200917924 九、發明說明 【發明所屬之技術領域】 本發明是關於增建型多層印刷配線板之製 其關於層間連接部含有台階通孔構造之多層撓 板之製造方法。 【先前技術】 近年來，越來越促進電子機器之小型化及 以該一環而言，以行動電路等之小型電子機器 層撓性印刷配線板廣泛普及（專利文獻1 [P 3， 。該爲經連接器等連接安裝各種電子零件之多 板或硬質印刷配線板之間的個體之撓性印刷配 使可撓性排線一體化之可撓性排線部者。 尤其’行動電話以小型化、高機能化爲目 被安裝於多層撓性印刷配線板之零件也置換成 尺寸封裝），高機能並且高密度予以封裝，有 板尺寸，附加高機能之傾向。 然後’也提案不用增加工程，組合可高密 之段狀的通孔，所謂的台階通孔（參照專利文 1 圖])。 該是以可一起執行多層構造之層間連接之 往內層前進，考慮位置偏差等縮小雷射加工用 即所謂的正形光罩（conformal mask)，藉由 得層間連接。 造方法，尤 性印刷配線 高機能化。 爲中心，多 第1圖]) 層印刷配線 線板或持有 標，隨此有 CSP (晶片 不用增大基 度層間連接 獻2[P3 ，第 手法，隨著 之金屬光罩 電鍍等，取 -4- 200917924 但是，於形成該台階通孔上，則有幾個問題 般，考慮位置偏差必須將外層層之正形光罩形成 由於疊層等之位置精度問題，故也不一定成爲高 間連接。 第2圖爲持有以往之層間連接不含有台階通 纜線部之多層印刷配線板之剖面圖。如該第2圖 使用事先製作之雷射加工時之正形光罩201及形 之兩面核心基板1 1 〇之正形光罩202而執行雷射 由核心基板1 1 〇、增建基板1 2 0及黏接材1 3 0所 層電路基才，之後施予電鍍形成通孔之導通用？L 202A。 〔專利文獻1〕日本專利第34270 1 1號公報 〔專利文獻2 Ί日本專利第2502373號公報 〔專利文獻3〕日本特開200 1 - 1 77248號公韩 【發明內容】 〔發明所欲解決之課題〕 此時，如第2圖所示般，由於在疊層時引起 ，故正形光罩2〇1和正形光罩202中心無法對齊 大產生大約1 〇 〇 μηι左右之位置偏差，故難以對形 用孔202之下側之孔202Α執行安定之雷射加工。 並且，包含專利文獻3所示之技術出現有各 期待低價且安定製造具有可高密度安裝之纜線部 刷配線板之方法。 。如上述 較大，又 密度之層 孔構造之 所示般， 成於內層 加工，藉 構成之® t 201A ' 位置偏差 。由於最 成在導通 種提案， 的多層印 -5- 200917924 本發明係考慮上述點而所創作出，其目的爲提供可低 價且安定製造多層印刷配線板之方該多層印刷配線板係被 配置在每製造層間連接部包含台階通孔構造之多層印刷配 線板之時’台階通孔之上穴及下穴之各中心大略相等之位 置上。 〔用以解決課題之手段〕 爲了達成上述目的，本發明係一種多層印刷配線板之 製造方法’在由樹脂薄膜所構成之絕緣基材上形成具有至 少1層之導電層的內層核心基板，經黏著材將藉由至少在 一面具有導電層之疊層板所構成之外層增建層疊層於上述 內層核心基板而形成疊層電路基材，並在上述疊層電路基 材形成含有直徑如外層側般大之台階通孔的層間連接體， 形成連接上述外層增建層及上述內層核心基板之3層以上 之配線層之層間的台階通孔，其特徵爲：在上述內層核心 基板之上述台階通孔之形成位置，設置厚度較上述外層增 建層之導電層之厚度厚的焊盤，在上述焊盤開設直徑與上 述台階通孔之下穴直徑大略相等的開口，以上述開口爲中 心，執行可除去與上述台階通孔之上穴直徑相等之上述導 電層的雷射照射而使上述疊層電路基材穿孔，形成上述台 階通孔。 〔發明效果〕 若藉由本發明，藉由使連接3層之配線層之台階通孔 -6 - 200917924 之承受焊盤之銅厚，厚於僅在最外層和其1層下之配線層 執行層間連接之盲孔之承受焊盤之銅厚，使於形成台階通 孔之時，僅在最外層形成正形光罩，在其中心藉由直接雷 射加工適當形成台階通孔之下穴。因此，可謀求降低爲了 確保提升良率或信賴性所需之電鍍厚度。 其結果，若藉由本發明，則可以達成以往之製造方法 難以達成的將層間連接部包含台階通孔構造之多層印刷配 線板中，台階通孔之上穴及下穴之各中心安定性配置在大 略相等之位置。依此，由於可以縮小台階通孔之上穴，故 可以低價並且安定性製造可更高密度形成台階通孔之多層 印刷配線板。 【實施方式】 以下，參照第1圖A至第1圖c說明本發明之實施例 〔實施例1〕 第1圖A至第1圖c爲表示本發明之實施形態之剖面 工程圖。在該工程中’首先如第1圖Α(ι)所示般，準 備於聚醯亞fe：等之可撓性絕緣基材1(在此爲厚度25μηι 之聚醯亞胺）之兩面，具有厚度7μηι之銅箔2及3的所謂 雙面銅箔疊層板4。然後’以NC鑽頭等在該雙面銅箔疊 層板4形成導通用孔5。此時之銅箔2及3以彎曲性優良 之輥軋銅箔或特殊電解銅箔爲佳。 200917924 之後，執行導電化處理，在纜線等之配線圖案上，因 不施予電路而選擇性對位於內壁之部份執行電解，故形成 部份電鍍用光阻層6。 此時，也包含考慮到曝光之位置偏差、基板尺寸之偏 差、NC鑽頭加工位置偏差等之尺寸的貫穿銲墊（Land ) ，對位於導通用孔5之內壁以及增建層之層間連接用孔之 承受銲墊之部份，選擇性執行電解電鍍。但是，於增建後 以雷射使貫通之銲墊，因不施予電解電鍍，故即使在相當 於此之處也形成部份電鍍用光阻層6。 接著，如第1圖A ( 2 )所示般，對於導通用孔5及 位於上述承受銲墊之部份8執行ΙΟμιη左右之電解電鍍， 形成層間導通。以至此之工程，形成貫穿孔7。再者，於 位於上述承受銲墊之部份8也加厚電鍍。 接著，如第1圖 A ( 3 )所示般，藉由光加工（ photofabrication)手法，形成用以形成兩面電路圖案之光 阻層。使用光阻層，藉由光加工手法，於形成電路圖案9 及銲墊1 0 a、1 0 b之後，剝離光阻層。 並且，銲墊1 0 a之中心孔係當作之後之雷射加工之時 之正形光罩而發揮機能。在此，將正形光罩直徑設爲 1 0 0 μιη。以至此之工程，取得成爲多層印刷配線板之核心 基板的兩面合金基板1 1。在該實施例1中，雖然適用於貫 穿孔型之兩面核心基板’但是’亦可適用於通孔。 並且，之後，對兩面核心基板1 1之銅表面執行粗化 處理，使之後的覆蓋層形成時之密著性提升’並且使於增 -8- 200917924 建之後執行雷射加工之時之光的吸收安定性提升。在此使 用日本MacDer mid公司（股）之多重接合150而施予粗化 處理。 依此，可以確保密接，並且提升銅表面之二氧化碳雷 射光（波長：大約9.8μηι)之吸收。確認出於處理前後， 二氧化碳雷射光（波長：大約9.8μιη )之吸收，從大約 2 〇 %提升至大約3 0 %。 之後，如第1圖A ( 4 )所示般，準備在例如12μιη厚 度之聚醯亞胺膜12上具有厚度20μπι之丙烯酸環氧等之黏 接材13的所謂覆蓋層，以真空壓、層壓機等將覆蓋層14 貼合兩面核心基板1 1之兩面。以至此之工程取得具有覆 蓋層之兩面核心基板15。 接著，如第1圖Β(5)所示般，準備在聚醯亞胺膜 等之可撓性絕緣基材1 6 (在此厚度25Mm之聚醯亞胺）之 單面具有厚度7/tm之銅箔17的所謂單面銅箔疊層板18。 然後，將該單面銅箔疊層板18予以脫模，將此設爲多層 印刷配線板之增建層1 8 b。 事先脫模用以將增建層18b增建於具有覆蓋層之兩面 核心基板1 5的黏接材1 9，作爲黏接材1 9以低流動性型之 聚酯膠片或接合薄片等之流出較少者爲佳。 在此，因不需要塡充導體層，故黏接材19之厚度可 以選擇15/im左右或是更薄者。經黏接材19以真空壓等疊 層增建層18b和具有覆蓋層之兩面基板15。以至此之工程 取得多層電路基材20。 -9- 200917924 並且，之後，對多層電路基材20之增建層18b之銅 箔表面執行粗化處理，使於增建後執行雷射加工時之雷射 光之吸收安定性提升。在此，與上述相同使用日本 MacDermid公司（股）之多重接合150。 依此，可以確保密接，並且提升銅表面之二氧化碳雷 射光（波長：大約9.8 μιη )之吸收。確認出於處理前後， 二氧化碳雷射光（波長：大約9.8μπι )之吸收，從大約 2 0%提升至大約30%。再者，藉由該粗化處理，銅箔之厚 度變薄大約1 μηι。 並且，作爲對該銅箔表面執行粗化處理之工程順序， (1)首先在單面銅箔疊層板執行粗化處理，並疊層於兩 面核心基板，（2 )於疊層於兩面合金基板之後，執行粗 化處理之兩個工程順序，在該實施例1中藉由（2 )之工 程順序執行。該理由係因爲當如上述（1)般於疊層前執 行粗化處理時，由於疊層之熱或壓力等之履歷使關係到粗 化面形狀或色調之雷射光之吸收的表面狀態產生變化之故 〇 接著，如第1圖Β(6)所示般，對銅箔17執行直接 雷射加工，形成增建通孔用之導通用孔2 1 a。針對雷射加 工法，由於必須爲銅箔貫通加工，故必須要有藉由雷射照 射可除去銅之準分子雷射、UV-YAG雷射、YAG雷射、藉 由二氧化碳雷射等之加工。在該實施例1中，使用加工速 度快，且生產性優良之二氧化碳雷射。 首先，爲了形成台階通孔用之導通用孔2 1 a ’對銅箔 -10- 200917924 1 7之特定位置，照射與台階通孔之上穴直徑大略相等之光 束直徑，在此照射光束直徑2 00μιη之雷射光束。針對照射 雷射光束之位置，藉由X線，以瞄準內層之銲墊1 〇a中心 之不被雷射遮光的孔，即所謂之正形光罩之中心之方式， 執行定位。 依此，如第1圖B ( 6 )所示般，首先使銅箔17貫通 於2 00 μιη直徑，也除去至其下方之銲墊10a的樹脂，之後 ，藉由以事先電鍍增厚之銲墊l〇a而實施正形加工，形成 台階通孔用之導通用孔之上穴21a。再者，即使針對貫穿 孔用之導通用孔21b，也藉由照射光束直徑200μιη之雷射 光束之直接雷射加工而形成。 此時，銲墊l〇b由於以事先電鍍增厚，故不用貫通， 形成通孔用之導通用孔2 1 b。 亦可以採用將雷射光束定位於內層之銲墊1 〇a之中心 的不被雷射遮光之孔的另外手法。該爲在加工附近配置2 點以上之成爲內層之定位標靶的標記，藉由讀取該標記位 置，取得加工部位附近之基板之伸縮等之資訊，並執行運 算處理而修正加工部位之位置，並照射雷射光束。 如該實施例1般，藉由各種材料所構成之層疊構造體 也以不表示均勻之伸縮舉動爲多。爲了對應於此，上述標 記爲了較佳檢測出X方向、Y方向之位置偏差，以配置3 點以上爲佳。 接著，如第1圖C ( 7 )所示般，以X線等之畫像處 理等之手法，瞄準台階通孔用之導通用孔2 1 a之下穴中心 -11 - 200917924 ，即是內層之銲墊l〇a之正形光罩之中心’以特定之光圈 等將光束直徑加工縮小至200μιη。依此，藉由銅箔17貫 通於與雷射光束直徑大略相等之大小，並且施加照射，形 成台階通孔用之導通用孔之下穴。 當針對所形成之導通用孔2 1 a之形狀予以整理時，導 通用孔21a之上側之孔之直徑成爲200μιη，導通用孔21a 之下側孔係由1 ΟΟμιη之孔徑安定性被形成在導通用孔2 1 a 之上側之略中心。 並且，如第1圖B所示般，於被配置在導通用孔21a 和導通用孔21b之位置之時，考慮不使銲墊10b貫通，先 形成包含貫通加工之導通用孔21a，之後，以形成導通用 孔2 1 b爲佳。 因此，在第1圖C.中，先加工圖中之卜.側之導通用孔 21a，並加工下側之導通用孔21a及導通用孔21b。因此， 於位於導通用孔2 1 a和導通用孔2 1 b之位置時，當設計成 導通用孔2 1 a全部位於上側時，首先自上側所有之導通用 孔執行雷射加工，接著可對下側之所有導通用孔執行雷射 加工，爲有效率性。 就以從第1圖B(6)至第1圖C(7)之一連串雷射 加工之條件例而言，執行下述般。使用 ML605 GTXIII-5 100U2 (三菱電機（股）製），藉由X線等之畫像處理 等之手法，執行定位，首先，藉由以光圈等光束徑200μιη ，脈衝寬15psec，15mJ，5次射擊予以加工，在銅厚薄表 面狀態爲碳酸氣體雷射光之吸收佳之銅箔1 7之特定位置 -12- 200917924 開口直徑200μιη。 依此，也除去至以下之電鍍而增厚之銲墊10a爲止之 樹脂。然後以電鍍增厚之銲墊1〇3即使爲二氧化碳雷射光 之吸收佳之表面狀態，由於不貫通當作正形光罩發揮功能 ，故形成台階通孔用之導通用孔2 1 a。 爲了以安定銅箔17a及銲墊l〇a之銅箔之特定處的直 徑來貫通，必須爲具有雷射光之中心之能量密度高之高斯 (Gaussian)分布等之光束分布之雷射光學系統。 就以銅箔17之銅厚而言，也確認出若爲1〇μηι時，即 使爲上述雷射加工條件之正負3 0%左右之能量也以再現性 佳之方式貫通。當成爲5μιη以下之厚度時，因以上述粗化 工程，之後之電鍍前處理之蝕刻等所殘留之銲墊之銅應該 部份性消失，故銅厚以5〜1 0 μιη爲佳。 針對銲墊l〇a及銲墊10b之銅厚，藉由先增厚位於台 階通孔之下側之孔之雷射照射面之反對面的銲墊1 〇b之銅 厚，可以取得相對於銲墊1 〇b之貫通的邊界。 具體而言，也確認出若爲14μηι以上時，貫通所需之 雷射之能量成爲3倍以上，爲充分之邊界。因此，以 14μπι以上之銅厚爲佳。並且，藉由電解電鍍執行用以執 行層間連接之去鑽污處理、導電化處理。 接著，如第1圖C ( 8 )所示般，對具有導通用孔21 a 及導通用孔21b之多層電路基材22執行10〜15 μιη左右電 解，形成藉由導通用孔2 1a所取得之台階通孔23a，藉由 導通用孔2 1 b所取得之通孔2 3 b，並形成層間導通。 -13- 200917924 因台階通孔23a之上穴及下穴之中心無位置偏差，故 可以縮小台階通孔之上穴。因此，可以以更高密度形成台 階通孔。 再者，由於對導通用孔之下側之孔電鍍周圍爲安定， 難以產生電鍍空隙等之不良，施予電鍍所取得之台階通孔 構造性成爲對稱，故以溫度循環試驗等使在台階通孔23a 產生之熱應力軍於分散，故也可以期待層間連接信賴性提 升。依此，如上述般電解電鍍厚度爲1〇〜15μιη左右可以 確保良好之層間連接信賴性。 至此之工程，取得層間導通之完成的多層電路基材24 。再者，於需要插入零件等之安裝用之貫通穴之時，於形 成導通用孔之時，以NC鑽頭等形成貫通孔，並且於上述 通孔電鍍之時，亦可同時形成通孔。 並且，針對台階通孔，雖然記載於專利文獻3 ( Ρ3 ’ 第1圖）等，但是利用藉由本發明之直接雷射工，各配線 層無位置偏差之台階通孔之形成方法則無提及。 接著，如第1圖C(8)所示般，藉由通常之光加工 手法而形成外層之圖案2 5。此時，若有沈積於核心基板 15之覆蓋薄膜12上之電解層時，該也被除去。之後’因 應所需對基板表面施予銲錫電鍍、鍍鎳、鍍金等之表面處 理’藉由執行形成光敏抗銲劑-光阻層及外形加工’取得 在內層具有纜線部之多層印刷配線板26。 作爲高密度安裝基板所要求之圖案形成能力，當將安 裝例如0.5mm間距CSP之銲墊之大小設爲3 00μιη時，爲 -14- 200917924 了在銲墊間以1種模式共用，必須設爲線/行=50μπι/50μιη ’間距 1 0 0 μ m。 但是，如上述般，當在7μιη厚度之銅箔上執行10〜 1 5 μιη左右之電解電銨時，因外層之總導體厚成爲1 7〜 2 2μηι ’可良率佳充分形成間距ΙΟΟμιη之微細圖案，故可 以滿足高密度安裝之要求。 再者，由於纜線被配置在第2層，故爲了以最短距離 連接零件安裝部，連接第1層和第2層之通孔必須以窄間 距配置並且第2層之配線需微細。關於通孔之配置，通孔 23a、23b由於可以通孔直徑200μηι來形成，故間距可以 爲0.4mm以下。 藉由本發明之具有纜線部之多層印刷配線板之層間連 接構造由於採用通孔直徑2 0 0 μ m之通孔2 3 a，故成爲高密 度化有利之構造，可以滿足高密度安裝之要求。然後，可 以低價且安定性製造出層間連接部包含台階通孔構造之多 層印刷配線板，即被配置在台階通孔之上穴及下穴之各中 心大略相等之位置的多層印刷配線板。 【圖式簡單說明】 第1圖A爲表示本發明所涉及之多層印刷配線板之製 造方法之一實施例的工程剖面圖。 第1圖B爲表示本發明所涉及之多層印刷配線板之製 造方法之一實施例的工程剖面圖。 第1圖C爲表示本發明所涉及之多層印刷配線板之製 -15- 200917924 造方法之一實施例的工程剖面圖。 第2圖爲表示具有以往工法之纜線部之多層印刷配線 板之製造方法之槪念性剖面構成圖。 【主要元件符號說明】 1 :可撓性絕緣基材 2 :銅箔 3 :銅箔 4 :雙面銅箔疊層板 5 :導通用孔 6 :光阻層 7 :通孔 8 :部份 9 :電路圖案 1 0 a :婷塾 1 0 b :銲墊 1 1 :核心基板 1 2 :聚醯亞胺 1 3 :黏接材 1 4 :覆蓋層 1 5 :核心基板 1 6 :可撓性絕緣基材 1 7 :銅箔 1 8 :單面銅箔疊層板 -16- 200917924 1 8b :增建層 1 9 :黏接材 20 :多層電路基材 2 1 a :導通用孔 2 1 b :導通用孔 23a :台階通孔 2 3 b :通孔 24:多層電路基材 26 :多層印刷配線板 150 :多重接合 -17-BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a multilayer flexible printed wiring board having a stepped via structure with respect to an interlayer connection portion. [Prior Art] In recent years, the miniaturization of electronic devices has been increasingly promoted, and in this case, a small-sized electronic device layer flexible printed wiring board such as a mobile circuit has been widely used (Patent Document 1 [P 3,. Flexible printing of individual flexible boards and flexible wiring boards that are connected between a multi-board or a hard printed wiring board that is connected to various electronic components via a connector, etc. In particular, the mobile phone is miniaturized. The high-performance device is also replaced with a multi-layer flexible printed wiring board and is replaced by a size package. It is packaged in a high-performance and high-density package, and has a plate size and a high function. Then, it is also proposed to combine the high-density segment-shaped through holes, so-called stepped through holes (see Patent Document 1). This is to advance the inner layer which can perform the interlayer connection of the multilayer structure together, and to reduce the so-called conformal mask for laser processing in consideration of the positional deviation or the like, thereby achieving interlayer connection. The manufacturing method, especially the printed wiring, is highly functional. For the center, more than the first picture]) layer printed wiring board or holding the standard, there is CSP (the wafer does not need to increase the basic layer connection 2 [P3, the first method, with the metal mask plating, etc., take -4- 200917924 However, there are several problems in forming the through-hole of the step. Considering the positional deviation, it is necessary to form the positive-shaped mask of the outer layer due to the positional accuracy of the laminate or the like, so it does not necessarily become a high space. Fig. 2 is a cross-sectional view showing a multilayer printed wiring board which does not include a stepped cable portion in the conventional interlayer connection. As shown in Fig. 2, a positive-shaped mask 201 and a shape in the case of laser processing prepared in advance are used. The positive-shaped reticle 202 of the two-sided core substrate 1 1 执行 performs laser processing on the circuit substrate of the core substrate 1 1 增, the additional substrate 120 and the adhesive material 130, and then is plated to form a through hole. [Patent Document 1] Japanese Patent No. 34270 1 1 [Patent Document 2] Japanese Patent No. 2502373 (Patent Document 3) Japanese Patent Laid-Open Publication No. 2001- 1 77248 [Invention] [Problems to be solved by the invention] At this time, as in the second As shown in the figure, since it is caused at the time of lamination, the center of the positive-shaped mask 2〇1 and the positive-shaped mask 202 cannot be aligned to cause a positional deviation of about 1 〇〇μηι, so it is difficult to face the lower side of the shaped hole 202. In the technique shown in Patent Document 3, there is a method in which it is desired to manufacture a cable portion wiring board having a high-density mounting at a low cost and in a stable manner. As shown in the layer structure of the density, it is formed in the inner layer, and the position of the product is determined by the position of the t 201A '. Because of the proposal of the most advanced type, the multi-layer printing-5-200917924 The purpose of the present invention is to provide a multilayer printed wiring board which can be manufactured at a low cost and in a stable manner. The multilayer printed wiring board is disposed at the time of manufacturing a multilayer printed wiring board having a stepped via structure. The center of each of the upper and lower points is substantially equal. [Means for Solving the Problem] In order to achieve the above object, the present invention is a method for manufacturing a multilayer printed wiring board. An inner core substrate having at least one conductive layer is formed on the insulating substrate formed of the resin film, and the laminated layer is added to the outer layer by the adhesive layer by the laminated plate having the conductive layer at least on one side. Laminating a core substrate to form a laminated circuit substrate, and forming an interlayer connection body having a stepped through hole having a diameter as large as an outer layer side, and forming an outer layer additional layer and the inner layer core substrate a stepped through hole between the layers of the wiring layer of three or more layers, characterized in that: at a position where the stepped through hole of the inner core substrate is formed, a pad having a thickness thicker than a thickness of the conductive layer of the outer layer of the outer layer is provided, Opening the opening having a diameter substantially equal to the diameter of the hole below the stepped through hole, and performing laser irradiation on the conductive layer capable of removing the hole diameter equal to the diameter of the hole above the stepped through hole The laminated circuit substrate is perforated to form the stepped through hole. [Effect of the Invention] According to the present invention, by making the copper thickness of the stepped via hole -6 - 200917924 of the wiring layer connecting the three layers thicker than the wiring layer under the outermost layer and the first layer thereof, the interlayer is performed. The copper thickness of the receiving pad of the blind hole is such that when the stepped through hole is formed, the positive mask is formed only on the outermost layer, and the hole below the stepped through hole is appropriately formed at the center by direct laser processing. Therefore, it is possible to reduce the plating thickness required to secure the improvement in yield or reliability. As a result, according to the present invention, it is possible to achieve a multilayer printed wiring board having a stepped via structure in which the interlayer connection portion is difficult to achieve in the conventional manufacturing method, and the center of each of the stepped through hole and the lower hole is disposed in the center. A roughly equal position. According to this, since the hole above the stepped through hole can be narrowed, the multilayer printed wiring board which can form the stepped through hole with higher density can be manufactured at a low cost and stability. [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1A to 1c. [Embodiment 1] Figs. 1A to 1C are cross-sectional views showing an embodiment of the present invention. In this project, first, as shown in Fig. 1 (a), it is prepared on both sides of a flexible insulating substrate 1 (here, a polyimide having a thickness of 25 μm). A so-called double-sided copper foil laminate 4 having copper foils 2 and 3 having a thickness of 7 μm. Then, a common hole 5 is formed in the double-sided copper foil laminate 4 by an NC drill or the like. The copper foils 2 and 3 at this time are preferably rolled copper foil or special electrolytic copper foil having excellent flexibility. After 200917924, the electroconductive treatment is performed, and on the wiring pattern of the cable or the like, electrolysis is selectively performed on the portion located on the inner wall without applying the circuit, so that the partial photoresist layer 6 for plating is formed. In this case, a through pad (Land) that takes into consideration the positional deviation of the exposure, the variation in the substrate size, and the NC bit processing position deviation is also included, and the interlayer between the inner wall of the conductive hole 5 and the build-up layer is connected. The hole is subjected to the portion of the pad and selectively performs electrolytic plating. However, since the pad which is penetrated by the laser after the addition is not subjected to electrolytic plating, a part of the photoresist layer 6 for plating is formed even at a position equivalent thereto. Next, as shown in Fig. 1 (2), electrolytic conduction plating is performed on the conductive hole 5 and the portion 8 on the soldering pad to form an interlayer conduction. Throughout this project, a through hole 7 is formed. Further, the plating portion 8 is also thickened and plated. Next, as shown in Fig. 1 (3), a photoresist layer for forming a double-sided circuit pattern is formed by photofabrication. Using the photoresist layer, the photoresist layer is peeled off after the circuit pattern 9 and the pads 10 a, 10 b are formed by photo-processing. Further, the center hole of the pad 10 a functions as a positive mask at the time of subsequent laser processing. Here, the diameter of the regular mask is set to 1 0 0 μηη. In the course of this, a double-sided alloy substrate 11 which is a core substrate of a multilayer printed wiring board was obtained. In the first embodiment, although it is applied to the two-sided core substrate 'through the perforation type', it can be applied to the through hole. Then, after that, the copper surface of the double-sided core substrate 11 is subjected to roughening treatment to improve the adhesion of the subsequent cover layer, and the light of the laser processing is performed after the addition of the -8-200917924. Increased absorption stability. Here, the roughening treatment is applied using the multiple joint 150 of Japan MacDer Mid Co., Ltd. According to this, it is possible to ensure the adhesion and enhance the absorption of the carbon dioxide laser light (wavelength: about 9.8 μηι) on the copper surface. It was confirmed that the absorption of carbon dioxide laser light (wavelength: about 9.8 μιη) was raised from about 2 〇 % to about 30 % before and after the treatment. Then, as shown in Fig. 1 (4), a so-called coating layer having an adhesive 13 such as acrylic epoxy having a thickness of 20 μm on a polyimine film 12 having a thickness of 12 μm is prepared, and vacuum-pressed, layered. The cover layer 14 is bonded to both sides of the double-sided core substrate 11 by a press or the like. Thus, the two-sided core substrate 15 having the covering layer was obtained. Next, as shown in Fig. 1 (5), a flexible insulating base material 16 such as a polyimide film (here, a polyimide having a thickness of 25 Mm) is prepared to have a thickness of 7/tm on one side. The so-called single-sided copper foil laminate 18 of the copper foil 17 is used. Then, the one-sided copper foil laminate 18 is demolded, and this is referred to as an additional layer 18b of the multilayer printed wiring board. Debonding in advance to add the build-up layer 18b to the bonding material 159 of the two-sided core substrate 15 having the cover layer as a bonding material 19 to flow out of a low-flow type of polyester film or bonding sheet Less is better. Here, since the conductor layer is not required to be filled, the thickness of the bonding material 19 can be selected to be about 15/im or less. The laminated body 18 is laminated via a pressure-sensitive adhesive layer 19 by vacuum pressing, and a double-sided substrate 15 having a cover layer. The engineering of the multilayer circuit substrate 20 was obtained. -9- 200917924 Then, the surface of the copper foil of the build-up layer 18b of the multilayer circuit substrate 20 is subjected to roughening treatment to improve the absorption stability of the laser light during laser processing after the addition. Here, the multiple joint 150 of Japan MacDermid Co., Ltd. is used in the same manner as described above. According to this, it is possible to ensure the adhesion and enhance the absorption of the carbon dioxide laser light (wavelength: about 9.8 μmη) on the copper surface. It was confirmed that the absorption of carbon dioxide laser light (wavelength: about 9.8 μm) was raised from about 20% to about 30% before and after the treatment. Further, by the roughening treatment, the thickness of the copper foil is reduced by about 1 μm. Further, as a process sequence for performing roughening treatment on the surface of the copper foil, (1) first, a roughening treatment is performed on the single-sided copper foil laminate, and laminated on the both-sided core substrate, and (2) laminated on the double-sided alloy. After the substrate, the two engineering sequences for performing the roughening process are performed in the embodiment 1 by the engineering sequence of (2). This reason is because when the roughening treatment is performed before lamination as in the above (1), the surface state of the absorption of the laser light in relation to the roughened surface shape or the hue is changed due to the history of lamination heat or pressure. Therefore, as shown in Fig. 1 (6), direct laser processing is performed on the copper foil 17, and a common hole 2 1 a for the through hole is formed. For laser processing, since copper foil must be processed through the process, it is necessary to have a laser-exposed excimer laser, a UV-YAG laser, a YAG laser, a carbon dioxide laser, etc. by laser irradiation. . In this embodiment 1, a carbon dioxide laser which is fast in processing speed and excellent in productivity is used. First, in order to form a specific hole 2 1 a ' for the through hole for the stepped hole, a specific position of the copper foil-10-200917924 1 7 is irradiated with a beam diameter which is slightly equal to the diameter of the hole above the stepped through hole, where the beam diameter is 2 00μιη laser beam. With respect to the position of the irradiated laser beam, positioning is performed by X-rays in such a manner as to aim at the center of the pad 1 〇a of the inner layer which is not shielded by the laser, that is, the center of the so-called positive mask. Accordingly, as shown in Fig. 1 (B), first, the copper foil 17 is passed through a diameter of 200 μm, and the resin of the pad 10a is also removed, and then the solder is thickened by prior plating. The pad 10a is subjected to a positive process to form a hole 21a above the guide hole for the stepped through hole. Further, even the conductive hole 21b for the through hole is formed by direct laser processing of a laser beam having a beam diameter of 200 μm. At this time, since the pad 10b is thickened by plating in advance, it is not necessary to penetrate, and the via hole 2 1 b for the via hole is formed. It is also possible to use another method of positioning the laser beam at the center of the inner pad 1 〇a without being shielded by the laser. This is a mark in which two or more points are positioned as positioning targets in the vicinity of the processing, and by reading the mark position, information such as expansion and contraction of the substrate in the vicinity of the processed portion is obtained, and arithmetic processing is performed to correct the position of the processed portion. And illuminate the laser beam. As in the first embodiment, the laminated structure composed of various materials also has a large amount of stretching action which does not indicate uniformity. In order to cope with this, it is preferable to arrange three or more points in order to preferably detect the positional deviation in the X direction and the Y direction. Next, as shown in Fig. 1 (C), the method of image processing such as X-ray is used to aim at the hole in the hole for the stepped hole 2 1 a below the hole center -11 - 200917924, which is the inner layer. The center of the positive mask of the pad l〇a reduces the beam diameter to 200 μm with a specific aperture or the like. Accordingly, the copper foil 17 is traversed by a size substantially equal to the diameter of the laser beam, and irradiation is applied to form a hole below the conductive hole for the stepped through hole. When the shape of the formed common hole 2 1 a is arranged, the diameter of the hole on the upper side of the common hole 21a becomes 200 μm, and the hole on the lower side of the common hole 21a is formed by the pore stability of 1 ΟΟ μηη. The center of the general hole 2 1 a is slightly centered. Further, as shown in FIG. 1B, when being placed at the position of the common hole 21a and the common hole 21b, it is considered that the conductive pad 21a including the through process is formed without considering the penetration of the pad 10b. It is preferred to form the conductive hole 2 1 b. Therefore, in Fig. 1C, the general-purpose hole 21a on the side of the drawing is processed first, and the common-purpose hole 21a and the common-purpose hole 21b on the lower side are processed. Therefore, when the common hole 2 1 a and the common hole 2 1 b are located at the position of the common hole 2 1 a and the common hole 2 1 b, when all the conductive holes 2 1 a are designed to be located on the upper side, laser processing is first performed from all the common holes on the upper side, and then Laser processing is performed on all the common holes on the lower side, which is efficient. In the case of a series of laser processing from one of Fig. 1 (B) to Fig. 1 (C), the following is performed. Using the ML605 GTXIII-5 100U2 (Mitsubishi Electric Co., Ltd.), the positioning is performed by the image processing such as X-ray, etc. First, the beam diameter is 200 μm, the pulse width is 15 psec, 15 mJ, and 5 shots. It is processed to a specific position of the copper foil 17 which is absorbed by the carbon dioxide gas laser light in a thick copper surface state -12-200917924 opening diameter 200 μιη. Accordingly, the resin to the thickness of the pad 10a which has been plated by the following is also removed. Then, the pad 1 〇 3 thickened by electroplating is used as a positive-type reticle for the surface state of the carbon dioxide laser beam, and the common hole 2 1 a for the stepped through hole is formed. In order to penetrate through the specific diameter of the copper foil of the stabilized copper foil 17a and the pad l〇a, it is necessary to be a laser optical system having a beam distribution such as a Gaussian distribution having a high energy density at the center of the laser light. In the case of the copper thickness of the copper foil 17, it is also confirmed that if it is 1 〇 μηι, even the energy of about 30% of the above-mentioned laser processing conditions is excellent in reproducibility. When the thickness is 5 μm or less, the copper of the pad remaining after the above-mentioned roughening process and etching by the pre-plating treatment should be partially eliminated, so that the copper thickness is preferably 5 to 10 μm. For the copper thickness of the pad l〇a and the pad 10b, by thickening the copper thickness of the pad 1 〇b of the opposite surface of the laser irradiation surface of the hole located below the stepped through hole, The boundary of the pad 1 〇b. Specifically, when it is 14 μm or more, the energy of the laser beam required for penetration is three times or more, which is a sufficient boundary. Therefore, it is preferable to use a copper thickness of 14 μm or more. Further, the desmear treatment and the conductive treatment for performing the interlayer connection are performed by electrolytic plating. Next, as shown in Fig. 1 (C), the multilayer circuit substrate 22 having the conductive holes 21a and the common holes 21b is subjected to electrolysis of about 10 to 15 μm to form a common hole 2 1a. The stepped through hole 23a is formed by the through hole 2 3 b obtained by the common hole 2 1 b and is formed to be electrically connected between the layers. -13- 200917924 Since there is no positional deviation in the center of the upper hole and the lower hole of the stepped through hole 23a, the hole above the stepped through hole can be reduced. Therefore, the stepped through holes can be formed at a higher density. Further, since the plating of the hole on the lower side of the common hole is stable, it is difficult to cause a plating void or the like, and the stepped through hole structure obtained by the plating is symmetrical, so that the step is passed by a temperature cycle test or the like. The thermal stress generated by the hole 23a is dispersed, so that the reliability of the interlayer connection can be expected to be improved. Accordingly, as described above, the electrolytic plating thickness is about 1 〇 to 15 μm, which ensures good interlayer connection reliability. At this point, the multilayer circuit substrate 24 in which the interlayer conduction is completed is obtained. Further, when it is necessary to insert a through hole for mounting a component or the like, a through hole is formed by an NC drill or the like when the conductive hole is formed, and a through hole may be simultaneously formed when the through hole is plated. Further, the stepped through hole is described in Patent Document 3 (Ρ3 'Fig. 1), but the method of forming the stepped through hole having no positional deviation of each wiring layer by the direct laser worker of the present invention is not mentioned. . Next, as shown in Fig. 1 (C), the pattern 2 5 of the outer layer is formed by a usual light processing technique. At this time, if there is an electrolytic layer deposited on the cover film 12 of the core substrate 15, this is also removed. Then, 'the surface treatment of solder plating, nickel plating, gold plating, etc. is applied to the surface of the substrate as required. 'The multilayer printed wiring board having the cable portion in the inner layer is obtained by performing the formation of the photosensitive solder resist-photoresist layer and the outline processing. 26. As a pattern forming capability required for a high-density mounting substrate, when the size of a pad having a pitch of, for example, 0.5 mm is set to 300 μm, it is 14-200917924. It is shared between the pads in one mode, and must be set to Line/row = 50μπι/50μιη 'pitch 1 0 0 μ m. However, as described above, when electrolytic ammonium oxide of about 10 to 15 μm is applied to a copper foil having a thickness of 7 μm, the total conductor thickness of the outer layer becomes 1 7 to 2 2 μηι ', and the fineness is good, and the fineness of the pitch ΙΟΟμιη is sufficiently formed. The pattern can meet the requirements of high-density installation. Further, since the cable is disposed on the second layer, in order to connect the component mounting portion at the shortest distance, the through holes connecting the first layer and the second layer must be arranged at a narrow pitch and the wiring of the second layer should be fine. Regarding the arrangement of the through holes, the through holes 23a and 23b can be formed by having a through hole diameter of 200 μm, so the pitch can be 0.4 mm or less. According to the interlayer connection structure of the multilayer printed wiring board having the cable portion of the present invention, since the through hole 2 3 a having a through hole diameter of 200 μm is used, it is advantageous in high density and can meet the requirements of high density mounting. . Then, a multilayer printed wiring board having a stepped via structure in which the interlayer connection portion includes a stepped via structure, that is, a multilayer printed wiring board disposed at a position where the centers of the stepped via holes and the lower holes are substantially equal can be manufactured at a low cost and stability. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A is a cross-sectional view showing an embodiment of a method of manufacturing a multilayer printed wiring board according to the present invention. Fig. 1B is an engineering sectional view showing an embodiment of a method of manufacturing a multilayer printed wiring board according to the present invention. Fig. 1C is a cross-sectional view showing the construction of an embodiment of the method for producing a multilayer printed wiring board according to the present invention -15 - 200917924. Fig. 2 is a schematic cross-sectional structural view showing a method of manufacturing a multilayer printed wiring board having a cable portion of a conventional method. [Description of main components] 1 : Flexible insulating substrate 2 : Copper foil 3 : Copper foil 4 : Double-sided copper foil laminated board 5 : Conductor hole 6 : Photoresist layer 7 : Through hole 8 : Part 9 : Circuit pattern 1 0 a : Ting 塾 1 0 b : Pad 1 1 : Core substrate 1 2 : Polyimine 1 3 : Adhesive material 1 4 : Cover layer 1 5 : Core substrate 1 6 : Flexible insulation Substrate 1 7 : Copper foil 18 : Single-sided copper foil laminate - 16 - 200917924 1 8b : Additive layer 19 : Adhesive material 20 : Multi-layer circuit substrate 2 1 a : Guide hole 2 1 b : General purpose hole 23a: step through hole 2 3 b : through hole 24: multilayer circuit substrate 26: multilayer printed wiring board 150: multiple bonding -17-