JP3643004B2

JP3643004B2 - Printed wiring board manufacturing method and printed wiring board manufacturing mask

Info

Publication number: JP3643004B2
Application number: JP2000067830A
Authority: JP
Inventors: 和彦一色; 勝弘庄子
Original assignee: Japan Metals and Chemical Co Ltd
Current assignee: Japan Metals and Chemical Co Ltd
Priority date: 2000-03-10
Filing date: 2000-03-10
Publication date: 2005-04-27
Anticipated expiration: 2020-03-10
Also published as: JP2001257467A

Description

【０００１】
【発明の属する技術分野】
本発明はプリント配線基板の製造方法に係り、更に詳細には配線層間を貫通型の導体配線部で接続する、いわゆる導体貫通型の多層板の製造方法及び同製造方法に使用されるプリント配線基板製造用マスクに関する。
【０００２】
【従来の技術】
従来より、多層板の製造方法として、絶縁性基板の厚さ方向に略円錐形の導体バンプを圧入して絶縁性基板の両面に形成された二つの配線パターン間の電気的導通を図る、いわゆる導体貫通法が知られている。
【０００３】
図８は従来の代表的な導体貫通法の製造工程を模式的に示した垂直断面図である。
【０００４】
この導体貫通法では、まず、銅箔などの導体層１００（図８（ａ））に金属製の印刷用マスク１０１を重ねる（図８（ｂ））。この印刷用マスク１０１には厚さ方向に複数の貫通孔１０２，１０２，…が穿孔されており、これらの貫通孔１０２，１０２，…の中に図中上面側から銀ペーストなどの導電性組成物１０３ａをスキージすると導電性組成物１０３ａが貫通孔１０２内に充填される（図８（ｃ））。充填後に印刷用マスクを導体層１００から剥がすと、導電性組成物１０３ａ底面と導体層１００とが接着しているので導電性組成物１０３ａが導体層１００側に引っ張られて貫通孔１０２，１０２，…から離脱する。このとき導電性組成物１０３ａの上部が貫通孔１０２の内壁面側に引っ張られるため、導体層１００上には複数個の略円錐形の導体バンプ１０３ｂ，１０３ｂ，…が形成される（図８（ｄ））。
【０００５】
このように形成された導体バンプ１０３ｂ，１０３ｂ，…の上に絶縁性基板１０４ともう一枚別の導体層１０５とを載置し（図８（ｅ））、この状態でプレスして加圧下に加熱することにより絶縁性基板１０４を硬化させ、それと同時に絶縁性基板１０４の上に導体層１０５を接着する。
【０００６】
こうしていわゆるコア材１１０が形成され（図８（ｆ））、このコア材１１０の上下各面にエッチングなどにより配線パターン１０６，１０７を形成することにより２層の多層板１１１が得られる（図８（ｇ））。
【０００７】
ところで、貫通孔１０２，１０２，…内に導電性組成物１０３ａを充填した後に印刷用マスク１０１を導体層１００から剥がすことにより導体層１００上に形成される導体バンプ１０３ｂ，１０３ｂ，…が略円錐形になるメカニズムは十分に解明されてはいないが、貫通孔１０２，１０２，…内に充填された導電性組成物１０３ａの一部が貫通孔１０２，１０２，…内に残るためと考えられる。
【０００８】
【発明が解決しようとする課題】
しかし、貫通孔１０２，１０２…はＮＣボール盤を用いたドリル穴あけにより形成されるため内壁面の表面が粗く、また、略円柱形の内壁面を有するため貫通孔１０２，１０２，…内に充填された導電性組成物１０３ａが貫通孔１０２，１０２，…内に残りやすい。そのため、印刷用マスク１０１を剥がしたときに導体バンプ１０３ｂ，１０３ｂ，…が形成されなかったり、導体バンプ１０３ｂ，１０３ｂ，…の形状が略円錐形とならない場合があり、収率が低いという問題がある。
【０００９】
また、貫通孔１０２内に充填された状態では円柱形の導電性組成物１０３ａが印刷用マスク１０１剥離時には略円錐形へと無理に変形され、一度の印刷では十分な厚さの導体バンプ１０３ｂが得られないので、略円錐形の導体バンプ１０３ｂを形成するには３〜５回の印刷操作を繰り返す必要があり、工程数が多いという問題や、導体バンプ１０３ｂの側面が多段状になり導体バンプ１０３ｂの形状が不揃いになりやすいという問題がある。
【００１０】
本発明は上記従来の問題を解決するためになされた発明である。即ち、本発明は、少ない工程数で略円錐形の導体バンプを高い収率で形成することのできるプリント配線基板製造用マスク、及びそのようなプリント配線基板製造用マスクの製造方法を提供することを目的とする。
【００１１】
複数の貫通孔が穿設されたマスクであって、前記各貫通孔が、一方の面側の第 1 の口径を有する第１の開口部と他方の面側の第１の口径より大径の第２の口径を有する第２の開口部とを有し、前記各開口部間の内壁面が、第２の開口部から第１の開口部側に椀状に凹陥する形状とされたプリント配線基板製造用マスクの前記第２の開口部側を、導体層に当接させて保持する工程と、前記第１の開口部側から前記貫通孔内に導電性組成物を充填する工程と、前記導体層と前記プリント配線基板製造用マスクとを剥離して前記導体層上に略円錐形の導体バンプを形成する工程と、前記導体バンプを乾燥する工程と、前記導体バンプ上に絶縁性基板を載置する工程と、前記導体層と前記絶縁性基板とをプレスして前記導体バンプを前記絶縁性基板に貫通させる工程と、を具備する。
【００１２】
このプリント配線基板製造方法において、前記内壁面は椀状に凹陥する形状を備えていることが好ましい。
【００１３】
上記プリント配線基板製造方法において、前記貫通孔は、前記第１の口径：前記第２の口径＝１：１．２〜２．０の比を構成する第１の開口部と第２の開口部とを備えていることが好ましい。
【００１４】
また、前記貫通孔は、前記第２の口径：マスクの厚さ＝１：１．０〜１．５の比を構成する第２の開口部を備えていることが好ましい。
【００１５】
更に、前記導体層とは、エッチングしていない状態の銅箔などの導体板と、絶縁性基板上に配設された配線パターンとの両方を含む。
【００１６】
更に、前記内壁面は、前記導電性組成物に対する非付着性材料コーティング層を更に備えていることをが更に好ましく、この非付着性材料コーティング層は、テフロン（登録商標）コーティング層であることが好ましい。また、前記非付着性材料コーティング層は、厚さ１〜２μｍを有することが好ましい。
【００１７】
前記内壁面をこのような形状にしたり、テフロン（登録商標）などの非付着性材料コーティング層を内壁面上に形成したり、この非付着性材料コーティング層を適当な厚さで形成することにより貫通孔から導電性組成物が剥がれ易くなる。またプリント配線基板製造用マスクを剥がした後の導体層上に略円錐形の導体バンプが形成され易くなる。
【００１８】
また、前記貫通孔のパラメータを特定した上記のような形状にすることにより、導電性組成物が剥がれ易く、略円錐形の導体バンプが形成され易くなる。
【００１９】
本発明のプリント配線基板製造用マスクは、導電性組成物を充填するための複数の貫通孔が所定の配線パターンに沿って穿孔されたプリント配線基板製造用マスクであって、前記マスクは、目標とする導体バンプの高さとほぼ等しいか、やや大きい厚さを有し、前記貫通孔は、第１の口径を有し前記マスクの第１の面上に形成された第１の開口部と、前記第１の口径より大きい第２の口径を有し前記マスクの第２の面上に形成された第２の開口部と、を具備する。
【００２０】
このプリント配線基板製造用マスクにおいて、前記貫通孔は、マスク基材の所定位置に、前記マスク基材の導電性組成物供給側の一方の面から第１の口径を有する複数の第１の凹部を形成する工程と、他方の面の、前記第１の凹部に対応する位置に前記第１の口径より大きい第２の口径を有する第２の凹部を形成する工程と、前記第１の凹部及び前記第２の凹部をオーバーエッチングして第１の凹部と第２の凹部とが接続された椀状に凹陥する形状を有する内壁面を形成する工程と、を具備する方法により形成されたものであることが好ましい。
【００２１】
更に、前記第１の凹部を形成する工程及び前記第２の凹部を形成する工程は、
前記第１の口径を有する第１の窓が形成された第１のレジスト層を前記マスク基材の第１の面に適用し、
前記第２の口径を有する第２の窓が形成された第２のレジスト層を前記マスク基材の第２の面に適用し、
これら第１のレジスト層及び第２のレジスト層を介して前記マスク基材をエッチングすることにより行われることが好ましい。
【００２２】
このプリント配線基板製造用マスクにおいて、前記内壁面は椀状に凹陥する形状を備えていることが更に好ましい。
【００２３】
上記プリント配線基板製造用マスクにおいて、前記貫通孔は、前記第１の口径：前記第２の口径＝１：１．２〜２．０の比を構成する第１の開口部と第２の開口部とを備えていることが好ましい。
【００２４】
また、前記貫通孔は、前記第２の口径：マスクの厚さ＝１：１．０〜１．５の比を構成する第２の開口部を備えていることが好ましい。
【００２５】
更に、前記内壁面は、前記導電性組成物に対する非付着性材料コーティング層を更に備えていることをが更に好ましく、この非付着性材料コーティング層は、テフロン（登録商標）コーティング層であることが好ましい。また、前記非付着性材料コーティング層は、厚さ１〜２μｍを有することが好ましい。
【００２６】
前記内壁面をこのような形状にしたり、テフロン（登録商標）などの非付着性材料コーティング層を内壁面上に形成したり、この非付着性材料コーティング層を適当な厚さで形成することにより貫通孔から導電性組成物が剥がれ易くなる。またプリント配線基板製造用マスクを剥がした後の導体層上に略円錐形の導体バンプが形成され易くなる。
【００２７】
また、前記貫通孔のパラメータを特定した上記のような形状にすることにより、導電性組成物が剥がれ易く、略円錐形の導体バンプが形成され易くなる。
【００２８】
本発明によれば、前記プリント配線基板製造用マスクの導電性組成物供給方向上流側の第１の面に第１の開口部が配設され、前記第１の面と対向する第２の面に前記第１の開口部より大きな口径を備えた第２の開口部とが形成されているので、導電性組成物を充填後にプリント配線基板製造用マスクと導体層とを剥がすときに貫通孔から導電性組成物が剥がれ易く、貫通孔の内壁面形状に近い形状の導体バンプが形成され易い。そのため、収率が向上し、しかも一回の印刷で略円錐形の導体バンプを形成することができる。
【００２９】
【発明の実施の形態】
以下、本発明の実施形態に係るプリント配線基板製造用マスクの製造方法について説明する。
【００３０】
図１及び図２は本実施形態に係るプリント配線基板製造用マスク（以下、単に「マスク」と略記する。）の製造方法の各工程を模式的に示した垂直断面図であり、図３は同製造方法の流れを示したフローチャートである。
【００３１】
本実施形態に係るマスクを製造するには、まずマスク基材となる、例えば金属板の上下両面に感光性材料を塗布して第１のレジスト層としてのレジスト層２をマスク基材１の図中上面に形成し、第２のレジスト層としてのレジスト層３をマスク基材１の図中下面に形成する（図１（ａ）／ＳＴＥＰ．１）。
【００３２】
次にレジスト層２及び３にマスキング（図示省略）を施して導体バンプを形成する位置に対応して、レジスト層２には第1の窓４が形成されるように、レジスト層３には第２の窓５が形成されるようにそれぞれマスキングする。
【００３３】
即ち、図１（ｂ）に示すように、レジスト層２上には第1の凹部の入り口である第１の開口部の口径（第１の口径）と同じ口径の円形の第１の窓４が開くように、第1の窓４の口径Ｓ（第１の口径）に合わせてマスキングする。例えば、光硬化型のレジストを用いる場合には第1の窓４を形成する部分にのみマスキングして光が当たるのを防止する。同様に、レジスト層３上には第２の凹部の入り口である第２の開口部が開くように、第２の開口部の口径（第２の口径）と同じ口径の円形の第２の窓５が開くように、第２の窓５の口径Ｌ（第２の口径）に合わせてマスキングする。例えば、光硬化型のレジストを用いる場合には第２の窓５を形成する部分にのみマスキングして光が当たるのを防止する。
【００３４】
このとき第1の窓４の口径（第1の口径）Ｓ及び第２の窓５の口径（第２の口径）Ｌとの間には次の関係がなりたつような大きさのＳとＬになるようにマスキングする。
【００３５】
Ｓ：Ｌ＝１：１．５〜２．５
第１の窓４の口径（第１の口径）Ｓと第２の窓５の口径（第２の口径）Ｌとの比をこのような範囲にしたのは、この範囲の比率で第１の窓と第２の窓、ひいては、第１の開口部と第２の開口部とをこの範囲の比率で形成することにより、後続のオーバーエッチング処理により第２の開口部から第１の開口部側に椀状に凹陥する形状を有する内壁面を形成しやすくなるからである。
【００３６】
逆に、上記範囲外の比率で第１の窓４（第１の開口部）と第２の窓５（第２の開口部）とを形成すると、内壁面は上記のようなお椀状の型に形成しにくくなる。
【００３７】
また、第２の開口部の径Ｌ、とマスク１の厚さＤの間には以下の関係が成り立つことが好ましい。
【００３８】
Ｌ：Ｄ＝１：１．５〜２．５
第２の窓５（第２の開口部）の口径（第２の口径）Ｌとマスクの厚さＤとの間の比をこのような範囲にしたのは、この範囲の比率で第２の窓（第２の開口部）を形成することにより、後続のオーバーエッチング処理により第２の開口部から第１の開口部側に椀状に凹陥する形状の内壁面を形成しやすくなるからである。
【００３９】
逆に、上記範囲外の比率で第２の窓５（第２の開口部）を形成すると、内壁面は上記のようなお椀状の型に形成しにくくなる。
【００４０】
上記のようにしてマスキングを施した後に露光装置（図示省略）により、例えば紫外線などを露光し（ＳＴＥＰ．３）、レジスト層２及び３をそれぞれ感光させる。
【００４１】
露光によりレジスト層２，３のマスキングしていない露光部を硬化させた後にマスキングを剥がし、レジスト層２，３が付いたままのマスク１を例えば溶剤槽に浸漬して現像、即ち、マスキングしてあった未露光部を溶剤で溶解して取り除く（ＳＴＥＰ．４）。この未露光部を取り除くと、図１（ｂ）に示したように、マスク１の上下各面に第１の開口部４ａと第２の開口部５ａとを形成する部分が現れる。このときの第１の開口部４ａの口径及び第２の開口部５ａの口径はそれぞれ上記Ｓ，Ｌの値になっている。
【００４２】
次にこうしてレジスト層２，３にそれぞれ第１の開口部４ａと第２の開口部５ａとを形成する部分が露出したマスク１をエッチング槽（図示省略）にてスプレーしてエッチングを行う（ＳＴＥＰ．５）。このエッチングにより第１の窓４と第２の窓５からエッチング液がマスク１の侵蝕を開始し図１（ｃ）に示したような第１の凹部１４と第２の凹部１５とをそれぞれ形成する。
【００４３】
ただし、この段階では前記第１の開口部４、前記第２の開口部５からエッチング液がマスク１の表面をエッチングして内部方面まで侵食し、前記第１の凹部１４と前記第２の凹部１５とが一部連通し、図１（ｃ）に示すように前記第１の凹部１４と前記第２の凹部１５とが結合した部分の径が狭くなった状態迄に留めておく。
【００４４】
次に更にエッチングを進め、いわゆるオーバーエッチングを行う（ＳＴＥＰ．６）。このオーバーエッチング工程は、上記エッチング工程で表面の一部が部分的にせり出した断面を有する内壁面６の形状を整えて、図２（ａ）に示すように弧状に膨らんだ滑らかな曲線状に仕上げるのが目的であり、そのためには上記エッチング工程とは異なる条件、例えばより穏やかな条件でエッチングするようにしてもよい。逆により激しい条件でエッチングしてもよい。具体的にはマスク１の材質、厚さ、エッチング液の種類、温度その他の設計事項に応じて適宜条件を設定する。
【００４５】
このオーバーエッチング工程により最終的に得られる形状は図２（ａ）に示したような第２の開口部から第１の開口部側に椀状に凹陥する形状となるのが好ましく、このように構成することによって印刷回数の削減と、にじみの発生が少なくなるからである。また、このときの断面形状は極率半径Ｒの弧状になるのが好ましい。このＲの値は２００μｍ以上であるのが更に好ましい。
【００４６】
ここで、極率半径Ｒの値の好ましい範囲を上記範囲に特定したのは、この範囲であると、このマスクを使用した場合に形成される導体バンプがマスクから剥がれ易く、所期の略円錐形の導体バンプが形成されやすいためである。
【００４７】
一方、極率半径Ｒがこの範囲を超えると、マスクから導体バンプが剥がれにくくなったり、所期の略円錐形の導体バンプが形成されにくいという弊害を生じる。
【００４８】
オーバーエッチング工程が完了したら、マスク１表面のレジスト層２及び３を除去する（ＳＴＥＰ．７）。
【００４９】
この段階でマスク１の完成としてもよいが、更にマスク１の少なくとも内壁面６に、更に銀ペーストなどの導体バンプを形成するための導電性組成物に対して非付着性材料、例えばテフロン（登録商標）のような不活性な材料でコーティングを施すことが好ましい。従って、本実施形態ではテフロン（登録商標）コーティング工程を更に設けており（ＳＴＥＰ．８）、その結果マスク１表面には図２（ｃ）に示すように、テフロン（登録商標）コーティング層７が形成されている。
【００５０】
この非付着性材料によるコーティング層７の厚さは１〜２μｍとするのが好ましい。ここでコーティング層７の厚さを上記範囲に特定したのは、コーティング層７の厚さがこの範囲を下回ると、コーティング膜圧にムラが生じたり、コーティングの硬化が損なわれたりするからであり、反対に、コーティング層７の厚さがこの範囲を上回ってもコスト高になるだけである。
【００５１】
次に、このようにして形成したマスク１を用いて多層板を形成する手順について説明する。図４〜図６は多層板の製造される様子を模式的に示した垂直断面図であり、図７は多層板の製造工程のフローを示したフローチャートである。
【００５２】
多層板を製造するには、図４（ａ）に示したように、まず銅箔などの導体層８上に本実施形態に係るマスク１を、貫通孔の大きい方の開口部、即ち第２の開口部５ａが下になるように重ねてマスク・セッティングする（ＳＴＥＰ．９）。この状態で、例えば銀粒子を溶剤で液状に溶かした樹脂中に分散させた銀ペーストのような導電性組成物９をマスク１の第１の開口部に対して図中上面側から充填する（ＳＴＥＰ．１０）。具体的には、図４（ａ）に示したように、マスク１の上面に導電性組成物９を塗布し、更にゴムのような弾性材料でできたヘラ１０でスキージすることによりマスク１上面から第１の開口部４ａを介して貫通孔１６内に圧入して充填する。
【００５３】
こうして貫通孔１６内に導電性組成物９が充填された状態を示したのが図４（ｂ）である。
【００５４】
導電性組成物９の充填が完了したら、導体層８とマスク１とを剥離する（ＳＴＥＰ．１１）。この導体層８からマスク１を剥離する様子を示したのが図５（ａ）である。このマスク１を剥離する際に、貫通孔１６内の導電性組成物９の底面は導体層８面に強く付着しているため、貫通孔１６内の導電性組成物９には導体層８面上に残ろうとする図中下向きの力と、貫通孔１６の内壁面６に付着してマスク１と共に剥離されようとする図中上向きの力との二つの力とが作用するため、貫通孔１６内の導電性組成物９には図中略上下方向に引っ張ろうとする力が作用する。そのため図５（ａ）の真中の導電性組成物９のように上下方向にのびようとする結果、下部が広く、上部が狭くなった円錐形になる。また、貫通孔１６が椀状に凹陥する形状を有する内壁面になっていることと相俟って導電性組成物９はマスク１を剥離するときに略円錐形になる。更に貫通孔１６の内壁面６に形成されたテフロン（登録商標）コーティング層７の作用により、内壁面６には導電性組成物９が剥がれやすくなっているため、結局導電性組成物９の殆どは導体層８側に付着して残り、マスク１を完全に取り去った後にはきれいな略円錐形の導体バンプ１０が形成される（図５（ｂ））。
【００５５】
このように形成された導体バンプ１０，１０，…のアスペクト比、即ち高さｈと底面半径との間のいわゆる縦横比はｈ：ｒ＝１．５〜２．５：１の範囲であるのが好ましい。ここで導体バンプのアスペクト比を上記範囲が好ましいとしたのは、この範囲より低い値ではバンプの貫通が難しくなり、高い値ではバンプが貫通の際に折損したり、割れて飛散したりするからである。
【００５６】
マスク１の剥離が完了したら、導体バンプ１０，１０，…が形成された状態の導体層８を乾燥器（図示省略）に入れて乾燥し、導体バンプ１０，１０，…を硬化させる（ＳＴＥＰ．１２）。
【００５７】
こうして硬い導体バンプ１０，１０，…を形成した導体層８が得られたら、図６（ａ）に示すように、この導体層８の導体バンプ１０，１０，…の上に絶縁性基板（以下、単に「プリプレグ」という。）と、更にその上に銅箔のような導体層１２を重ね合わせてセッティングする（ＳＴＥＰ．１３）。
【００５８】
この状態でプレスすると同時に加熱する（ＳＴＥＰ．１４）。
【００５９】
プレスにより導体バンプ１０，１０，…はプリプレグ１１を貫通し、その先端がもう一つの導体層１２面に押圧され、この導体層１２と導体バンプ１０，１０，…との間、ひいては導体層８ともう一つの導体層１２との間での電気的導通が達成される。また、加熱によりプリプレグ１１が硬化して図６（ｂ）に示したような、重ね合わされた、いわゆるコア材２０が形成される。
【００６０】
更にこのコア材２０の導体層８，１２をそれぞれエッチングなどを施してパターニングすることにより、図６（ｃ）に示したような多層板２１が得られる（ＳＴＥＰ．１５）。
【００６１】
以上説明したように、本実施形態に係るマスク１によれば、貫通孔の上側に第１の開口部が形成される一方、マスク１の下面側には前記第１の開口部より大きい径の第２の開口部が形成され、貫通孔が第２の開口部から第１の開口部側に椀状に凹陥する形状に形成されており、マスク１剥離時に導電性組成物が剥がれ易く、所期の略円錐形の導体バンプを高収率で形成することができる。
【００６２】
また、導電性組成物が貫通孔から離脱しやすく、しかも貫通孔の形状が略円錐形の導体バンプが形成されやすい形状となっているので、厚みが大きく、所期の略円錐形状を備えた導体バンプを一回の印刷操作で形成することができる。
【００６３】
更に、貫通孔から導電性組成物が離脱し易いので、印刷後に貫通孔内に導電性組成物が付着する量が少なく、使用後のマスクの洗浄を簡略化することができる。
【００６４】
また、マスク１の内壁面にテフロン（登録商標）などの非付着性材料のコーティング層を形成することにより、より一層上記効果を発揮することができる。
【００６５】
本実施形態に係るマスクの製造方法によれば、マスクの開口部あけをエッチングにより行うので、一度に多数の貫通孔を穿孔することができ、しかも貫通孔の断面形状を均質化することができる。
【００６６】
また、オーバーエッチングにより貫通孔の表面仕上げを行うので、貫通孔の内壁面が滑らかになり、導電性組成物が離脱しやすく、またマスクを剥離したときに得られる導体バンプの表面を滑らかなものにすることができる。
【００６７】
更に、エッチング条件やオーバーエッチングの条件を適宜変更することにより貫通孔の断面形状を微調節することができる。
【００６８】
なお、上記実施形態は本発明の範囲を限定するものではない。例えば、上記実施形態では、マスクの上下各面から行う開口部あけ操作をエッチングにより行っているが、先端がテーパ状に形成されたドリルで穴あけしてもよい。
【００６９】
また、上記実施形態では導体層上に導体バンプを形成しているが、配線パターン上に導体バンプを形成してもよく、更に４層以上の多層板に適用することも可能である。
【００７０】
本発明によれば、前記プリント配線基板製造用マスクの導電性組成物供給側の一方の面側に第１の開口部が配設され、対向する他方の面側に前記第１の開口部より大きな口径を備えた第２の開口部が形成され、かつ、貫通孔が第２の開口部から第１の開口部側に椀状に凹陥する形状となっているので、導電性組成物を充填後にプリント配線基板製造用マスクと導体層とを剥がすときに貫通孔から導電性組成物が剥がれ易く、貫通孔の内壁面の形状に近い形状の導体バンプが形成され易い。そのため、収率が向上し、しかも一回の印刷で略円錐形の導体バンプを形成することができる。
【図面の簡単な説明】
【図１】本実施形態のプリント配線基板製造用マスク製造方法の各工程を示した垂直断面図である。
【図２】本実施形態のプリント配線基板製造用マスク製造方法の各工程を示した垂直断面図である。
【図３】本実施形態のプリント配線基板製造用マスク製造方法のフローチャートである。
【図４】多層板の製造工程を模式的に示した垂直断面図である。
【図５】多層板の製造工程を模式的に示した垂直断面図である。
【図６】多層板の製造工程を模式的に示した垂直断面図である。
【図７】多層板の製造工程のフローを示したフローチャートである。
【図８】従来の導体貫通法の製造工程を示した垂直断面図である。
【符号の説明】
９…導電性組成物、
１６…貫通孔、
１…マスク基材、
２…第１のレジスト層、
３…第２のレジスト層、
４…第１の窓、
５…第２の窓、
４ａ…第１の開口部、
５ａ…第２の開口部、
６…内壁面、
１４…第１の凹部、
１５…第２の凹部、
７…非付着性材料コーティング層。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a printed wiring board, and more specifically, a method for manufacturing a so-called conductor-through multilayer board in which wiring layers are connected by a through-type conductor wiring portion, and a printed wiring board used in the manufacturing method. The present invention relates to a manufacturing mask.
[0002]
[Prior art]
Conventionally, as a method of manufacturing a multilayer board, a so-called conical conductor bump is press-fitted in the thickness direction of an insulating substrate to achieve electrical continuity between two wiring patterns formed on both surfaces of the insulating substrate. A conductor penetration method is known.
[0003]
FIG. 8 is a vertical sectional view schematically showing a manufacturing process of a conventional typical conductor penetration method.
[0004]
In this conductor penetration method, first, a metal printing mask 101 is overlaid on a conductor layer 100 (FIG. 8A) such as a copper foil (FIG. 8B). In this printing mask 101, a plurality of through holes 102, 102,... Are drilled in the thickness direction, and a conductive composition such as silver paste is provided in these through holes 102, 102,. When the object 103a is squeezed, the conductive composition 103a is filled into the through hole 102 (FIG. 8C). When the printing mask is peeled off from the conductor layer 100 after filling, since the bottom surface of the conductive composition 103a and the conductor layer 100 are adhered, the conductive composition 103a is pulled toward the conductor layer 100 and the through holes 102, 102, Leave. At this time, since the upper portion of the conductive composition 103a is pulled toward the inner wall surface side of the through hole 102, a plurality of substantially conical conductor bumps 103b, 103b,... Are formed on the conductor layer 100 (FIG. 8 ( d)).
[0005]
On the thus formed conductor bumps 103b, 103b,..., An insulating substrate 104 and another conductor layer 105 are placed (FIG. 8E), and pressed in this state under pressure. Then, the insulating substrate 104 is cured by heating, and at the same time, the conductor layer 105 is bonded onto the insulating substrate 104.
[0006]
Thus, the so-called core material 110 is formed (FIG. 8F), and the wiring patterns 106 and 107 are formed on the upper and lower surfaces of the core material 110 by etching or the like to obtain a two-layered multilayer board 111 (FIG. 8). (G)).
[0007]
By the way, the conductive bumps 103b, 103b,... Formed on the conductor layer 100 by peeling the printing mask 101 from the conductor layer 100 after filling the through holes 102, 102,. Although the mechanism of forming the shape is not fully understood, it is considered that a part of the conductive composition 103a filled in the through holes 102, 102,... Remains in the through holes 102, 102,.
[0008]
[Problems to be solved by the invention]
However, since the through holes 102, 102... Are formed by drilling using an NC drilling machine, the inner wall surface is rough, and since they have a substantially cylindrical inner wall surface, the through holes 102, 102,. The conductive composition 103a tends to remain in the through holes 102, 102,. Therefore, when the printing mask 101 is peeled off, the conductor bumps 103b, 103b,... May not be formed, or the shape of the conductor bumps 103b, 103b,. is there.
[0009]
In addition, when the through hole 102 is filled, the cylindrical conductive composition 103a is forcibly deformed into a substantially conical shape when the printing mask 101 is peeled off, and a conductor bump 103b having a sufficient thickness can be formed by one printing. In order to form the substantially conical conductor bump 103b, it is necessary to repeat the printing operation 3 to 5 times, and there are many processes, and the side surface of the conductor bump 103b is multi-stepped. There is a problem that the shape of 103b tends to be uneven.
[0010]
The present invention has been made to solve the above conventional problems. That is, the present invention provides a mask for manufacturing a printed wiring board capable of forming a substantially conical conductor bump with a small number of steps and a high yield, and a method for manufacturing such a mask for manufacturing a printed wiring board. With the goal.
[0011]
A mask having a plurality of through holes are drilled, the respective through holes, the larger diameter than the first first diameter of the opening portion and the other side having a first diameter of the one side A printed wiring having a second opening having a second diameter, and having an inner wall surface between the openings recessed from the second opening toward the first opening. A step of holding the second opening side of the mask for manufacturing a substrate in contact with a conductor layer; a step of filling a conductive composition into the through hole from the first opening side; and Peeling the conductor layer and the mask for manufacturing the printed wiring board to form a substantially conical conductor bump on the conductor layer; drying the conductor bump; and providing an insulating substrate on the conductor bump. And placing the conductor layer and the insulating substrate so that the conductor bumps penetrate the insulating substrate. Passing through.
[0012]
In this printed wiring board manufacturing method, it is preferable that the inner wall surface has a concave shape.
[0013]
In the printed wiring board manufacturing method, the through hole has a first opening and a second opening constituting a ratio of the first diameter: the second diameter = 1: 1.2 to 2.0. Are preferably provided.
[0014]
Moreover, it is preferable that the said through-hole is provided with the 2nd opening part which comprises the ratio of said 2nd aperture diameter: mask thickness = 1: 1.0-1.5.
[0015]
Further, the conductor layer includes both a conductor plate such as a copper foil that has not been etched and a wiring pattern disposed on an insulating substrate.
[0016]
Furthermore, the inner wall surface preferably further includes a non-adhesive material coating layer for the conductive composition, and the non-adhesive material coating layer is a Teflon (registered trademark) coating layer. preferable. The non-adhesive material coating layer preferably has a thickness of 1 to 2 μm.
[0017]
By forming the inner wall surface in such a shape, forming a non-adhesive material coating layer such as Teflon (registered trademark) on the inner wall surface, or forming this non-adhesive material coating layer with an appropriate thickness. The conductive composition easily peels from the through hole. Moreover, it becomes easy to form a substantially conical conductor bump on the conductor layer after the printed wiring board manufacturing mask is peeled off.
[0018]
Moreover, by making the shape as described above specifying the parameters of the through hole, the conductive composition is easily peeled off, and a substantially conical conductor bump is easily formed.
[0019]
The mask for manufacturing a printed wiring board according to the present invention is a mask for manufacturing a printed wiring board in which a plurality of through holes for filling the conductive composition are perforated along a predetermined wiring pattern. A first opening formed on the first surface of the mask, the through hole having a first diameter, and a thickness substantially equal to or slightly greater than the height of the conductor bump A second opening having a second diameter larger than the first diameter and formed on the second surface of the mask.
[0020]
In this printed wiring board manufacturing mask, the through hole has a plurality of first recesses having a first diameter from one surface of the mask base material on the conductive composition supply side at a predetermined position of the mask base material. Forming a second recess having a second aperture larger than the first aperture at a position corresponding to the first recess on the other surface , the first recess and Forming the inner wall surface having a shape that is recessed in a bowl shape in which the first recess and the second recess are connected by over-etching the second recess. Preferably there is.
[0021]
Further, the step of forming the first recess and the step of forming the second recess include
Applying a first resist layer formed with a first window having the first aperture to the first surface of the mask substrate;
Applying a second resist layer formed with a second window having the second aperture to the second surface of the mask substrate;
The etching is preferably performed by etching the mask base material through the first resist layer and the second resist layer.
[0022]
In this printed wiring board manufacturing mask, it is more preferable that the inner wall surface has a shape recessed in a bowl shape .
[0023]
In the printed wiring board manufacturing mask, the through hole has a first opening and a second opening that constitute a ratio of the first diameter: the second diameter = 1: 1.2 to 2.0. It is preferable to provide a part.
[0024]
Moreover, it is preferable that the said through-hole is provided with the 2nd opening part which comprises the ratio of said 2nd aperture diameter: mask thickness = 1: 1.0-1.5.
[0025]
Furthermore, the inner wall surface preferably further includes a non-adhesive material coating layer for the conductive composition, and the non-adhesive material coating layer is a Teflon (registered trademark) coating layer. preferable. The non-adhesive material coating layer preferably has a thickness of 1 to 2 μm.
[0026]
By forming the inner wall surface in such a shape, forming a non-adhesive material coating layer such as Teflon (registered trademark) on the inner wall surface, or forming this non-adhesive material coating layer with an appropriate thickness. The conductive composition easily peels from the through hole. Moreover, it becomes easy to form a substantially conical conductor bump on the conductor layer after the printed wiring board manufacturing mask is peeled off.
[0027]
Moreover, by making the shape as described above specifying the parameters of the through hole, the conductive composition is easily peeled off, and a substantially conical conductor bump is easily formed.
[0028]
According to the present invention, the first opening is disposed on the first surface upstream of the conductive composition supply direction of the printed wiring board manufacturing mask, and the second surface faces the first surface. And a second opening having a larger diameter than the first opening, so that when the printed wiring board manufacturing mask and the conductor layer are peeled off after filling with the conductive composition, The conductive composition is easily peeled off, and a conductor bump having a shape close to the shape of the inner wall surface of the through hole is easily formed. Therefore, the yield is improved, and a substantially conical conductor bump can be formed by one printing.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for manufacturing a mask for manufacturing a printed wiring board according to an embodiment of the present invention will be described.
[0030]
1 and 2 are vertical sectional views schematically showing respective steps of a method for manufacturing a printed wiring board manufacturing mask (hereinafter simply abbreviated as “mask”) according to the present embodiment. It is the flowchart which showed the flow of the manufacturing method.
[0031]
In order to manufacture the mask according to this embodiment, first, a photosensitive material is applied to the upper and lower surfaces of a metal plate, for example, and a resist layer 2 as a first resist layer is used as a mask substrate. A resist layer 3 as a second resist layer is formed on the middle upper surface, and is formed on the lower surface of the mask substrate 1 in the figure (FIG. 1 (a) /STEP.1).
[0032]
Next, masking (not shown) is applied to the resist layers 2 and 3 so that the first window 4 is formed in the resist layer 2 corresponding to the position where the conductor bumps are formed. Masking is performed so that two windows 5 are formed.
[0033]
That is, as shown in FIG. 1B, on the resist layer 2, a circular first window 4 having the same diameter as the diameter of the first opening (first diameter) that is the entrance of the first recess is formed. Is masked in accordance with the diameter S (first diameter) of the first window 4 so as to open. For example, in the case of using a photo-curing resist, only the portion where the first window 4 is formed is masked to prevent light from hitting it. Similarly, a circular second window having the same diameter as the diameter of the second opening (second diameter) so that the second opening that is the entrance of the second recess opens on the resist layer 3. Masking is performed in accordance with the aperture L (second aperture) of the second window 5 so that the aperture 5 opens. For example, in the case of using a photo-curing resist, only the portion where the second window 5 is formed is masked to prevent light from hitting it.
[0034]
At this time, the size of the first window 4 (first diameter) S and the diameter of the second window 5 (second diameter) L is such that S and L have the following relationship. Mask to be.
[0035]
S: L = 1: 1.5-2.5
The ratio of the aperture (first aperture) S of the first window 4 to the aperture (second aperture) L of the second window 5 is set to such a range. By forming the window and the second window, and thus, the first opening and the second opening at a ratio in this range, the second opening to the first opening side by the subsequent overetching process . This is because it becomes easier to form an inner wall surface having a shape that is recessed in a bowl shape .
[0036]
Conversely, when the first window 4 (first opening) and the second window 5 (second opening) are formed at a ratio outside the above range, the inner wall surface has a bowl-like shape as described above. It becomes difficult to form.
[0037]
Further, it is preferable that the following relationship is established between the diameter L of the second opening and the thickness D of the mask 1.
[0038]
L: D = 1: 1.5 to 2.5
The ratio between the diameter (second diameter) L of the second window 5 (second opening) and the thickness D of the mask is in such a range. By forming the window (second opening), it becomes easier to form an inner wall surface shaped like a bowl from the second opening toward the first opening by the subsequent over-etching process . .
[0039]
Conversely, when the second window 5 (second opening) is formed at a ratio outside the above range, the inner wall surface is difficult to form in the bowl-shaped mold as described above.
[0040]
After masking as described above, for example, ultraviolet rays are exposed by an exposure apparatus (not shown) (STEP. 3), and the resist layers 2 and 3 are exposed, respectively.
[0041]
After exposing the unmasked exposed portions of the resist layers 2 and 3 by exposure, the masking is peeled off, and the mask 1 with the resist layers 2 and 3 attached is immersed in, for example, a solvent bath and developed, that is, masked. The unexposed part which existed is dissolved and removed with a solvent (STEP.4). When this unexposed portion is removed, as shown in FIG. 1B, portions where the first opening 4a and the second opening 5a are formed on the upper and lower surfaces of the mask 1 appear. At this time, the diameter of the first opening 4a and the diameter of the second opening 5a are the values of S and L, respectively.
[0042]
Next, etching is performed by spraying the mask 1 in which the portions for forming the first opening 4a and the second opening 5a are respectively exposed in the resist layers 2 and 3 in an etching tank (not shown) (STEP). .5). By this etching, the etching solution starts to erode the mask 1 from the first window 4 and the second window 5 to form the first recess 14 and the second recess 15 as shown in FIG. To do.
[0043]
However, at this stage, the etching solution etches the surface of the mask 1 from the first opening 4 and the second opening 5 to erode the inner surface, and the first recess 14 and the second recess 15 is partly communicated, and as shown in FIG. 1C, the diameter of the portion where the first concave portion 14 and the second concave portion 15 are coupled is reduced.
[0044]
Next, etching is further advanced, so-called over-etching is performed (STEP. 6). In this over-etching process, the shape of the inner wall surface 6 having a cross section in which a part of the surface is partially protruded in the above-described etching process is arranged, and as shown in FIG. The purpose is to finish, and for that purpose, etching may be performed under conditions different from the above-described etching step, for example, under milder conditions. Conversely, etching may be performed under more severe conditions. Specifically, conditions are appropriately set according to the material, thickness, type of etching solution, temperature, and other design items of the mask 1.
[0045]
The shape finally obtained by this over-etching process is preferably a shape that is recessed from the second opening to the first opening as shown in FIG. 2A. This is because the configuration reduces the number of printings and reduces the occurrence of bleeding. In addition, the cross-sectional shape at this time is preferably an arc with a radius of curvature R. The value of R is more preferably 200 μm or more.
[0046]
Here, the preferable range of the value of the radius of curvature R is specified in the above range. If this range is used, the conductor bump formed when this mask is used is easily peeled off from the mask, and the desired substantially conical shape. This is because a shaped conductor bump is easily formed.
[0047]
On the other hand, when the radius of curvature R exceeds this range, the conductive bumps are hardly peeled off from the mask, and the desired substantially conical conductive bumps are hardly formed.
[0048]
When the overetching process is completed, the resist layers 2 and 3 on the surface of the mask 1 are removed (STEP.7).
[0049]
Although the mask 1 may be completed at this stage, a non-adhesive material, such as Teflon (registered) , is further applied to the conductive composition for forming a conductive bump such as silver paste on at least the inner wall surface 6 of the mask 1. Preferably, the coating is applied with an inert material such as the trademark . Therefore, in this embodiment, a Teflon (registered trademark) coating process is further provided (STEP. 8). As a result, the surface of the mask 1 has a Teflon (registered trademark) coating layer 7 as shown in FIG. Is formed.
[0050]
The thickness of the coating layer 7 made of this non-adhesive material is preferably 1 to 2 μm. Here, the reason why the thickness of the coating layer 7 is specified in the above range is that when the thickness of the coating layer 7 is less than this range, unevenness in the coating film pressure occurs or the curing of the coating is impaired. On the contrary, even if the thickness of the coating layer 7 exceeds this range, only the cost is increased.
[0051]
Next, a procedure for forming a multilayer board using the mask 1 thus formed will be described. 4 to 6 are vertical sectional views schematically showing how the multilayer board is manufactured, and FIG. 7 is a flowchart showing the flow of the manufacturing process of the multilayer board.
[0052]
In order to manufacture a multilayer board, as shown in FIG. 4A, first, the mask 1 according to this embodiment is placed on the conductor layer 8 such as copper foil, that is, the opening having the larger through hole, that is, the second. Then, the mask is set so that the opening 5a faces downward (STEP. 9). In this state, for example, a conductive composition 9 such as a silver paste in which silver particles are dissolved in a resin dissolved in a liquid in a solvent is filled from the upper surface side in the drawing into the first opening of the mask 1 ( STEP.10). Specifically, as shown in FIG. 4A, the conductive composition 9 is applied to the upper surface of the mask 1, and further squeezed with a spatula 10 made of an elastic material such as rubber, whereby the upper surface of the mask 1. To press-fit into the through hole 16 through the first opening 4a.
[0053]
FIG. 4B shows a state in which the conductive composition 9 is filled in the through hole 16 in this way.
[0054]
When the filling of the conductive composition 9 is completed, the conductor layer 8 and the mask 1 are peeled off (STEP. 11). FIG. 5A shows how the mask 1 is peeled from the conductor layer 8. When the mask 1 is peeled off, the bottom surface of the conductive composition 9 in the through hole 16 is strongly attached to the conductor layer 8 surface. Two forces are exerted: a downward force in the figure to remain on the upper side and an upward force in the figure to adhere to the inner wall surface 6 of the through-hole 16 and peel off together with the mask 1. A force to pull the conductive composition 9 in the vertical direction in FIG. Therefore, as a result of trying to extend in the vertical direction like the conductive composition 9 in the middle of FIG. 5A, a conical shape having a wide lower portion and a narrow upper portion is obtained. In addition, the conductive composition 9 has a substantially conical shape when the mask 1 is peeled off in combination with the inner wall surface having a shape in which the through hole 16 is recessed in a bowl shape . Further, since the conductive composition 9 is easily peeled off from the inner wall surface 6 by the action of the Teflon (registered trademark) coating layer 7 formed on the inner wall surface 6 of the through-hole 16, most of the conductive composition 9 is eventually formed. Remains on the conductor layer 8 side, and after the mask 1 is completely removed, a clean substantially conical conductor bump 10 is formed (FIG. 5B).
[0055]
The aspect ratio of the conductive bumps 10, 10,..., That is, the so-called aspect ratio between the height h and the bottom radius is in the range of h: r = 1.5 to 2.5: 1. Is preferred. Here, the reason why the above-mentioned range of the aspect ratio of the conductor bump is preferable is that if the value is lower than this range, it is difficult to penetrate the bump, and if the value is higher, the bump breaks or breaks and scatters when penetrating. It is.
[0056]
When the peeling of the mask 1 is completed, the conductor layer 8 on which the conductor bumps 10, 10,... Are formed is placed in a dryer (not shown) and dried to cure the conductor bumps 10, 10,. 12).
[0057]
When the conductor layer 8 formed with the hard conductor bumps 10, 10,... Is obtained in this way, an insulating substrate (hereinafter referred to as “insulating substrate”) is formed on the conductor bumps 10, 10,. , Simply referred to as “prepreg”), and a conductor layer 12 such as a copper foil is further set thereon (STEP. 13).
[0058]
In this state, pressing and heating are performed simultaneously (STEP. 14).
[0059]
The conductor bumps 10, 10,... Penetrate through the prepreg 11 and are pressed against the other conductor layer 12 surface by pressing, and between the conductor layer 12 and the conductor bumps 10, 10,. And another conductor layer 12 is achieved. In addition, the prepreg 11 is cured by heating to form a so-called core material 20 that is overlapped as shown in FIG.
[0060]
Further, by patterning the conductor layers 8 and 12 of the core material 20 by etching or the like, a multilayer board 21 as shown in FIG. 6C is obtained (STEP. 15).
[0061]
As described above, according to the mask 1 according to the present embodiment, the first opening is formed on the upper side of the through hole, and the lower surface side of the mask 1 has a diameter larger than that of the first opening. The second opening is formed, and the through hole is formed in a bowl-like shape from the second opening to the first opening, and the conductive composition is easily peeled off when the mask 1 is peeled off. The substantially conical conductor bump of the period can be formed with high yield.
[0062]
Further, since the conductive composition is easy to be detached from the through hole, and the shape of the through hole is easy to form a conductor bump having a substantially conical shape, the thickness is large and the desired substantially conical shape is provided. Conductive bumps can be formed by a single printing operation.
[0063]
Furthermore, since the conductive composition is easily detached from the through hole, the amount of the conductive composition attached to the through hole after printing is small, and the cleaning of the mask after use can be simplified.
[0064]
Further, by forming a coating layer of a non-adhesive material such as Teflon (registered trademark) on the inner wall surface of the mask 1, the above effect can be further exhibited.
[0065]
According to the method for manufacturing a mask according to this embodiment, since the opening of the mask is formed by etching, a large number of through holes can be drilled at once, and the cross-sectional shape of the through holes can be homogenized. .
[0066]
In addition, the surface finish of the through hole is performed by over-etching, so that the inner wall surface of the through hole is smooth, the conductive composition is easily detached, and the surface of the conductor bump obtained when the mask is peeled off is smooth. Can be.
[0067]
Furthermore, the cross-sectional shape of the through hole can be finely adjusted by appropriately changing the etching conditions and over-etching conditions.
[0068]
The above embodiment does not limit the scope of the present invention. For example, in the above embodiment, the opening operation performed from the upper and lower surfaces of the mask is performed by etching, but the tip may be drilled with a drill having a tapered tip.
[0069]
In the above embodiment, the conductor bumps are formed on the conductor layer. However, the conductor bumps may be formed on the wiring pattern, and can be applied to a multilayer board having four or more layers.
[0070]
According to the present invention, the first opening is disposed on one side of the mask for manufacturing the printed wiring board on the conductive composition supply side, and the other side of the first opening is opposed to the first opening. It is formed a second opening with a large caliber, and in the through hole has a shape that recessed in a bowl shape in the first opening side from the second opening, a conductive composition When the printed wiring board manufacturing mask and the conductor layer are peeled after filling, the conductive composition is easily peeled off from the through hole, and a conductor bump having a shape close to the shape of the inner wall surface of the through hole is easily formed. Therefore, the yield is improved, and a substantially conical conductor bump can be formed by one printing.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view showing each step of a mask manufacturing method for manufacturing a printed wiring board according to an embodiment.
FIG. 2 is a vertical sectional view showing each step of a mask manufacturing method for manufacturing a printed wiring board according to the present embodiment.
FIG. 3 is a flowchart of a mask manufacturing method for manufacturing a printed wiring board according to the present embodiment.
FIG. 4 is a vertical sectional view schematically showing a manufacturing process of a multilayer board.
FIG. 5 is a vertical sectional view schematically showing a manufacturing process of a multilayer board.
FIG. 6 is a vertical sectional view schematically showing a manufacturing process of a multilayer board.
FIG. 7 is a flowchart showing a flow of a manufacturing process of a multilayer board.
FIG. 8 is a vertical sectional view showing a manufacturing process of a conventional conductor penetration method.
[Explanation of symbols]
9 ... conductive composition,
16 ... through hole,
1 ... mask substrate,
2 ... 1st resist layer,
3 ... second resist layer,
4 ... the first window,
5 ... Second window,
4a ... 1st opening part,
5a ... second opening,
6 ... Inner wall surface,
14 ... 1st recessed part,
15 ... second recess,
7: Non-adhesive material coating layer.

Claims

A mask having a plurality of through holes,
Each through-hole has a first opening having a first diameter on one surface side and a second opening having a second diameter larger than the first diameter on the other surface side. The second opening side of the mask for manufacturing a printed wiring board in which the inner wall surface between the openings is recessed from the second opening to the first opening is a conductor layer. A process of contacting and holding
Filling the through hole with a conductive composition from the first opening side of the printed wiring board manufacturing mask;
Peeling the conductor layer and the printed wiring board manufacturing mask to form a substantially conical conductor bump on the conductor layer; and drying the conductor bump;
Placing an insulating substrate on the conductor bump;
Pressing the conductor layer and the insulating substrate and penetrating the conductor bumps through the insulating substrate;
The manufacturing method of the printed wiring board which comprises this.

It is a manufacturing method of the printed wiring board of Claim 1, Comprising: Said 1st aperture and said 2nd aperture are said 1st aperture: said 2nd aperture = 1: 1.2-2.0. A method of manufacturing a printed wiring board, wherein

2. The printed wiring board manufacturing method according to claim 1, wherein the second aperture is formed at a ratio of second aperture: mask thickness = 1: 1.0 to 1.5. 3. A printed wiring board manufacturing method characterized by the above.

It is a manufacturing method of the printed wiring board of Claims 1-3, Comprising: The said inner wall surface is further equipped with the non-adhesive material coating layer with respect to the said electrically conductive composition, Manufacturing of the printed wiring board characterized by the above-mentioned. Method.

The method for manufacturing a printed wiring board according to claim 4, wherein the non-adhesive material coating layer is a Teflon (registered trademark) coating layer.

6. The method for manufacturing a printed wiring board according to claim 4 or 5, wherein the non-adhesive material coating layer has a thickness of 1 to 2 [mu] m.

A plurality of through holes for filling the conductive composition are perforated along a predetermined wiring pattern,
Each of the through holes has a first opening having a first diameter on one side and a second opening having a second diameter larger than the first diameter on the other side. A mask for manufacturing a printed wiring board, wherein the inner wall surface between the openings is recessed from the second opening toward the first opening.

The printed wiring board manufacturing mask according to claim 7,
The through hole has a step of forming a plurality of first recesses having a first diameter from one surface side at a predetermined position of the mask base material, and a position corresponding to the first recess from the other surface side. Forming a second recess having a second diameter larger than the first diameter, and forming an inner wall surface in which the first recess and the second recess communicate with each other by etching. by the manufacturing method to have a door,
A mask for manufacturing a printed wiring board, wherein the inner wall surface is formed to have a shape that is recessed in a bowl shape from the second opening to the first opening.

9. The printed wiring board manufacturing mask according to claim 8, wherein the step of forming the first concave portion and the step of forming the second concave portion form a first window having the first aperture. The first resist layer is applied to the first surface of the mask base material, and the second resist layer on which the second window having the second aperture is formed is used as the second surface of the mask base material. A mask for manufacturing a printed wiring board, which is applied by etching the mask base material through the first resist layer and the second resist layer.

10. The printed wiring board manufacturing mask according to claim 7 , wherein the first diameter and the second diameter are the first diameter: the second diameter = 1: A mask for manufacturing a printed wiring board, which is formed at a ratio of 1.2 to 2.0.

It is a mask for printed wiring board manufacture of Claim 10 , Comprising: Said 2nd aperture is formed by ratio of 2nd aperture: mask thickness = 1: 1.0-1.5. A mask for manufacturing a printed circuit board characterized by

A printed wiring board manufacturing mask according to any one of claims 7-11, wherein the inner wall surface, characterized in that it further comprises a non-adherent material coating layer for the conductive composition Mask for manufacturing printed circuit boards.

The printed wiring board manufacturing mask according to claim 12 , wherein the non-adhesive material coating layer is a Teflon (registered trademark) coating layer.

The printed wiring board manufacturing mask according to claim 13 , wherein the non-adhesive material coating layer has a thickness of 1 to 2 μm.