JP2004022733A

JP2004022733A - Polishing apparatus for wiring board, polishing method, and multilayer wiring board

Info

Publication number: JP2004022733A
Application number: JP2002174358A
Authority: JP
Inventors: Haruhiko Makino; 牧野　晴彦; Takeshi Iwashita; 岩下　斌; Hidetoshi Kusano; 草野　英俊
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 2002-06-14
Filing date: 2002-06-14
Publication date: 2004-01-22

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polishing apparatus and a polishing method, whereby a warped wiring board can be polished uniformly in the thickness direction, and to provide a multi-layer wiring board comprising polished wiring boards that are stacked. <P>SOLUTION: A lower damper member 41 provided with a porous copper plate 44 is fitted onto a vacuum chuck 13 of a movable table 11, and a wiring board P is chucked on the copper plate 44 with its polished face up. A polishing belt 21 is placed on the polished face so that the abrasive grain face of the belt 21 is in contact with the polished face; the polishing belt 21 is moved in the x directions, while a pusher 31 presses against the rear side of the polishing belt 21 via a fluororesin sheet 32 and an upper damper member 42; the movable table 11 is reciprocated in the y directions; and the pusher 31 is made to reciprocate in the x directions to uniformly polish the warped wiring board P in the thickness direction. In this way, a smooth multilayer wiring board 50 is obtained by stacking the polished wiring boards P. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は配線基板の研磨装置、研磨方法、および多層配線基板に関するものであり、更に詳しくは、研磨前の配線基板が反りを有する場合には、反りを有したまま厚さを一様に薄く研磨し得る研磨装置、研磨方法、および研磨された配線基板を積層してなる多層配線基板に関するものである。
【０００２】
【従来の技術】
近年、電子機器の小型化、多機能化に伴って配線基板の高密度化、実装部品の小型化に対する要請が大になっており、配線基板においては、一方では回路の狭幅化が図られると共に、他方では例えば厚さ２００μｍ程度の配線基板を積層することにより搭載時における配線基板の占有面積を減少させる多層配線基板が採用されるようになっている。
【０００３】
配線基板を積層して多層配線基板を得んとする場合には、元の配線基板を一様な厚さのものとすることが技術的に極めて重要である。すなわち、片面に銅箔を貼り合わせた合成樹脂板からなる原料配線基板にフォトリソグラフィ技術を適用し回路を形成して得られる配線基板の回路面は、銅が残された回路部分が凸部分となり、銅がエッチングされ除去された非回路部分が凹部分となっているので、これを平坦化させるために例えば紫外線硬化型アクリル樹脂が２０〜３０μｍの厚さに塗付される。しかし、この塗付を施すだけでは回路面の凹凸は低減されるものの、平坦化されず回路も露出されないので、回路面を厚さで１０〜２０μｍ程度の研磨が行われる。
【０００４】
配線基板の研磨方法には、バフロールで研磨する方法とサンダーベルトで研磨する方法がある。このうち、バフロールで研磨する方法は、一般的に、被研磨体に柔らかい部分と硬い部分とが共存すると硬い部分は研磨されるが柔らかい部分は研磨されにくいと言う特性があり、回路を備えた配線基板を均等に薄く研磨するには適していない。従って、配線基板の回路面の研磨には研磨面に砥粒が接着された研磨ベルトであるサンダーベルトで研磨する方法が採用される。なお、サンダーベルト方式による研磨は、特開２００１−２２５２５３号公報に示されているように、元来は木材の研磨に使用されたものである。そして、特開２００１−３４７４４４号公報にはウェーハの研磨にサンダーベルトを使用する場合が示されている。
【０００５】
（従来例）
図４は従来の研磨ベルト方式の研磨装置１００の構成を概略的に示す側面図である。図４に示すように、研磨装置１００は可動テーブル１０１上に設置されている真空チャック１０３上に載置されて真空チャッキングされる配線基板Ｐの被研磨面にエンドレスの研磨ベルト２０１がその砥粒面を接するよう架張されている。すなわち、研磨ベルト２０１は駆動モータ２０２によって回転される主動プーリー２０３と従動プーリー２０４、およびテンションプーリー２０５に巻装されており、一定の張力下に時計回りの方向、配線基板Ｐ上では矢印ｘで示す方向へ回転される。そして、研磨ベルト２０１を配線基板Ｐに押圧するための上下のｚ方向に可動のプッシャー３０１が研磨ベルト２０１の背面側に配置されており、研磨時には研磨ベルト２０１上においてプッシャー３０１が容易に摺動し得るように、プッシャー３０１と研磨ベルト２０１との間に四フッ化エチレン樹脂またはその類縁のフッ素樹脂からなるフッ素樹脂シート３０２を介して当接される。
【０００６】
そして、配線基板Ｐの研磨時には、研磨ベルト２０１が配線基板上をｘ方向へ高速で移動されると共に、配線基板Ｐを固定した可動テーブル１０１は駆動モータ１０２によって研磨ベルト２０１の幅方向であるｙ方向への微動を伴いつつ、少なくとも配線基板Ｐのｙ方向のサイズよりは大の距離をｙ方向へ往復され、プッシャー３０１は研磨ベルト２０１の進行方向であるｘ方向に、少なくとも配線基板Ｐのｘ方向のサイズよりは大の距離で往復されるようになっている。なお、この研磨時に、回路の銅が酸化されることを防ぐために、研磨面に水を供給して研磨面を濡らせる湿式研磨が行われる。
【０００７】
【発明が解決しようとする課題】
上記のような研磨装置１００による研磨では、図５に部分拡大して示すように、フラットな配線基板Ｐが研磨される場合には厚さ方向に均等に研磨されるが、同様な図６に示すように、配線基板Ｐが反りを有している場合には、凸部分のみが研磨され、厚さ方向に一様に研磨されないと言うことがある。元来、配線基板Ｐは、回路の銅と基板の主体である合成樹脂との熱膨張係数の違いや受けた熱履歴によって、小さい凹凸や大きい反り、ないしは‘うねり’を有しているのが普通である。そのために、配線基板Ｐは真空チャック１０３によるチャッキング時に矯正されてフラットになる部分もあるが、矯正されない部分も残る。また、研磨ベルト２０１の回転を損なわない程度のプッシャー３０１の押圧では配線基板Ｐの大きい反りや‘うねり’は解消されないのである。従って、配線基板Ｐは反りや‘うねり’の凸部分のみが研磨され、期待する厚さ方向に一様な研磨は行われない。なお、以降においては反りと‘うねり’をまとめて反りと称する。
【０００８】
そのほか、図７に示すように、配線基板Ｐは薄いためにフラットであっても、真空チャック１０３の直径２ｍｍ程度の吸引穴１０３ｈ上に位置する部分が矢印で示す方向へ真空吸引されることによって窪み、研磨が完了した後の配線基板Ｐには吸引穴１０３ｈが型移りして窪みＰｃが残り、フラットな配線基板Ｐが得られないと言う問題もある。なお、図７において実線で示した配線基板Ｐは真空チャッキングされている時には真空チャック１０３上の一点鎖線で示す位置にあったものである。
【０００９】
本発明は上述の問題に鑑みてなされ、反りを有する配線基板であっても厚さ方向に一様に研磨することができる研磨装置、研磨方法、および多層配線基板を提供することを課題とする。
【００１０】
【課題を解決するための手段】
上記の課題は請求項１、請求項７、または請求項１３の構成によって解決されるが、それらの解決手段を説明すれば次の如くである。
【００１１】
請求項１の配線基板の研磨装置は、テーブル上に固定された配線基板の被研磨面に研磨ベルトの砥粒面を押圧機具によって押圧し、少なくとも研磨ベルトを移動させる配線基板の研磨装置において、テーブルと配線基板との間にテーブルに取り付けて第１ダンパー材が介在され、押圧機具と研磨ベルトとの間に押圧機具に取り付けて第２ダンパー材が介在されているものである。
このような配線基板の研磨装置は、配線基板と研磨ベルトとを挟持する第１ダンパー材および第２ダンパー材の配線基板側がそれぞれ配線基板の反りに沿って変形されることにより、反りを有する配線基板をそのままの状態で厚さ方向に一様に研磨することができる。
【００１２】
請求項１に従属する請求項２の配線基板の研磨装置は、テーブルおよび押圧機具がそれぞれ研磨ベルトと独立して研磨ベルトの移動方向に平行な方向へ往復動可能とされているものである。
このような配線基板の研磨装置は、配線基板を効率よく研磨する。
【００１３】
請求項１に従属する請求項３の配線基板の研磨装置は、テーブル上に真空チャックが設置されており、その真空チャック上に厚さ方向の多数の連通孔を備えた第１ダンパー材が取り付けられ、第１ダンパー材の上面には多数の微細孔を備えた金属薄板が貼り合わされており、配線基板が金属薄板上に載置され真空チャッキングされるものである。
このような配線基板の研磨装置は、配線基板をテーブル上に容易に固定することができ、かつ金属薄板の存在によって真空チャックの吸引穴が配線基板に型移りすることを防ぐ。
【００１４】
請求項１に従属する請求項４の配線基板の研磨装置は、第２ダンパー材に取り付けたフッ素樹脂シートが第２ダンパー材と研磨ベルトの間に介在されているものである。
このような配線基板の研磨装置は、第２ダンパー材と研磨ベルトとの間の摺動を円滑化させる。
【００１５】
請求項１に従属する請求項５の配線基板の研磨装置は、第１ダンパー材および第２ダンパー材がウレタンゴム、シリコーンゴム、ブタジエン系合成ゴム、および天然ゴムのうちの少なくとも一種からなり、ゴム硬度が４０から２０までの範囲内にあるものが使用されているものである。
このような配線基板の研磨装置は、第１ダンパー材および第２ダンパー材の配線基板側が配線基板の反りに沿って容易に変形され、反りを有する配線基板をそのまま厚さ方向に一様に研磨することを可能にする。
【００１６】
請求項１に従属する請求項６の配線基板の研磨装置は、研磨ベルトが織布を基材とし８００メッシュから３０００メッシュまでのサイズの砥粒を接着して砥粒面とされているものである。
このような配線基板の研磨装置は、変形が容易でありながら強度を有する研磨ベルトによって配線基板の反りに沿う研磨が工業的に効率よく行われ、かつ平滑に研磨することを可能ならしめる。
【００１７】
請求項７の配線基板の研磨方法は、テーブル上に固定された配線基板の被研磨面に研磨ベルトの砥粒面を押圧機具によって押圧し、研磨ベルトを移動させる配線基板の研磨方法において、テーブル上に取り付けた第１ダンパー材を介してテーブルに配線基板を固定し、かつ押圧機具に取り付けた第２ダンパー材を介して押圧機具により研磨ベルトを配線基板に押圧した状態で、少なくとも研磨ベルトを移動させる方法である。
このような配線基板の研磨方法は、配線基板を研磨ベルトと共に挟持する第１ダンパー材および第２ダンパー材の配線基板側がそれぞれ配線基板の反りに沿って変形されることから、反りを有する配線基板をそのままの状態で厚さ方向に一様に研磨することができる。
【００１８】
請求項７に従属する請求項８の配線基板の研磨方法は、研磨時にテーブルおよび押圧機具をそれぞれ研磨ベルトと独立して研磨ベルトの移動方向に平行な方向へ往復動させる方法である。
このような配線基板の研磨方法は、配線基板を効率よく研磨する。
【００１９】
請求項７に従属する請求項９の配線基板の研磨方法は、テーブル上に真空チャックを設置し、その真空チャック上に厚さ方向の多数の連通孔を備えた第１ダンパー材を取り付け、かつ第１ダンパー材の上面に貼り合わせた多数の微細孔を有する金属薄板上に配線基板を載置して真空チャッキングする方法である。
このような配線基板の研磨方法は、配線基板をテーブル上に容易に確実に固定することができ、かつ金属薄板の存在により、配線基板に真空チャックの吸引穴が型移りすることを防ぐ。
【００２０】
請求項７に従属する請求項１０の配線基板の研磨方法は、第２ダンパー材に取り付けたフッ素樹脂シートを第２ダンパー材と研磨ベルトの間に介在させる　　方法である。
このような配線基板の研磨方法は、第２ダンパー材と研磨ベルトとの間の摺動、ひいては研磨を円滑化させる。
【００２１】
請求項７に従属する請求項１１の配線基板の研磨方法は、第１ダンパー材および第２ダンパー材としてウレタンゴム、シリコーンゴム、ブタジエン系合成ゴム、および天然ゴムのうちの少なくとも一種からなり、ゴム硬度が４０から２０までの範囲内にあるものを使用する方法である。
このような配線基板の研磨方法は、第１ダンパー材および第２ダンパー材の配線基板側がそれぞれ配線基板の反りに沿って容易に変形されることから、反りを有する配線基板をそのままの状態で厚さ方向に一様に研磨することができる。
【００２２】
請求項７に従属する請求項１２の配線基板の研磨方法は、研磨ベルトとして、基材が織布からなり８００メッシュから３０００メッシュまでのサイズの砥粒が接着して砥粒面としたものを使用する方法である。
このような配線基板の研磨方法は、研磨ベルトが変形容易でありながら強度を有することにより配線基板をその反りに沿って工業的に効率よく、かつ平滑に研磨することができる。
【００２３】
請求項１３の多層配線基板は、テーブル上に固定された配線基板の被研磨面に研磨ベルトの砥粒面を押圧機具によって押圧し、研磨ベルトを移動させることによって研磨された配線基板を積層してなる多層配線基板において、テーブル上に取り付けた第１ダンパー材を介してテーブルに配線基板を固定し、かつ押圧機具に取り付けた第２ダンパー材を介して押圧機具により研磨ベルトを配線基板に押圧した状態で、少なくとも研磨ベルトを移動させて研磨された配線基板が積層されたものである。
このような多層配線基板は、研磨ベルトと共に配線基板を挟持する第１ダンパー材および第２ダンパー材の配線基板側が配線基板の反りに沿って変形されて研磨されることから、反りを有する配線基板が反りを有したまま厚さ方向に一様に研磨されて積層されたものとなる。
【００２４】
請求項１３に従属する請求項１４の多層配線基板は、研磨時にテーブルおよび押圧機具をそれぞれ研磨ベルトとは独立して研磨ベルトの移動方向に平行な方向へ往復動させて研磨された配線基板が積層されたものである。
このような多層配線基板は、効率よく研磨された配線基板が積層されたものとなる。
【００２５】
請求項１３に従属する請求項１５の多層配線基板は、テーブル上に設置された真空チャックに厚さ方向の多数の連通孔を備えた第１ダンパー材を取り付け、かつ第１ダンパー材の上面に貼り合わされた多数の微細孔を有する金属薄板の上に載置して真空チャッキングし研磨された配線基板が積層されたものである。
このような多層配線基板は、真空チャックによって容易かつ確実に固定されて研磨され、かつ金属薄板の存在により真空チャックの吸引穴の型移りのないフラットな配線基板が積層されたものとなる。
【００２６】
請求項１３に従属する請求項１６の多層配線基板は、第２ダンパー材に取り付けたフッ素樹脂シートを第２ダンパー材と研磨ベルトの間に介在させて研磨された配線基板が積層されたものである。
このような多層配線基板は、第２ダンパー材と研磨ベルトとの間の摺動がフッ素樹脂シートの介在によって円滑化されることから、研磨面が平滑に研磨された配線基板が積層されたものとなる。
【００２７】
請求項１３に従属する請求項１７の多層配線基板は、第１ダンパー材および第２ダンパー材としてウレタンゴム、シリコーンゴム、ブタジエン系合成ゴム、および天然ゴムのうちの少なくとも一種からなり、ゴム硬度が４０から２０までの範囲内にあるものを使用して研磨された配線基板が積層されたものである。
このような多層配線基板は、第１ダンパー材および第２ダンパー材の配線基板側がそれぞれ配線基板の反りに沿って容易に変形され、研磨ベルトが配線基板の反りに沿って変形させることから、反りがあるままの状態で厚さ方向に一様に研磨された配線基板が積層されたものとなる。
【００２８】
請求項１３に従属する請求項１８の多層配線基板は、研磨ベルトとして基材が織布からなり、８００メッシュから３０００メッシュまでのサイズの砥粒が接着されたものを使用して研磨された配線基板が積層されたものである。
このような多層配線基板は、変形が容易でありながら強度を有する研磨ベルトにより配線基板の反りに沿い工業的に効率よくかつ平滑に研磨された配線基板が積層されたものとなる。
【００２９】
【発明の実施の形態】
本発明の配線基板の研磨装置において、研磨ベルトは第２ダンパー材と配線基板との間にあり、かつ配線基板は真空チャック上の第１ダンパー材によって支持された状態にある。第２ダンパー材は押圧機具によって押圧されるが、配線基板が反りを有する場合、その押圧によって第２ダンパー材の配線基板側は配線基板の反りに沿って変形され、同様に第１ダンパー材の配線基板側も配線基板の反りに沿って変形されるものであることを要する。
【００３０】
従って、第１ダンパー材および第２ダンパー材には共に、ウレタンゴム、シリコーンゴム、ブタジエン系合成ゴム、および天然ゴムのうちの少なくとも一種からなり、ゴム硬度は４０から２０までの範囲内にあるものが使用される。すなわち、ゴム硬度が４０以上では第１ダンパー材および第２ダンパー材は配線基板の反りに沿う変形が不十分になり、研磨ベルトを配線基板の反りに沿わせないので、反りがある配線基板をそのままの状態で厚さ方向に一様に研磨することが困難になり易い。又、ゴム硬度が２０以下では第１ダンパー材および第２ダンパー材が柔軟過ぎて研磨が円滑に進行しなくなる。
【００３１】
そして、第２ダンパー材の変形に伴って第２ダンパー材と配線基板との間の研磨ベルトも同様に配線基板の反りに沿って変形されることを要する。従って、研磨ベルトの基材には、例えばナイロン糸やポリエステル糸をベースとした厚さ２〜１０ｍｍの織布が使用され、その基材の片面にダイヤモンドやアルミナの砥粒を接着して砥粒面としたものが研磨ベルトとして使用される。平滑な研磨面を得るために、砥粒にはサイズが８００メッシュから３０００メッシュまでのものが使用される。すなわち、砥粒のサイズが８００メッシュ以上では研磨面が荒れ気味となる。また３０００メッシュ以下の小サイズの砥粒は敢えて必要としない。砥粒はそのサイズのまま基材に接着してもよいが、バインダーによって例えば小さい角錐状または円錐状に成型したものを基材の全面に接着したものとすることにより研磨ベルトの寿命を大幅に長時間化することができる。研磨ベルトは配線基板上を３０〜５０ｍ／秒程度の高速で移動される。
【００３２】
また、本発明の配線基板の研磨装置においては、真空チャックの上に設けられる第１ダンパー材を介して配線基板を真空チャッキングすることを要するので、第１ダンパー材にも、真空チャックの表面から配線基板の下面に至る多数の真空吸引穴を設けておくことを要する。そして、第１ダンパー材の吸引穴が配線基板に型移りしないように、第１ダンパー材と配線基板との間には例えば孔径２０〜３０μｍの微細孔を多数に設けた薄い金属板を介在させる。この金属板は第１ダンパー材が配線基板の反りに沿って変形される時には、その変形に伴って金属板も変形されねばならないので、金属の中でも軟らかい銅が厚さ０．２ｍｍ程度の板として好適に使用される。
【００３３】
本発明の配線基板の研磨方法は、テーブル上に固定された配線基板の被研磨面に研磨ベルトの砥粒面を押圧機具によって押圧し、研磨ベルトを移動させる配線基板の研磨方法において、テーブル上に取り付けた第１ダンパー材を介してテーブルに配線基板を固定し、かつ押圧機具に取り付けた第２ダンパー材を介して押圧機具により研磨ベルトを配線基板に押圧した状態で、少なくとも研磨ベルトを移動させる方法である。
【００３４】
すなわち、本発明の研磨方法においては、真空チャッキングの可能な第１ダンパー材の上に載置して固定された配線基板に対し、押圧機具によって第２ダンパー材を介して研磨ベルトを配線基板に押圧し、研磨ベルトを移動させて研磨することが従来の研磨方法と異なるが、それ以外は同様に行われる。すなわち、研磨は配線基板の披研磨面に接して研磨ベルトを移動させることによって行われるが、研磨ベルトの移動とは独立してテーブルおよび押圧機具を研磨ベルトに平行な方向へ往復動させてもよく、そのことによって配線基板の研磨を効率よく行い得る。
【００３５】
そして上記のような研磨装置、研磨方法によって研磨された研磨前にフラットな配線基板は研磨によって厚さ方向に一様に研磨されることは勿論であるが、研磨前に反りを有する配線基板は、反りを有したままの状態で厚さ方向に一様に研磨される。このような研磨後に反りを有する配線基板であっても、これらを積層して多層配線板とする場合には真空下に加熱、加圧することにより平坦化され、厚さの極めて均等な多層配線基板を与える。
【００３６】
【実施例】
次に本発明の配線基板の研磨装置、研磨方法および多層配線基板について、実施例により図面を参照して具体的に説明する。
【００３７】
（実施例）
図１は本発明の実施例による配線基板の研磨装置１０の構成を概略的に示す側面図である。研磨装置１０は図４に示した従来の研磨装置１００と基本的には同様に構成されているが、研磨装置１０が従来の研磨装置１００と大きく異なるところは、配線基板Ｐが研磨ベルト２１と共に、厚さ２ｍｍ前後の下ダンパー材４１と厚さ１０ｍｍ前後の上ダンパー材４２とによって挟持され押圧されるようになっていることにある。すなわち、図１に示すように、研磨装置１０は可動テーブル１１上に設置され、多数の吸引穴を有する真空チャック１３の上に、同じく真空チャッキング用の吸引穴（直径２ｍｍ程度）を設けた下ダンパー材４１が固定され、その下ダンパー材４１の上面には吸引用の多数の微細孔（直径２０〜５０μｍ）を設けた厚さ０．２ｍｍ程度の銅板４４が貼り合わされている。そして、その銅板４４上に厚さ１００〜３００μｍで所定の大きさ（例えば２０〜３０ｍｍ角）のガラス繊維強化エポキシ樹脂系の配線基板Ｐが回路面である被研磨面を上にして載置されて真空チャッキングされる。
【００３８】
そして、配線基板Ｐの被研磨面にエンドレスの研磨ベルト２１がその砥粒面を接するよう架張されている。すなわち、研磨ベルト２１は駆動モータ２２によって回転される主動プーリー２３と従動プーリー２４、およびテンションプーリー２５に巻装されており、一定の張力（例えば１×１０^４〜２×１０^４Ｐａ程度）のもと、図１において時計回りの方向、配線基板Ｐ上では矢印ｘで示す方向へ回転される。そして、研磨ベルト２１を配線基板Ｐに押圧するための上下のｚ方向に可動で（１０ｃｍ×１０ｃｍ）程度の当たり面を有するプッシャー３１が下面に上ダンパー材４２を取り付けて研磨ベルト２１の背面側に配置されており、上ダンパー材４２は研磨ベルト２１との間に四フッ化エチレン樹脂またはその類縁フッ素樹脂からなるフッ素樹脂シート３２を介して当接される。
【００３９】
そして、配線基板Ｐの研磨時には、全長４ｍ程度の研磨ベルト２１が配線基板上を５００〜８００ｒｐｍ程度の回転速度で回転されると共に、配線基板Ｐを固定した可動テーブル１１は駆動モータ１２によって研磨ベルト２１の幅方向であるｙ方向に少なくとも配線基板Ｐのｙ方向の寸法よりは大の距離をしゃくりながら、すなわちｙ方向への微動を伴いながら、往復され、プッシャー３１は研磨ベルト２１の進行方向であるｘ方向に少なくとも配線基板Ｐのｘ方向の寸法よりは大の距離で往復されるようになっている。そして、下ダンパー材４１と上ダンパー材４２にはゴム硬度３０のシリコーンゴムからなるものが使用され、研磨ベルト２１には、砥粒面に粒度が８００メッシュ程度のダイヤモンドの砥粒を小角錐状に成型した砥粒体２１ｇが全面に接着されている。
【００４０】
実施例の研磨装置１０は以上のように構成されるが、次にその作用を説明する。図１を参照して、可動テーブル１１上の真空チャック１３に固定された下ダンパー材４１の表面に貼り合わされている微小孔付きの銅板４４上に、配線基板Ｐ、すなわち、フォトリソグラフィによって回路が形成された回路面に紫外線硬化型アクリル樹脂を厚さ２０〜３０μｍに塗布したものが回路面を上にして載置されて真空チャッキングされる。この時、研磨されるべき配線基板Ｐ、すなわち２０〜３０ｍｍ角で厚さ１００〜３００μｍの配線基板Ｐは真空チャッキングによって凹凸を矯正されて平らになる部分もあるが、大きい反りなど矯正されない部分も残る。
【００４１】
そして、プッシャー３１を下降させ、間にフッ素樹脂シート３２を挟んで上ダンパー材４２を押圧することにより、図２の拡大断面図に示すように、上ダンパー材４２の下面側は研磨ベルト２１を伴い配線基板Ｐの反りに沿って変形され、下ダンパー材４１の上面側も同様に配線基板Ｐの反りに沿って変形される。なお図２において真空チャック１３および下ダンパー材４１の設けられている吸引穴と、銅板４４に設けられている微細孔は図を簡明にするために省略されている。そして、このような状態で、研磨ベルト２１を高速で回転させ矢印ｘで示す方向へ移動させながら、可動テーブル１１をｙ方向にしゃくりながら配線基板Ｐの大きさに応じた距離を往復させると共に、プッシャー３１もｘ方向に配線基板Ｐの大きさに応じて往復させることにより、上ダンパー材４２および研磨ベルト２１と、下ダンパー材４１との間に挟持された状態にある配線板Ｐは配線板Ｐの反りに沿って変形される研磨ベルト２１によって被研磨面すなわち回路面が厚さ方向に一様に研磨される。
【００４２】
図３は上記のようにして研磨された反りを有するが厚さは一様な配線基板と、そのような配線基板を積層して得られる多層配線基板の一例を示す断面図である。すなわち、図３のＡは研磨された反りを有する配線基板５１、５２を模式的に示す断面図であり、厚さ方向に拡大して示されている。図３のＡにおいて、配線基板５１の上側の回路面には、回路パターン５５_１、電極パッド５６_１が形成されており、配線基板５２の上側の回路面には、同じく、回路パターン５５_２、電極パッド５６_２が形成されている。また、図３のＢは、反りを有する配線基板５１、５１、５２の３枚が真空下に加熱、加圧されてフラットに積層された多層配線基板５０を示す。そして、多層配線基板５０は要すれば両面を仕上げ研磨した後、配線基板５１、５１、５２の３枚を導通させるビアホール等が設けられる。
【００４３】
以上、本発明の研磨装置、研磨方法および研磨された配線基板を積層してなる多層配線基板実施例によって説明したが、勿論、本発明はこれに限られることなく、本発明の技術的思想に基づいて種々の変形が可能である。
【００４４】
例えば本実施例においては、配線基板Ｐの被研磨面を上に向けて真空チャッキングし、その被研磨面の上に研磨ベルト２１の砥粒面を接触させるような配置としたが、この上下の配置は逆にしてもよく、また配線基板Ｐの被研磨面および研磨ベルト２１の砥粒面が垂直となるような配置としてもよい。
また本実施例においては、エンドレスの研磨ベルト２１を示したが、巻き出しロールから巻き出され、研磨位置を過ぎた後、巻き取りロールに巻き上げられるような研磨ベルトであってもよい。
また本実施例においては、配線基板Ｐとしてエポキシ樹脂を主体とするものを例示したが、それ以外に配線基板に使用される合成樹脂、例えばポリイミド樹脂、ビスマレイミドトリアジン樹脂等を主体とする配線基板に付いても本発明は同様に適用される。
【００４５】
また本実施例においては、特に記述しなかったが、織布を基材とする研磨ベルトによる研磨の後、不織布を基材として砥粒を接着した研磨ベルトによって仕上げ研磨を施すようにしてもよい。不織布を基材とする研磨ベルトは配線基板Ｐの被研磨面に対する砥粒の当たりが軟らかくなるので仕上げ研磨に好適である。
また本実施例においては、配線基板の一面が回路面であり、その回路面を被研磨面として研磨する場合を説明したが、両面が回路面とされている配線基板に付いても、本発明の研磨装置を適用し、一方の面を研磨した後に裏返しにして他方の面を研磨することができる。
また本実施例においては、研磨された配線基板を積層して多層配線基板とした後に、スルーホールを設ける場合を説明したが、積層する前の配線基板に他の配線基板と接続するためのスタッド等を設けておいてもよい。
【００４６】
【発明の効果】
本発明の配線基板の研磨装置、研磨方法、および多層配線基板は以上に説明したような形態で実施され、次に述べるような効果を奏する。
【００４７】
請求項１の配線基板の研磨装置によれば、テーブルと配線基板との間に第１ダンパー材が介在され、押圧機具と研磨ベルトとの間に第２ダンパー材が介在されているので、第１ダンパー材および第２ダンパー材の配線基板側がそれぞれ配線基板の反りに沿って変形され、反りを有する配線基板をそのままの状態で厚さ方向に一様に研磨することができる。
請求項２の配線基板の研磨装置によれば、テーブルおよび押圧機具がそれぞれ研磨ベルトと独立して研磨ベルトの移動方向に平行な方向へ往復動可能とされているので、配線基板が効率よく研磨される。
【００４８】
請求項３の配線基板の研磨装置によれば、テーブル上に真空チャックが設置されており、その真空チャック上に厚さ方向の多数の連通孔を備えた第１ダンパー材が取り付けられ、第１ダンパー材の上面には多数の微細孔を備えた金属薄板が貼り合わされており、配線基板が金属薄板上に載置され真空チャッキングされるので、配線基板をテーブル上に容易に固定することができ、かつ金属薄板の存在によって真空チャックの吸引穴が配線基板に型移りすることを防ぎ得る。
請求項４の配線基板の研磨装置によれば、第２ダンパー材と研磨ベルトの間に第２ダンパー材に取り付けたフッ素樹脂シートが介在されるので、第２ダンパー材と研磨ベルトとの間の摺動を円滑化させる。
【００４９】
請求項５の配線基板の研磨装置によれば、第１ダンパー材および第２ダンパー材がウレタンゴム、シリコーンゴム、ブタジエン系合成ゴム、および天然ゴムのうちの少なくとも一種からなり、ゴム硬度が４０から２０までの範囲内にあるものが使用されているので、第１ダンパー材および第２ダンパー材の配線基板側が配線基板の反りに沿って容易に変形され、反りを有する配線基板をそのまま厚さ方向に一様に研磨することを可能にする。
請求項６の配線基板の研磨装置によれば、研磨ベルトが、織布を基材とし８００メッシュから３０００メッシュまでのサイズの砥粒を接着して砥粒面とされているので、変形が容易でありながら強度を有する研磨ベルトによって配線基板の反りに沿う研磨が工業的に効率よく行われ、かつ平滑に研磨することを可能ならしめる。
【００５０】
請求項７の配線基板の研磨方法によれば、研磨ベルトと配線基板を挟持する第１ダンパー材および第２ダンパー材の配線基板側がそれぞれ配線基板の反りに沿って変形されて研磨するので、反りを有する配線基板をそのまま厚さ方向に一様に研磨することができる。
請求項８の配線基板の研磨方法によれば、研磨時にテーブルおよび押圧機具をそれぞれ研磨ベルトとは独立して研磨ベルトの移動方向に平行な方向へ往復動させるので、配線基板を効率よく研磨する。
【００５１】
請求項９の配線基板の研磨方法によれば、テーブル上に真空チャックを設置し、その真空チャック上に厚さ方向の多数の連通孔を備えた第１ダンパー材を取り付け、かつ第１ダンパー材の上面に貼り合わせた多数の微細孔を有する金属薄板上に配線基板を載置して真空チャッキングするので、配線基板をテーブル上に容易に確実に固定することができ、かつ金属薄板の存在により、配線基板に真空チャックの吸引穴が型移りして窪みが形成されることを防ぐ。
請求項１０の配線基板の研磨方法によれば、第２ダンパー材に取り付けたフッ素樹脂シートを第２ダンパー材と研磨ベルトの間に介在させるので、第２ダンパー材と研磨ベルトとの間の摺動、ひいては研磨を円滑化させる。
【００５２】
請求項１１の配線基板の研磨方法によれば、第１ダンパー材および第２ダンパー材としてウレタンゴム、シリコーンゴム、ブタジエン系合成ゴム、および天然ゴムのうちの少なくとも一種からなり、ゴム硬度が４０から２０までの範囲内にあるものを使用するので、第１ダンパー材および第２ダンパー材の配線基板側がそれぞれ配線基板の反りに沿って容易に変形され、反りを有する配線基板をそのまま厚さ方向に一様に研磨することができる。
請求項１２の配線基板の研磨方法によれば、研磨ベルトとして基材が織布からなり８００メッシュから３０００メッシュまでのサイズの砥粒を接着して砥粒面としたものを使用するので、研磨ベルトが変形容易でありながら強度を有することにより配線基板をその反りに沿って工業的に効率よく、かつ平滑に研磨することができる。
【００５３】
請求項１３の多層配線基板によれば、研磨ベルトと配線基板とを挟持する第１ダンパー材および第２ダンパー材の配線基板側がそれぞれ配線基板の反りに沿って変形され、配線基板が反りを有する場合には反りを有したまま厚さ方向に一様に研磨された配線基板が積層されているので、厚さ方向に均等に積層されたものとなっている。
請求項１４の多層配線基板によれば、研磨時にテーブルおよび押圧機具をそれぞれ研磨ベルトとは独立して研磨ベルトの移動方向に平行な方向へ往復動させて研磨された配線基板が積層されているので、効率よく研磨された配線基板が積層されたものとなる。
【００５４】
請求項１５の多層配線基板によれば、テーブル上に設置された真空チャックに厚さ方向の多数の連通孔を備えた第１ダンパー材を取り付け、かつ第１ダンパー材の上面に貼り合わされた多数の微細孔を有する金属薄板の上に載置して真空チャッキングし研磨された配線基板が積層されているので、真空チャックによって容易かつ確実に固定されて研磨され、かつ金属薄板の存在により真空チャックの吸引穴の型移りのないフラットな配線基板が積層されたものとなる。
請求項１６の多層配線基板によれば、第２ダンパー材に取り付けたフッ素樹脂シートを第２ダンパー材と研磨ベルトの間に介在させて研磨された配線基板が積層されているので、第２ダンパー材と研磨ベルトとの間の摺動がフッ素樹脂シートの介在によって円滑化され研磨面が平滑に研磨された配線基板が積層されたものとなる。
【００５５】
請求項１７の多層配線基板によれば、第１ダンパー材および第２ダンパー材としてウレタンゴム、シリコーンゴム、ブタジエン系合成ゴム、および天然ゴムのうちの少なくとも一種からなり、ゴム硬度が４０から２０までの範囲内にあるものを使用して研磨された配線基板が積層されているので、第１ダンパー材および第２ダンパー材の配線基板側がそれぞれ配線基板の反りに沿って容易に変形されて、研磨ベルトが配線基板の反りに沿って変形され、反りがあるままの状態で厚さ方向に一様に研磨された配線基板が積層されたものとなる。
請求項１８の多層配線基板によれば、研磨ベルトとして基材が織布からなり、８００メッシュから３０００メッシュまでのサイズの砥粒が接着されて砥粒面としたものを使用して研磨された配線基板が積層されているので、変形が容易でありながら強度を有する研磨ベルトにより配線基板の反りに沿い工業的に効率よくかつ平滑に研磨された配線基板が積層されたものとなる。
【図面の簡単な説明】
【図１】実施例の研磨装置の構成を概略的に示す側面図である。
【図２】反りを有す配線基板が反りを有したまま研磨されている状態を模式的に示す断面図である。
【図３】Ａは研磨された配線基板の断面図、Ｂは研磨された配線基板が積層された多層配線基板の一例の断面図である。
【図４】従来の研磨装置の構成を概略的に示す側面図である。
【図５】フラットな配線基板が可動テーブル上に載置された状態を示す図である。
【図６】反りを有する配線基板が可動テーブル上に載置された状態を示す図である。
【図７】真空チャックの吸引穴が配線基板に型移りした状態を示す断面図である。
【符号の説明】
１０……配線基板の研磨装置、１１……可動テーブル、１２……駆動モータ、１３……真空チャック、２１……研磨ベルト、２２……駆動モータ、２３……主動プーリー、２４……従動プーリー、２５……テンションプーリー、３１……プッシャー、３２……フッ素樹脂シート、４１……下ダンパー材、４２……上ダンパー材、４４……銅板、５０……多層配線基板、５１、５２……　配線基板、Ｐ……配線基板。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for polishing a wiring board, a polishing method, and a multilayer wiring board.More specifically, when the wiring board before polishing has a warp, the thickness is uniformly reduced while having the warp. The present invention relates to a polishing apparatus capable of polishing, a polishing method, and a multilayer wiring board formed by laminating polished wiring boards.
[0002]
[Prior art]
In recent years, with the miniaturization and multifunctionality of electronic devices, there has been an increasing demand for higher density of wiring boards and miniaturization of mounted components. On the other hand, in wiring boards, the circuit width has been reduced. At the same time, on the other hand, a multilayer wiring board has been adopted in which a wiring board having a thickness of, for example, about 200 μm is laminated to reduce the area occupied by the wiring board during mounting.
[0003]
When a multilayer wiring board is obtained by laminating wiring boards, it is technically extremely important that the original wiring board has a uniform thickness. In other words, the circuit surface of the wiring board obtained by applying a photolithography technique to a raw wiring board made of a synthetic resin plate having a copper foil bonded to one side to form a circuit has a circuit portion in which copper is left and a convex portion. Since the non-circuit portion from which copper has been etched and removed is a concave portion, for example, an ultraviolet curable acrylic resin is applied to a thickness of 20 to 30 μm to flatten the non-circuit portion. However, by merely applying this coating, although the unevenness of the circuit surface is reduced, the circuit surface is not flattened and the circuit is not exposed. Therefore, the circuit surface is polished to a thickness of about 10 to 20 μm.
[0004]
As a method of polishing a wiring board, there is a method of polishing with a buff roll and a method of polishing with a sander belt. Of these, the method of polishing with a buff roll generally has a characteristic that when a soft part and a hard part coexist on the object to be polished, the hard part is polished but the soft part is hard to be polished, and a circuit is provided. It is not suitable for uniformly and thinly polishing a wiring board. Therefore, for polishing the circuit surface of the wiring substrate, a method of polishing with a sander belt, which is a polishing belt having abrasive particles adhered to the polishing surface, is employed. In addition, the grinding | polishing by a sander belt system is what was originally used for grinding | polishing wood as shown in Unexamined-Japanese-Patent No. 2001-225253. Japanese Patent Application Laid-Open No. 2001-347444 discloses a case where a sander belt is used for polishing a wafer.
[0005]
(Conventional example)
FIG. 4 is a side view schematically showing the configuration of a conventional polishing apparatus 100 of the polishing belt type. As shown in FIG. 4, the polishing apparatus 100 includes an endless polishing belt 201 on a surface to be polished of a wiring substrate P which is mounted on a vacuum chuck 103 mounted on a movable table 101 and vacuum-chucked. It is stretched so as to touch the grain surface. That is, the polishing belt 201 is wound around a driving pulley 203, a driven pulley 204, and a tension pulley 205 that are rotated by a driving motor 202. The polishing belt 201 is rotated clockwise under a constant tension, and indicated by an arrow x on the wiring board P. It is rotated in the direction shown. A pusher 301 movable in the vertical z direction for pressing the polishing belt 201 against the wiring substrate P is disposed on the back side of the polishing belt 201, and the pusher 301 slides easily on the polishing belt 201 during polishing. As shown in FIG. 2, the polishing belt 201 is brought into contact with the pusher 301 via a fluororesin sheet 302 made of tetrafluoroethylene resin or its related fluororesin.
[0006]
When the wiring substrate P is polished, the polishing belt 201 is moved at a high speed in the x direction on the wiring substrate, and the movable table 101 to which the wiring substrate P is fixed is driven by the drive motor 102 in the width direction of the polishing belt 201. With the fine movement in the direction, the wiring board P is reciprocated in the y direction at least a distance larger than the size of the wiring board P in the y direction, and the pusher 301 is moved at least in the x direction of the polishing belt 201 in the x direction. It is designed to reciprocate at a greater distance than the size in the direction. At the time of this polishing, in order to prevent the copper of the circuit from being oxidized, wet polishing in which water is supplied to the polishing surface to wet the polishing surface is performed.
[0007]
[Problems to be solved by the invention]
In the polishing by the polishing apparatus 100 as described above, when a flat wiring substrate P is polished, the polishing is performed uniformly in the thickness direction as shown in FIG. As shown, when the wiring board P has a warp, it may be said that only the protruding portions are polished and are not uniformly polished in the thickness direction. Originally, the wiring board P has small unevenness, large warpage, or 'undulation' due to the difference in the coefficient of thermal expansion between the copper of the circuit and the synthetic resin that is the main component of the board and the heat history received. Normal. For this reason, the wiring substrate P is corrected at the time of chucking by the vacuum chuck 103, and there are portions that are flattened, but portions that are not corrected remain. Further, the pressing of the pusher 301 to such an extent that the rotation of the polishing belt 201 is not impaired does not eliminate the large warpage or the undulation of the wiring board P. Therefore, the wiring substrate P is polished only at the convex portion of the warp or the undulation, and the uniform polishing in the expected thickness direction is not performed. In the following, the term “warp” is collectively referred to as “warpage”.
[0008]
In addition, as shown in FIG. 7, even if the wiring substrate P is thin and flat, even if the portion of the vacuum chuck 103 located on the suction hole 103 h having a diameter of about 2 mm is vacuum-sucked in the direction indicated by the arrow. There is also a problem that the suction holes 103h are transferred to the wiring substrate P after the depression and polishing are completed, and the depressions Pc remain, so that a flat wiring substrate P cannot be obtained. In FIG. 7, the wiring substrate P indicated by a solid line is located at a position indicated by a dashed line on the vacuum chuck 103 when vacuum chucking is performed.
[0009]
The present invention has been made in view of the above problems, and has as its object to provide a polishing apparatus, a polishing method, and a multilayer wiring board that can uniformly polish in a thickness direction even if the wiring board has a warp. .
[0010]
[Means for Solving the Problems]
The above-mentioned problem is solved by the structure of claim 1, claim 7, or claim 13. The means for solving the problem is as follows.
[0011]
The polishing apparatus for a wiring substrate according to claim 1, wherein the polishing device presses the abrasive grain surface of the polishing belt against a surface to be polished of the wiring substrate fixed on a table by a pressing device, and at least moves the polishing belt. A first damper member is attached to the table between the table and the wiring board, and a second damper member is attached to the pressing device between the pressing device and the polishing belt.
In such a polishing apparatus for a wiring substrate, the wiring substrate having the first damper material and the second damper material sandwiching the wiring substrate and the polishing belt is deformed along the warpage of the wiring substrate, so that the wiring having the warpage is formed. The substrate can be uniformly polished in the thickness direction while keeping the state as it is.
[0012]
According to a second aspect of the present invention, in the polishing apparatus for a wiring substrate, the table and the pressing device can reciprocate independently of the polishing belt in a direction parallel to the moving direction of the polishing belt.
Such a polishing apparatus for a wiring board efficiently polishes the wiring board.
[0013]
According to a third aspect of the present invention, there is provided the polishing apparatus for a wiring board according to the third aspect, wherein a vacuum chuck is provided on the table, and a first damper member having a plurality of communication holes in a thickness direction is mounted on the vacuum chuck. A thin metal plate having a large number of fine holes is bonded to the upper surface of the first damper material, and the wiring board is placed on the thin metal plate and vacuum chucked.
Such a polishing apparatus for a wiring substrate can easily fix the wiring substrate on the table, and prevents the suction hole of the vacuum chuck from being transferred to the wiring substrate due to the presence of the thin metal plate.
[0014]
According to a fourth aspect of the present invention, there is provided a wiring board polishing apparatus according to the first aspect, wherein the fluororesin sheet attached to the second damper material is interposed between the second damper material and the polishing belt.
Such a polishing apparatus for a wiring board smoothens the sliding between the second damper material and the polishing belt.
[0015]
The polishing apparatus for a wiring board according to claim 5 according to claim 1, wherein the first damper material and the second damper material are made of at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber. Those having a hardness in the range of 40 to 20 are used.
In such a wiring board polishing apparatus, the wiring board side of the first damper material and the second damper material is easily deformed along the warpage of the wiring board, and the warped wiring board is uniformly polished in the thickness direction as it is. To be able to
[0016]
A polishing apparatus for a wiring substrate according to claim 6 which is dependent on claim 1, wherein the polishing belt is made of a woven fabric as a base material and adheres abrasive grains of a size from 800 mesh to 3000 mesh to form an abrasive grain surface. is there.
Such a polishing apparatus for a wiring substrate enables the polishing along the warpage of the wiring substrate to be performed industrially efficiently by a polishing belt having strength while being easily deformed, and enables smooth polishing.
[0017]
8. The method of polishing a wiring board according to claim 7, wherein the abrasive grain surface of the polishing belt is pressed against a surface to be polished of the wiring board fixed on the table by a pressing device, and the polishing belt is moved. The wiring board is fixed to the table via the first damper material mounted thereon, and at least the polishing belt is pressed against the wiring board by the pressing device via the second damper material mounted on the pressing device. It is a method of moving.
Such a method of polishing a wiring board is characterized in that the wiring board side of the first damper material and the second damper material holding the wiring board together with the polishing belt is deformed along the warpage of the wiring board. Can be uniformly polished in the thickness direction in the same state.
[0018]
The method for polishing a wiring substrate according to claim 8 is a method of reciprocating a table and a pressing device independently of the polishing belt in a direction parallel to the moving direction of the polishing belt during polishing.
Such a method for polishing a wiring substrate efficiently polishes the wiring substrate.
[0019]
According to a ninth aspect of the present invention, there is provided the wiring substrate polishing method according to the ninth aspect, wherein a vacuum chuck is provided on a table, and a first damper member having a plurality of communication holes in a thickness direction is mounted on the vacuum chuck; This is a method in which a wiring substrate is placed on a metal thin plate having a large number of fine holes bonded to the upper surface of a first damper material and vacuum chucking is performed.
Such a method of polishing a wiring substrate can easily and reliably fix the wiring substrate on the table, and prevents the suction hole of the vacuum chuck from being transferred to the wiring substrate due to the presence of the thin metal plate.
[0020]
According to a tenth aspect of the present invention, there is provided a wiring board polishing method according to the tenth aspect, wherein a fluororesin sheet attached to the second damper material is interposed between the second damper material and the polishing belt.
Such a method of polishing a wiring board facilitates the sliding between the second damper material and the polishing belt, and thus the polishing.
[0021]
The method for polishing a wiring board according to claim 11 is dependent on claim 7, wherein the first damper material and the second damper material comprise at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber. In this method, a material having a hardness in the range of 40 to 20 is used.
In such a method of polishing a wiring board, the wiring board side of the first damper material and the second damper material is easily deformed along the warpage of the wiring board, and therefore, the thickness of the warped wiring board is maintained as it is. Polishing can be performed uniformly in the vertical direction.
[0022]
A polishing method for a wiring board according to claim 12 which is dependent on claim 7, wherein the polishing belt has a base material made of a woven fabric, and abrasive grains having a size from 800 mesh to 3000 mesh are bonded to form an abrasive surface. The method to use.
According to such a method for polishing a wiring substrate, the wiring belt can be industrially efficiently and smoothly polished along the warp because the polishing belt has strength while being easily deformed.
[0023]
The multilayer wiring board according to claim 13 is configured such that the abrasive surface of the polishing belt is pressed against the surface to be polished of the wiring board fixed on the table by a pressing device, and the wiring board polished by moving the polishing belt is laminated. In the multi-layer wiring board, the wiring board is fixed to the table via the first damper material mounted on the table, and the polishing belt is pressed against the wiring board by the pressing tool via the second damper material mounted on the pressing tool. In this state, wiring boards polished by moving at least the polishing belt are stacked.
In such a multilayer wiring board, since the wiring board side of the first damper material and the second damper material sandwiching the wiring board together with the polishing belt is deformed along the warpage of the wiring board and polished, the wiring board having a warp is formed. Are polished uniformly in the thickness direction while being warped, and are laminated.
[0024]
The multilayer wiring board according to claim 13 is dependent on claim 13, wherein the polishing board is reciprocated in a direction parallel to a moving direction of the polishing belt independently of the polishing belt during polishing. They are stacked.
Such a multilayer wiring board is obtained by stacking wiring boards polished efficiently.
[0025]
According to a thirteenth aspect of the present invention, in the multilayer wiring board according to the thirteenth aspect, a first damper having a plurality of communication holes in a thickness direction is attached to a vacuum chuck installed on a table, and the upper surface of the first damper is mounted on the vacuum chuck. A circuit board is mounted on a metal thin plate having a large number of fine holes and vacuum-chucked and polished to be laminated.
Such a multi-layer wiring board is formed by laminating a flat wiring board which is fixed and polished easily and reliably by a vacuum chuck and which has no transfer of suction holes of the vacuum chuck due to the presence of a thin metal plate.
[0026]
A multilayer wiring board according to claim 16 which is dependent on claim 13, wherein the polished wiring boards are laminated by interposing a fluororesin sheet attached to the second damper material between the second damper material and the polishing belt. is there.
Such a multilayer wiring board is formed by laminating wiring boards whose polished surfaces are polished smoothly because the sliding between the second damper material and the polishing belt is facilitated by the interposition of the fluororesin sheet. It becomes.
[0027]
A multilayer wiring board according to claim 17 which is dependent on claim 13, wherein the first damper material and the second damper material are made of at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber, and have a rubber hardness. The wiring board polished using the one in the range of 40 to 20 is laminated.
In such a multilayer wiring board, the wiring board side of the first damper material and the second damper material is easily deformed along the warpage of the wiring board, and the polishing belt is deformed along the warpage of the wiring board. As a result, the wiring substrates polished uniformly in the thickness direction are laminated.
[0028]
A multilayer wiring board according to claim 18 which is dependent on claim 13, wherein the base material is a woven cloth as a polishing belt, and the wiring is polished using an abrasive having a size of 800 mesh to 3000 mesh bonded thereto. The substrates are stacked.
Such a multilayer wiring board is obtained by laminating wiring boards polished industrially efficiently and smoothly along the warpage of the wiring board by a polishing belt which is easy to deform and has strength.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
In the polishing apparatus for a wiring substrate according to the present invention, the polishing belt is located between the second damper material and the wiring substrate, and the wiring substrate is supported by the first damper material on the vacuum chuck. The second damper material is pressed by the pressing device. When the wiring board has a warp, the wiring board side of the second damper material is deformed along the warp of the wiring board by the pressing, and similarly, the first damper material is deformed. The wiring board must also be deformed along the warpage of the wiring board.
[0030]
Therefore, both the first damper material and the second damper material are made of at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber, and have a rubber hardness in the range of 40 to 20. Is used. That is, if the rubber hardness is 40 or more, the first damper material and the second damper material are insufficiently deformed along the warpage of the wiring board, and the polishing belt does not follow the warpage of the wiring board. It tends to be difficult to uniformly polish in the thickness direction as it is. If the rubber hardness is 20 or less, the first damper material and the second damper material are too soft, so that the polishing does not proceed smoothly.
[0031]
In addition, the polishing belt between the second damper material and the wiring board needs to be similarly deformed along the warpage of the wiring board with the deformation of the second damper material. Therefore, as the base material of the polishing belt, for example, a woven fabric having a thickness of 2 to 10 mm based on nylon yarn or polyester yarn is used, and diamond or alumina abrasive particles are adhered to one surface of the base material. The surface is used as a polishing belt. In order to obtain a smooth polished surface, abrasive grains having a size of 800 mesh to 3000 mesh are used. That is, when the size of the abrasive grains is 800 mesh or more, the polished surface tends to be rough. Also, small-sized abrasive grains of 3000 mesh or less are not required. Although the abrasive grains may be adhered to the base material as it is, the life of the polishing belt can be greatly increased by using a binder formed, for example, in a small pyramid or cone shape over the entire surface of the base material. It can be long. The polishing belt is moved on the wiring substrate at a high speed of about 30 to 50 m / sec.
[0032]
Further, in the wiring substrate polishing apparatus of the present invention, it is necessary to vacuum chuck the wiring substrate via the first damper material provided on the vacuum chuck, so that the first damper material also has the surface of the vacuum chuck. It is necessary to provide a large number of vacuum suction holes from the bottom to the lower surface of the wiring board. Then, a thin metal plate provided with a large number of fine holes having a hole diameter of, for example, 20 to 30 μm is interposed between the first damper material and the wiring board so that the suction holes of the first damper material do not transfer to the wiring board. . When the first damper material is deformed along the warp of the wiring board, the metal plate must also be deformed with the deformation, so the softest copper among metals is a plate having a thickness of about 0.2 mm. It is preferably used.
[0033]
The polishing method of a wiring substrate of the present invention is a method of polishing a wiring substrate, in which the abrasive surface of a polishing belt is pressed by a pressing device onto a surface to be polished of the wiring substrate fixed on a table, and the polishing belt is moved. The wiring board is fixed to the table via the first damper material attached to the device, and at least the polishing belt is moved while the polishing belt is pressed against the wiring substrate by the pressing device via the second damper material attached to the pressing device. It is a method to make it.
[0034]
That is, in the polishing method of the present invention, the polishing belt is attached to the wiring substrate mounted and fixed on the first damper material capable of vacuum chucking via the second damper material by a pressing tool. , And the polishing is moved by moving the polishing belt, which is different from the conventional polishing method. That is, polishing is performed by moving the polishing belt in contact with the polishing surface of the wiring substrate, but it is also possible to reciprocate the table and the pressing device in a direction parallel to the polishing belt independently of the movement of the polishing belt. In this case, the wiring substrate can be efficiently polished.
[0035]
And the polishing apparatus as described above, the flat wiring substrate before polishing polished by the polishing method is, of course, uniformly polished in the thickness direction by polishing, but the wiring substrate having a warp before polishing is, , And is uniformly polished in the thickness direction while having warpage. Even in the case of a wiring board having such a warp after polishing, when these are laminated to form a multilayer wiring board, the multilayer wiring board is flattened by heating and pressing under vacuum, and has an extremely uniform thickness. give.
[0036]
【Example】
Next, a polishing apparatus, a polishing method, and a multilayer wiring board for a wiring board according to the present invention will be specifically described with reference to the drawings by way of examples.
[0037]
(Example)
FIG. 1 is a side view schematically showing a configuration of a polishing apparatus 10 for a wiring substrate according to an embodiment of the present invention. The polishing apparatus 10 has basically the same configuration as the conventional polishing apparatus 100 shown in FIG. 4. However, the difference between the polishing apparatus 10 and the conventional polishing apparatus 100 is that the wiring substrate P and the polishing belt 21 are different from each other. And the lower damper member 41 having a thickness of about 2 mm and the upper damper member 42 having a thickness of about 10 mm. That is, as shown in FIG. 1, the polishing apparatus 10 is installed on a movable table 11, and a suction hole (about 2 mm in diameter) for vacuum chucking is provided on a vacuum chuck 13 having many suction holes. A lower damper member 41 is fixed, and a copper plate 44 having a thickness of about 0.2 mm provided with a plurality of fine holes (diameter: 20 to 50 μm) for suction is attached to the upper surface of the lower damper member 41. A glass fiber reinforced epoxy resin-based wiring board P having a thickness of 100 to 300 μm and a predetermined size (for example, 20 to 30 mm square) is mounted on the copper plate 44 with the surface to be polished, which is the circuit surface, facing upward. And vacuum chucked.
[0038]
Then, an endless polishing belt 21 is stretched on the surface to be polished of the wiring substrate P such that the abrasive grain surface thereof is in contact with the surface. That is, the polishing belt 21 is wound around a driving pulley 23, a driven pulley 24, and a tension pulley 25 rotated by a driving motor 22, and has a constant tension (for example, 1 × 10 ⁴ ~ 2 × 10 ⁴ 1), and in the clockwise direction in FIG. 1 and in the direction indicated by the arrow x on the wiring board P. Then, a pusher 31 having a contact surface of about (10 cm × 10 cm) movable in the vertical z direction for pressing the polishing belt 21 against the wiring board P has an upper damper material 42 attached to the lower surface, and the rear side of the polishing belt 21 The upper damper member 42 is in contact with the polishing belt 21 via a fluororesin sheet 32 made of tetrafluoroethylene resin or its related fluororesin.
[0039]
When the wiring board P is polished, the polishing belt 21 having a total length of about 4 m is rotated on the wiring board at a rotation speed of about 500 to 800 rpm, and the movable table 11 to which the wiring board P is fixed is The wiring board P is reciprocated in the y-direction, which is the width direction of the wiring board 21, at least with a distance greater than the dimension of the wiring board P in the y-direction, that is, with slight movement in the y-direction. The wiring board P is reciprocated at least in a certain x direction at a distance larger than the dimension of the wiring board P in the x direction. The lower damper member 41 and the upper damper member 42 are made of silicone rubber having a rubber hardness of 30, and the polishing belt 21 is formed by applying diamond abrasive grains having a grain size of about 800 mesh on the abrasive grain surface in a small pyramid shape. The abrasive grains 21g formed in the same manner are adhered to the entire surface.
[0040]
The polishing apparatus 10 according to the embodiment is configured as described above, and its operation will be described next. Referring to FIG. 1, a circuit is formed on a wiring board P, that is, a circuit by photolithography, on a copper plate 44 having micro holes adhered to a surface of a lower damper material 41 fixed to the vacuum chuck 13 on the movable table 11. A UV-curable acrylic resin applied to the formed circuit surface to a thickness of 20 to 30 μm is placed with the circuit surface up and vacuum chucked. At this time, the wiring substrate P to be polished, that is, the wiring substrate P having a thickness of 20 to 30 mm square and a thickness of 100 to 300 μm has a portion that is flattened by correcting irregularities by vacuum chucking, but a portion that is not corrected such as a large warp. Also remains.
[0041]
Then, by lowering the pusher 31 and pressing the upper damper member 42 with the fluororesin sheet 32 interposed therebetween, as shown in the enlarged sectional view of FIG. Accordingly, the lower surface of the lower damper member 41 is similarly deformed along the warpage of the wiring board P. In FIG. 2, the suction holes provided in the vacuum chuck 13 and the lower damper material 41 and the fine holes provided in the copper plate 44 are omitted for simplification of the drawing. Then, in such a state, while the polishing belt 21 is rotated at a high speed and moved in the direction indicated by the arrow x, the movable table 11 is reciprocated a distance corresponding to the size of the wiring board P while sucking the movable table 11 in the y direction. The pusher 31 is also reciprocated in the x direction in accordance with the size of the wiring board P, so that the wiring board P sandwiched between the upper damper material 42 and the polishing belt 21 and the lower damper material 41 becomes a wiring board. The surface to be polished, that is, the circuit surface, is uniformly polished in the thickness direction by the polishing belt 21 deformed along the warp of P.
[0042]
FIG. 3 is a cross-sectional view showing an example of a wiring substrate having warpage but uniform thickness polished as described above and a multilayer wiring substrate obtained by laminating such wiring substrates. That is, FIG. 3A is a cross-sectional view schematically showing the polished wiring substrates 51 and 52 having warpage, and is shown enlarged in the thickness direction. In FIG. 3A, a circuit pattern 55 is provided on the upper circuit surface of the wiring board 51. ₁ , Electrode pad 56 ₁ Are formed on the circuit surface on the upper side of the wiring board 52. ₂ , Electrode pad 56 ₂ Is formed. FIG. 3B shows a multilayer wiring substrate 50 in which three warped wiring substrates 51, 51, and 52 are heated and pressed under vacuum and flatly laminated. If necessary, the multilayer wiring board 50 is provided with via holes and the like for conducting three of the wiring boards 51, 51 and 52 after finishing and polishing both sides.
[0043]
As described above, the polishing apparatus, the polishing method, and the multilayer wiring board in which the polished wiring boards of the present invention are laminated have been described. However, needless to say, the present invention is not limited to this, and the technical idea of the present invention is not limited thereto. Various modifications are possible based on this.
[0044]
For example, in the present embodiment, vacuum chucking is performed with the surface to be polished of the wiring substrate P facing upward, and the abrasive grains of the polishing belt 21 are brought into contact with the surface to be polished. May be reversed, or the arrangement may be such that the surface to be polished of the wiring substrate P and the abrasive grain surface of the polishing belt 21 are perpendicular to each other.
Further, in this embodiment, the endless polishing belt 21 is shown, but a polishing belt that is unwound from an unwinding roll, and can be wound up by a take-up roll after passing a polishing position may be used.
In this embodiment, the wiring board P is mainly composed of an epoxy resin. However, other than that, a wiring board mainly composed of a synthetic resin used for the wiring board, for example, a polyimide resin, a bismaleimide triazine resin, or the like. The present invention is similarly applied to
[0045]
Although not particularly described in the present embodiment, after polishing with a polishing belt using a woven fabric as a base material, finish polishing may be performed using a polishing belt to which abrasive grains are bonded using a nonwoven fabric as a base material. . The polishing belt using a nonwoven fabric as a base material is suitable for finish polishing because the contact of the abrasive grains to the surface to be polished of the wiring substrate P becomes soft.
Further, in this embodiment, the case where one surface of the wiring board is a circuit surface and the circuit surface is polished as a surface to be polished has been described. , One side can be polished and then turned over, and the other side can be polished.
Further, in this embodiment, the case where through holes are provided after the polished wiring boards are laminated to form a multilayer wiring board has been described, but the stud for connecting the wiring board before lamination to another wiring board is described. May be provided.
[0046]
【The invention's effect】
The polishing apparatus, the polishing method, and the multilayer wiring board for a wiring board according to the present invention are embodied in the forms described above, and have the following effects.
[0047]
According to the polishing apparatus of the first aspect, the first damper material is interposed between the table and the wiring substrate, and the second damper material is interposed between the pressing device and the polishing belt. The wiring board side of the first damper material and the second damper material are respectively deformed along the warpage of the wiring board, and the warped wiring board can be uniformly polished in the thickness direction as it is.
According to the polishing apparatus of the second aspect, the table and the pressing device can reciprocate independently of the polishing belt in a direction parallel to the moving direction of the polishing belt. Is done.
[0048]
According to the polishing apparatus for a wiring substrate of the third aspect, the vacuum chuck is provided on the table, and the first damper member having a plurality of communication holes in the thickness direction is mounted on the vacuum chuck. A metal sheet with many fine holes is attached to the upper surface of the damper material, and the wiring board is placed on the metal sheet and vacuum chucked, so that the wiring board can be easily fixed on the table It is possible to prevent the suction hole of the vacuum chuck from being transferred to the wiring substrate due to the presence of the metal sheet.
According to the polishing apparatus of the fourth aspect, since the fluororesin sheet attached to the second damper material is interposed between the second damper material and the polishing belt, the distance between the second damper material and the polishing belt is increased. Smooth sliding.
[0049]
According to the polishing apparatus for a wiring board of the fifth aspect, the first damper material and the second damper material are made of at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber, and have a rubber hardness of from 40. Since the ones within the range of up to 20 are used, the wiring board side of the first damper material and the second damper material is easily deformed along the warpage of the wiring board, and the warped wiring board is directly used in the thickness direction. Enables uniform polishing.
According to the polishing apparatus for a wiring substrate according to the sixth aspect, since the polishing belt is made of a woven fabric as a base material and adheres abrasive grains of a size from 800 mesh to 3000 mesh to form an abrasive grain surface, deformation is easy. However, the polishing along the warpage of the wiring substrate can be industrially efficiently performed by the polishing belt having strength, and the polishing can be performed smoothly.
[0050]
According to the method of polishing a wiring board of the seventh aspect, since the wiring board side of the first damper material and the second damper material sandwiching the polishing belt and the wiring board is deformed and polished along the warpage of the wiring board, the warpage is caused. Can be uniformly polished in the thickness direction as it is.
According to the polishing method of the wiring substrate of the present invention, the table and the pressing device are reciprocated independently of the polishing belt in the direction parallel to the moving direction of the polishing belt during polishing, so that the wiring substrate is efficiently polished. .
[0051]
According to the method for polishing a wiring substrate of claim 9, a vacuum chuck is provided on a table, a first damper material having a plurality of communication holes in a thickness direction is mounted on the vacuum chuck, and the first damper material is provided. Since the wiring board is placed on a metal thin plate having a large number of micro holes bonded to the upper surface of the substrate and vacuum chucked, the wiring substrate can be easily and reliably fixed on the table, and the presence of the metal thin plate Accordingly, it is possible to prevent the suction hole of the vacuum chuck from being transferred from the mold to the wiring substrate, thereby forming a depression.
According to the method for polishing a wiring substrate of claim 10, since the fluororesin sheet attached to the second damper material is interposed between the second damper material and the polishing belt, the sliding between the second damper material and the polishing belt is performed. Movement and, consequently, polishing.
[0052]
According to the method for polishing a wiring board of claim 11, the first damper material and the second damper material are made of at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber, and have a rubber hardness of 40 or more. Since the ones within the range of up to 20 are used, the wiring board side of the first damper material and the second damper material is easily deformed along the warp of the wiring board, respectively, and the warped wiring board is directly moved in the thickness direction. It can be polished uniformly.
According to the polishing method of the twelfth aspect of the present invention, since the base material is made of a woven fabric and the abrasive grains having a size of 800 mesh to 3000 mesh are bonded to form a polishing belt, the polishing belt is used. Since the belt is easily deformed and has strength, the wiring board can be polished industrially efficiently and smoothly along the warpage.
[0053]
According to the multilayer wiring board of the thirteenth aspect, the wiring board side of the first damper material and the second damper material sandwiching the polishing belt and the wiring board is respectively deformed along the warpage of the wiring board, and the wiring board is warped. In this case, since the wiring substrates polished uniformly in the thickness direction while having warpage are stacked, the wiring substrates are stacked evenly in the thickness direction.
According to the multi-layer wiring board of the present invention, the wiring board polished by reciprocating the table and the pressing device in the direction parallel to the moving direction of the polishing belt independently of the polishing belt at the time of polishing is laminated. Therefore, the polished wiring boards are laminated efficiently.
[0054]
According to the multilayer wiring board of the present invention, the first damper provided with the plurality of communication holes in the thickness direction is attached to the vacuum chuck provided on the table, and the first damper is attached to the upper surface of the first damper. Since the wiring substrate is placed on a metal sheet having micro holes and vacuum-chucked and polished, it is easily and reliably fixed and polished by a vacuum chuck, and the presence of the metal sheet causes a vacuum. A flat wiring substrate having no suction holes in the chuck is transferred.
According to the multilayer wiring board of the sixteenth aspect, since the polished wiring boards are laminated with the fluororesin sheet attached to the second damper material interposed between the second damper material and the polishing belt, the second damper is formed. The sliding between the material and the polishing belt is smoothed by the interposition of the fluororesin sheet, and the wiring substrate having the polished surface polished smoothly is laminated.
[0055]
According to the multilayer wiring board of claim 17, the first damper material and the second damper material are made of at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber, and have a rubber hardness of 40 to 20. Since the wiring boards polished using the ones within the range are laminated, the wiring board side of the first damper material and the second damper material is easily deformed along the warpage of the wiring board, and the polishing is performed. The belt is deformed along the warpage of the wiring board, and the wiring boards polished uniformly in the thickness direction while the warping remains are laminated.
According to the eighteenth aspect of the present invention, the polishing belt is polished by using a substrate made of a woven cloth, and having abrasive grains of 800 mesh to 3000 mesh bonded to form an abrasive surface. Since the wiring boards are stacked, the wiring boards are industrially efficiently and smoothly polished along the warpage of the wiring boards by the polishing belt which is easy to deform and has strength.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing a configuration of a polishing apparatus according to an embodiment.
FIG. 2 is a cross-sectional view schematically showing a state in which a warped wiring board is polished while having warpage.
FIG. 3A is a cross-sectional view of a polished wiring board, and FIG. 3B is a cross-sectional view of an example of a multilayer wiring board in which polished wiring boards are stacked.
FIG. 4 is a side view schematically showing a configuration of a conventional polishing apparatus.
FIG. 5 is a view showing a state where a flat wiring board is placed on a movable table.
FIG. 6 is a diagram showing a state in which a warped wiring board is placed on a movable table.
FIG. 7 is a cross-sectional view showing a state in which a suction hole of a vacuum chuck has been transferred to a wiring board.
[Explanation of symbols]
Reference Signs List 10: Polishing device for wiring substrate, 11: Movable table, 12: Drive motor, 13: Vacuum chuck, 21: Polishing belt, 22: Drive motor, 23: Pulley driven, 24: Pulley driven , 25 tension pulley, 31 pusher, 32 fluororesin sheet, 41 lower damper material, 42 upper damper material, 44 copper plate, 50 multilayer wiring board, 51, 52 Wiring board, P ... Wiring board.

Claims

In the polishing apparatus for a wiring substrate, which presses the abrasive surface of the polishing belt against the surface to be polished of the wiring substrate fixed on the table by a pressing device, and moves at least the polishing belt,
A first damper member is attached to the table between the table and the wiring board, and a second damper member is attached to the pressing device between the pressing device and the polishing belt. A polishing apparatus for a wiring substrate, comprising:

The apparatus according to claim 1, wherein the table and the pressing device are reciprocally movable independently of the polishing belt in a direction parallel to a moving direction of the polishing belt. .

A vacuum chuck is installed on the table, a first damper member having a plurality of communication holes in a thickness direction is mounted on the vacuum chuck, and a plurality of fine holes are formed on an upper surface of the first damper member. 2. The apparatus for polishing a wiring board according to claim 1, wherein the metal sheet provided is adhered, and the wiring substrate is placed on the metal sheet and vacuum chucked. 3.

2. The apparatus according to claim 1, wherein a fluororesin sheet attached to the second damper material is interposed between the second damper material and a polishing belt.

The first damper material and the second damper material are made of at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber, and have a rubber hardness in the range of 40 to 20. The polishing apparatus for a wiring substrate according to claim 1, wherein

2. The polishing apparatus for a wiring board according to claim 1, wherein the polishing belt is made of a woven fabric as a base material and adheres abrasive grains having a size from 800 mesh to 3000 mesh to form the abrasive grain surface. .

In the method of polishing the wiring substrate, wherein the abrasive surface of the polishing belt is pressed against a surface to be polished of the wiring substrate fixed on a table by a pressing device, and the polishing belt is moved.
The wiring board was fixed to the table via a first damper material mounted on the table, and the polishing belt was pressed against the wiring board by the pressing tool via a second damper material mounted on a pressing tool. A method for polishing a wiring substrate, wherein at least the polishing belt is moved in a state.

8. The method according to claim 7, wherein, during polishing, the table and the pressing device are reciprocated independently of the polishing belt in a direction parallel to a moving direction of the polishing belt.

A vacuum chuck is set on the table, the first damper member having a plurality of communication holes in the thickness direction is mounted on the vacuum chuck, and a plurality of fine holes are attached to an upper surface of the first damper member. The method according to claim 7, wherein the wiring substrate is placed on a thin metal plate having a vacuum chuck.

The method according to claim 7, wherein a fluororesin sheet attached to the second damper material is interposed between the second damper material and the polishing belt.

The first damper material and the second damper material are made of at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber, and have a rubber hardness in a range of 40 to 20. The method for polishing a wiring board according to claim 7, wherein:

8. The wiring board according to claim 7, wherein the polishing belt uses a base material made of a woven fabric, and adheres abrasive grains having a size from 800 mesh to 3000 mesh to form the abrasive grain surface. Polishing method.

A multi-layer wiring board formed by stacking wiring boards polished by pressing the abrasive surface of a polishing belt on a surface to be polished of a wiring board fixed on a table by a pressing device and moving the polishing belt,
A state in which the wiring substrate is fixed to the table via a first damper material attached to the table, and the polishing belt is pressed against the wiring substrate by the pressing device via a second damper material attached to the pressing device. Then, at least the wiring substrate polished by moving the polishing belt is laminated.
A multilayer wiring board characterized by the above-mentioned.

Wherein the wiring substrate is polished by reciprocating the table and the pressing device in a direction parallel to a moving direction of the polishing belt independently of the polishing belt during polishing. Item 14. The multilayer wiring board according to item 13.

The wiring board has the first damper member provided with a plurality of communication holes in a thickness direction attached to a vacuum chuck provided on the table, and a plurality of fine holes bonded to an upper surface of the first damper member. 14. The multilayer wiring board according to claim 13, wherein the wiring board is mounted on a thin metal plate having a vacuum chuck and polished.

14. The multilayer according to claim 13, wherein the wiring substrate is polished with a fluororesin sheet attached to the second damper material interposed between the second damper material and the polishing belt. Wiring board.

The wiring board is made of at least one of urethane rubber, silicone rubber, butadiene-based synthetic rubber, and natural rubber as the first damper material and the second damper material, and has a rubber hardness within a range of 40 to 20. 14. The multilayer wiring board according to claim 13, which is polished using a certain material.

The wiring substrate is polished by using a substrate made of a woven fabric as the polishing belt and bonding the abrasive grains having a size of 800 mesh to 3000 mesh to form the abrasive grain surface. The multilayer wiring board according to claim 13, wherein: