next, a conductive layer 14 is formed on the wiring pattern portion 11b of the transparent transfer substrate 11 by plating (FIG. 2B).
[0031]
Next, the insulating layer 15 is formed over the conductive layer 14 (FIG. 2C). The insulating layer 15 can be formed by an electrodeposition method, an electrolytic polymerization method, a photolithography method, or the like.
[0032]
When the insulating layer 15 is formed on the conductive layer 14 by the electrodeposition method, an electrodepositable insulating material made of an anionic or cationic synthetic polymer resin having an insulating property can be used. Specifically, acrylic resin, polyester resin, maleated oil resin, polybutadiene resin, epoxy resin, or the like can be used alone or as a mixture of any combination of these resins as the anionic synthetic polymer resin. Furthermore, you may use together said crosslinking | crosslinked resin, such as said anionic synthetic polymer resin, a melamine resin, a phenol resin, and a urethane resin.
[0033]
As the cationic synthetic polymer resin, an acrylic resin, an epoxy resin, a urethane resin, a polybutadiene resin, a polyamide resin, a polyimide resin, or the like can be used alone or as a mixture of any combination thereof. Furthermore, you may use together said cationic synthetic polymer resin and crosslinkable resin, such as a polyester resin and a urethane resin.
[0034]
For the above-mentioned electrodepositable insulating material, a known thermosetting resin having a thermally polymerizable unsaturated bond such as blocked isocyanate is added for the purpose of improving the reliability such as insulation and heat resistance. After transferring and forming all the layers, all the insulating layers may be cured by heat treatment. Of course, in addition to the thermosetting resin, if a resin having a polymerizable unsaturated bond (for example, acrylic group, vinyl group, allyl group, etc.) is added to the electrodepositable insulating material, the entire multilayer printed wiring board can be used. After the layer is transferred, all the insulating resin layers can be cured by electron beam irradiation.
[0035]
Further, when the insulating layer 15 is formed on the conductive layer 14 by electrolytic polymerization, either electrolytic reduction polymerization or electrolytic oxidation polymerization may be used. That is, the insulating layer 15 can be formed by an electrolytic polymerization method using the following electrolytic polymerization solution for electrolytic reduction polymerization or the following electrolytic polymerization solution for electrolytic oxidation polymerization, and the applied voltage, energization time, etc. By adjusting the thickness, the thickness of the insulating layer can be controlled.
(Electrolytic polymerization solution for electrolytic reduction polymerization)
The following monomers alone, those obtained by adding a polymerizable functional group to the following monomers, and those obtained by dissolving at least one copolymer of the following monomers in the following solvent or a mixture thereof: Yes, the following additives can be added as needed.
[0036]
Monomer
・ Acrylic nitrile or its derivatives
・ Acrolein or its derivatives
・ Acrylic acid or its derivatives
・ Acrylamide or its derivatives
·maleic anhydride
・ Styrene or its derivatives
・ Vinylpyridine or its derivatives
・ Vinylimidazole or its derivatives
Xylene derivatives such as xylene or halogenated xylene
・ Divinylbenzene or its derivatives
solvent
・ Alcohol such as methanol, ethanol, propanol, isopropyl alcohol
Cellulose solvents such as methyl cellosolve, cellosolve, butyl cellosolve, cellosolve acetate
・ Glycols such as ethylene glycol, propylene glycol, trimethylene glycol and 1,5 pentadiol
・ Dimethylformamide
・ Dimethylacetamide
·acetone
・ Acetonitrile
・ Dichloromethane
・ Ion exchange water
Additive
・ Amine derivatives such as allylamine, ethylenediamine, and propylamine
・ Surfactants such as polyoxyethylene and Triton X-100 (Rohm and Haas)
・ Bases such as potassium hydroxide and sodium hydroxide
・ Acids such as oxalic acid
・ Salts such as sodium silicate, sodium sulfite, ammonium perchlorate (electrolytic polymerization liquid for electrolytic oxidation polymerization)
The following monomers alone, those obtained by adding a polymerizable functional group to the following monomers, and those obtained by dissolving at least one copolymer of the following monomers in the following solvent or a mixture thereof: Yes, the following additives can be added as needed.
[0037]
Monomer
Phenol or its derivatives: diphenylphenol, dimethylphenol, hydroxybenzaldehyde, hydroxypropiophenone, 4- (P-hydroxyphenyl) -2-butanone, hydroxyacetophenone, hydroxybenzophenone, allylphenol, hydroxycinnamic acid, halogenated phenol etc
-Aniline or its derivatives: aminocinnamic acid, phenylenediamine, dicarboxyaniline, etc.
・ Thiophene or its derivatives
・ Thiophenol or its derivatives
・ Pyrrole or its derivatives
・ Quinolinol or its derivatives: aminoquinolinol, etc.
・ Quinone or its derivatives: 1,4-naphthoquinone, etc.
solvent
・ Alcohol such as methanol, ethanol, propanol, isopropyl alcohol
Cellulose solvents such as methyl cellosolve, cellosolve, butyl cellosolve, cellosolve acetate
・ Glycols such as ethylene glycol, propylene glycol, trimethylene glycol and 1,5 pentadiol
・ Dimethylformamide
・ Dimethylacetamide
·acetone
・ Acetonitrile
・ Dichloromethane
・ Ion exchange water
Additive
・ Amine derivatives such as allylamine, ethylenediamine, and propylamine
・ Surfactants such as polyoxyethylene and Triton X-100 (Rohm and Haas)
・ Bases such as potassium hydroxide and sodium hydroxide
・ Acids such as oxalic acid
・ Salts such as sodium silicate and sodium sulfite
In addition, when the insulating layer 15 is formed on the conductive layer 14 by photolithography, quinonediazide, nitrobenzyl sulfonate, dihydropyridine, etc. as a substance that promotes dissolution in novolak resin, polyimide resin, etc. by light irradiation. The insulating layer 15 can be formed by applying a positive insulating photosensitive resin to which is added, exposing and developing from below the transparent transfer substrate 11 using the conductive layer as a mask.
[0038]
Next, a film 16 provided with a negative-type adhesive photosensitive resin layer 18 on a support 17 is placed on the transparent transfer substrate 11 so as to be in contact with the insulating layer 15 and then pressure-bonded (FIG. 2D). As the support 17 constituting the film 16, a resin film of polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, polyvinyl alcohol or the like is preferably used. Further, the negative-type adhesive photosensitive resin layer 18 can be formed using, for example, a photosensitive resin described in JP-A-3-28404, and specifically, a negative-type diazo resin. And a photosensitive resin composed of a binder, a photopolymerizable composition, a photosensitive resin composed of an azide compound and a binder, a cinnamic acid photosensitive resin, and the like. Then, the adhesive photosensitive resin layer 18 is exposed using the conductive layer 14 as a mask by irradiating light from the back surface (the surface where the insulating layer 15 is not formed) of the transparent transfer substrate 11 (FIG. 2D). )). The portion irradiated with light is exposed to light and the adhesive photosensitive resin layer 18 is cured and loses its adhesiveness, and is fixed to the support 17. On the other hand, the portion not irradiated with light has adhesiveness as it is. It adheres to the insulating layer 15. In this exposure step, mask alignment which has been conventionally performed is not necessary, and the apparatus and the process can be simplified. Thereafter, the support 17 is peeled off and release development is performed, whereby the adhesive photosensitive resin layer 18 remains only on the insulating layer 15 to form an adhesive resin layer 19 (FIG. 2E).
[0039]
Thereby, the wiring pattern layer transfer plate 10 provided with the wiring pattern layer 13 for the first layer having the conductive layer 14, the insulating layer 15, and the adhesive resin layer 19 is obtained.
[0040]
Similarly, as shown in FIGS. 3 and 4, conductive layers 24 and 34, insulating layers 25 and 35, and adhesive resin layers 29 and 39 are formed on the transparent transfer substrates 21 and 31, The wiring pattern layer transfer plate 20 for the second layer having the wiring pattern layers 23 and 33 and the wiring pattern layer transfer plate 30 for the third layer are prepared.
[0041]
The production of each of the wiring pattern layer transfer plates 10, 20, and 30 described above does not include a coating process and uses the film 16, so that a so-called dry treatment can be performed.
[0042]
Next, the wiring pattern layer transfer plate 10 is pressure-bonded onto the insulating substrate 2 so that the adhesive resin layer 19 contacts the substrate 2. The pressure bonding may be performed by any method such as roller pressure bonding, plate pressure bonding, or vacuum pressure bonding. Moreover, when said adhesive resin layer 19 expresses adhesiveness or adhesiveness by heating, thermocompression bonding can also be performed. Thereafter, the transparent transfer 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, the insulating layer 3b, and the resin layer 3c is transferred to the substrate 2. It is formed on the top (FIG. 5A). After that, alignment with the first wiring pattern layer is performed on the substrate 2 on which the first wiring pattern layer 3 is transferred and formed using the wiring pattern layer transfer plate 20 for the second layer. Similarly, the wiring pattern layer is transferred to form the second wiring pattern layer 4 having the conductive layer 4a, the insulating layer 4b, and the resin layer 4c (FIG. 5B). Further, on the substrate 2 on which the first-layer wiring pattern layer 3 and the second-layer wiring pattern layer 4 are transferred, the same alignment is performed using the wiring pattern layer transfer plate 30 for the third layer. Then, the wiring pattern layer is transferred to form a third wiring pattern layer 5 having the conductive layer 5a, the insulating layer 5b, and the resin layer 5c (FIG. 5C).
[0043]
As described above, each of the wiring pattern layers 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. The multilayer printed wiring board 1 has a so-called overprint type structure composed of wiring pattern layers 3, 4, and 5. For example, the wiring pattern layer 3 and the wiring pattern layer 4 constituting the multilayer printed wiring board 1 are partially composed of the conductive layers 3a and 4a of the wiring pattern layers 3 and 4 as shown in FIG. At the intersection, the insulation between the wiring pattern layer 3 and the wiring pattern layer 4 is maintained by the insulating layer 4b constituting the wiring pattern layer 4 which is the upper layer. In addition, as shown in FIG. 7, the intersection of the wiring pattern layers, or a portion where the wiring pattern layers are close to each other (proximity portion, in the illustrated example, the wiring pattern layer 3 and the wiring pattern layer 4 are close to each other). ) Can be easily connected to each other.
[0044]
FIG. 8 is a schematic sectional view showing another example of the multilayer printed wiring board of the present invention. In FIG. 8, a multilayer printed wiring board 41 includes an insulating substrate 42, a first wiring pattern layer 43 provided on the substrate 42, and a second layer formed on the wiring pattern layer 43. A multilayer printed wiring board having a three-layer structure including the wiring pattern layer 44 and a third wiring pattern layer 45 formed on the wiring pattern layer 44.
[0045]
The wiring pattern layers 43, 44, 45 constituting the multilayer printed wiring board 41 are respectively formed by curing the conductive layers 43a, 44a, 45a and the adhesive insulating photosensitive resin located under the conductive layers. Insulating resin layers 43b, 44b, 45b. The multilayer printed wiring board 41 has an overprint structure in which the wiring pattern layer 43 is transferred onto the substrate 42 and the wiring pattern layers 44 and 45 are sequentially transferred onto the lower wiring pattern layer. In portions (intersections) where the pattern layers intersect each other, the insulation between the upper and lower wiring pattern layers is maintained by the insulating resin layer constituting the upper wiring pattern layer.
[0046]
For this reason, the multilayer printed wiring board 41 of the present invention is not covered with the wiring pattern by the insulating layer as seen in the conventional multilayer printed wiring board, and the conductive layers 43a, 43, 44a and 45a are partly bare at all times, and as will be described later, it is easy to connect the wiring pattern layers to each other at an intersection of the wiring pattern layers or a portion where the wiring pattern layers are close to each other (proximity portion). Can be done.
[0047]
The substrate 42 constituting the multilayer printed wiring board 41 of the present invention can be the same as the substrate 2 constituting the multilayer printed wiring board 1 described above.
[0048]
The thickness of each wiring pattern layer 43, 44, 45 is set to 100 μm or less, preferably in the range of 10 to 60 μm in order to overcome the lower wiring pattern layer in the lamination transfer without any defects. In addition, the thickness of the conductive layers 43a, 44a, 45a constituting each of the wiring pattern layers 43, 44, 45 is set to 1 μm or more, preferably in the range of 5 to 40 μm in order to keep the electric resistance of the wiring pattern layer low. Furthermore, the thickness of the insulating resin layers 43b, 44b, 45b is set to at least 1 μm or more, preferably 5 to 50 μm in order to maintain insulation between the upper and lower wiring pattern layers at the intersection. The line widths of the wiring pattern layers 43, 44, and 45 can be arbitrarily set up to a minimum width of about 10 μm.
[0049]
The material of the conductive layers 43a, 44a, and 45a can be the same as that of the conductive layers 3a, 4a, and 5a of the multilayer printed wiring board 1 described above.
[0050]
The insulating resin layers 43b, 44b, and 45b are obtained by curing a negative-type adhesive insulating photosensitive resin. As the negative-type adhesive insulating photosensitive resin for forming the insulating resin layers 43b, 44b, 45b, for example, a photosensitive resin described in JP-A-3-28404 can be used. Specifically, a photosensitive resin composed of a negative diazo resin and a binder, a photopolymerizable composition, a photosensitive resin composed of an azide compound and a binder, a cinnamic acid photosensitive resin, and the like can be used.
[0051]
Next, another example of the method for producing a multilayer printed wiring board according to the present invention will be described with reference to FIG. 9 taking the multilayer printed wiring board 41 as an example.
[0052]
First, a photoresist layer 52 is formed by applying a photoresist on a transparent transfer substrate 51 having a transparent conductive film 51a such as indium tin oxide (ITO) on the surface. Then, using a predetermined photomask, the photoresist layer 52 is closely exposed and developed to expose the wiring pattern portion 51b of the transparent transfer substrate 51 (FIG. 9A). Next, a conductive layer 54 is formed on the wiring pattern portion 51b of the transparent transfer substrate 51 by plating (FIG. 9B).
[0053]
Next, a film 56 provided with a negative-type adhesive insulating photosensitive resin layer 58 on a support 57 is placed on the transparent transfer substrate 51 so as to be in contact with the conductive layer 54, and then pressure-bonded (FIG. 9C). . As the support 57 constituting the film 56, the same support as the support 17 constituting the film 16 described above can be used. In addition, the negative-type adhesive insulating photosensitive resin layer 58 can be formed using, for example, a photosensitive resin described in JP-A-3-28404, specifically, a negative-type diazo A photosensitive resin composed of a resin and a binder, a photopolymerizable composition, a photosensitive resin composed of an azide compound and a binder, a cinnamic acid photosensitive resin, and the like can be used to form a thickness of about 1 to 50 μm. Then, by irradiating light from the back surface of the transparent transfer substrate 51 (the surface on which the conductive layer 54 is not formed), the adhesive insulating photosensitive resin layer 58 is exposed using the conductive layer 54 as a mask (FIG. 9). (C)). The portion irradiated with light is exposed to light and the adhesive insulating photosensitive resin layer 58 is cured to lose the adhesiveness and is fixed to the support 57, while the portion not irradiated with light has adhesiveness as it is. Therefore, it adheres to the conductive layer 54. In this exposure step, mask alignment which has been conventionally performed is not necessary, and the apparatus and the process can be simplified. Thereafter, the support 57 is peeled off and peeling development is performed, so that the adhesive insulating photosensitive resin layer 58 remains only on the conductive layer 54 and the adhesive insulating resin layer 19 is formed (FIG. 9D). ).
[0054]
Thereby, the wiring pattern layer transfer plate 50 provided with the wiring pattern layer 53 for the first layer having the conductive layer 54 and the adhesive insulating resin layer 59 is obtained.
[0055]
Similarly, a conductive layer and an adhesive insulating resin layer are formed on a transparent transfer substrate, and a wiring pattern layer transfer plate for a second layer and a wiring pattern layer transfer plate for a third layer having a wiring pattern layer are provided. (Not shown).
[0056]
The production of each wiring pattern layer transfer plate described above does not include a coating process and uses the film 56, so that a so-called dry treatment can be performed.
[0057]
Next, the wiring pattern layer transfer plate 50 is pressure-bonded onto the insulating substrate 42 so that the adhesive insulating resin layer 57 contacts the substrate 42. The pressure bonding may be performed by any method such as roller pressure bonding, plate pressure bonding, or vacuum pressure bonding. Moreover, when said adhesive resin layer expresses adhesiveness or adhesiveness by heating, thermocompression bonding can also be performed. Thereafter, the transparent transfer substrate 51 is peeled off and the wiring pattern layer 53 is transferred onto the substrate 42, whereby the first wiring pattern layer 43 having the conductive layer 43a and the insulating resin layer 43b is formed on the substrate 42. can do. Thereafter, the second wiring pattern layer 43 is transferred and formed on the substrate 42 on which the first wiring pattern layer 43 is transferred and aligned with the first wiring pattern layer. Similarly, the wiring pattern layer is transferred to form a second wiring pattern layer 44 having a conductive layer 44a and an insulating resin layer 44b. Further, alignment is performed in the same manner on the substrate 42 on which the first wiring pattern layer 43 and the second wiring pattern layer 44 are transferred and formed using a wiring pattern layer transfer plate for the third layer. The wiring pattern layer is transferred to form a third wiring pattern layer 45 having a conductive layer 45a and an insulating resin layer 45b.
[0058]
As described above, the formation of each wiring pattern layer 43, 44, 45 is performed by sequentially transferring the wiring pattern layer of each wiring pattern layer transfer plate onto the substrate, so that the multilayer printed wiring board 41 has each wiring pattern. This is a so-called overprint structure composed of layers 43, 44, and 45. The wiring pattern layer 43 and the wiring pattern layer 44 constituting the multilayer printed wiring board 41 are similar to the wiring pattern layer 3 and the wiring pattern layer 4 constituting the multilayer printed wiring board 1 described above. 44, the conductive layers 43a, 44a are always partially exposed, and at the intersection, the insulation between the wiring pattern layer 43 and the wiring pattern layer 44 constitutes the upper wiring pattern layer 44. It is held by the insulating resin layer 44b. In addition, the wiring pattern layers can be easily connected to each other at the intersections of the wiring pattern layers or at portions where the wiring pattern layers are close to each other.
[0059]
Next, the connection in the intersection part or proximity part of each wiring pattern layer is demonstrated using the multilayer printed wiring board 41 of this invention as an example.
[0060]
10 to 14 are perspective views showing the connection state of the intersections of the wiring pattern layers of the multilayer printed wiring board 41. FIG. FIG. 10 shows the connection 61 formed and connected to the through hole formed in the upper wiring pattern layer 44. Further, FIG. 11 shows a structure in which a joining portion 62 is formed at a part of the intersection, and the conductive layer 43a of the wiring pattern layer 43 and the conductive layer 44a of the wiring pattern layer 44 are connected. Further, FIG. 12 shows a joint 63 formed so as to cover the intersection between the wiring pattern layer 43 and the wiring pattern layer 44. Further, FIG. 13 shows a connection part 64 formed so as to straddle a part of the proximity part, and the wiring pattern layer 43 and the wiring pattern layer 44 are connected. FIG. 14 shows the wiring pattern layer 43 and the wiring pattern. A connecting portion 65 is formed and connected so as to cover the proximity portion with the layer 44.
[0061]
Connections by forming joints at the intersections or adjacent parts of each wiring pattern layer include (1) printing method, (2) dispensing method, (3) ultrafine particle spraying method, and (4) laser drawing method. (5) Selective electroless plating method, (6) Selective vapor deposition method, (7) Welding and joining method, and the like.
[0062]
The connection of the intersecting or adjacent portions of the wiring pattern layers of the multilayer printed wiring board 1 by the printing method (1) described above is conducted with the conductive paste or the conductive paste so as to straddle between the conductive layers constituting each wiring pattern layer by printing. This is performed by fixing the solder to form a joint. The printing method to be used is not particularly limited, but screen printing generally suitable for thick film printing and frequently used in the electronics industry is preferable. When screen printing is performed, a screen printing plate having an opening in a portion corresponding to a connecting portion between wirings is prepared in advance, and aligned on a multilayer wiring board, and a conductive paste such as a silver paste. What is necessary is just to print an ink.
[0063]
In addition, the connection at the intersection or proximity of the wiring pattern layers of the multilayer printed wiring board 1 by the dispensing method (2) is similar to the above printing method, but the conductive ink is ejected from fine nozzles. Then, the bonding portion is directly drawn and formed between the wirings. Specifically, a dispenser having a needle-like spout that is generally used for attaching a small amount of adhesive or the like to a required portion can be used. Moreover, the inkjet system currently used for output devices, such as a computer, can also be used depending on the viscosity of the conductive ink to be used.
[0064]
In the ultrafine particle spraying method of (3) above, ultrafine particles are transported in a high-speed air stream, and are sprayed onto a multilayer printed wiring board from a fine nozzle provided close to the multilayer printed wiring board. The film is formed by mutually sintering by the collision energy between the substrate and the multilayer printed wiring board, and a method called a gas deposition method can be used. The apparatus used for this method basically comprises two vacuum chambers of high vacuum and low vacuum, and connection pipes connecting the vacuum chambers. The ultrafine particles are formed by a vacuum evaporation method in a low vacuum chamber into which argon gas or the like is introduced, and the substrate is placed in the high vacuum chamber. The connection pipe has an opening in the vicinity of the generation of ultrafine particles in the low vacuum chamber and in the vicinity of the multilayer printed wiring board in the high vacuum chamber, and in a direction perpendicular to the wiring board. Yes. Since each vacuum chamber is maintained at a constant pressure by the vacuum exhaust system, a high-speed air flow (gas flow) from the low vacuum chamber to the high vacuum chamber is generated in the connection pipe due to the pressure difference between the vacuum chambers. The ultrafine particles generated in the low-vacuum chamber are carried in this air stream and conveyed to the high-vacuum chamber side, collide with the wiring pattern layer of the multilayer printed wiring board, and are sintered together to form a film. By using this method using a metal such as gold, silver, copper, or nickel as a base material, a conductor (junction) can be selectively formed at a location that requires connection between wirings.
[0065]
In the laser drawing method (4), a solution in which conductive fine particles are dispersed is applied to a multilayer printed wiring board, and a desired portion of the coating film is heated by a laser to decompose or evaporate the resin binder. Then, the conductive fine particles are deposited and aggregated on the heated portion to selectively form a conductor. As the solution, a fine resin of about several tens of μm can be drawn by using a polyester resin, an acrylic resin, or the like in which conductive fine particles such as gold and silver are dispersed and irradiating with an argon laser.
[0066]
As the selective electroless plating method (5), a selective electroless plating technique generally known as a photoforming method can be used. In this technique, a photosensitizer layer containing a metal in an oxidized state that can be reduced and becomes a catalyst for electroless plating is formed on a multilayer printed wiring board, and the photosensitizer layer is selectively exposed, Metal particles that serve as a catalyst for electroless plating are deposited, and then immersed in an electroless plating solution, thereby selectively plating only the exposed portion.
[0067]
Further, the selective vapor deposition method (6) uses a selective film deposition technique which is one of thin film formation techniques. That is, an organic metal gas containing a conductive element such as metal, carbon or the like, or an organic vapor containing a conductive element is introduced into the vacuum chamber, and the above-mentioned gas or Vapor is adsorbed, and then a laser or ion beam is focused or focused to irradiate the substrate, and the gas or vapor adsorbed on that part is decomposed by heat or collision energy, so that metal, carbon, etc. A conductive substance is deposited on a multilayer printed wiring board. Such a selective vapor deposition method has been put into practical use as an LSI wiring correction technique. More specifically, a focused argon laser decomposes organometallic gases containing chromium, cobalt, platinum, tungsten, etc., and deposits these metals on the desired correction site, or pyrene by a gallium ion beam. A technique of depositing a carbon film by decomposing vapor of an organic material such as the above can be used.
[0068]
Further, the welding joint method of (7) described above is a method in which an intersection of wiring pattern layers is selectively heated with a laser, and an insulating resin layer (insulating resin layer constituting the upper layer) existing between conductive layers of the upper and lower wiring pattern layers. ) Are melted and evaporated, and the conductive layer itself is also heated to a high temperature, whereby the conductive layers constituting the respective wiring pattern layers are fused to each other to form a joint and connect them.
[0069]
Further, the interconnections of the wiring pattern layers constituting the multilayer printed wiring board of the present invention are (8) wire bonding method, (9) one-shot method using a wire bonding apparatus, (10) laser plating method, (11) It can be performed by a batch transfer method of a laminate of a conductor and solder plating, (12) a metal lump insertion method, (13) an electroless plating method, or the like. In the wire bonding method (8) described above, for example, as shown in FIG. 15, the wiring pattern layers 43 and 44 that are not electrically connected to the adjacent portion (which can be dealt with similarly in the crossing portion) are connected to the wire bonding apparatus. In this method, wire bonding is performed, and the conductive layers 43 a and 44 a are connected by the wire bridge 66.
[0070]
The one-shot method using the wire bonding apparatus (9) described above is, for example, as shown in FIG. 16, where the wiring pattern layers 43 and 44 are not electrically connected (can be dealt with similarly at the intersection). In this method, bonding is performed by one shot (one time) using a wire bonding apparatus, and the conductive layers 43a and 44a are connected by a bonding lump (pad) 67 without a bridge.
[0071]
The laser plating method of the above (10) is, for example, a laser in which a predetermined spot diameter, power on an irradiated surface, etc. are adjusted in a state in which a multilayer printed wiring board before connection operation is immersed in a palladium plating solution (for example, , Argon laser) is irradiated to a proximity portion or intersection portion to be conducted for a predetermined time, and a Pd film, for example, is deposited to a predetermined thickness and connected to the irradiated portion. It is preferable to irradiate the laser while circulating the palladium plating solution. Further, the plating solution is removed by washing with water, and the conductive layers 43a and 44a are connected by the plating film 68 deposited as shown in FIG.
[0072]
The batch transfer method for the laminate of the conductor (11) and the solder plating is performed as shown in FIGS. 18 (A) and 18 (B). First, as shown in FIG. 18B, a laminate 70 of a conductor layer 71 and a solder plating layer 72 is produced in the following manner. That is, a conductive layer 71 is formed, for example, by electroplating on a transparent transfer substrate on which a desired pattern (conductive pattern) is formed on a conductive substrate 75 by development using a resist method. Solder plating is performed on the conductor layer using a predetermined solder plating bath composition to form a solder plating layer 72. The solder plating layer 72 can be similarly formed by screen printing or dipping of solder paste in addition to solder plating. As shown in FIG. 18A, the laminated body 70 laminated in this way is collectively heat-transferred to a non-conducting proximity portion of the wiring pattern layers 43 and 44 (which can be dealt with similarly at the intersection). The conductive layers 43a and 44a are connected. At this time, the thermal transfer temperature is performed in a temperature range of about 200 to 300 ° C., which is a temperature at which the solder plating layer 72 can be melted and deformed.
[0073]
In the metal lump insertion method (12) described above, as shown in FIG. 19A, for example, a metal ball 81 having a diameter of about 30 to 100 μm is formed in the wiring gap in the adjacent portion of the wiring pattern layers 43 and 44 where no conduction is made. After that, as shown in FIG. 19B, a sheet 82 coated with a pressure-sensitive adhesive is pressure-bonded thereon to connect the conductive layers 43a and 44a. The use of metal balls is a more preferable use mode, but it is also possible to use so-called metal pieces (lumps) that are not spherical. Further, such metal balls (lumps) can also be used to improve the reliability of the connection part in the printing method and the dispensing method. That is, after the metal ball is installed, the printing or dispensing is performed.
[0074]
The electroless plating method (13) will be described with reference to FIGS. First, an electroless plating catalyst is applied on the entire surface of a multilayer printed wiring board having wiring pattern layers 43 and 44 as shown in FIG. 20A to form a catalyst layer 91 (FIG. 20B). ). Next, after a photoresist is applied thereon to form a resist layer 93, the resist layer 93 is closely exposed and developed using a predetermined photomask to expose a portion H corresponding to the position where the wiring pattern is to be connected. (FIG. 20C). Then, after this exposed portion H is activated, electroless plating is performed to form a connection portion 95 to connect the conductive layers 43a and 44a (FIG. 20D). Thereafter, the remaining unnecessary resist and the catalyst layer are sequentially removed to leave only the connection portion 95 (catalyst layer 91a) (FIGS. 20E and 20F).
[0075]
The multilayer printed wiring board of the present invention can be connected between each wiring pattern layer at any place without being restricted by the through hole formation place by using the connection method as described in (2) to (13) above. Therefore, the degree of freedom in changing the circuit design after producing the multilayer printed wiring board is greater than that of the conventional multilayer printed wiring board.
[0076]
In the above example, the multilayer printed wiring board 1 has a three-layer structure. However, the multilayer printed wiring board manufacturing method of the present invention includes a desired number of wiring pattern layers by repeating the same layer transfer. A multilayer printed wiring board can be manufactured.
[0077]
In addition, the multilayer printed wiring board of the present invention having a two-layer structure solves the problem of the conventional double-sided printed wiring board, that is, the problem of high density resulting from the precision of drilling for forming holes in the double-sided printed wiring board. can do. 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 the wiring pattern layers can be easily connected to each other in the proximity portion.
[0078]
【Example】
Next, an Example is shown and this invention is demonstrated further in detail.
(Example 1)
(1) Formation of conductive layer in wiring pattern layer transfer plate (corresponding to FIG. 2 (B))
As a transparent transfer substrate, a glass substrate (thickness 1.1 mm) having an ITO transparent conductive film (thickness 2000 mm) on the surface was prepared, and a commercially available photoresist for plating (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was prepared on this transparent transfer substrate. PMER P-AR900) is applied and dried to a thickness of 20μm, and after each contact exposure using three types of photomasks on which wiring patterns are formed, it is developed, washed with water, dried, and then thermally cured. Transparent transfer substrates (3 types) with the wiring pattern portions exposed were prepared.
[0079]
The transparent transfer substrate and the platinum electrode are opposed to each other and immersed in a copper pyrophosphate plating bath (pH = 8, liquid temperature = 55 ° C.) having the following composition, the platinum electrode is connected to the anode of the DC power source, and the cathode is connected. Connect the above transparent transfer substrate, current density 10A / dm² Was applied for 5 minutes, and a copper plating film having a thickness of 10 μm was formed on the bare ITO portion of the transparent transfer substrate that was not coated with the photoresist to form a conductive layer. This conductive layer was formed on three types of transparent transfer substrates.
[0080]
(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 insulating photosensitive resin liquid for insulating layer
4.00 g of 4,4 ′ diaminophenyl ether (hereinafter abbreviated as DDE) and 6.38 g of pyromellitic acid dimethyl ester dichloride were dissolved in 95 g of N-methylpyrrolidone (hereinafter abbreviated as NMP). 6 g was added and reacted at room temperature for 6 hours.
[0081]
After completion of the reaction, this solution was put into 1 liter of water, and the precipitate was filtered and dried to obtain 8.06 g of resin powder. 3 g of the obtained resin powder was redissolved in 17 g of NMP to prepare a polyamic acid ester solution having a solid content of 15% by weight.
[0082]
On the other hand, 4.00 g of DDE and 4.23 g of pyromellitic dianhydride were dissolved in 47 g of NMP and reacted at room temperature for 6 hours to obtain a polyamic acid solution. 2 g of this polyamic acid solution and 18 g of the above polyamic acid ester solution were mixed to prepare a polyamic acid ester / polyamic acid mixed solution having a solid content of 15% by weight.
[0083]
To this mixed solution was added 0.90 g of a 3,3,4,4'-tetrahydroxybenzophenone 1,2-naphthoquinone-2-diazide-5-sulfonic acid 3 molar substitution compound, and the mixture was stirred at room temperature for 3 hours. The mixture was filtered through a 0 μm filter to prepare a positive insulating photosensitive resin solution.
(3) Formation of insulating layer in wiring pattern layer transfer plate (corresponding to FIG. 2C))
The insulating photosensitive resin liquid prepared in (2) above is applied by spin coating to the conductive layer forming surface side of the transparent transfer substrate (3 types) on which the conductive layer is formed in (1) above and dried (80 The insulating photosensitive resin layer was formed by heating at 60 ° C. for 60 minutes. Thereafter, exposure (backside exposure) is performed from the lower side of the transparent transfer substrate using the conductive layer as a mask under the following conditions, followed by development, rinsing and drying, and further heat curing (250 ° C., 30 minutes). An insulating layer (thickness: about 12 μm) was formed on the conductive layer.
[0084]
(Exposure conditions)
Contact exposure machine: Dainippon Screen Mfg. Co., Ltd. P-202-G
Vacuum drawing: 60 seconds
Exposure time: 600 counts
(4) Production of film provided with adhesive photosensitive resin layer for resin layer
As a support, a polyethylene naphthalate film having a thickness of 100 μm (Lumirror T-60 manufactured by Toray Industries, Inc.) coated with a vinylidene chloride / methyl acrylate / itaconic acid copolymer was prepared. The undercoat layer coating solution was applied by a die coating method to form an undercoat layer (thickness 5 μm).
[0085]
(Composition of coating solution for undercoat layer)
・ Ethylene-vinyl acetate copolymer: 7 parts by weight
・ Paraffin wax: 3 parts by weight
・ Benzene: 90 parts by weight
Next, an adhesive photosensitive resin liquid having the following composition was applied on the undercoat layer by a die coating method to form a negative adhesive photosensitive resin layer (thickness 5 μm).
[0086]

(5) Formation of resin layer in wiring pattern layer transfer plate (corresponding to FIG. 2 (E))
The film prepared in (4) above is applied to the adhesive photosensitive resin layer on the surface of the transparent transfer substrate (3 types) in which the insulating layer is formed on the conductive layer in (3) above. Are stacked in contact with the insulating layer and thermocompression bonded under the following conditions. After that, exposure (backside exposure) is performed from the back surface of the transparent transfer substrate using the conductive layer as a mask under the following conditions, followed by peeling development and insulation. An adhesive resin layer (thickness of about 5 μm) was formed on the layer to obtain three types of wiring pattern layer transfer plates A1, A2 and A3.
[0087]
(Thermocompression conditions)
Pressure: 0.45 kgf / cm²
Temperature: 100 ° C
(Exposure conditions)
Contact exposure machine: Dainippon Screen Mfg. Co., Ltd. P-202-G
Vacuum drawing: 60 seconds
Exposure time: 30 counts
(6) Fabrication of multilayer printed wiring board (corresponding to FIG. 5)
On the polyimide film substrate having a thickness of 25 μm, the wiring pattern layer transfer master A1 prepared in the above (5) is thermocompression bonded under the following conditions, and comprises a conductive layer, an insulating layer, and an adhesive resin layer. The first wiring pattern layer was transferred.
[0088]
(Thermocompression conditions)
Pressure: 10kgf / cm²
Temperature: 100 ° C
Next, on the film substrate on which the first wiring pattern layer is formed, the conductive pattern A2 for wiring pattern layer produced in the above (5) is subjected to thermocompression bonding under the same conditions as described above to make it conductive. A second wiring pattern layer composed of a layer, an insulating layer, and an adhesive resin layer was transferred.
[0089]
Similarly, on the film substrate on which the second wiring pattern layer is formed, the transfer pattern layer A3 for wiring pattern layer produced in the above (5) is subjected to thermocompression bonding under the same conditions as described above to make it conductive. A third wiring pattern layer composed of a layer, an insulating layer, and an adhesive resin layer was transferred.
[0090]
Next, the adhesive resin layer was cured at 180 ° C. for 30 minutes to produce a multilayer printed wiring board of the present invention having three wiring pattern layers as shown in FIG.
[0091]
【The invention's effect】
As described above in detail, according to the present invention, the wiring pattern layer provided on the transparent transfer substrate is transferred onto the substrate, so that the wiring pattern layer having the conductive layer on the top and the insulating layer and the resin layer on the bottom is provided. Alternatively, a wiring pattern layer having a conductive layer at the top and an insulating resin layer at the bottom can be formed in multiple layers on the substrate. This multilayer formation is performed in parallel with a transfer substrate on which a predetermined wiring pattern layer is formed. Since this is a parallel serial process in which a plurality of transfer substrates are sequentially transferred using these transfer substrates, defective products can be eliminated by inspection before transfer, the manufacturing yield is improved, and the throughput is high. In addition, the wiring layer formation and plating for patterning and the photoetching process, which have been conventionally performed on the substrate, are not necessary, and the manufacturing process can be simplified.
[0092]
In addition, when the wiring pattern layer is formed on the transparent transfer substrate to produce a wiring pattern layer transfer plate, the adhesive photosensitive resin layer or the adhesive insulating photosensitive resin layer formed on the transparent transfer substrate is transparently transferred. Since exposure is performed by irradiating light from the back surface of the substrate and using the conductive layer as a mask, mask alignment in exposure from the upper side of the conventional transfer substrate becomes unnecessary, and the apparatus and the process can be simplified. Furthermore, since a film including an adhesive photosensitive resin layer or a film including an adhesive insulating photosensitive resin layer is used in the manufacturing process, so-called dry processing can be performed, and the manufacturing process can be greatly improved in efficiency.
[0093]
In addition, the multilayer printed wiring board does not have a wiring pattern covering with an insulating layer as seen in conventional multilayer printed wiring boards, and the conductive layers constituting each wiring pattern layer are always partially exposed. In addition, the wiring pattern layers can be easily connected to each other at the intersections of the wiring pattern layers or portions where the wiring pattern layers are close to each other, and a multilayer printed wiring board having extremely high versatility can be achieved.
[Brief description of the 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 drawing for explaining a method for producing 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 producing 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 producing a multilayer printed wiring board according to the present invention.
FIG. 5 is a drawing for explaining a method for producing 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 a proximity portion of a wiring pattern layer of a multilayer printed wiring board according to the present invention.
FIG. 8 is a schematic sectional view showing another example of the multilayer printed wiring board of the present invention.
FIG. 9 is a drawing for explaining another example of the method for producing a 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 of the present invention.
FIG. 11 is a perspective view showing a connection state at an intersection of wiring pattern layers of the multilayer printed wiring board of the present invention.
FIG. 12 is a perspective view showing a connection state at the intersection of the wiring pattern layers of the multilayer printed wiring board of the present invention.
FIG. 13 is a perspective view showing a connection state in the proximity portion of the wiring pattern layer of the multilayer printed wiring board of 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 a proximity portion of a wiring pattern layer of a multilayer printed wiring board according to the present invention.
FIG. 16 is a perspective view showing a connection state in the proximity portion of the wiring pattern layer of the multilayer printed wiring board of the present invention.
FIG. 17 is a perspective view showing a connection state in the proximity portion of the wiring pattern layer of the multilayer printed wiring board of the present invention.
FIG. 18 is a view for explaining a connection state in a proximity portion of a wiring pattern layer of a multilayer printed wiring board according to the present invention.
FIG. 19 is a perspective view showing a state in which connections are sequentially formed at adjacent portions of the wiring pattern layer of the multilayer printed wiring board according to the present invention.
FIG. 20 is a diagram for explaining a connection state in a proximity portion of a wiring pattern layer of a multilayer printed wiring board according to the present invention.
[Explanation of symbols]
1,40 ... Multilayer printed wiring board
2, 42 ... substrate
3, 4, 5, 43, 44, 45 ... wiring pattern layer
3a, 4a, 5a, 43a, 44a, 45a ... conductive layer
3b, 4b, 5b ... insulating layer
3c, 4c, 5c ... Resin layer
43b, 44b, 45b ... insulating resin layer
10, 20, 30, 50 ... wiring pattern layer transfer plate
11, 51 ... Transparent transfer substrate
11a, 51a ... Transparent conductive film
13, 23, 33, 53 ... wiring pattern layer
16, 56 ... film
17, 57 ... Support
18 ... Adhesive photosensitive resin layer
58. Adhesive insulating photosensitive resin layer
19 ... Resin layer
59. Insulating resin layer
61, 62, 63, 64, 65, 66, 67, 68, 70, 81, 91...

Claims (4)

  A pattern made of an insulating material is formed on a transparent transfer substrate having at least a surface conductive, a conductive layer is formed by plating on a portion where the pattern is not formed, and an insulating layer is formed on the conductive layer. After that, a film having a negative-type adhesive photosensitive resin layer on a support is superimposed on the surface of the transparent transfer substrate, and the adhesive photosensitive resin layer is stacked and pressure-bonded so as to be in contact with the insulating layer. The back surface of the transfer substrate is irradiated with light to expose the adhesive photosensitive resin layer using the conductive layer as a mask, and then the support is peeled off to form a resin layer on the insulating layer. A plurality of wiring pattern layer transfer plates provided with a wiring pattern layer having a layer, the insulating layer and the resin layer, and then the wiring on one surface of a substrate for a multilayer printed wiring board via the resin layer Pattern layer A multilayer printed wiring board, wherein a plurality of wiring pattern layers are formed on the substrate by sequentially repeating an operation of transferring the wiring pattern layer by pressing a printing plate and peeling off the transparent transfer substrate. Production method. The method for manufacturing a multilayer printed wiring board according to claim 1 , wherein the insulating layer is formed by any one of an electrodeposition method, an electrolytic polymerization method, and a photolithography method.   A pattern made of an insulating material is formed on a transparent transfer substrate having at least a surface conductive, a conductive layer is formed by plating on a portion where the pattern is not formed, and a negative type is formed on the surface of the transparent transfer substrate. A film provided with the adhesive insulating photosensitive resin layer on the support is stacked and pressure-bonded so that the adhesive insulating photosensitive resin layer is in contact with the conductive layer, and light is irradiated from the back surface of the transparent transfer substrate to conduct the conductive. The adhesive insulating photosensitive resin layer is exposed using the conductive layer as a mask, and then the support is removed to form an insulating resin layer on the conductive layer, and the conductive layer and the insulating resin layer are formed. Producing a plurality of wiring pattern layer transfer plates provided with a wiring pattern layer having, and then crimping the wiring pattern layer transfer plate on one side of a substrate for a multilayer printed wiring board via the insulating resin layer, Transparent transfer group Sequentially repeating the operation of transferring the wiring pattern layer by peeling, a method for manufacturing a multilayer printed wiring board and forming a plurality of said wiring pattern layer on the substrate. Forming a junction so as to straddle between the conductive layers constituting each wiring pattern layer at 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; The method for manufacturing a multilayer printed wiring board according to any one of claims 1 to 3 , wherein the wiring pattern layers are connected to each other.

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