200536444 (1) % 九、發明說明 ' 【發明所屬之技術領域】 本發明係有關因應電子機器類的小型化、輕量化要求 之可撓性印刷配線板用基板及其製造方法。特別是配線加 工後聚醯亞胺薄膜部不產生撓曲的高品質單面導體的可撓 性印刷配線板用基板及其製造方法。 0 【先前技術】 近年，伴隨高功能化之行動電話或數位相機、導覽 器、其他各種電子機械類的小型化、輕量化的進展，作爲 此等所使用之電子配線材料的可撓性印刷基板（配線用基 板）的小型化、多層化、緻密化、低介電化等的要求高。 有關該可撓性印刷配線板用基板，以前係將聚醯亞胺薄膜 與可低溫硬化之接著劑貼合所製造。但是，接著劑降低配 線基板的特性，特別是有損聚醯亞胺薄膜的優良耐熱特 Φ 性，難燃性等，又有其他接著劑層的問題，配線回路加工 性惡化。 '具體的，貫通孔加工時因鑽孔產生樹脂斑點，或導體 • 貫通孔加工時尺寸變化率大等的問題。特別是兩面貫通孔 構造，絕緣體層之基層薄膜爲中心其兩面藉由接著劑將導 體的銅箔貼合的形成物，與單面的可撓性印刷配線板用基 板比較一般其柔軟性低。一方面，伴隨I c的高密度化、 印刷配線的微細化，發熱變大，必要貼合良導熱體。又， 由於爲更加緻密化，亦有將殼與配線一體化的方法。更又 -4- 200536444 (2)200536444 (1)% IX. Description of the invention '[Technical field to which the invention belongs] The present invention relates to a flexible printed wiring board substrate and a method for manufacturing the same in response to the requirements for miniaturization and weight reduction of electronic equipment. In particular, a substrate for a flexible printed wiring board of a high-quality single-sided conductor that does not deflect a polyimide film portion after wiring processing and a method for manufacturing the same. 0 [Prior art] In recent years, with the advancement of miniaturization and weight reduction of highly functional mobile phones or digital cameras, navigators, and various other electronic machinery, it has been used as flexible printing of electronic wiring materials used in these areas. Substrates (wiring substrates) have high requirements for miniaturization, multilayering, densification, and low dielectricity. This flexible printed wiring board substrate was previously manufactured by bonding a polyimide film with a low-temperature-curable adhesive. However, the adhesive reduces the characteristics of the wiring board, particularly the excellent heat resistance and flame retardancy of the polyimide film, and other problems with the adhesive layer, which deteriorates the wiring circuit processability. 'Specifically, there are problems such as resin spots due to drilling during through-hole machining, or conductors with large dimensional change rates during through-hole machining. In particular, the double-sided through-hole structure has a base film of an insulator layer as its center, and a copper foil of a conductor bonded to each other with an adhesive on both sides thereof, which is generally less flexible than a single-sided flexible printed wiring board substrate. On the other hand, with the increase in the density of I c and the miniaturization of printed wiring, heat generation becomes large, and it is necessary to adhere a good thermal conductor. In addition, there is also a method for integrating the case and the wiring in order to further densify. More -4- 200536444 (2)
IL 必要不同電容量的配線，需要更耐高溫的配線材料。所 ' 以，提案種種不使用接著劑以直接塗敷硬化前的聚醯胺酸 溶液於銅箔等導體上加熱硬化之可撓性印刷配線板用基板 的製造方法。 例如，可列舉於金屬箔塗敷硬化物的熱膨脹係數爲 3 · 0 X 1 (Γ 5以下由二胺與四羧酸酐的所合成的聚醯胺酸加熱 硬化者（例如參閱專利文獻1 )，或於導體上塗敷含具 Φ 有特定構造單元的聚醯亞胺先驅物化合物之樹脂溶液醯亞 胺化者（例如參閱專利文獻2 )，於導體上直接塗敷具有 含二胺基苯醯苯胺或其衍生物之二胺類與芳香族四羧酸反 應所得之構造單元之絕緣材料的先驅物溶液所硬化者（例 如參閱專利文獻3 )等。又提案爲提高與金屬箔的密接性 於導體上使用複數的聚醯亞胺先驅物樹脂溶液，進行複數 次塗敷與乾燥製造具有複數的聚醯亞胺樹脂層之可撓性印 刷配線板用基板的方法（例如參閱專利文獻4 )。 φ 專利文獻1 ··日本特開昭62-2 1 2 1 40號公報 專利文獻2 :日本特開昭6 3 - 8 4 1 8 8號公報 _ 專利文獻3 :日本特開昭6 3 - 2 4 5 9 8 8號公報 專利文獻4:日本特公平6-49185號公報 【發明內容】 〔發明所欲解決之課題〕 依上述專利文獻4之可撓性印刷配線用基板的製造方 法，可得到抑制導體的基板與樹脂的密接性及金屬箔與樹 -5- 200536444 (3) ^ 脂之熱膨脹係數差爲起因的基板撓曲之良質可撓性印刷配 ‘ 線用基板。但是，成爲如此基板其金屬箔的單面相關的複 數層聚醯亞胺樹脂的構成未滿足特定的條件者，知其實際 於導體側施以回路加工，去除不要的的金屬箔時露出聚醯 亞胺薄膜容易產生撓曲的問題。 引起如此現象的要因，係於聚醯亞胺先驅物樹脂溶液 塗敷，由乾燥之加熱處理之醯亞胺化之過程，預想所形成 φ 之聚醯亞胺樹脂層的厚度方向產生聚醯亞胺分子的配向度 差。但是，其機構尙未弄淸楚。因而本發明的目的爲提供 對導體側的回路加工後亦不產生撓曲之品質安定的撓性印 刷配線用基板及其製造方法。 〔課題解決手段〕 本發明者等，對上述課題經深入的硏究結果，發現由 多層聚醯亞胺層厚度方向之聚醯亞胺分子的配向度差所產 φ 生，預測其厚度方向的熱膨脹係數差，存在於導體的接觸 層與頂層兩者之中間設置比基層熱膨脹係數高的聚醯亞胺 ' 樹脂層，且與導體接觸層的厚度比頂層的厚度小，可 成 •本發明的目的，完成本發明。 即，本發明的撓性印刷配線用基板，於導體的單面上 具有熱膨脹係數相異的多層聚醯亞胺層之撓性印刷配線用 基板，與導體接觸之底層及導體反側的頂層的中間設置由 至少一種熱膨脹係數爲3 0 X 1 〇_6 ( 1 / °C )以下的低熱膨 脹性聚醯亞胺系樹脂所成之基層，且底層與頂層由比基層 -6 - (4) 200536444 ' 的熱膨脹係數大的熱可塑性聚醯亞胺系樹脂所成，又相對 - 於底層的厚度P 1其兩側的底層與頂層的合計厚度的比Pm / ( P】+P2 )滿足 2〜100的範圍者爲理想。 又，底層的厚度？！爲0.2〜10//m的範圍，且與頂層 的厚度P2之比 P】/ P2滿足0.2〜0.8的範圍者爲理想。 本發明的可撓性印刷配線板用基板的製造方法，其係 藉由直接於導體的一面上將數層的聚亞胺先驅物樹脂溶液 φ 塗敷 乾燥後加熱硬化，製造具有多層熱膨脹係數相異的 聚醯亞胺層的可撓性印刷配線板用基板之方法，與導體接 觸之底層及與導體反側的頂層之中間配置由至少一種可變 換爲熱膨脹係數爲3 0 X 1 0 _6 ( 1 / °C )以下的低熱膨脹性 聚醯亞胺樹脂所成之基層，且，底層與頂層上將可變換爲 熱可塑性聚醯亞胺系樹脂的熱膨脹係數比基層大的聚醯亞 胺系先驅物樹脂溶液，塗敷•乾燥後加熱硬化至可滿足底 層的厚度P!與頂層的厚度P2，爲P! < P2的條件之底層與 φ 頂層爲其特徵。 上述本發明相對於基層的厚度Pm之其兩側的底層及 '頂層的合計厚度之比Pm/ (Pi + P2)滿足 2〜100的範圍 .爲理想。 又，上述本發明係塗敷聚醯亞胺先驅物溶液，使底層 的厚度匕爲0.2〜10//m的範圍，且與頂層的厚度P2之比 P 1 / P 2滿足0.2〜0.8的範圍爲理想。 〔發明之效果〕 200536444 (5) 依本發明，施以回路加工除去不要的金屬箔聚醯亞胺 * 薄膜亦不產生撓曲，可製造尺寸安性優的可撓性印刷配線 板用基板。 〔用以實施發明之最佳型態〕 以下，詳細說明實施本發明的最佳型態。 首先於本發明所使用的導體，可列舉如厚度5〜150 φ # m的銅、鋁、鐵、銀、鈀、鎳、鉻、鉬、鎢、鋅及此等 之合金等的導電性金屬箔，理想爲銅。銅可使用壓延銅箔 與電解銅箔之任一者。又爲提高接著力的目的，亦可於其 表面由加側線、鍍鎳、鍍銅-鋅合金、或鋁醇鹽、鋁螫合 物、矽烷合劑等化學或機械的表面處理。 於導體的導電性金屬箔的單面由形成複數的聚醯亞胺 系樹脂層可形成絕緣體層，作爲絕緣體層的聚醯亞胺系樹 脂係具有醯亞胺環構造樹脂的總稱，可舉例如聚醯胺醯亞 φ 胺、聚酯醯亞胺等。如此，聚醯亞胺系樹脂層可利用上述 專利文獻1〜4所記載的低熱膨脹性物，或加熱時溶融或 ' 軟化之熱可塑性聚醯亞胺等無特別限定。但是特別理想的 • 絕緣體層爲配置至少三層由熱膨脹係數（或線膨脹係數） 爲30 X 1 (Γ6 ( 1 / K )以下的低熱膨脹性聚醯亞胺樹脂所成 之基層，其上下以比基層的熱膨脹係數大的熱可塑性聚醯 亞胺系樹脂所成的二層（底層與頂層）的聚醯亞胺系樹脂 層所成者爲理想。 此處形成基層的低熱膨脹聚醯亞胺系樹脂，其熱膨脹 -8 - 200536444 (6) 係數爲3 0 x 1 0 _6 ( 1 / t：)以下爲理想，以具有優良薄膜 的耐熱性、可撓性的性能者爲佳。此處之熱膨脹係數係使 用充分醯亞胺化反應的試料，使用熱機構分析器（thermo mechanical analyzer (TMA))昇溫至 250 °C 後，以 10 °C/ 分的速度冷卻，求相關240〜1 〇〇t範圍平均的熱膨脹係 數。具有此性質的低熱膨脹聚醯亞胺系樹脂的具體例，以 具有下述一般式（I )的單元構造之聚醯亞胺系樹脂爲理 木貝〇IL requires wiring with different capacitance, and requires higher temperature resistant wiring materials. Therefore, various methods for manufacturing a flexible printed wiring board substrate by directly applying a polyamic acid solution before curing without applying an adhesive on a conductor such as copper foil are proposed. For example, the thermal expansion coefficient of a metal foil-coated hardened product is 3. 0 X 1 (Γ5 or less, which is a polyamic acid heat-cured from a diamine and a tetracarboxylic anhydride (see, for example, Patent Document 1). Or apply a resin solution containing a polyfluorene imine precursor compound with a specific structural unit to the conductor and imidize it (see, for example, Patent Document 2), and directly coat the conductor with diamine-containing phenylaniline A solution of a precursor of an insulating material of a structural unit obtained by the reaction of a diamine of its derivative with an aromatic tetracarboxylic acid (see, for example, Patent Document 3), etc. It is also proposed to improve the adhesion with a metal foil to a conductor A method for producing a flexible printed wiring board substrate having a plurality of polyimide resin layers by applying and drying a plurality of polyimide precursor resin solutions in multiple times (see, for example, Patent Document 4). Patent Literature 1 · Japanese Patent Laid-Open No. 62-2 1 2 1 40 Patent Literature 2: Japanese Patent Laid-Open No. 6 3-8 4 1 8 8 _ Patent Literature 3: Japanese Patent Laid-Open No. 6 3-2 4 5 9 8 8 Patent Document 4: Japan Japanese Patent Publication No. 6-49185 [Summary of the Invention] [Problems to be Solved by the Invention] According to the method for manufacturing a flexible printed wiring board of the above-mentioned Patent Document 4, it is possible to obtain a substrate and a resin that suppress the adhesion between a conductor and a metal. Foil and Tree-5-200536444 (3) ^ Good quality flexible printed wiring substrates for substrate flexing due to the difference in thermal expansion coefficient of grease. However, this substrate has multiple layers related to one side of the metal foil. Those who do not meet the specific requirements for the composition of fluorene imine, know that it is actually subjected to circuit processing on the conductor side, and when the unnecessary metal foil is removed, the polyimide film is exposed, which is prone to deflection. The cause of this phenomenon, It is based on the application of polyimide precursor resin solution, and the process of hydrazine imidization by drying and heat treatment. It is expected that the orientation of the polyimide molecules will be poor in the thickness direction of the φ polyimide resin layer formed. However, the mechanism has not been solved. Therefore, an object of the present invention is to provide a flexible printed wiring board having stable quality without causing deflection even after processing of a conductor-side circuit, and to provide a flexible printed wiring substrate and a circuit board therefor. [Solutions to solve the problem] The present inventors and others, as a result of in-depth research on the above-mentioned problems, found that the polyimide molecules in the thickness direction of the multilayer polyimide layer are caused by the difference in the degree of alignment of the polyimide molecules, and predicted that The thermal expansion coefficient in the thickness direction is poor. A polyimide 'resin layer with a higher thermal expansion coefficient than the base layer exists between the contact layer and the top layer of the conductor. The thickness of the contact layer with the conductor is smaller than the thickness of the top layer. An object of the present invention is to complete the present invention. That is, the flexible printed wiring substrate of the present invention has a flexible printed wiring substrate having a plurality of polyimide layers having different thermal expansion coefficients on one side of the conductor, and is in contact with the conductor. The middle layer of the bottom layer and the top layer on the opposite side of the conductor is provided with a base layer made of at least one kind of low thermal expansion polyfluorene-based resin having a thermal expansion coefficient of 30 X 1 0_6 (1 / ° C) or less, and the bottom layer and the top layer It is made of a thermoplastic polyimide resin with a larger thermal expansion coefficient than that of the base layer-6-(4) 200536444 ', and it is relative to the thickness of the bottom layer P 1 The ratio of the total thickness of the bottom layer to the top layer on both sides P It is desirable that m / (P) + P2) satisfy a range of 2 to 100. And the thickness of the bottom layer? !! It is preferably in the range of 0.2 to 10 // m and the ratio P] / P2 to the thickness P2 of the top layer satisfies the range of 0.2 to 0.8. In the method for manufacturing a flexible printed wiring board substrate of the present invention, a plurality of layers of the polyimide precursor resin solution φ is applied and dried directly on one side of a conductor, and then heated and hardened to produce a phase having a multi-layer thermal expansion coefficient. A method for a flexible printed wiring board substrate with a different polyimide layer, and the intermediate arrangement between the bottom layer in contact with the conductor and the top layer on the opposite side of the conductor can be converted into a thermal expansion coefficient of 3 0 X 1 0 _6 ( Base layer made of polyimide resin with low thermal expansion below 1 / ° C), and the thermal expansion coefficient of the polyimide-based resin on the bottom and top layers can be changed to a polyimide-based resin with a larger thermal expansion coefficient than the base layer The precursor resin solution is coated and dried and then heat-hardened to meet the thickness of the bottom layer P! And the thickness of the top layer P2, which is the condition of P! ≪ P2. The bottom layer and φ top layer are characteristics. The ratio Pm / (Pi + P2) of the total thickness of the bottom layer and the top layer on both sides of the present invention with respect to the thickness Pm of the base layer described above satisfies a range of 2 to 100. It is desirable. In addition, the above-mentioned invention applies the polyimide precursor solution so that the thickness of the bottom layer is in the range of 0.2 to 10 // m, and the ratio of the thickness P2 to the thickness of the top layer P 1 / P 2 satisfies the range of 0.2 to 0.8. As ideal. [Effects of the Invention] 200536444 (5) According to the present invention, circuit processing is performed to remove unnecessary metal foil polyimide *. The film does not deflect, and a flexible printed wiring board substrate with excellent dimensional security can be manufactured. [Best Mode for Carrying Out the Invention] Hereinafter, a best mode for carrying out the invention will be described in detail. The conductor used in the present invention includes conductive metal foils such as copper, aluminum, iron, silver, palladium, nickel, chromium, molybdenum, tungsten, zinc, and alloys thereof having a thickness of 5 to 150 φ # m. , Ideally copper. As the copper, either a rolled copper foil or an electrolytic copper foil can be used. For the purpose of improving adhesion, the surface may be chemically or mechanically treated with side wires, nickel plating, copper-zinc plating, or aluminum alkoxides, aluminum compounds, and silane compounds. An insulator layer can be formed by forming a plurality of polyimide-based resin layers on one side of a conductive metal foil on a conductor. The polyimide-based resins serving as an insulator layer are collectively referred to as resins having a iminium ring structure. Polyamidoamine imine φ amine, polyester amidine and so on. As described above, the polyimide-based resin layer may be a low-thermal-expansible material described in the aforementioned Patent Documents 1 to 4, or a thermoplastic polyimide that melts or softens during heating, and the like is not particularly limited. However, the ideal insulator layer is a base layer made of low thermal expansion polyimide resin with a thermal expansion coefficient (or linear expansion coefficient) of 30 X 1 (Γ6 (1 / K) or less). A two-layer polyimide resin layer (bottom layer and top layer) made of a thermoplastic polyfluorene resin having a larger thermal expansion coefficient than that of the base layer is ideal. A low thermal expansion polyfluorene imide forming the base layer here is preferable. Series resin, its thermal expansion -8-200536444 (6) coefficient is preferably 30 x 1 0 _6 (1 / t :) or less, it is better to have excellent heat resistance and flexibility of the film. Here it is The coefficient of thermal expansion is based on the use of a sample with sufficient amidation reaction, the temperature is increased to 250 ° C using a thermo mechanical analyzer (TMA), and the sample is cooled at a rate of 10 ° C / min. Coefficient of average thermal expansion in the t range. A specific example of the low-thermal-expansion polyfluorene-based resin having this property is a polyimide-based resin having a unit structure of the following general formula (I).
Ri Μ R3 R4 (I) (但，式中 R!〜R4爲低級烷基、低級烷氧基、鹵基或 氫） 又，形成於基層上下所使用的底層與頂層之熱可塑性 聚醯亞胺系樹脂，比基層的熱膨脹係數大，其玻璃轉移溫 度爲3 5 0 °C以下者即可。理想以加熱加壓下壓接時其界面 的接著強度充分者爲佳。此時底層與頂層的熱可塑性聚醯 亞胺系樹脂種類爲滿足上述條件限度，爲同種亦可，具有 相異單元構造亦可。此處所謂熱可塑性聚醯亞胺系樹脂， 於玻璃轉移點以上的通常狀態未必要顯示充分的流動性亦 可，含由加壓可接著者。具有該性質的熱可塑性聚醯亞胺 系樹脂的具體例，係具有下述一般式（II )或一般式 (III )所示的單元構造者。 200536444 (7) (但，式中Ar!爲2價的芳香族基其碳數爲1 2以上者） ^^^S〇2«：：>- (1) (但，式中Ar2爲2價的芳香族基其碳數爲12以上者） 此處，2價的An或Ar2的具體例可列舉如下。 • -0〇0s〇20o-0- s -00-00-0- CHs ch3 又，製造單面導體的可撓性印刷配線板用基板的方 法，如上述專利文獻4所記載於聚醯亞胺先驅物溶液或聚 醯亞胺溶液，加入公知的酸酐系或胺系硬化劑等的硬化 劑、矽烷耦合劑、鈦酸鹽耦合劑、環氧化合物等的接著性 -10- 200536444 (8) 賦與劑、橡膠等的可撓性賦與劑等的各種添加劑或觸媒塗 * 敷於導電性金屬箔的單面。其次由熱處理熱硬化可得到單 面導體層合板。又，單面導體的層合物，係將導電性金屬 箔藉由比基層更高熱膨脹係數之熱可塑性聚醯亞胺系樹脂 層之底層，至少一種低熱膨脹性的酿亞胺系樹脂層於中間 的基層，更於最外由比基層更高熱膨脹係數的熱可塑性聚 醯亞胺系樹脂層的頂層的順序層合者爲理想。 φ 此處，中間基層不得不爲比底層或頂層的熱可塑性聚 醯亞胺系樹脂更小熱膨脹係數的聚醯亞胺系樹脂層。基層 具有抑制所製造之可撓性印刷配線板用基板產生撓曲的作 用，與導體接觸的底層具有確保與導電性金屬箔的接著 性，頂層之使用係期待其抑制薄膜單體的撓曲的作用。又 依情形，使用頂層與其他導電性金屬箔層合加熱壓合作爲 兩面導體的可撓性印刷配線板用基板使用時可確保接著性 的作用。此時，低熱膨性聚醯亞胺系樹脂層（基層）的厚 φ 度Pm之其兩側的熱可塑性聚醯亞胺系樹脂層（底層及頂 層）的合計厚度之比Pm/ (Pi + P2)爲 2〜100的範圍， ^ 理想以5〜20的範圍爲佳。該厚度小於2時，聚醯工胺系 1 樹脂層全體的熱膨脹係數與金屬箔相比過高，所得之可撓 性印刷配線板用基板彎曲或撓曲變大，回路加工時的作業 性顯著降低。又，兩側的熱可塑性聚醯亞胺系樹脂層的合 計厚度（ΡΘΡ2)過小，厚度比大至超過100，與導電性金 屬箔的接著力產生未能充分發揮的情形。 與導體接觸的底層的厚度（p 1 )與導體反側的頂層的 -11 - 200536444 (9) 厚度（P 2 )的比P !< P 2爲極重要。其厚度的比例依具有 低熱膨脹性之基層的厚度而變化，P!/P2爲0.2〜0.8 ，更 理想爲〇 · 3〜0 · 7。比此範圍小時薄膜撓曲的修正效果過強 產生逆撓曲，另一方面，大於該範圍時薄膜沒有發現撓曲 的抑制效果。又，與導體層接觸之底層厚度（P】）以0.2 〜1 0 // m的範圍爲理想。薄於該範圍時不能確保接著力， 又過厚時成爲耐熱性降低的原因。 φ 對導電性金屬箔上塗敷此等可變換的複數聚醯亞胺系 樹脂的聚醯亞胺先驅物樹脂，可由該樹脂溶液的形態進 行，理想爲如上述專利文獻4所記載的先驅物溶液形態， 一次或逐次的塗敷複數的先驅物或於醯亞胺閉環以下溫度 脫溶劑處理後，先驅物的聚醯亞胺的加熱變換以一次進行 爲理想。於完全變換爲聚醯亞胺之層上更塗敷別的聚醯亞 胺系先驅物溶液，熱處理醯亞胺閉環時，各聚醯亞胺系樹 脂層間的接著力不能充分的發揮，成爲製品的面面層合物 φ 的品質降低的原因。 於導電性金屬箔上塗敷聚醯亞胺先驅物樹脂溶液（聚 ' 醯胺酸溶液）或含有其先驅物化合物之樹脂溶液的方法， - 可由公知的括刀塗敷器、模頭塗敷器、輥輪塗敷器、簾式 塗敷器等法進行’進行特厚塗敷時以模頭塗敷器或括刀塗 敷器爲適用。又’塗敷使用之聚醯亞胺系先驅物樹脂溶液 的聚合物濃度’依聚合物的聚合度而異’通常爲5〜30重 量％，理想爲1 〇〜2 〇重量％。聚合物的濃度低於5重量％ 時，一次的塗敷不能得到充分的膜厚，又，高於3 0重量％ -12- (10) 200536444 時溶液的黏度變高塗敷有困難。 • 於導電金屬箔塗敷均勻厚度之聚醯亞胺先驅物樹脂溶 液（聚醯胺酸溶液），由其次的熱處理除去溶劑進行醯亞 胺閉環。此時，以急激的高溫處理時’於樹脂的表面生成 表皮層溶劑的蒸發變爲困難，會產生發泡現象’以低溫緩 緩昇溫至高溫熱處理爲理想。此時的最終熱處理溫度，通 常以3 0 0〜4 0 (TC爲理想，4 0 0 °C以上聚醯亞胺緩緩開始引 φ 起熱分解，又，3 0 0 °C以下聚醯亞胺皮膜於導電性金屬箔 上不能充分配向，不能得到平面性良好的單面導體層合 物。如此所形成的絕緣物之聚醯亞胺系樹脂層的全體厚度 通常爲10〜150//m。 【實施方式】 以下以實施例與比較例具體的說明本發明的實施型 態。又，於以下實施例，熱膨脹係數、單面銅貼銅品的撓 φ 曲及接著力，以及薄膜的撓曲依以下方法測定。 即，熱膨脹係數使用日本精工電子工業股份有限公司Ri Μ R3 R4 (I) (However, R! ~ R4 in the formula are lower alkyl, lower alkoxy, halo or hydrogen.) Also, the thermoplastic polyimide is formed on the bottom and top layers used above and below the base layer. The resin has a larger thermal expansion coefficient than the base layer, and its glass transition temperature may be less than 350 ° C. It is desirable that the bonding strength at the interface is sufficient when pressure bonding is performed under heat and pressure. In this case, the types of the thermoplastic polyfluorene-imide resins on the bottom layer and the top layer satisfy the above-mentioned conditional limitations, and they may be the same type or have different unit structures. The thermoplastic polyfluorene-imide resin here does not necessarily show sufficient fluidity in a normal state above the glass transition point, and may include those which can be connected by pressure. Specific examples of the thermoplastic polyfluorene-imide resin having this property are those having a unit structure represented by the following general formula (II) or general formula (III). 200536444 (7) (However, Ar! Is a divalent aromatic group whose carbon number is 12 or more) ^^^ S〇2 «:: >-(1) (However, Ar2 in the formula is 2 Valent aromatic group having a carbon number of 12 or more) Here, specific examples of the divalent An or Ar2 are listed below. • -0〇0s〇20o-0- s -00-00-0- CHs ch3 In addition, a method for manufacturing a flexible printed wiring board substrate for a single-sided conductor is described in Polyimide as described in Patent Document 4 above. Adhesiveness of precursor solution or polyimide solution, adding known hardeners such as anhydride or amine hardeners, silane coupling agents, titanate coupling agents, epoxy compounds, etc. -10- 200536444 (8) Various additives such as flexible additives such as additives, rubbers, or catalysts are applied * One side of conductive metal foil. Secondly, single-sided conductor laminates can be obtained by heat curing and heat curing. In addition, the laminate of the single-sided conductor is made of a conductive metal foil with a thermoplastic polyimide-based resin layer having a higher thermal expansion coefficient than the base layer, and at least one low-thermal-expansion melamine-based resin layer in the middle. It is preferable to sequentially laminate the top layer of the thermoplastic polyimide-based resin layer with a higher thermal expansion coefficient than the base layer. φ Here, the intermediate base layer has to be a polyimide-based resin layer having a smaller thermal expansion coefficient than the thermoplastic polyimide-based resin of the bottom or top layer. The base layer has a function of suppressing deflection of the manufactured flexible printed wiring board substrate, and the bottom layer which is in contact with the conductor has the adhesiveness with the conductive metal foil. The use of the top layer is expected to suppress the deflection of the thin film monomer. effect. In some cases, the use of a flexible printed wiring board with a top layer laminated with another conductive metal foil to form a double-sided conductor can ensure the adhesion when used. At this time, the ratio of the total thickness of the thermoplastic polyimide-based resin layers (bottom and top layers) on both sides of the thickness φ degree Pm of the low thermal expansion polyimide-based resin layer (base layer) is Pm / (Pi + P2) is in the range of 2 to 100, and preferably in the range of 5 to 20. When the thickness is less than 2, the thermal expansion coefficient of the entire polyamidoamine 1 resin layer is too high compared to the metal foil, and the resulting flexible printed wiring board substrate is bent or deflected, and the workability during circuit processing is remarkable. reduce. In addition, the total thickness (PΘP2) of the thermoplastic polyfluorene-based resin layers on both sides is too small, and the thickness ratio exceeds 100, and the adhesive force with the conductive metal foil may not be fully exerted. The thickness of the bottom layer (p 1) in contact with the conductor and that of the top layer on the opposite side of the conductor is -11-200536444 (9) The ratio of the thickness (P 2) P! ≪ P 2 is extremely important. The thickness ratio varies depending on the thickness of the base layer having low thermal expansion, and P! / P2 is 0.2 to 0.8, and more preferably 0.3 to 0.7. If the thickness is smaller than this range, the effect of correcting the deflection of the film will be too strong to cause reverse deflection. On the other hand, if it is larger than this range, the effect of suppressing the deflection of the film will not be found. The thickness of the bottom layer (P) in contact with the conductor layer is preferably in the range of 0.2 to 1 0 // m. When the thickness is smaller than this range, the adhesive force cannot be ensured, and when it is too thick, the heat resistance is reduced. φ A polyimide precursor resin in which such a plurality of switchable polyimide-based resins are coated on a conductive metal foil can be performed in the form of the resin solution, and is preferably a precursor solution as described in Patent Document 4 above. In the form, one or more coatings of a plurality of precursors or desolvation treatment at a temperature below the ring closure of the fluorene imine are applied once or successively, and it is desirable to perform the heating conversion of the fluorene imine of the precursor at one time. On the layer completely transformed into polyimide, another polyimide-based precursor solution is applied, and when heat treatment is performed, the adhesion between the polyimide-based resin layers cannot be fully exerted, and the product becomes a product. The reason why the quality of the surface laminate φ decreases. A method for applying a polyimide precursor resin solution (poly'amidic acid solution) or a resin solution containing the precursor compound to a conductive metal foil, by a known knife applicator, die applicator, etc. , Roller applicator, curtain applicator, etc., are used for the application of extra-thick coating with a die applicator or a knife applicator. The polymer concentration of the polyimide-based precursor resin solution to be used for coating varies according to the degree of polymerization of the polymer, and is usually 5 to 30% by weight, and preferably 10 to 20% by weight. When the concentration of the polymer is less than 5% by weight, a sufficient film thickness cannot be obtained in one application, and when the concentration is higher than 30% by weight -12- (10) 200536444, the viscosity of the solution becomes high, and it is difficult to apply. • Apply polyimide precursor resin solution (polyamidic acid solution) to conductive metal foil with a uniform thickness, and remove the solvent by subsequent heat treatment to close the imine ring. At this time, when subjected to a rapid high-temperature treatment, 'the evaporation of the solvent of the skin layer on the surface of the resin becomes difficult, and a foaming phenomenon occurs', and it is preferable to heat slowly to a high temperature from a low temperature. At this time, the final heat treatment temperature is usually 300 ~ 4 0 (TC is ideal, polyimide above 400 ° C slowly starts to cause thermal decomposition, and polyimide below 300 ° C The amine film cannot be sufficiently aligned on the conductive metal foil, and a single-sided conductor laminate having good planarity cannot be obtained. The overall thickness of the polyimide resin layer of the insulator thus formed is usually 10 to 150 // m [Embodiments] The following describes the embodiments of the present invention in detail with examples and comparative examples. In the following examples, the coefficient of thermal expansion, the deflection φ of the single-sided copper-clad copper product, the adhesive force, and the flexure of the film The curve is measured according to the following method. That is, the thermal expansion coefficient is determined by Nippon Seiko Instruments Inc.
• 製熱機構分析器（TMA 100 )，昇溫至2 5 0 °C後以10°C . /分速度冷卻，算出240 °C〜l〇(TC間的平均線膨脹係數求 出。 單面貼銅品的撓曲，以處理醯亞胺化後測定100 mm X 1 0 0 m m的尺寸的貼銅品的極率半徑。 單面貼銅品的接著力，依據Π S C 5 0 1 6 : 7. 1項爲 準，使用導體寬3 mm的模型，將銅箔以180°的方向於50 -13- 200536444 (11) m m /分拉伸求出剝離時的値（k g / c m )。 β 焊錫耐熱性依據JI S C 5 0 1 6爲準，由2 6 0 °C緩緩以1 〇 °C的間隔將銲錫浴溫上昇，測定至最高40(TC。 又，實施例及比較例中使用的略號如下。 PDMA:均苯四甲酸 BTDA: 3,3,4,4’-二苯甲酮四竣酸酐 DDE : 4,4-二胺基二苯醚 • MABA : 2’-甲氧基-4,4’-二胺基苯醯苯胺 (合成例1 ) 於玻璃製反應器邊通氮氣邊投入2 5 3 2 g N，N-二甲基 乙醯胺，接著於攪拌下投入0.5莫耳的DDE與0.5莫耳的 Μ ΑΒΑ，將其完全溶解。將該溶液冷卻至1 0°C，反應液保 持於3 0 °C以下的溫度以每次少量添加1莫耳的ρ μ D A，添 加終了後接著於室溫進行2小時攪拌，完成聚合。反應所 # 得的聚醯亞胺先驅物溶液以1 5重量％聚合物濃度及使用B 型黏度δ十其於25C的假黏度爲lOOOmPa。s。 ' (合成例2 ) 除使用1莫耳DDE爲二胺成分，1莫耳BTDA爲酸酐 以外，與合成例1同樣調整聚醯亞胺先驅物溶液。所得的 聚醯亞胺先驅物溶液以1 5重量％聚合物濃度及使用B型 黏度計其於2 5 °C的假黏度爲3 0 0 m P a。s。 -14- 200536444 (12) 實施例1 以 3 5 // m捲同狀的電解銅范（日本日礦古德 (Gourde )公司製）的粗化面爲底層使用模頭塗敷器將合 成例2所調整的聚醯亞胺先驅物溶液2塗敷成均勻的20 // m厚度後，於1 20°C熱風乾燥爐連續處理除去溶劑。其 次於該聚醯亞胺先驅物層上使用逆輥輪塗敷器將合成例1 所調整的聚醯亞胺先驅物溶液1均勻的塗敷成200 # m作 φ 爲基層，於1 20°C熱風乾燥爐連續處理除去溶劑後，更以 合成例2所調整的聚醯亞胺先驅物溶液2塗敷成均勻的40 // m厚度，其次於熱風乾燥爐以30分鐘時間將溫度由120 °C昇溫至3 60 t熱處理醯亞胺化，得到25 // m厚度聚醯亞 胺樹脂層無彎曲或撓曲的良好平面性單面導體層合物（單 面貼銅品a )。但，測定底層的厚度的基點爲導電體粗面 的粗度的1 / 2。該單面導體層合物a的銅箔層與聚醯亞胺 樹脂層之間的180°拉伸剝離強度（JIS C 5016)測定的結 φ 果爲1.8 Kg/ cm。其次該單面導體層合物a的導體側施以 回路加工，除去不要的金屬箔時露出的聚醯亞胺薄膜無產 - 生撓曲，又蝕刻後的薄膜的線膨脹係數爲2 3 · 5 x 1 〇 - 6 ( 1 / 實施例2〜3及比較例1〜3 變更於實施例1底層、基層及頂層的聚醯亞胺樹脂的 種種厚度，同樣的乾燥，其次於熱風乾燥爐以3 0分鐘時 間將溫度由1 2 〇 °C昇溫至3 6 0 t：熱處理得到單面導體層合 -15- (13) 200536444 物a。該單面導體層合物a產生彎曲及燒曲的狀況、1 80° 拉伸剝離強度、及於導體側施加回路加工除去不要的金屬 箔時露出的聚醯亞胺薄膜產生撓曲狀況，及蝕刻後的薄膜 的線膨脹係數等彙集如表1及表2。• Heating mechanism analyzer (TMA 100), after heating up to 250 ° C and cooling at 10 ° C. / min., Calculate the average linear expansion coefficient between 240 ° C and 10 °. The deflection of the copper product is measured after processing the imidization. The polar radius of the copper-clad product with a size of 100 mm X 100 mm is measured. The adhesive force of the copper-clad product on one side is based on Π SC 5 0 1 6: 7 . Based on one term, using a model with a conductor width of 3 mm, pull the copper foil in a 180 ° direction at 50 -13- 200536444 (11) mm / min to obtain the 値 (kg / cm) at the time of peeling. Β Solder The heat resistance is based on JI SC 50 01, and the solder bath temperature is gradually increased from 26 ° C to 10 ° C, and the temperature is measured to a maximum of 40 ° C. In addition, those used in Examples and Comparative Examples The abbreviations are as follows: PDMA: pyromellitic acid BTDA: 3,3,4,4'-benzophenone tetrahydroanhydride DDE: 4,4-diaminodiphenyl ether • MABA: 2'-methoxy- 4,4'-Diaminobenzidine aniline (Synthesis Example 1) In a glass reactor, 2 5 3 2 g of N, N-dimethylacetamidamine was put under nitrogen, and then 0.5 mol was added with stirring. DDE and 0.5 mol ΑΑΒΑ, completely dissolved it. The solution was cooled to 10 ° C, and the reaction solution was maintained at a temperature below 30 ° C. 1 mole of ρ μ DA was added in small amounts at a time. After the addition, the mixture was stirred at room temperature for 2 hours to complete the polymerization. Reaction # The obtained polyimide precursor solution had a polymer concentration of 15% by weight and a pseudoviscosity using B-type viscosity δ at 25C of 1000 mPa · s. (Synthesis Example 2) Except the use of 1 mole DDE as the diamine Component, except that 1 mol BTDA is acid anhydride, the polyimide precursor solution was adjusted in the same manner as in Synthesis Example 1. The obtained polyimide precursor solution was 15% by weight of the polymer concentration and used a B-type viscosity meter to 2 The pseudoviscosity at 5 ° C is 300 m P a. S. -14- 200536444 (12) Example 1 Electrolytic copper fan with the same shape as 3 5 // m roll (manufactured by Gourde) The roughened surface is the bottom layer. Using a die coater, the polyimide precursor solution 2 adjusted in Synthesis Example 2 was applied to a uniform thickness of 20 // m, and then continuously processed in a hot air drying furnace at 1 20 ° C. The solvent was removed. Next, the polyimide precursor solution 1 prepared in Synthesis Example 1 was adjusted on the polyimide precursor layer using a reverse roll coater. Uniformly apply 200 # m as φ as the base layer. After continuous processing in a hot air drying oven at 120 ° C to remove the solvent, the polyimide precursor solution 2 adjusted in Synthesis Example 2 was applied to form a uniform 40 / / m thickness, followed by a hot air drying furnace in 30 minutes to increase the temperature from 120 ° C to 3 60 t. Heat treatment 醯 imidization, to obtain a 25 // m thickness poly 醯 imide resin layer without bending or flexing a good plane Single-sided conductor laminate (copper a). However, the base point for measuring the thickness of the bottom layer is 1/2 of the thickness of the rough surface of the conductor. The 180 ° tensile peel strength (JIS C 5016) measured between the copper foil layer and the polyimide resin layer of this single-sided conductor laminate a was 1.8 Kg / cm. Next, the conductor side of the single-sided conductor laminate a was subjected to circuit processing, and the polyimide film exposed when the unnecessary metal foil was removed was not produced-the film was deflected, and the linear expansion coefficient of the etched film was 2 3 · 5 x 1 〇-6 (1 / Examples 2 to 3 and Comparative Examples 1 to 3 The thicknesses of the polyimide resins of the bottom layer, the base layer and the top layer of Example 1 were changed, and the same drying was performed, followed by a hot air drying furnace with a thickness of 3 The temperature was raised from 120 ° C to 360 ° in 0 minutes: heat treatment to obtain a single-sided conductor laminate -15- (13) 200536444 Object a. The single-sided conductor laminate a was bent and burnt. Table 1 and Table 1 show the tensile peel strength of 80 °, the polyimide film exposed when the circuit is applied to the conductor side to remove unnecessary metal foil, and the linear expansion coefficient of the etched film. 2.
表1 實施例 底層厚 基層厚 頂層厚 接著力 單面貼銅品 (// m) (// m) (// m) (Kg/cm) 的燒曲狀況 1 1 . 1 2 1.5 2.4 1.8 無撓曲 2 1 .5 20.7 2.8 2.0 無撓曲 3 2.0 20.0 3.0 1.9 _無撓曲_ 表2 比較例 底層厚 (// m) 基層厚 (β m) 頂層厚 (U m) 接著力 (Kg/cm) 單面貼銅品 的撓曲狀況 1 2.4 2 1.5 1 . 1 1 .7 6 mm (於頂側產生 撓曲） 2 2.8 20.Ί 1 .5 1 .6 2 mm (於頂側產生 撓曲） 3 3.0 20.0 2.0 1.6 10 mm (於頂側產 生撓曲） 4 2.5 20.0 2.5 1.6 7 mm (於頂側產生 撓曲） -16- (14) (14)200536444 〔產業上之利用領域〕 本發明的可撓性印刷配線板用基板及其製造方法，係、 與導體接觸的底層及導體與反側頂層的中間配置由至少一 種低熱膨脹性聚醯亞胺樹脂所成之基層，且底層與頂層由 比基層的熱膨脹係數大的熱可塑性聚醯亞胺系樹脂所成， 於加工後得到薄膜產生撓曲少品質安定利用於產業的可能 性高的基板。Table 1 Example Bottom Layer Thick Base Layer Thick Top Layer Thick Adhesive Copper Products (// m) (/ m) (/ m) (/ m) (Kg / cm) Scorching Condition 1 1. 1 2 1.5 2.4 1.8 None Deflection 2 1 .5 20.7 2.8 2.0 No deflection 3 2.0 20.0 3.0 1.9 _No deflection_ Table 2 Comparative example Bottom thickness (// m) Base thickness (β m) Top thickness (U m) Adhesive force (Kg / cm) Deflection of single-sided copper-clad products 1 2.4 2 1.5 1.. 1 1 .7 6 mm (deflection on the top side) 2 2.8 20.Ί 1 .5 1 .6 2 mm (deflection on the top side (3) 2 3.0 20.0 2.0 1.6 10 mm (deflection on the top side) 4 2.5 20.0 2.5 1.6 7 mm (deflection on the top side) -16- (14) (14) 200536444 [Industrial use area] The invention relates to a substrate for a flexible printed wiring board and a method for manufacturing the same. A base layer made of at least one low thermal expansion polyimide resin is arranged between the bottom layer in contact with the conductor and the middle layer between the conductor and the top layer on the opposite side. The top layer is made of a thermoplastic polyimide-based resin with a larger thermal expansion coefficient than the base layer. After processing, a thin film with low distortion and high quality can be used in the industry.
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