TWI687311B - Polyimide dry film and application thereof - Google Patents

Abstract

A polyimide dry film including a substrate and a polyimide layer is provided. The polyimide layer contains (a) a polyimide precursor or soluble polyimide and (b) a solvent. The solvent includes a hydrophilic solvent and a hydrophobic solvent and the weight ratio of the hydrophilic solvent to the hydrophobic solvent is in the range from about 0.05 to about 2. The polyimide dry film of the present disclosure has water absorbability and is relatively stable even in the presence of water, and the surface thereof is not sticky. The resulting polyimide has excellent physical properties and can be used in the process in which water or an aqueous solution is involved to form a coverlay with excellent physical properties.

Description

Polyimide dry film and its use

The invention relates to a polyimide layer dry film, in particular to a polyimide layer dry film suitable for a wet process, and a method for using the above dry film.

In recent years, due to the emphasis on light, thin, short, and small electronic products, the size of various electronic components must also be made smaller and smaller. Under this development trend, flexible printed circuit boards that are light, thin, and high temperature resistant, and can be mass-produced have more room for development. At present, the popular electronic products such as mobile phones, liquid crystal displays and organic light-emitting diodes can see traces of flexible printed circuit boards. Flexible printed circuit (FPC) is obtained by arranging circuits and other electronic components on a flexible substrate, which has better flexibility than printed circuit boards using traditional silicon substrates or glass substrates. It can also be called soft board. A coverlay is usually added on the surface of the flexible board, which can be used as an insulating protective layer to protect the copper circuit on the surface of the flexible board and increase the bending resistance of the circuit. Suitable cover film materials must have better heat resistance, dimensional stability, insulating properties and chemical resistance. In general, the method of laminating the cover film on the soft board is as follows: first, the cover film is processed into a prescribed shape, so that the cover film has an opening corresponding to the circuit on the soft board, and an adhesive layer is applied on the surface of the cover film side , And then align the cover film to the corresponding position of the flexible board, and then lamination (lamination) for lamination. However, because the above method must perform processes such as processing and opening on a very thin cover film, and almost all rely on manual operation when the cover film is attached to the flexible board, it causes problems such as low process yield and high cost, so it cannot be satisfied More precise assembly requirements; in addition, there are adhesive overflow problems. In order to overcome the above-mentioned problems, it is known that it can be improved by using a photo-imageable coverlay (PIC). The photo-imageable coverlay does not need to be pre-opened, and the originally complicated and complicated process will be greatly simplified. However, when using a dry lamination process to attach the photosensitive cover film to a patterned circuit board, undesirable gases may remain between the patterned circuit board and the photosensitive cover film, which will affect the reliability of the final product Degree and quality. In order to remove the gas between the circuit board and the photosensitive cover film, some industries use high pressure degassing machines (high pressure degassing machine) to eliminate the bubbles generated during the bonding process, but it is difficult to completely remove the bubbles, and it is easy to produce complex Bubble phenomenon, or you can use vacuum laminating equipment (for example, vacuum laminator or vacuum hot press), after the air is first exhausted, and then pressurized lamination, however, use vacuum pressure Most of the methods of membrane equipment can only be pressed in a single piece, that is, after each pressing step is completed, a pause is required to remove the test piece that has been pressed and replace it with another test piece. Not only is it time-consuming, it cannot achieve the goal of rapid production, but also the equipment is expensive and not cost-effective. In the wet lamination process, a liquid (usually water or an aqueous solution) is first applied to the surface to be laminated to fill the concave area of the surface, so that the air existing between the cover film material and the surface to be laminated can be excluded. However, at present, most photosensitive cover films are photosensitive dry film solder mask (DFSM), which are mostly composed of epoxy resin or acrylate resin; however, epoxy resin and acrylate The cover film made of resin has insufficient heat resistance, insulation, chemical resistance and mechanical strength for high-end products. Moreover, because the organic solvent content of the photosensitive solder resist dry film is less than 1 wt%, it is not Suitable for wet lamination process. Another photosensitive cover film is a solvent-containing dry film, such as a polyimide dry film, although the polyimide dry film has better heat resistance, dimensional stability, insulating properties, and chemical resistance. However, if the selected solvent has poor compatibility with water or aqueous solutions, it is also not suitable for wet compression processes, and polyimide and its precursors (such as polyamic acid or polyamic acid ester, etc.) Due to easy hydrolysis, it leads to chain scission or premature amide imidization, resulting in undesirable low molecular weight polyimide precipitation, which affects the properties of the resulting cover film. Therefore, it is considered in the technical field that polyimide dry film generally needs to be at a low temperature It can also be stored or processed in a water-free environment, but it is not suitable for wet lamination processes. Therefore, there is a need in the technical field for a novel dry film that can be easily pressed onto a patterned surface without generating excessive gas residues, and can provide a coating with good heat resistance, insulation, chemical resistance, and mechanical strength membrane. In addition, there is also a need in the technical field for a more economical and more convenient lamination method to apply a cover film to the patterned surface.

One aspect of the present invention is to provide a polyimide dry film including a base material and a polyimide layer, wherein the polyimide layer includes: (a) a polyimide precursor or a soluble polyimide and ( b) A solvent, wherein the solvent comprises a hydrophilic solvent and a hydrophobic solvent, and the weight ratio of the hydrophilic solvent to the hydrophobic solvent is between about 0.05 and about 2. Another aspect of the present invention is to provide a method for applying the above dry film on a substrate. The polyimide dry film of the present invention can be applied to the substrate without using the prior art high-pressure deaerator or vacuum film pressing equipment, and can be applied to the wet process, and retains the good heat resistance of the polyimide dry film , Dimensional stability, insulation characteristics and chemical resistance, not only the process is simple, the equipment is easy to obtain, it is more cost-effective than the previous technology.

式(A) 其中， G為四價有機基團； P為二價有機基團； n為大於0之整數，較佳是1至1000之整數。 可視需要使用不同基團對上述聚醯亞胺前驅物進行改質。例如，藉由感光性基團進行改質可製備感光型聚醯亞胺前驅物；或藉由調整與式(A)重複單元鍵結之末端基團，可改良聚醯亞胺前驅物之反應性及改良後續製得之聚醯亞胺之性質。 舉例言之，中華民國發明專利第100149594號申請案揭示具有以下式(1)至(4)表示之重覆單元之聚醯亞胺前驅物：

(1)，

(2)，

(3)，或

(4)， 其中，G₁ 獨立為四價有機基團； R_x 各自獨立為H或乙烯系不飽和基； R各自獨立為C₁ -C₁₄ 烷基、C₆ -C₁₄ 芳基、C₆ -C₁₄ 芳烷基、酚基或乙烯系不飽和基； D各自獨立為含氮之雜環基團或為OR*基團，其中R*為C₁ -C₂₀ 烷基； m為0至100之整數，較佳是5至50之整數，更佳是10至25之整數；及 G及P係如本文先前所定義。 上述乙烯系不飽和基，並無特殊限制，其實例包括(但不限於)乙烯基、丙烯基、甲基丙烯基、正丁烯基、異丁烯基、乙烯基苯基、丙烯基苯基、丙烯氧基甲基、丙烯氧基乙基、丙烯氧基丙基、丙烯氧基丁基、丙烯氧基戊基、丙烯氧基己基、甲基丙烯氧基甲基、甲基丙烯氧基乙基、甲基丙烯氧基丙基、甲基丙烯氧基丁基、甲基丙烯氧基戊基、甲基丙烯氧基己基、具下式(5)的基團及具下式(6)的基團：

(5)

(6)， 其中R₁₂ 為伸苯基、C₁ -C₈ 伸烷基、C₂ -C₈ 伸烯基、C₃ -C₈ 伸環烷基或C₁ -C₈ 羥基伸烷基；且R₁₃ 為氫或C₁ -C₄ 烷基。 (b) 可溶性聚醯亞胺 一般聚醯亞胺雖具有耐熱性及耐化學性佳之優點，但卻有加工性不良之缺點，且能溶解聚醯亞胺之溶劑不多。因此，在應用時多半係使用以聚醯亞胺前驅物進行加工，並在製程後期將其醯亞胺化成聚醯亞胺。可溶性聚醯亞胺則是在聚醯亞胺結構上進行改良，增加聚醯亞胺與溶劑間之溶解度，以改善其加工性。上述溶劑之種類可例如本文以下所述者。 本發明之可溶性聚醯亞胺並無特殊限制，且可為本發明所屬技術領域中具有通常知識者所習知者，如中華民國發明專利第097101740號、第099105794號、第097138725號或第097138792號申請案。上述文獻係全文併入本文中做為參考。 本發明之可溶性聚醯亞胺主要係具有以式(B)表示之重複單元：

式(B) 其中， C'為四價有機基團； E'為二價有機基團； t'為大於0之整數，較佳是1至1000之整數。 上述C'四價有機基團之態樣可如本文先前對G基團所定義者。 上述E'二價有機基團之態樣可如本文先前對P基團所定義者。 可視需要使用不同基團對上述可溶性聚醯亞胺進行改質。例如藉由感光性基團進行改質可製備感光型聚醯亞胺；或藉由調整與式(B)重複單元鍵結之末端基團，可改良可溶性聚醯亞胺之性質。 藉由調整與式(B)重複單元鍵結之末端基團之可得經改質可溶性聚醯亞胺，其結構例如(但不限於)：

(1') ；

(2')；

(3')； 其中， R₂₀ '為C₂ -C₂₀ 飽和或不飽和之2價有基機團，較佳為-C=C-、

、

； R₂₁ '為C₂ -C₂₀ 可為雜原子取代之具不飽和基之1價有基機團或-OH C'、E'及t'’係如本文先前所定義。 藉由感光性基團進行改質之可溶性聚醯亞胺較佳（但不限於）係第099105794號、第099105794號、第097138725號或第097138792號申請案所揭示者。 3. 溶劑 一般而言，聚醯亞胺前驅物及可溶性聚醯亞胺係在極性非質子有機溶劑下製備或調配。 習知技術中為避免乾膜在使用時產生高濃度之揮發性有機物及降低乾膜在儲存時發生塗布膠液流動的溢膠(excessive glue)現象，會將完成塗佈之乾膜半成品送入烘箱，使樹脂層乾燥並與基材完全貼合。有機溶劑於此步驟幾乎完全揮發，因此，一般而言，習知乾膜產品之有機溶劑含量小於1 wt%。此外，乾膜產品需儲存於低溫環境，以降低水解現象。 不同於以往技術，本發明之乾膜可含有溶劑，且本案發明人經廣泛研究和反覆實驗後發現：藉由控制溶劑種類及含量比例，所得聚醯亞胺乾膜具有吸水性，且縱使在水存在下其性質相對穩定，且表面不沾黏，轉印能力佳，且由其固化所製得之聚醯亞胺具有良好的物性。因此，不但可增加儲存安定性，且可應用至需使用水或水性溶液的加工製程。 本發明所用之溶劑包含親水溶劑與疏水溶劑，其中該親水溶劑與該疏水溶劑之重量比係介於約0.05至約2之間，較佳介於約0.1至約1之間，更佳係介於約0.25至約0.8之間，所得乾膜具有吸水性，良好轉印能力，表面不沾黏，且性質穩定，並具有良好物性。當親水溶劑與疏水溶劑之重量比過低時（例如低於0.05時），聚醯亞胺乾膜吸水性不佳，且聚醯亞胺層對基板之密著性較差；當親水溶劑與疏水溶劑之重量比過高時，尤其是大於2時，將使乾膜表面易有沾黏現象，操作性較差，不易對位，且不利於重工。 本發明添加疏水溶劑可與液體(水或醇類)互溶，可用於本發明之親水溶劑包含：二甲基亞碸(DMSO)、二乙基亞碸、N,N-二甲基甲醯胺(DMF)、N,N-二乙基甲醯胺、N,N-二甲基乙醯胺(N,N-dimethylacetamide，DMAc)、N,N-二乙基乙醯胺、N-甲基-2-吡咯烷酮(N-methyl-2-pyrrolidone，NMP)、N-乙基-2-吡咯烷酮(N-ethyl-2-pyrrolidone，NEP)、N-丙基-2-吡咯烷酮、N-乙烯基-2-吡咯烷酮、苯酚、鄰甲酚、間甲酚、對甲酚、二甲苯酚、鹵代苯酚、鄰苯二酚、四氫呋喃(THF)、二噁烷、二氧戊環、環丙二醇甲醚(PGME)、四乙二醇二甲醚(TGDE)、丁基溶纖劑、γ-丁內酯(γ-butyrolactone；GBL)、二甲苯(xylene)、甲苯(toluene)、六甲基鄰醯胺、丙二醇甲醚醋酸酯(PGMEA)或其混合物。 根據本發明之一實施例，所用親水溶劑較佳包含：二乙基亞碸、N,N-二甲基甲醯胺、N,N-二乙基甲醯胺、N,N-二甲基乙醯胺、N,N-二乙基乙醯胺、N-甲基-2-吡咯烷酮、N-乙基-2-吡咯烷酮、N-丙基-2-吡咯烷酮、環丙二醇甲醚、γ-丁內酯、丙二醇甲醚醋酸酯或其混合物。更佳包含：N,N-二甲基甲醯胺、N-甲基-2-吡咯烷酮、N-乙基-2-吡咯烷酮、γ-丁內酯或其混合物。 本發明添加疏水溶劑可提升乾膜對水之穩定性外，同時可使乾膜表面不易有沾黏現象，操作性較佳。可用於本發明之疏水溶劑包含：

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、或其組合， 其中： R₁ ''、R₉ ''及R₁₀ ''各自獨立為C₁ -C₂₀ 烷基、C₂ -C₂₀ 烯基或C₂ -C₂₀ 炔基； R₇ ''為H或C₁ -C₃ 烷基； R₂ ''為C₁ -C₁₀ 烷基； R₃ ''為C₄ -C₂₀ 烷基或-C₂ -C₁₀ 烷基-O-C₂ -C₁₀ 烷基； R₄ ''及R₅ ''各自獨立為C₁ -C₁₀ 烷基，或R₄ ''及R₅ ''與其所連接之氧原子一起形成5至6員雜環； R₆ ''為C₄ -C₁₅ 烷基、C₄ -C₈ 環烷基或

； R₈ ''為C₂ -C₁₀ 伸烷基； R₁₁ ''及R₁₂ ''各自獨立為C₁ -C₁₀ 烷基； R₁₃ ''及R₁₄ ''各自獨立為C₁ -C₁₀ 烷基，或R₁₃ ''及R₁₄ ''與其所連接之氮原子一起形成5至6員雜環； R₁₅ ''為C₄ -C₁₅ 烷基或C₄ -C₈ 環烷基； R₁₆ ''為C₁ -C₄ 烷基；且 R₁₇ ''為C₄ -C₁₀ 烷基。 根據本發明之一實施例，所用疏水溶劑較佳包含：

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、

、

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、

、

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、N,N-二甲基癸醯胺((N,N- dimethylcapramide，簡稱DMC))或其組合。 在本發明中，溶劑總含量並無特殊限制，可視乾膜之製造程序或者後續加工製程所需進行調整。在本發明之一實施態樣中，以聚醯亞胺層總重量計，溶劑之總含量係介於約30 wt%至約70 wt%之間，較佳係介於約35 wt%至約65 wt%之間，更佳係介於約40 wt%至約60 wt%之間。 4. 添加劑 本發明之聚醯亞胺層可視需要含有本發明所屬技術領域中具有通常知識者習知之任何適當添加劑，例如(但不以此為限)：穩定劑(stabilizer)、閉環促進劑、整平劑、消泡劑、偶合劑、催化劑、丙烯酸酯類單體及光起始劑等。上述添加劑之含量亦為本發明所屬技術領域中具有通常知識者可經由例行實驗調整者。 在本發明之一實施態樣中，本發明之聚醯亞胺層可視需要含有選自下列之穩定劑：

、

或其組合， 其中： R₁₇ ''、R₁₈ ''、R₁₉ ''及R₂₀ ''各自獨立為C₁ -C₄ 烷基，或者R₁₉ ''及R₂₀ ''與其連接之氧原子一起形成5至6員雜環，或者R₁₉ ''及R₁₇ ''或 R₂₀ ''及R₁₈ ''與其連接之氧原子及氮原子一起形成5至6員雜環； R₂₁ ''及R₂₂ ''各自獨立為C₁ -C₄ 烷基，或者R₂₁ ''與R₂₂ ''與其連接之碳原子一起形成5至6員碳環；且 R₂₃ ''及R₂₄ ''各自獨立為C₁ -C₄ 烷基。 根據本發明之一較佳實施例，該穩定劑較佳包含：

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或其組合。 添加穩定劑有助於提升乾膜的穩定性及操作性，並進一步提升後續形成之聚醯亞胺的物性。在本發明之一實施態樣中，以聚醯亞胺層總重量計，穩定劑之總含量係介於約0.01wt%至約5wt%之間，較佳係介於約0.05wt%至約3wt%之間。若含量超過5wt%可能導致形成之聚醯亞胺物性(例如可撓曲性)降低 在本發明之一實施態樣中，該聚醯亞胺層為感光型聚醯亞胺，可視需要選用添加劑包含光起始劑、丙烯酸酯類單體。 上述光起始劑可單獨使用或混合多種使用。適用於本發明之光起始劑係用來經光照射以產生自由基，透過自由基之傳遞來引發聚合反應。可用於本發明之光起始劑並無特殊限制。較佳地，所用之光起始劑係包含可吸收波長約350奈米至約500奈米之光而產生自由基的化合物。 光起始劑之用量，以100重量份之聚醯亞胺前驅物或可溶性聚醯亞胺固含量計，係約0.01至約20重量份，較佳係約0.05至約5重量份。適用於本發明之光起始劑可例如選自以下群組：二苯甲酮、二苯乙醇酮、2-羥基-2-甲基-1-苯丙酮、2,2-二甲氧基-1,2-二苯基乙-1-酮、1-羥基-環己基-苯基酮、2,4,6-三甲基苯甲醯基二苯基膦氧化物、肟酯、2,4,6-三甲基苯甲醯基二苯基膦氧化物（2,4,6-trimethylbenzoyl diphenyl phosphine oxide）、雙4,4'-二乙基胺基苯甲酮（bis-4,4'-diethylaminobenzophenone）、苯甲酮（benzophenone）、樟腦酮（camphorquinone）、3,5-雙(二乙基胺基苯亞甲基)-N-甲基-4-哌啶酮（3,5-bis(diethylaminobenzylidene)- N-methyl-4-piperidone）、3,5-雙(二甲基胺基苯亞甲基)-N-甲基-4-哌啶酮（3,5-bis(dimethylaminobenzylidene)-N-methyl-4- piperidone）、3,5-雙(二乙基胺基苯亞甲基)-N-乙基-4-哌啶酮（3,5-bis(diethylaminobenzylidene)-N-ethyl-4-piperidone）、3,3'-羰基-雙(7-二乙基胺基)香豆素（3,3'-carbonyl- bis(7-diethylamino)cumarin）、3,3'-羰基-雙(7-二甲基胺基)香豆素(3,3'-carbonyl-bis(7-dimethylamino)cumarin)、核黃素四丁酸酯(riboflavin tetrabutyrate)、2-甲基-1-[4-(甲基硫代)苯基]-2-嗎啉基丙-1-酮(2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan -1-one)、2,4-二甲基硫基氧雜蒽酮(2,4-dimethylthioxanthone)、2,4-二乙基硫基氧雜蒽酮(2,4-diethylthioxanthone)、2,4-二異丙基硫基氧雜蒽酮(2,4-diisopropylthioxanthone)、3,5-二甲基硫基氧雜蒽酮(3,5-dimethylthioxanthone)、3,5-二異丙基硫基氧雜蒽酮(3,5-diisopropylthioxanthone)、1-苯基-2-(乙氧基羰基)氧亞胺基丙-1-酮(1-phenyl-2-(ethoxycarbonyl)oxyiminopropan-1-one)、安息香醚(benzoin ether)、安息香異丙基醚(bezoin isopropyl ether)、苯繞蔥酮(benzanthrone)、5-硝基苊(5-nitroacenaphthene)、2-硝基芴(2-nitrofluorene)、菎酮(anthrone)、1,2-苯並并蒽(1,2-benzanthraquinone)、1-苯基-5-巰基-1H-四氮唑(1-phenyl-5-mercapto-1H-tetrazole)、噻噸-9-酮(thioxanthen- 9-one)、10-噻噸酮(10-thioxanthenone)、3-吲哚乙醯(3-acetylindole)、2,6-二(對二甲基胺基苯亞甲基)-4-羧基環己酮(2,6-di(p-dimethylaminobenzal)-4-carboxycyclohexanone)、2,6-二(對二甲基胺基苯亞甲基)-4-羥基環己酮(2,6-di (p-dimethylaminobenzal)-4-hydroxycyclohexanone)、2,6-二(對二乙基胺基苯亞甲基)-4-羧基環己酮(2,6-di(p-diethylaminobenzal) -4-carboxcyclohexanone)、2,6-二(對二乙基胺基苯亞甲基)-4-羥基環己酮(2,6-di(p-diethylaminobenzal))-4-hydroxycyclohexanone)、4,6-二甲基-7-乙基胺基香豆素(4,6-dimethyl-7- ethylaminocumarin)、7-二乙基胺基-4-甲基香豆素(7-diethylamino-4-methylcumarin)、7-二乙基胺基-3-(1-甲基苯并咪唑基)香豆素(7-diethylamino-3-(1-methylbenzoimidazolyl) cumarin)、3-(2-苯并咪唑基)-7-二甲乙基胺基香豆素(3-(2-benzoimidazolyl)-7-diethylaminocumarin)、3-(2-苯並并噻唑基)-7-二甲乙基胺基香豆素(3-(2-benzothiazolyl)-7- diethylaminocumarin)、2-(對二甲基胺基苯乙烯基)苯並噁唑(2-(p-dimethylaminostyryl)benzooxazole)、2-(對二甲基胺基苯乙烯基)喹啉(2-(p-dimethylaminostyryl)quinoline)、4-(對二甲基胺基苯乙烯基)喹啉(4-(p-dimethylaminostyryl)quinoline)、2-(對二甲基胺基苯乙烯基)苯並并噻唑(2-(p-dimethylaminostyryl) benzothiazole)、2-(對二甲基胺基苯乙烯基)-3,3-二甲基-3H-吲哚(2-(p-dimethylaminostyryl)-3,3- dimethyl-3H-indole)及其組合。較佳之光起始劑為二苯甲酮、2,4,6-三甲基苯甲醯基二苯基膦氧化物、二苯乙醇酮、2-羥基-2-甲基-1-苯丙酮、2,2-二甲氧基-1,2-二苯基乙-1-酮、1-羥基-環己基-苯基酮、2,4,6-三甲基苯甲醯基二苯基膦氧化物、肟酯或其組合。 上述丙烯酸酯類單體，係具有至少一個-C=C-之丙烯酸酯類單體，較佳為具有兩個或兩個以上-C=C-之多官能基丙烯酸酯單體(multi-functional acrylate monomer)，添加這類單體能使分子與分子間形成交聯，便於提高組合物的實用度。較佳地，本發明使用選自以下群組之丙烯酸酯類單體：乙二醇二(甲基丙烯酸)酯、乙二醇二丙烯酸酯、雙酚A乙二醇-改質二丙烯酸酯、雙酚A乙二醇-改質二(甲基丙烯酸)酯、雙酚F乙二醇-改質二丙烯酸酯、雙酚F乙二醇-改質二(甲基丙烯酸)酯、丙二醇二(甲基丙烯酸)酯、三丙烯乙二醇二丙烯酸酯、乙氧基化三羥甲基丙烷三丙烯酸酯、二季戊四醇六丙烯酸酯、三羥甲基丙烷三丙烯酸酯、三羥甲基丙烷三(甲基丙烯酸)酯、四羥基甲烷三丙烯酸酯、四羥基甲烷三(甲基丙烯酸)酯、及其組合。當丙烯酸酯類單體存在時，以100重量份之聚醯亞胺前驅物或可溶性聚醯亞胺固含量計，其添加量係約5至約80重量份，較佳為約10至約40重量份。 可用於本發明之偶合劑可選自由以下所組成之群組(但不以此為限)：3-胺基丙基三甲氧基矽烷(APrTMOS)、3-三胺基丙基三乙氧基矽烷(APrTEOS)、3-胺基苯基三甲氧基矽烷(APTMOS)、3-胺基苯基三乙氧基矽烷(APTEOS)及其組合。 根據本發明之一實施態様，可視需要在本發明之聚醯亞胺前驅物之製備過程中加入閉環促進劑。較佳選用能在加熱，產生鹼性化合物，提供鹼性環境促進醯亞胺化(imidization)反應進行之閉環促進劑。可用於本發明之閉環促進劑包含:

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Y^θ 、

Y^θ 、

Y^θ 、

Y^θ 或

Y^θ ，其中Y^θ 為陰離子基團。 形成乾膜之方法 本發明之聚醯亞胺乾膜可藉由例如下列步驟製備： (1) 準備聚醯亞胺調配物，混合包含聚醯亞胺前驅物或可溶性聚醯亞胺和親水溶劑； (2) 添加適量之疏水溶劑、及視需要之添加劑至前述調配物中； (3) 將步驟(2)所得之調配物塗佈於基材形成一乾膜半成品； (4) 將乾膜半成品送入烘烤爐，加熱乾燥移除部份溶劑，藉此調整聚醯亞胺層中之溶劑含量；形成一聚醯亞胺乾膜； (5) 可視需要於聚醯亞胺乾膜上施加一保護膜。 上述步驟(4)加熱所需溫度及時間並無特殊限制，其主要目的係以減少在樹脂層中的溶劑含量，例如可使用介於60℃至150℃間中之一適合溫度，歷時30秒至10分鐘進行加熱乾燥。在傳統製備乾膜過程中，為避免使用乾膜時產生高濃度之揮發性有機物，在相對於前述步驟(4)的移除溶劑步驟中，常加熱致使溶劑達幾乎完全揮發程度(含量小於1 wt%)，然而，與習知步驟相反地，本發明並未在此步驟中將溶劑完全移除，反而保留適量比例之親水溶劑及疏水性溶劑於乾膜中。 上述步驟(4)的溶劑包含親水溶劑及疏水溶劑。一般而言，藉由不同溶劑種類的沸點差異，適當地調整加熱溫度及時間，可控制所欲得到之乾膜中溶劑之總含量及比例，例如將親水溶劑與疏水溶劑之重量比係介於約0.05至約2之間。 上述步驟(5)的保護膜，其例如但不限於：聚酯樹脂(polyester resin)，如聚對苯二甲酸乙二酯(polyethylene terephthalate, PET)或聚萘二甲酸乙二酯(polyethylene naphthalate, PEN)；聚甲基丙烯酸酯樹脂(polymethacrylate resin)，如聚甲基丙烯酸甲酯(polymethyl methacrylate, PMMA)；聚醯亞胺樹脂(polyimide resin)；聚苯乙烯樹脂(polystyrene resin)；聚環烯烴樹脂(polycycloolefin resin)；聚烯烴樹脂(polycycloolefin resin)；聚碳酸酯樹脂(polycarbonate resin)；聚胺基甲酸酯樹脂(polyurethane resin)；三醋酸纖維素(triacetate cellulose, TAC)；或彼等之混合物。較佳為聚對苯二甲酸乙二酯、聚甲基丙烯酸甲酯、聚環烯烴樹脂、三醋酸纖維素或其混合物，更佳為聚對苯二甲酸乙二酯。 於基板上施加乾膜之方法 本發明另提供一種於基板上施加聚醯亞胺乾膜之方法，其包含：於移除視需要添加之保護膜後，將上述聚醯亞胺乾膜以聚醯亞胺層之面與基板進行壓合。上述基板可為印刷電路板、晶圓、玻璃、顯示器或觸控面板，或其他基板。根據本發明之一實施態樣，上述基板係為印刷電路板，尤佳為軟性印刷電路板(Flexible Print Circuit；FPC)，且乾膜之聚醯亞胺層係壓合至該圖案化表面。 於基板上施加乾膜可選任何方式，較佳以卷對卷(roll to roll)方式進行操作壓合，捲對捲之操作係本發明所屬技術領域中具有通常知識者所熟知者，係指透過自呈捲繞形式之樣品拉出樣品，經處理後再以捲繞方式將經處理後之樣品收回。舉例言之，如圖1所示，呈捲繞形式之基板A於拉出後，在滾輪2及3之間與來自乾膜捲1之乾膜進行滾輪壓合，再以捲繞方式收回形成產品B。本發明之乾膜可使用連續製程壓合至基板，有利於簡化製程及加快製程速度。上述壓合方式，例如但不限於：滾輪壓合(roller lamination)、熱板壓合(hot press)、真空壓合(vacuum lamination)、真空快壓(vacuum press)或濕式壓合(wet lamination)。 如前所述，藉由控制適當的溶劑種類及含量比例，本發明之聚醯亞胺乾膜具有吸水性，且表面不沾黏，並且所形成之覆蓋膜具有優異的物性。此外，縱使在水存在下，也能保持穩定，不會影響所得聚醯亞胺之性質，因此適用於濕式壓合，且藉由濕式壓合可提升乾膜對於圖案化基板之均覆性。 圖2為本發明之乾膜應用於濕式壓合之示意圖。如圖2所示，本發明提供一種藉由濕式壓合於基板上施加乾膜之方法，該方法包含： (1) 於該基板10待壓合之表面11上施加液體30；及 (2) 將本發明之乾膜20（包含基材21及聚醯亞胺層22）以聚醯亞胺層之面壓合至該基板10待壓合之表面11。 步驟(1)中所用之液體包含水、醇類溶劑或其組合，以使製程更為環保且更經濟。較佳液體為甲醇、乙醇、異丙醇、丁醇、水或其混合物。該液體可填覆於待壓合表面11上之凹陷區域，形成一層液體膜，藉此趕走原存在於凹陷區域中之空氣。 在步驟(2)中，係藉由滾輪將乾膜20壓合至該基板10待壓合之表面11。此時步驟(1)中所用之液體可被吸收至本發明之聚醯亞胺層中。較佳係在加熱下進行步驟(2)，例如在60^o C至100^o C之溫度，以提升聚醯亞胺層與帶壓合表面間之均覆性及密著性。 若有液體殘留時，可視需要進行一靜置步驟(3)，在壓合後靜置一段時間（例如，5分鐘至240分鐘），將殘留之液體充分吸收至乾膜中。 本發明另提供一種濕式壓合用系統，其包含: (1) 本發明之乾膜； (2) 基板；及 (3) 液體。 上述之基板、液體係如前所述。 本發明之乾膜，特別係使用於濕式製程時，具有良好均覆性，並且相較於習知的乾膜，可以有效填覆厚銅線路。 本發明乾膜之應用 本發明之聚醯亞胺乾膜，可在不使用高壓脫泡機或真空壓膜設備的情況下，使用一般壓合技術（特別是濕式壓合）與如印刷電路板、晶圓、玻璃、顯示器或觸控面板之基板進行壓合，因此可在相較於先前技術簡單之製程步驟下進行操作，所用設備亦較先前技術所使用者更容易取得。因此，相較於使用真空壓膜機或其他製程設備之先前技術更為符合成本效益。 本發明之乾膜適用於印刷電路板，作為供保護印刷電路板上之塗膜用的覆蓋膜，具絕緣性，可保護線路，且具有避免線路氧化及焊接短路之優異效能。此外，本發明之乾膜因具有高解析度、顯影速度快、耐電解電鍍性、耐無電解電鍍性及耐高溫高濕性等特性，因此也可以使用於晶圓製程中作為光阻劑。 此外，本發明之聚醯亞胺乾膜，縱使在水存在下其性質相對穩定，且表面不沾黏，轉印能力佳。此外，乾膜中的水份或溶劑可於後續製程中移除，不會影響所得聚醯亞胺之物理性質，因此，當用作覆蓋膜時尤具優勢。有鑑於此，在本發明之一較佳實施態樣中，係使用濕式製程將本發明之聚醯亞胺乾膜施加至基板上作為覆蓋膜。 圖3係以使用本發明之感光型聚醯亞胺乾膜作為軟性印刷電路板覆蓋膜為例，進一步說明其後續加工步驟（但不以此為限）： (1) 利用濕式壓合，將本發明之聚醯亞胺乾膜20與基板10壓合； (2) 在光罩40存在下，進行曝光，使本發明之聚醯亞胺前驅物或可溶性聚醯亞胺上之感光性基團（如具有乙烯系不飽和基之基團）發生交聯反應； (3) 移除乾膜20之支撐基材21，並進行曝後烤(Post-exposure Bake)； (4) 進行顯影，以移除非曝光區之聚醯亞胺層；及 (5) 視需要將聚醯亞胺前驅物醯亞胺化(固化)成聚醯亞胺。 上述步驟(2)之曝光步驟可以任何本發明所屬領域具有通常知識者所知之方式進行，例如，使用紫外線、可見光、電子束或雷射照射，較佳係使用紫外線。曝光能量及時間並無特別限制，為本發明所屬技術領域中具有通常知識者可視需要依其經驗調整者。根據本發明之一實施態樣，所用之曝光能量約50至1200mJ/cm² 。 上述步驟(3)之曝後烤係藉由加熱增加曝光區與非曝光區在顯影時的溶解度差異。加熱溫度及時間並無特殊限制，可視需要調整，只要能達成前述目的即可。加熱可以單階段或多階段進行。在本發明之一具體實施例中，係於60至150^o C之溫度範圍持續加熱5至90分鐘。聚醯亞胺層中所含之溶劑（例如前述親水、疏水溶劑）以及於濕式壓合時所吸收之液體可在此加熱步驟中部分排出。 上述步驟(4)係藉由顯影步驟使未經曝光區域之樹脂(使用負型感光型聚醯亞胺乾膜時)溶解去除或使經曝光區域之樹脂(使用正型感光型聚醯亞胺乾膜時)溶解去除，再以水進行清洗(rinse)，而得到所需之圖案。所使用之顯影劑，係本發明所屬技術領域中具有通常知識者所熟知者。顯影劑之實例例如(但不限於)K₂ CO₃ 水溶液、Na₂ CO₃ 水溶液、KOH水溶液、NaOH水溶液、四甲基氫氧化銨(TMAH)水溶液。 此外，當聚醯亞胺層包含聚醯亞胺前驅物時，進行步驟(5)，例如藉由加熱，使該聚醯亞胺前驅物環化、聚合成聚醯亞胺。並且將聚醯亞胺層中尚存的溶劑或液體，進一步移除。 以下實施例係用於對本發明作進一步說明，唯非用以限制本發明之範圍。任何熟悉此項技藝之人士可輕易達成之修飾及改變均包括於本案說明書揭示內容及所附申請專利範圍之範圍內。 實施例 以下實施例中所提及的縮寫定義如下： DA1：

1-MI：1-甲基咪唑(1-methylimidazole) PTZ：吩噻嗪(10H-phenothiazine) DA3：

DMC：N,N-二甲基癸醯胺

NOP：

NOEP：

D-PC：

醋酸癸酯：

1,6-己二醇二丙烯酸酯：

製備例 1 ：合成感光型聚醯亞胺前驅樹脂PAA-1 將21.81克(0.1莫耳)的均苯四酸二酐(pyromellitic dianhydride，下文簡稱為PMDA)溶於200克的N-甲基吡咯烷酮(N-methyl-2- pyrrolidone；下文簡稱為NMP)中，加熱所得混合物至50℃且反應攪拌兩個小時。慢慢滴入1.161克(0.01莫耳)的丙烯酸2-羥基乙酯(2-hydroxyethyl acrylate，下文簡稱為HEA)，於50℃的固定溫度下反應攪拌兩個小時。其後，將20.024克(0.1莫耳)的4,4'-氧化二苯胺(4,4'-oxydianiline，下文簡稱為ODA) 加至溶液中，待完全溶解後，再於50℃的固定溫度下反應攪拌六個小時，可得到感光型聚醯亞胺前驅樹脂PAA-1，固形份約17wt%（在250或300℃下烘烤1小時移除所有溶劑後，量測烘烤前後的重量差，便可得到非揮發性物質的重量，計算其在PAA-1中的重量百分含量即為固形份）。製備例 2 ：合成感光型聚醯亞胺前驅樹脂PAA-2 將21.81克(0.1莫耳)的PMDA溶於200克的N-乙基吡咯烷酮(N-methyl-2-pyrrolidone；下文簡稱為NEP)中，加熱所得混合物至50℃且反應攪拌兩個小時。慢慢滴入1.161克(0.01莫耳)的HEA，於50℃的固定溫度下反應攪拌兩個小時。其後，將20.024克(0.1莫耳)的ODA加至溶液中，待完全溶解後，再於50℃的固定溫度下反應攪拌六個小時可得到感光型聚醯亞胺前驅樹脂PAA-2，固形份約17wt%（在250或300℃下烘烤1小時，量測其烘烤前後的重量差，便可得到實際非揮發性物質的重量，計算其在PAA-2中的重量百分含量即為固形份）。製備例 3 ：合成感光型聚醯亞胺前驅樹脂PAA-3 將21.81克(0.1莫耳)的PMDA溶於200克的NMP中，加熱至50℃且反應攪拌兩個小時。慢慢滴入13.01克(0.01莫耳)的甲基丙烯酸2-羥基乙酯(2-hydroxyethyl methacrylate；下文簡稱為HEMA)，於50℃的固定溫度 下反應攪拌兩個小時。再將20.024克(0.1莫耳)的ODA加至溶液中，待完全溶解後，再於50℃的固定溫度下反應攪拌六個小時，可得感光型聚醯亞胺前驅樹脂PAA-3，固形份約21wt%。製備例 4 ：合成感光型聚醯亞胺前驅樹脂PAA-4 將29.42克(0.1莫耳)的3,3,4,4-聯苯四甲酸二酐(4,4'-Biphthalic dianhydride；下文簡稱為BPDA)溶於200克的NMP中，加熱至50℃且反應攪拌兩個小時。慢慢滴入13.01克(0.01莫耳)的HEMA，於50℃的固定溫度 下反應攪拌24小時。再將32.024克(0.1莫耳)的間二(三氟甲基)對二胺基聯苯(2,2'-bis(trifluoromethyl) benzidine；下文簡稱為TFMB)加至溶液中，待完全溶解後，再於50℃的固定溫度下反應攪拌六個小時，可得感光型聚醯亞胺前驅樹脂PAA-4，固形份約20wt%。製備例 5 ： 合成聚醯亞胺前驅樹脂PAA-5 將21.81克(0.1莫耳)的PMDA溶於200克的NMP中，加熱至50℃且反應攪拌兩個小時。慢慢滴入0.601克(0.01莫耳)的異丙醇，於50℃的固定溫度下反應攪拌兩個小時。再將32.02克(0.1莫耳)的TFMB加至溶液中，待完全溶解後，再於50℃的固定溫度下反應攪拌六個小時，可得聚醯亞胺前驅樹脂PAA-5，固形份約21wt%。製備例 6 ：合成聚醯亞胺前驅樹脂PAA-6 將29.42克(0.1莫耳)的BPDA溶於200克的NMP中，加熱至50℃且反應攪拌兩個小時。慢慢滴入0.601克(0.01莫耳)的異丙醇，於50℃的固定溫度下反應攪拌兩個小時。再將20.024克(0.1莫耳)的ODA加至溶液中，待完全溶解後，再於50℃的固定溫度下反應攪拌六個小時，可得聚醯亞胺前驅樹脂PAA-6，固形份約19 wt %。製備例 7 ：合成具有羧基(-COOH)的可溶性聚醯亞胺SPI-1 稱取43.62克(0.2莫耳)的PMDA與30.43 g (0.2莫耳)的3,5-二胺基苯甲酸(3,5-diamino benzoic acid；下文簡稱為DABA)，加入300 mL NMP，於室溫下攪拌1小時，再升溫至50℃後攪拌4小時。4小時後，加入50 mL甲苯，在150℃下，以迪安-斯塔克(dean-stark)裝置除水。待除水完全後再去除甲苯，便可得到具有羧基的聚醯亞胺溶液SPI-1，固形份約19 wt%。製備例 8 ：合成異氰酸酯改質的可溶性聚醯亞胺SPI-2 稱取64.85克(0.2莫耳)的DA1與42.46克(0.2莫耳)的2,2'-二甲基聯苯基-4,4'-二胺(2,2'-dimethylbiphenyl-4,4'-diamine，下文簡稱為DMDB)，加入300 mL NMP，於室溫下攪拌1小時，再升溫至50°C後攪拌4小時。4小時後，加入50 mL甲苯，在130°C下，以迪安-斯塔克裝置除水。待除水、除甲苯完全後，將溶液降至室溫，再加入7克(0.05莫耳) 的丙烯酸2-異氰酸基乙酯(2-isocyanatoethyl acrylate，下文簡稱為2-IEA)、0.05克1-MI與0.06克PTZ。加完後將溶液升溫至80℃，攪拌8小時。即可得異氰酸酯改質的可溶性聚醯亞胺SPI-2，固形份約27 wt %。 製備例9：合成具有羧基(-COOH)的可溶性聚醯亞胺SPI-3 稱取100.074克(0.2莫耳)的DA3與42.46克(0.2莫耳)的DMDB，加入450毫升NMP，於室溫下攪拌1小時，再升溫至50℃後攪拌4小時。之後，加入50毫升甲苯，在130℃下，以迪安-斯塔克裝置除水。待除水、除甲苯完全後，得到具有-COOH基的可溶性聚醯亞胺SPI-3，固形份約24 wt %製備例 10 ：合成環氧改質的可溶性感光型聚醯亞胺SPI-4 稱取142.5克的由製備例9所制得的聚醯亞胺SPI-3，再加入6.11克(0.05莫耳)的甲基丙烯酸縮水甘油酯(glycidyl methacrylate，下文簡稱為GMA)、0.015克溴化四丁基銨(tetrabutylammonium bromide，下文簡稱為TBAB)與0.06克對苯二酚單甲醚(Hydroquinone Monomethyl Ether，下文簡稱為MEHQ)。加完後將溶液升溫至90°C，攪拌12小時，獲得環氧改質的可溶性感光型聚醯亞胺SPI-4，固型份約25 wt %。製備例 11 ： 合成具有壓克力感光基團的聚醯亞胺溶液SPI-5 稱取32.023克(0.1莫耳)的TFMB與48.8664克(0.11 mol)的4,4'-(六氟異丙烯)二酞酸酐(4,4'-(Hexafluoroisopropylidene)diphthalic anhydride，下文簡稱為6FDA)，加入300 mL NMP，於室溫下攪拌1小時。再升溫至50℃攪拌4小時。4小時後，加入50 mL的甲苯，在150°C下，以迪安-斯塔克裝置除水。待完全除水及除甲苯後，將2.322克(0.02莫耳)的HEA在50℃下，加入攪拌4小時，便可得到具有壓克力感光基團的聚醯亞胺溶液SPI-5，固形份約21 wt %。製備例 12 ：合成聚醯亞胺前驅樹脂PAA-7 將21.81克(0.1莫耳)的PMDA溶於200克的N,N-二甲基乙醯胺(N,N-dimethylacetamide；下文簡稱為DMAc)中，加熱至50℃且反應攪拌兩個小時。慢慢滴入0.601克(0.01莫耳)的異丙醇，於50℃的固定溫度下反應攪拌兩個小時。再將32.02克(0.1莫耳)的TFMB加至溶液中，待完全溶解後，再於50℃的固定溫度下反應攪拌六個小時，可得聚醯亞胺前驅樹脂PAA-7，固形份約20 wt %。製備例 13 ：合成聚醯亞胺前驅樹脂PAA-8 將21.81克(0.1莫耳)的PMDA溶於200克的γ-丁內酯中，加熱至50℃且反應攪拌兩個小時。慢慢滴入0.601克(0.01莫耳)的異丙醇，於50℃的固定溫度下反應攪拌三個小時。再將32.02克(0.1莫耳)的TFMB加至溶液中，待完全溶解後，再於50℃的固定溫度下反應攪拌六個小時，可得聚醯亞胺前驅樹脂PAA-8，固形份約21 wt %。製備例 14 ：合成具有羧基(-COOH)的可溶性聚醯亞胺SPI-6 稱取43.62克(0.2莫耳)的PMDA與30.43 g (0.2莫耳)的DABA，加入300 mL DMAc，於室溫下攪拌1小時，再升溫至50℃後攪拌4小時。4小時後，加入50 mL甲苯，在150℃下，以迪安-斯塔克(dean-stark)裝置除水。待除水完全後再去除甲苯，便可得到具有羧基的聚醯亞胺溶液SPI-6，固形份約20 wt %。乾 膜的製備 取上述製備例1至14製備的聚醯亞胺前驅物溶液或可溶性聚醯亞胺溶液100重量份，以表1至表5所示比例（重量份）加入疏水溶劑或視需要之穩定劑，並加入2重量份的熱鹼產生劑（

）。此外，另若為感光型聚醯亞胺前驅物溶液或感光型可溶性聚醯亞胺溶液(例如PAA-1至PAA-4、SPI-2、SPI-4及SPI-5)時，則再加入1重量份光起始劑（2,4,6-三甲基苯甲醯基二苯基膦氧化物及二苯乙醇酮，比例為1:1），製成塗料組合物。 將各塗料組合物以刮刀均勻塗布在聚對苯二甲酸乙二酯（型號：R310，三菱製）基材上，以烘箱烘烤，烘烤溫度與時間如各表所示。隨後將塗有前述塗料組合物之面覆蓋上離型膜(型號：L150L，南亞製)，即可得到具有聚醯亞胺前驅物塗層或可溶性聚醯亞胺塗層的乾膜，塗層厚度約40μm。 塗佈前的親水溶劑含量及疏水溶劑添加量(重量份)均基於每100重量份聚醯亞胺前驅物溶液或可溶性聚醯亞胺溶液計，而經烘烤乾燥後的親水溶劑及疏水溶劑含量(wt%)則基於樹脂層總重量計。乾膜的測試 檢測上述乾膜之溶劑含量並測試乾膜之物性，如沾黏性、轉印完整性、溶水性、耐折性以及感光性，各項測試詳述如下：1. 溶劑含量檢測 取0.01克聚醯亞胺前驅物塗層或可溶性聚醯亞胺塗層(即不包含PET基材及離型膜)，溶解於二甲基亞碸(DMSO)中，使用安捷倫公司的7890GC氣相層析儀，毛細管(column)型號：DB1701(0.53mm, 30mm, 1.5μm)，實施氣相色層定量分析。 2. 乾膜沾黏性檢測 取各實施例及比較例之乾膜，撕除離型膜，觀察離型膜上是否有殘留的聚醯亞胺層樹脂。完全無殘留為0，＜10%殘留為1，10%~20%殘留為2，＞20%殘留為NG。 3. 轉印測試 取20*20cm之乾膜，撕除離型膜後，分別以下述乾式壓合及濕式壓合方法，將乾膜膜塗覆有聚醯亞胺層之面壓合至已製作線路的銅箔基板上（L/S=30/30μm；L/S為線寬/線距）： (a) 濕式壓合 於銅箔基板具線路之表面上，施覆去離子水，使用熱滾輪，以60℃及5kg的下壓力進行壓合。 (b) 乾式壓合 於銅箔基板具線路之表面上，使用熱滾輪，以60℃及5kg的下壓力進行壓合。 分別靜置10分鐘後撕除乾膜上之PET膜，觀察PET膜是否有殘留的聚醯亞胺層樹脂，PET膜上完全無殘留為0，＜10%殘留為1，10%~20%殘留為2，＞20%殘留在PET膜為NG。4. 溶水性測試 取20*20cm之乾膜，以上述濕式壓合方法，將乾膜塗覆有聚醯亞胺層的一面壓合至銅箔基板具有線路之面上，靜置並使用顯微鏡觀察銅箔基板上之水被完全吸收之時間。第一小時內每5分鐘觀察一次，之後每30分鐘觀察一次。5. 氣泡測試 取20*20cm之乾膜，分別以上述濕式壓合與乾式壓合方法，將乾膜塗覆有聚醯亞胺層的一面壓合至銅箔基板具有線路之面上，靜置10分鐘後觀察氣泡殘留狀況。無氣泡為Pass，有氣泡為NG。 6. 物性測試 ( 耐折測試 1) 取20*20cm之乾膜，分別以上述濕式壓合與乾式壓合方法，將乾膜塗覆有聚醯亞胺層的一面壓合至銅箔基板具有線路之面上，靜置120分鐘後，以250^o C烘烤120分鐘，隨後降至室溫，並以耐折檢驗機(Measure Infect Turn (MIT) test machine，金德豪公司)設備，以彎折角度135度，彎曲半徑R=0.38mm，荷重500g進行耐折測試，記錄電路板至電路性質失效時所承受之彎曲次數。耐折測試次數越大表示所形成之聚醯亞胺層物性越好。7. 物性測試 ( 耐折測試 2- 感光性材料用 ) 取20*20cm之乾膜，分別以上述濕式壓合與乾式壓合方法，將乾膜塗覆有聚醯亞胺層的一面壓合至銅箔基板具有線路之面上，靜置120分鐘後，以UV曝光機進行曝光（曝光能量400mJ/cm² ），之後撕除PET膜以90^o C烘烤10分鐘，以1wt%濃度的K₂ CO₃ 水溶液進行圖案顯影，再以250^o C烘烤120分鐘，隨降至室溫後，並以耐折檢驗機(Measure Infect Turn (MIT) test machine，金德豪公司)設備，以彎折角度135度，彎曲半徑R=0.38mm，荷重500g進行耐折測試，記錄電路板至電路性質失效時所承受之彎曲次數。耐折測試次數越大表示所形成之聚醯亞胺層物性越好。 8. 物性測試 ( 耐折測試 3) ： 取20*20cm之乾膜(各實施例分別取4片)，放置於室溫下，之後在分別在第1、3、5、7天以上述濕式壓合方法，將乾膜塗覆有聚醯亞胺層的一面貼附於銅箔基板具線路之表面上，靜置120分鐘後以250^o C烘烤120分鐘，待降至室溫後，以耐折檢驗機(Measure Infect Turn (MIT) test machine，金德豪公司)設備，以彎折角度135度，彎曲半徑R=0.38mm，荷重500g進行耐折測試，紀錄耐折測試小於200次的放置天數，放置天數越長表示乾膜儲存穩定性越佳。 9. 物性測試 ( 耐折測試 4) ： 將取20*20cm之乾膜，之後以上述濕式壓合方法，將乾膜塗覆有聚醯亞胺層的一面貼附於銅箔基板具線路之表面上，之後於室溫下靜置，每6小時取2*10cm之壓合後基板以250^o C烘烤120分鐘，待降至室溫後，以耐折檢驗機(Measure Infect Turn (MIT) test machine，金德豪公司)設備，以彎折角度135度，彎曲半徑R=0.38mm，荷重500g進行耐折測試，紀錄耐折測試小於200次的放置時數，放置時數越長表示乾膜製程穩定性越佳。 10. 感光測試： 取20*20cm之乾膜，分別以上述濕式壓合與乾式壓合方法，將乾膜塗覆有聚醯亞胺層的一面壓合至銅箔基板具線路之表面上，靜置120分鐘後，使用L/S為60/60µm和開孔(via)大小為60µm之玻璃光罩，分別以不同UV能量(50mJ/cm² 、100mJ/cm² 、150 J/cm² 、200 J/cm² 、250 J/cm² )對聚醯亞胺層進行曝光。 曝光後撕除PET膜，置入烘箱以90^o C烘烤10分鐘，再以1wt%濃度的K₂ CO₃ 水溶液進行圖案顯影，隨後以SEM量測顯影後聚醯亞胺層上L/S(µm)和via(µm)之解析度，紀錄解析度符合要求之曝光能量，曝光能量較低表示材料的感光性較佳。 各實施例及比較例的測試結果記錄如表1至表7。 表1 ＜比較不同疏水溶劑之效果＞

NA：無法量測 表2 ＜比較不同樹脂/不同親水溶劑之效果＞

表3 ＜比較不同親水/疏水溶劑比例之效果＞

表4 ＜比較添加穩定劑之效果＞

表5 ＜比較不同溶劑總量之效果＞

表6 ＜比較不同壓合方法之效果＞

表7 ＜感光測試＞

表1顯示沒有添加疏水溶劑與添加不同疏水溶劑之效果。由表1可知，若僅使用製備習知聚醯亞胺前驅物或可溶聚醯亞胺時的常用溶劑（如NMP），則聚醯亞胺樹脂大幅沾黏在離型膜上，難以應用至後續加工，添加疏水溶劑則可改善沾黏現象，並且有良好的轉印能力與溶水性，適用於濕式壓合製程。 表2顯示選擇特定親水溶劑與疏水溶劑搭配，並控制其比例在本發明所述範圍內時，所得乾膜不沾黏，且具有良好轉印能力與溶水性，適用於濕式壓合製程。 表3顯示當親水溶劑及疏水溶劑之重量比例過高（如，超過2）時，乾膜過度沾黏，無法使用，且乾膜的儲存穩定性不佳(耐折測試3)；當親水溶劑及疏水溶劑之重量比例過低（如，低於0.05）雖可增加儲存穩定性，但此時乾膜轉印能力與溶水性不佳，由表3結果顯示調整適當之親水溶劑及疏水溶劑之重量比例(如，0.05~2，較佳0.1~1)所得之乾膜同時具有抗沾黏性、優良的轉印能力與溶水性，且乾膜的儲存穩定性佳(耐折測試3)，後續所形成之聚醯亞胺層亦具有優異的物性(耐折測試1)。 表4顯示添加適當用量之穩定劑，有助於提升乾膜的製程穩定性(耐折測試4)與溶水率，且不影響後續所得聚醯亞胺層之物性(耐折測試1)。 表5顯示乾膜溶劑總量控制在30wt%至70wt%之間時，乾膜沾黏性、轉印能力及溶水性較佳，且縱使在水存在下，最後製得的聚醯亞胺層亦具有良好物性（耐折測試1）。溶劑總量低於30wt%時，乾膜無法通過轉印測試，溶水性差，且最後製得的聚醯亞胺層物性亦不佳（耐折測試1）。溶劑總量高於70wt%時，乾膜過度沾黏，無法進行後續加工製程。 表6及7顯示，本發明之乾膜適用於濕式壓合方法，不但不會在圖案化表面與聚醯亞胺樹脂層間留下氣泡，且所得聚醯亞胺層物性較佳。此外，使用本發明之乾膜搭配濕式壓合方法相較於乾式壓合方法，可以用較低的曝光能量達到相同的解析度。To facilitate understanding of the disclosures set forth herein, several terms are defined below. The term "about" means an acceptable error for a particular value as determined by those of ordinary skill in the art, which depends in part on how to measure or determine the value. In the present invention, the term "alkyl" refers to a saturated linear or branched hydrocarbon group, preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms; examples thereof include (but are not limited to) methyl , Ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiary butyl, pentyl, hexyl and similar groups. In the present invention, the term "alkenyl" refers to an unsaturated linear or branched hydrocarbon group having at least one carbon-carbon double bond, preferably having 2 to 30 carbon atoms, more preferably 10 to 20 carbon atoms; Examples include (but not limited to) vinyl, propenyl, methacryl, isopropenyl, pentenyl, hexenyl, heptenyl, 1-propenyl, 2-butenyl, 2-methyl -2-butenyl and similar groups. In the present invention, the term "alkynyl" refers to an unsaturated linear or branched hydrocarbon group having at least one carbon-carbon reference bond, preferably having 2 to 30 carbon atoms, more preferably 10 to 20 carbon atoms; Examples include, but are not limited to, ethynyl, propargyl, 3-methyl-1-pentynyl, 2-heptynyl, and the like. In the present invention, the term "aryl" or "aromatic compound" refers to, for example, a monocyclic, bicyclic or tricyclic aromatic carbocyclic group containing 6 to 14 carbon ring atoms, examples of which include (but are not limited to) benzene Group, tolyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl and similar groups. In the present invention, the term "haloalkyl" refers to an alkyl group substituted with halogen, wherein "halogen" means fluorine, chlorine, bromine or iodine, preferably fluorine and chlorine. In the present invention, the term "alkoxy" refers to an alkyl group attached to an oxygen atom, examples of which include (but are not limited to) methoxy, ethoxy, propoxy, isopropoxy, n-butoxy Group, isobutoxy group, pentyloxy group, hexyloxy group, benzyloxy group, fluorene methoxy group and the like. In the present invention, the term "heterocyclic group" refers to a saturated, partially saturated (for example, prefixed with dihydrogen, trihydrogen, tetrahydrogen, etc.) composed of carbon atoms and at least one hetero atom selected from N, O, or S. (Named hexahydro, etc.) or unsaturated 3 to 14 membered ring groups, preferably 4 to 10 membered ring groups, more preferably 5 or 6 membered ring groups; preferably 1 to 4 heteroatoms, more preferably 1 to 3 heteroatoms. The heterocyclic group may be a monocyclic, bicyclic or tricyclic ring system, which includes a fused ring (for example, a fused ring formed together with another heterocyclic ring or another aromatic carbocyclic ring). Unless otherwise specified, in the present invention, "heterocyclic group" may be substituted or unsubstituted. Substituents such as, but not limited to: halogen, hydroxyl, oxo, alkyl, hydroxyalkyl, —NO ₂ and the like. In the present invention, the term "nitrogen-containing heterocyclic group" refers to a 3- to 14-membered heterocyclic group in which at least one ring carbon atom is replaced by an N atom, preferably a 4- to 10-membered nitrogen-containing heterocyclic group, more preferably 5 or 6-membered nitrogen-containing heterocyclic group. Examples include but are not limited to: pyrrolyl, imidazolyl, pyrazolyl, pyrimidinyl, thiazolyl, pyridyl, indolyl , Isoindolyl (isoindolyl), benzimidazole (benzimidazolyl), benzothiazolyl (benzothiazolyl), quinolinyl (quinolyl), quinolinyl (isoquinolyl), etc. Unless otherwise specified, in the present invention, the "nitrogen-containing heterocyclic group" may be substituted or unsubstituted. The substituents are as defined above for "heterocyclic group". In the present invention, the term "polyimide layer" refers to a resin layer containing polyimide resin, polyimide precursor or polyetherimide (PEI) resin, "polyimide" It can be a polyimide homopolymer or copolymer. The invention provides a polyimide dry film, comprising a base material and a polyimide layer, wherein the polyimide layer contains a polyimide precursor or a soluble polyimide and a solvent, and the above solvent includes a hydrophilic solvent and Hydrophobic solvent, based on the total weight of the polyimide layer, the total content of the solvent is between about 30 wt% to about 70 wt%, and the weight ratio of the hydrophilic solvent to the hydrophobic solvent is between about 0.05 to Between about 2. Polyimide dry film of the present invention 1. Substrate The substrate used in the present invention can be any known by those skilled in the art to which the present invention belongs, such as glass or plastic. The above plastic substrates are not particularly limited. Examples include, but are not limited to: polyester resins, such as polyethylene terephthalate (PET) or polyethylene naphthalate (polyethylene naphthalate, PEN); polymethacrylate resin, such as polymethyl methacrylate (PMMA); polyimide resin; polystyrene resin; polycycloolefin Resin (polycycloolefin resin); polyolefin resin (polycycloolefin resin); polycarbonate resin (polycarbonate resin); polyurethane resin (polyurethane resin); triacetate cellulose (triacetate cellulose, TAC); or their equivalent mixture. It is preferably polyethylene terephthalate, polymethyl methacrylate, polycycloolefin resin, cellulose triacetate, or a mixture thereof, and more preferably polyethylene terephthalate. The thickness of the substrate generally depends on the needs of the desired electronic product, and it is preferably between about 16 µm and about 250 µm. 2. Polyimide layer The polyimide dry film of the present invention can be applied to different elements, so the polyimide layer can be a photosensitive polyimide layer or a non-photosensitive polyimide layer. The polyimide layer in the dry film of the present invention may contain a polyimide precursor or a soluble polyimide. The thickness of the polyimide layer in the dry film of the present invention is not particularly limited, and generally ranges from about 10 µm to about 60 µm, preferably from about 20 µm to about 40 µm. (a) Polyimide precursors The polyimide precursors used in the present invention are not particularly limited, and can be well known to those with ordinary knowledge in the technical field to which the present invention belongs, such as polyamic acid, polyamide Ester, any material that can form polyimide through reaction or a mixture thereof. A variety of different polyimide precursors have been developed in the technical field, for example, Republic of China Invention Patent No. 095138481, No. 095141664, No. 096128743, No. 097151913, or No. 100149594. The above-mentioned documents are incorporated by reference in their entirety. The polyimide precursor mainly has a repeating unit represented by formula (A):

Formula (A) wherein, G is a tetravalent organic group; P is a divalent organic group; n is an integer greater than 0, preferably an integer from 1 to 1000. If necessary, different groups may be used to modify the above-mentioned polyimide precursor. For example, a photosensitive polyimide precursor can be prepared by modifying a photosensitive group; or by adjusting the terminal group bonded to the repeating unit of formula (A), the reaction of the polyimide precursor can be improved And improve the properties of polyimide obtained in the future. For example, the Republic of China Invention Patent No. 100149594 discloses polyimide precursors having repeating units represented by the following formulas (1) to (4):

(1),

(2),

(3), or

(4), wherein G _{1 is} independently a tetravalent organic group; R _{x is} independently H or an ethylenically unsaturated group; R is independently C ₁ -C ₁₄ alkyl, C ₆ -C ₁₄ aryl, C ₆ -C ₁₄ aralkyl, phenol or ethylenically unsaturated group; D is independently a nitrogen-containing heterocyclic group or an OR* group, where R* is a C ₁ -C ₂₀ alkyl group; m is 0 An integer to 100, preferably an integer of 5 to 50, more preferably an integer of 10 to 25; and G and P are as previously defined herein. The above-mentioned ethylenic unsaturated group is not particularly limited, and examples thereof include, but are not limited to, vinyl, propenyl, methacryl, n-butenyl, isobutenyl, vinylphenyl, propenylphenyl, propylene Oxymethyl, propyleneoxyethyl, propyleneoxypropyl, propyleneoxybutyl, propyleneoxypentyl, propyleneoxyhexyl, methacryloxymethyl, methacryloxyethyl, Methacryloxypropyl, methacryloxybutyl, methacryloxypentyl, methacryloxyhexyl, groups having the following formula (5) and groups having the following formula (6) :

(5)

(6), wherein R ₁₂ is phenylene, C ₁ -C ₈ alkylene, C ₂ -C ₈ alkenyl, C ₃ -C ₈ cycloalkyl or C ₁ -C ₈ hydroxyalkyl; And R ₁₃ is hydrogen or C ₁ -C ₄ alkyl. (b) Soluble polyimide General polyimide has the advantages of good heat resistance and chemical resistance, but it has the disadvantage of poor processability, and there are not many solvents that can dissolve polyimide. Therefore, in application, it is mostly processed with polyimide precursors, and its imide is converted into polyimide later in the process. Soluble polyimide improves the structure of polyimide to increase the solubility between polyimide and solvent to improve its processability. The type of the above-mentioned solvent may be as described below. The soluble polyimide of the present invention is not particularly limited, and may be known to those with ordinary knowledge in the technical field to which the present invention belongs, such as Republic of China Invention Patent No. 097101740, No. 099105794, No. 097138725 or No. 097138792 Application. The above-mentioned documents are incorporated by reference in their entirety. The soluble polyimide of the present invention mainly has a repeating unit represented by formula (B):

Formula (B) wherein C′ is a tetravalent organic group; E′ is a divalent organic group; t′ is an integer greater than 0, preferably an integer from 1 to 1000. The above-mentioned C'tetravalent organic group can be as defined previously for the G group herein. The above-mentioned E'divalent organic group can be as defined earlier for the P group. If necessary, different groups can be used to modify the soluble polyimide. For example, a photosensitive polyimide can be prepared by modifying a photosensitive group; or by adjusting the terminal group bonded to the repeating unit of formula (B), the properties of the soluble polyimide can be improved. By adjusting the terminal group bonded to the repeating unit of formula (B), a modified soluble polyimide can be obtained. Its structure is (but not limited to):

(1') ;

(2');

(3'); wherein, R ₂₀ 'is a C ₂ -C ₂₀ saturated or unsaturated divalent radical group, preferably -C=C-,

,

; R ₂₁ 'is C ₂ -C ₂₀ may be a heteroatom substituted monovalent organic group having an unsaturated group or -OH C', E'and t'' as previously defined herein. The soluble polyimide modified by the photosensitive group is preferably (but not limited to) disclosed in the application No. 099105794, No. 099105794, No. 097138725 or No. 097138792. 3. Solvents In general, polyimide precursors and soluble polyimides are prepared or formulated under polar aprotic organic solvents. In the conventional technology, in order to avoid the high concentration of volatile organic compounds in the dry film during use and reduce the phenomenon of excessive glue that the coating film flows during storage of the dry film, the semi-finished product of the dry film that has been coated is sent into In an oven, the resin layer is dried and completely attached to the substrate. The organic solvent is almost completely volatilized in this step. Therefore, in general, the organic solvent content of conventional dry film products is less than 1 wt%. In addition, dry film products need to be stored in a low temperature environment to reduce hydrolysis. Unlike the prior art, the dry film of the present invention may contain a solvent, and after extensive research and repeated experiments, the inventor of the present invention found that: by controlling the type and content ratio of the solvent, the obtained polyimide dry film has water absorption, and even In the presence of water, its properties are relatively stable, and the surface is non-sticky, with good transfer ability, and the polyimide prepared by curing has good physical properties. Therefore, not only can the storage stability be increased, but it can also be applied to processes requiring the use of water or aqueous solutions. The solvent used in the present invention includes a hydrophilic solvent and a hydrophobic solvent, wherein the weight ratio of the hydrophilic solvent to the hydrophobic solvent is between about 0.05 to about 2, preferably between about 0.1 to about 1, more preferably between Between about 0.25 and about 0.8, the resulting dry film has water absorption, good transfer ability, non-sticky surface, stable properties, and good physical properties. When the weight ratio of the hydrophilic solvent to the hydrophobic solvent is too low (for example, less than 0.05), the water absorption of the polyimide dry film is not good, and the adhesion of the polyimide layer to the substrate is poor; when the hydrophilic solvent is hydrophobic When the weight ratio of the solvent is too high, especially when it is greater than 2, it will make the dry film surface sticky, the operability is poor, it is not easy to align, and it is not conducive to heavy industry. The hydrophobic solvent added in the present invention is miscible with liquid (water or alcohol), and the hydrophilic solvent used in the present invention includes: dimethyl sulfoxide (DMSO), diethyl sulfoxide, N,N-dimethylformamide (DMF), N,N-diethylformamide, N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N-methyl N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), N-propyl-2-pyrrolidone, N-vinyl- 2-pyrrolidone, phenol, o-cresol, m-cresol, p-cresol, xylenol, halogenated phenol, catechol, tetrahydrofuran (THF), dioxane, dioxolane, cyclopropylene glycol methyl ether ( PGME), tetraethylene glycol dimethyl ether (TGDE), butyl cellosolve, γ-butyrolactone (γ-butyrolactone; GBL), xylene (xylene), toluene (toluene), hexamethyl ortho-amide, propylene glycol Dimethyl ether acetate (PGMEA) or mixtures thereof. According to an embodiment of the present invention, the hydrophilic solvent used preferably comprises: diethyl sulfoxide, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethyl Acetamide, N,N-diethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, cyclopropylene glycol methyl ether, γ-butane Lactone, propylene glycol methyl ether acetate or mixtures thereof. More preferably, it includes: N,N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, or a mixture thereof. The addition of a hydrophobic solvent in the present invention can improve the stability of the dry film to water, and at the same time make the surface of the dry film less prone to sticking and better operability. The hydrophobic solvents that can be used in the present invention include:

,

,

,

,

,

, Or a combination thereof, wherein: R ₁ '', R ₉ '' and R ₁₀ '' are each independently C ₁ -C ₂₀ alkyl, C ₂ -C ₂₀ alkenyl or C ₂ -C ₂₀ alkynyl; R ₇ '' is H or C ₁ -C ₃ alkyl; R ₂ '' is C ₁ -C ₁₀ alkyl; R ₃ '' is C ₄ -C ₂₀ alkyl or -C ₂ -C ₁₀ alkyl-OC ₂ -C ₁₀ alkyl; R ₄ '' and R ₅ '' are each independently C ₁ -C ₁₀ alkyl, or R ₄ '' and R ₅ '' together with the oxygen atom to which they are attached form a 5- to 6-membered heterocyclic ring ; R ₆ '' is C ₄ -C ₁₅ alkyl, C ₄ -C ₈ cycloalkyl or

; R ₈ '' is C ₂ -C ₁₀ alkylene; R ₁₁ '' and R ₁₂ '' are each independently C ₁ -C ₁₀ alkyl; R ₁₃ '' and R ₁₄ '' are each independently C _1- C ₁₀ alkyl, or R ₁₃ '' and R ₁₄ '' together with the nitrogen atom to which they are attached form a 5 to 6 membered heterocyclic ring; R ₁₅ '' is C ₄ -C ₁₅ alkyl or C ₄ -C ₈ cycloalkane R _{16 ″} is C ₁ -C ₄ alkyl; and R _{17 ”} is C ₄ -C ₁₀ alkyl. According to an embodiment of the present invention, the hydrophobic solvent used preferably includes:

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

, N,N-dimethylcaprolamide ((N,N-dimethylcapramide, DMC for short)) or a combination thereof. In the present invention, the total solvent content is not particularly limited, and can be adjusted according to the manufacturing process of the dry film or the subsequent processing process. In one embodiment of the present invention, based on the total weight of the polyimide layer, the total content of the solvent is between about 30 wt% and about 70 wt%, preferably between about 35 wt% and about Between 65 wt%, more preferably between about 40 wt% and about 60 wt%. 4. Additives The polyimide layer of the present invention may optionally contain any suitable additives known to those with ordinary knowledge in the technical field to which the present invention belongs, such as (but not limited to): stabilizers, ring closure accelerators, Levelers, defoamers, coupling agents, catalysts, acrylate monomers, photoinitiators, etc. The contents of the above additives are also those that can be adjusted through routine experiments by those with ordinary knowledge in the technical field to which the invention belongs. In one embodiment of the present invention, the polyimide layer of the present invention may optionally contain a stabilizer selected from the following:

,

Or a combination thereof, wherein: R ₁₇ '', R ₁₈ '', R ₁₉ '' and R ₂₀ '' are each independently C ₁ -C ₄ alkyl, or R ₁₉ '' and R ₂₀ '' are connected to the oxygen Atoms together form a 5 to 6 membered heterocyclic ring, or R ₁₉ '' and R ₁₇ '' or R ₂₀ '' and R ₁₈ '' together with the oxygen and nitrogen atoms to which they are attached form a 5 to 6 membered heterocyclic ring; R ₂₁ '''And R ₂₂ '' are each independently C ₁ -C ₄ alkyl, or R ₂₁ '' and R ₂₂ '' together with the carbon atom to which they are attached form a 5 to 6 member carbocycle; and R ₂₃ '' and R ₂₄ '''Each is independently C ₁ -C ₄ alkyl. According to a preferred embodiment of the present invention, the stabilizer preferably comprises:

,

,

,

,

,

Or a combination thereof. Adding a stabilizer helps to improve the stability and operability of the dry film, and further improve the physical properties of the polyimide formed later. In one embodiment of the present invention, based on the total weight of the polyimide layer, the total content of the stabilizer is between about 0.01 wt% and about 5 wt%, preferably between about 0.05 wt% and about Between 3wt%. If the content exceeds 5 wt%, the physical properties (eg, flexibility) of the formed polyimide may be reduced. In one embodiment of the present invention, the polyimide layer is a photosensitive polyimide, and additives may be selected as needed Contains photoinitiator and acrylic monomers. The above photoinitiators can be used alone or in combination. The photoinitiator suitable for the present invention is used to generate free radicals by light irradiation, and initiate polymerization by the transmission of free radicals. The photoinitiator that can be used in the present invention is not particularly limited. Preferably, the photoinitiator used includes a compound that can absorb light with a wavelength of about 350 nm to about 500 nm to generate free radicals. The amount of the photoinitiator is about 0.01 to about 20 parts by weight, preferably about 0.05 to about 5 parts by weight, based on 100 parts by weight of the solid content of the polyimide precursor or soluble polyimide. The photoinitiator suitable for the present invention can be selected from the following group, for example: benzophenone, benzophenone, 2-hydroxy-2-methyl-1-phenylacetone, 2,2-dimethoxy- 1,2-diphenylethyl-1-one, 1-hydroxy-cyclohexyl-phenyl ketone, 2,4,6-trimethylbenzyl diphenylphosphine oxide, oxime ester, 2,4 ,6-trimethylbenzoyl diphenyl phosphine oxide (2,4,6-trimethylbenzoyl diphenyl phosphine oxide), bis 4,4'-diethylaminobenzophenone (bis-4,4' -diethylaminobenzophenone), benzophenone, camphorquinone, 3,5-bis(diethylaminobenzylidene)-N-methyl-4-piperidone (3,5-bis (diethylaminobenzylidene)- N-methyl-4-piperidone), 3,5-bis(dimethylaminobenzylidene)-N-methyl-4-piperidone (3,5-bis(dimethylaminobenzylidene)- N-methyl-4-piperidone), 3,5-bis(diethylaminobenzylidene)-N-ethyl-4-piperidone (3,5-bis(diethylaminobenzylidene)-N-ethyl- 4-piperidone), 3,3'-carbonyl-bis (7-diethylamino) coumarin (3,3'-carbonyl-bis (7-diethylamino) cumarin), 3,3'-carbonyl-bis (7-dimethylamino) coumarin (3,3'-carbonyl-bis (7-dimethylamino) cumarin), riboflavin tetrabutyrate, 2-methyl-1-(4 -(Methylthio)phenyl]-2-morpholinopropan-1-one (2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan -1-one), 2,4- Dimethylthioxanthone (2,4-dimethylthioxanthone), 2,4-diethylthioxanthone (2,4-diethylthioxanthone), 2,4-diisopropylthioxanthone Anthrone (2,4-diisopropylthioxanthone), 3,5-dimethylthioxanthone (3,5-dimethylthioxanthone), 3,5-diisopropylthioxanthone (3,5- diisopropylthioxanthone), 1-phenyl-2-(ethoxycarbonyl)oxyimino Propyl-1-one (1-phenyl-2-(ethoxycarbonyl)oxyiminopropan-1-one), benzoin ether (benzoin ether), benzoin isopropyl ether (bezoin isopropyl ether), benzalthrone (benzanthrone), 5- 5-nitroacenaphthene, 2-nitrofluorene, anthrone, 1,2-benzanthraquinone, 1-phenyl-5-mercapto -1H-tetrazole (1-phenyl-5-mercapto-1H-tetrazole), thioxanthen-9-one (thioxanthen-9-one), 10-thioxanthenone (10-thioxanthenone), 3-indole ethyl 3-acetylindole, 2,6-bis(p-dimethylaminobenzyl)-4-carboxycyclohexanone (2,6-di(p-dimethylaminobenzal)-4-carboxycyclohexanone), 2, 6-di(p-dimethylaminobenzyl)-4-hydroxycyclohexanone (2,6-di (p-dimethylaminobenzal)-4-hydroxycyclohexanone), 2,6-bis(p-diethylamine Benzylbenzylidene)-4-carboxycyclohexanone (2,6-di(p-diethylaminobenzal) -4-carboxcyclohexanone), 2,6-di(p-diethylaminobenzal)-4- Hydroxycyclohexanone (2,6-di(p-diethylaminobenzal))-4-hydroxycyclohexanone), 4,6-dimethyl-7-ethylaminocoumarin (4,6-dimethyl-7-ethylaminocumarin) , 7-diethylamino-4-methylcumarin (7-diethylamino-4-methylcumarin), 7-diethylamino-3-(1-methylbenzimidazolyl) coumarin ( 7-diethylamino-3-(1-methylbenzoimidazolyl) cumarin), 3-(2-benzimidazolyl)-7-dimethylethylaminocoumarin (3-(2-benzoimidazolyl)-7-diethylaminocumarin), 3 -(2-benzothiazolyl)-7-dimethylethylaminocoumarin (3-(2-benzothiazolyl)-7-diethylaminocumarin), 2-(p-dimethylaminostyryl)benzene 2-(p-dimethylaminostyryl)benzooxazole, 2-(p-dimethylaminostyryl)quinoline, 4-(p-dimethylaminostyryl)quinoline, 4-(p-dimethylaminostyryl)quinoline Vinyl) quinoline (4-(p-dimethylaminostyryl) quinoline), 2-(p-dimethylaminostyryl) benzothiazole (2-(p-dimethylaminostyryl) benzothiazole), 2-(p-dimethylaminostyryl) benzothiazole Aminoaminostyryl)-3,3-dimethyl-3H-indole (2-(p-dimethylaminostyryl)-3,3-dimethyl-3H-indole) and combinations thereof. Preferred photoinitiators are benzophenone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, benzophenone, 2-hydroxy-2-methyl-1-phenylacetone , 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl ketone, 2,4,6-trimethylbenzoyl diphenyl Phosphine oxide, oxime ester or a combination thereof. The above acrylate monomer is an acrylate monomer having at least one -C=C-, preferably a multi-functional acrylate monomer (multi-functional) having two or more -C=C- acrylate monomer), the addition of such monomers can form crosslinks between molecules, which is convenient for improving the practicality of the composition. Preferably, the present invention uses acrylic monomers selected from the group consisting of ethylene glycol di(methacrylate), ethylene glycol diacrylate, bisphenol A ethylene glycol-modified diacrylate, Bisphenol A ethylene glycol-modified di(methacrylic acid) ester, bisphenol F ethylene glycol-modified diacrylate, bisphenol F ethylene glycol-modified di(methacrylic acid) ester, propylene glycol di( Methacrylic acid) ester, tripropylene glycol diacrylate, ethoxylated trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, trimethylolpropane tri( Methacrylic acid) ester, tetrahydroxymethane triacrylate, tetrahydroxymethane tri(methacrylic acid) ester, and combinations thereof. When the acrylate monomer is present, based on 100 parts by weight of the solid content of the polyimide precursor or soluble polyimide, the added amount is about 5 to about 80 parts by weight, preferably about 10 to about 40 Parts by weight. The coupling agent that can be used in the present invention can be selected from the group consisting of (but not limited to) the following: 3-aminopropyltrimethoxysilane (APrTMOS), 3-triaminopropyltriethoxy Silane (APrTEOS), 3-aminophenyltrimethoxysilane (APTMOS), 3-aminophenyltriethoxysilane (APTEOS) and combinations thereof. According to one embodiment of the present invention, a ring-closing accelerator may be added during the preparation of the polyimide precursor of the present invention if necessary. It is preferable to select a ring-closing accelerator that can generate an alkaline compound upon heating and provide an alkaline environment to promote the progress of the imidization reaction. The ring closure accelerators that can be used in the present invention include:

,

,

,

,

,

,

,

,

,

,

Y ^θ ,

Y ^θ ,

Y ^θ ,

Y ^θ or

Y ^θ , where Y ^θ is an anionic group. Method for forming dry film The polyimide dry film of the present invention can be prepared by, for example, the following steps: (1) Preparation of a polyimide formulation, mixed with a polyimide precursor or a soluble polyimide and a hydrophilic solvent ; (2) Add appropriate amount of hydrophobic solvent and optional additives to the aforementioned formulation; (3) Apply the formulation obtained in step (2) to the substrate to form a dry film semi-finished product; (4) Dry film semi-finished product Feed it into a baking oven, heat and dry to remove part of the solvent, thereby adjusting the solvent content in the polyimide layer; form a polyimide dry film; (5) Apply on the polyimide dry film as needed One protective film. The temperature and time required for heating in the above step (4) are not particularly limited, and its main purpose is to reduce the solvent content in the resin layer. For example, one suitable temperature between 60°C and 150°C can be used for 30 seconds Heat and dry to 10 minutes. In the traditional process of preparing dry film, in order to avoid the high concentration of volatile organic compounds when using dry film, in the solvent removal step relative to the previous step (4), the heating is often caused to cause the solvent to be almost completely volatile (content less than 1 wt%), however, contrary to the conventional step, the present invention does not completely remove the solvent in this step, but instead retains an appropriate proportion of the hydrophilic solvent and the hydrophobic solvent in the dry film. The solvent in the above step (4) includes a hydrophilic solvent and a hydrophobic solvent. Generally speaking, the total content and ratio of the solvent in the dry film can be controlled by appropriately adjusting the heating temperature and time through the difference in boiling point of different solvent types. For example, the weight ratio of the hydrophilic solvent to the hydrophobic solvent is between Between about 0.05 to about 2. The protective film of the above step (5), such as but not limited to: polyester resin, such as polyethylene terephthalate (polyethylene terephthalate, PET) or polyethylene naphthalate (polyethylene naphthalate, PEN); polymethacrylate resin, such as polymethyl methacrylate (PMMA); polyimide resin; polystyrene resin; polycycloolefin Resin (polycycloolefin resin); polyolefin resin (polycycloolefin resin); polycarbonate resin (polycarbonate resin); polyurethane resin (polyurethane resin); triacetate cellulose (triacetate cellulose, TAC); or their equivalent mixture. It is preferably polyethylene terephthalate, polymethyl methacrylate, polycycloolefin resin, cellulose triacetate, or a mixture thereof, and more preferably polyethylene terephthalate. Method for applying a dry film on a substrate The present invention also provides a method for applying a polyimide dry film on a substrate, which comprises: after removing a protective film added as needed, the above polyimide dry film is polymerized The surface of the amide imide layer is pressed against the substrate. The substrate may be a printed circuit board, wafer, glass, display or touch panel, or other substrate. According to an embodiment of the present invention, the substrate is a printed circuit board, particularly preferably a flexible printed circuit (FPC), and the polyimide layer of the dry film is pressed onto the patterned surface. Any method can be used to apply the dry film on the substrate, preferably in a roll-to-roll (roll-to-roll) manner. The roll-to-roll operation is well-known to those of ordinary skill in the technical field to which the present invention pertains. By pulling out the sample from the sample in the form of winding, after processing, the processed sample is recovered by winding. For example, as shown in FIG. 1, after being drawn out, the substrate A in a wound form is roller-pressed between the rollers 2 and 3 and the dry film from the dry film roll 1, and then retracted to form Product B. The dry film of the present invention can be laminated to the substrate using a continuous process, which is beneficial to simplify the process and speed up the process. The above-mentioned pressing methods, such as but not limited to: roller lamination, hot press, vacuum lamination, vacuum press or wet lamination ). As mentioned above, by controlling the appropriate solvent type and content ratio, the polyimide dry film of the present invention has water absorption, and the surface is not sticky, and the formed cover film has excellent physical properties. In addition, even in the presence of water, it can remain stable without affecting the properties of the resulting polyimide, so it is suitable for wet lamination, and the wet film can improve the uniform coverage of the dry film on the patterned substrate Sex. FIG. 2 is a schematic diagram of the dry film of the present invention applied to wet lamination. As shown in FIG. 2, the present invention provides a method for applying a dry film on a substrate by wet pressing. The method includes: (1) applying a liquid 30 on the surface 11 of the substrate 10 to be pressed; and (2 ) The dry film 20 (including the base material 21 and the polyimide layer 22) of the present invention is pressed onto the surface 11 of the substrate 10 to be pressed with the surface of the polyimide layer. The liquid used in step (1) contains water, alcohol solvents or a combination thereof to make the process more environmentally friendly and economical. The preferred liquid is methanol, ethanol, isopropanol, butanol, water or a mixture thereof. The liquid can fill the recessed area on the surface to be pressed 11 to form a liquid film, thereby expelling the air originally present in the recessed area. In step (2), the dry film 20 is pressed to the surface 11 of the substrate 10 to be pressed by a roller. At this time, the liquid used in step (1) can be absorbed into the polyimide layer of the present invention. Preferably step under heating system (2), for example at a temperature of 60 ^o C to 100 ^o C, the average in order to enhance the coating property and adhesion between the polyimide layer and the surface of the laminated tape. If there is residual liquid, a standing step (3) may be carried out if necessary. After pressing, it is allowed to stand for a period of time (for example, 5 minutes to 240 minutes) to fully absorb the remaining liquid into the dry film. The present invention also provides a system for wet lamination, comprising: (1) the dry film of the present invention; (2) the substrate; and (3) the liquid. The above-mentioned substrate and liquid system are as described above. The dry film of the present invention, especially when used in a wet process, has good uniformity, and compared with the conventional dry film, it can effectively fill thick copper lines. Application of the dry film of the present invention The polyimide dry film of the present invention can use general pressing technology (especially wet pressing) and such as printed circuit without using high-pressure defoaming machine or vacuum film pressing equipment The substrates of the board, wafer, glass, display or touch panel are pressed together, so they can be operated in a simpler process step than the prior art, and the equipment used is also easier to obtain than the users of the prior art. Therefore, it is more cost-effective than the prior art using a vacuum laminator or other process equipment. The dry film of the present invention is suitable for a printed circuit board, as a cover film for protecting the coating film on the printed circuit board, has insulation, can protect the circuit, and has excellent performance to avoid circuit oxidation and welding short circuit. In addition, the dry film of the present invention has high resolution, fast development speed, electrolytic plating resistance, electroless plating resistance, high temperature and high humidity resistance, etc., so it can also be used as a photoresist in the wafer manufacturing process. In addition, the polyimide dry film of the present invention has a relatively stable property in the presence of water, has no sticky surface, and has a good transfer ability. In addition, the moisture or solvent in the dry film can be removed in the subsequent process without affecting the physical properties of the resulting polyimide. Therefore, it is particularly advantageous when used as a cover film. In view of this, in a preferred embodiment of the present invention, the wet polyimide dry film of the present invention is applied to the substrate as a cover film. FIG. 3 uses the photosensitive polyimide dry film of the present invention as a flexible printed circuit board cover film as an example to further illustrate its subsequent processing steps (but not limited to this): (1) Using wet lamination, Pressing the polyimide dry film 20 of the present invention and the substrate 10; (2) Exposure in the presence of a photomask 40 to make the polyimide precursor or soluble polyimide of the present invention sensitive to light Groups (such as those with ethylenic unsaturated groups) undergo cross-linking reaction; (3) Remove the supporting substrate 21 of the dry film 20 and perform post-exposure bake; (4) Develop , To remove the polyimide layer in the non-exposed area; and (5) if necessary, polyimide precursor imide imidization (curing) into polyimide. The exposure step of the above step (2) can be performed in any manner known to those of ordinary skill in the art to which the present invention belongs, for example, ultraviolet light, visible light, electron beam or laser irradiation, preferably ultraviolet light. The exposure energy and time are not particularly limited, and are those with ordinary knowledge in the technical field to which the invention belongs can be adjusted according to their experience as needed. According to one embodiment of the present invention, the exposure energy used is about 50 to 1200 mJ/cm ² . The post-exposure baking in the above step (3) increases the solubility difference between the exposed area and the non-exposed area during development by heating. The heating temperature and time are not particularly limited, and can be adjusted as needed, as long as the aforementioned purpose can be achieved. The heating can be performed in a single stage or in multiple stages. In one specific embodiment of the present invention, based on a temperature range of 60 to 150 ^o C the heating was continued for 5-90 minutes. The solvent (such as the aforementioned hydrophilic and hydrophobic solvents) contained in the polyimide layer and the liquid absorbed during the wet press can be partially discharged in this heating step. The above step (4) is to dissolve and remove the resin in the unexposed area (when using the negative photosensitive polyimide dry film) or the resin in the exposed area (using the positive photosensitive polyimide by the development step) (Dry film) Dissolve and remove, then rinse with water to get the desired pattern. The developer used is well known to those of ordinary skill in the technical field to which the present invention belongs. Examples of the developer are, for example, but not limited to, aqueous K ₂ CO ₃ solution, aqueous Na ₂ CO ₃ solution, aqueous KOH solution, aqueous NaOH solution, aqueous tetramethylammonium hydroxide (TMAH) solution. In addition, when the polyimide layer contains a polyimide precursor, step (5) is performed, for example, by heating, the polyimide precursor is cyclized and polymerized into a polyimide. And the solvent or liquid remaining in the polyimide layer is further removed. The following examples are used to further illustrate the present invention, and are not intended to limit the scope of the present invention. Any modifications and changes that can be easily achieved by anyone familiar with this skill are included in the scope of the disclosure of the description of the case and the scope of the attached patent application. Examples The abbreviations mentioned in the following examples are defined as follows: DA1:

1-MI: 1-methylimidazole (1-methylimidazole) PTZ: phenothiazine (10H-phenothiazine) DA3:

DMC: N,N-dimethyldecylamide

NOP:

NOEP:

D-PC:

Decyl acetate:

1,6-hexanediol diacrylate:

Preparation Example 1 : Synthesis of photosensitive polyimide precursor resin PAA-1 21.81 g (0.1 mol) of pyromellitic dianhydride (hereinafter referred to as PMDA) was dissolved in 200 g of N-methylpyrrolidone (N-methyl-2-pyrrolidone; hereinafter abbreviated as NMP), the resulting mixture was heated to 50°C and the reaction was stirred for two hours. Slowly add 1.161 g (0.01 mol) of 2-hydroxyethyl acrylate (hereinafter referred to as HEA), and stir at a fixed temperature of 50°C for two hours. Thereafter, 20.024 g (0.1 mol) of 4,4'-oxydianiline (4,4'-oxydianiline, hereinafter referred to as ODA) was added to the solution, and after being completely dissolved, it was then fixed at a temperature of 50°C The reaction is stirred for six hours to obtain the photosensitive polyimide precursor resin PAA-1, with a solid content of about 17wt% (after baking at 250 or 300 ℃ for 1 hour to remove all solvents, measure the weight before and after baking If the difference is not enough, the weight of the non-volatile substance can be obtained, and its weight percentage in PAA-1 is calculated as the solid content). Preparation Example 2 : Synthesis of photosensitive polyimide precursor resin PAA-2 21.81 g (0.1 mol) of PMDA was dissolved in 200 g of N-ethyl-2-pyrrolidone (hereinafter referred to as NEP) In, heat the resulting mixture to 50 °C and stir the reaction for two hours. 1.161 g (0.01 mol) of HEA was slowly added dropwise, and the reaction was stirred at a fixed temperature of 50°C for two hours. Thereafter, 20.024 grams (0.1 mol) of ODA was added to the solution, and after complete dissolution, the reaction was stirred at a fixed temperature of 50°C for six hours to obtain a photosensitive polyimide precursor resin PAA-2. Solid content is about 17wt% (bake at 250 or 300 ℃ for 1 hour, measure the weight difference before and after baking, you can get the actual weight of non-volatile matter, calculate its weight percentage in PAA-2 That is the solid content). Preparation Example 3 : Synthesis of photosensitive polyimide precursor resin PAA-3 21.81 g (0.1 mol) of PMDA was dissolved in 200 g of NMP, heated to 50° C. and the reaction was stirred for two hours. Slowly add 13.01 g (0.01 mol) of 2-hydroxyethyl methacrylate (hereinafter referred to as HEMA), and stir at a fixed temperature of 50°C for two hours. Then add 20.024 g (0.1 mol) of ODA to the solution. After complete dissolution, the reaction is stirred at a fixed temperature of 50°C for six hours to obtain the photosensitive polyimide precursor resin PAA-3, solid form The portion is about 21wt%. Preparation Example 4 : Synthesis of photosensitive polyimide precursor resin PAA-4 29.42 g (0.1 mol) of 3,3,4,4-biphenyltetracarboxylic dianhydride (4,4'-Biphthalic dianhydride; abbreviated below) BPDA) dissolved in 200 g of NMP, heated to 50° C. and the reaction was stirred for two hours. Slowly add 13.01 g (0.01 mol) of HEMA, and stir at a fixed temperature of 50°C for 24 hours. Then add 32.024 g (0.1 mol) of m-bis (trifluoromethyl) p-diaminobiphenyl (2,2'-bis (trifluoromethyl) benzidine; hereinafter referred to as TFMB) to the solution, after completely dissolved Then, the reaction was stirred at a fixed temperature of 50°C for six hours to obtain a photosensitive polyimide precursor resin PAA-4 with a solid content of about 20 wt%. Preparation Example 5 : Synthesis of Polyimide Precursor Resin PAA-5 21.81 g (0.1 mol) of PMDA was dissolved in 200 g of NMP, heated to 50° C. and the reaction was stirred for two hours. Slowly add 0.601 g (0.01 mol) of isopropanol, and stir at a fixed temperature of 50°C for two hours. Then add 32.02 g (0.1 mol) of TFMB to the solution. After complete dissolution, the reaction is stirred at a fixed temperature of 50°C for six hours to obtain polyimide precursor resin PAA-5 with a solid content of about 21wt%. Preparation Example 6 : Synthesis of Polyimide Precursor Resin PAA-6 29.42 g (0.1 mol) of BPDA was dissolved in 200 g of NMP, heated to 50° C. and the reaction was stirred for two hours. Slowly add 0.601 g (0.01 mol) of isopropanol, and stir at a fixed temperature of 50°C for two hours. Then add 20.024 g (0.1 mol) of ODA to the solution. After complete dissolution, the reaction is stirred at a fixed temperature of 50° C. for six hours to obtain polyimide precursor resin PAA-6 with a solid content of about 19 wt %. Preparation Example 7 : Synthesis of soluble polyimide SPI-1 with carboxyl group (-COOH) Weigh 43.62 g (0.2 mol) of PMDA and 30.43 g (0.2 mol) of 3,5-diaminobenzoic acid ( 3,5-diamino benzoic acid (hereinafter referred to as DABA), add 300 mL of NMP, stir at room temperature for 1 hour, then warm to 50°C and stir for 4 hours. After 4 hours, 50 mL of toluene was added, and water was removed at 150° C. using a dean-stark device. After the water removal is complete, the toluene is removed to obtain a polyimide solution SPI-1 with a carboxyl group, with a solid content of about 19 wt%. Preparation Example 8 : Synthesis of isocyanate-modified soluble polyimide SPI-2 Weigh 64.85 g (0.2 mol) of DA1 and 42.46 g (0.2 mol) of 2,2'-dimethylbiphenyl-4 ,4'-diamine (2,2'-dimethylbiphenyl-4,4'-diamine, hereinafter referred to as DMDB), add 300 mL of NMP, stir at room temperature for 1 hour, then warm to 50°C and stir for 4 hours . After 4 hours, 50 mL of toluene was added, and the water was removed in a Dean-Stark apparatus at 130°C. After the removal of water and toluene is complete, the solution is cooled to room temperature, and then 7 grams (0.05 mol) of 2-isocyanatoethyl acrylate (hereinafter referred to as 2-IEA), 0.05 Grams 1-MI and 0.06 grams PTZ. After the addition, the solution was heated to 80°C and stirred for 8 hours. The isocyanate-modified soluble polyimide SPI-2 can be obtained with a solid content of about 27 wt %. Preparation Example 9: Synthesis of soluble polyimide SPI-3 with carboxyl group (-COOH) Weigh 100.074 g (0.2 mol) of DA3 and 42.46 g (0.2 mol) of DMDB, add 450 ml of NMP at room temperature The mixture was stirred for 1 hour, and then heated to 50°C and stirred for 4 hours. After that, 50 ml of toluene was added, and the water was removed in a Dean-Stark apparatus at 130°C. After the removal of water and toluene is complete, soluble polyimide SPI-3 with -COOH group is obtained, with a solid content of about 24 wt %. Preparation Example 10 : Synthesis of epoxy-modified soluble photosensitive polyimide SPI-4 Weigh 142.5 g of the polyimide SPI-3 prepared in Preparation Example 9, then add 6.11 g (0.05 mol) of glycidyl methacrylate (hereinafter referred to as GMA), 0.015 g of bromine Tetrabutylammonium bromide (hereinafter referred to as TBAB) and 0.06 grams of hydroquinone monomethyl ether (hereinafter referred to as MEHQ). After the addition, the solution was heated to 90°C and stirred for 12 hours to obtain an epoxy-modified soluble photosensitive polyimide SPI-4 with a solid content of about 25 wt %. Preparation Example 11 : Synthesis of polyimide solution with acrylic photosensitive group SPI-5 Weigh 32.023 g (0.1 mol) of TFMB and 48.8664 g (0.11 mol) of 4,4'-(hexafluoroisopropylene ) Diphthalic anhydride (4,4'-(Hexafluoroisopropylidene) diphthalic anhydride (hereinafter referred to as 6FDA)), add 300 mL of NMP, and stir at room temperature for 1 hour. The temperature was raised to 50°C and stirred for 4 hours. After 4 hours, 50 mL of toluene was added, and the water was removed in a Dean-Stark apparatus at 150°C. After completely removing water and toluene, add 2.322 g (0.02 mol) of HEA at 50°C and stir for 4 hours to obtain a polyimide solution SPI-5 with an acrylic photosensitive group, solid form The portion is about 21 wt %. Preparation Example 12 : Synthesis of polyimide precursor resin PAA-7 21.81 g (0.1 mol) of PMDA was dissolved in 200 g of N,N-dimethylacetamide (N,N-dimethylacetamide; hereinafter referred to as DMAc ), heat to 50°C and stir the reaction for two hours. Slowly add 0.601 g (0.01 mol) of isopropanol, and stir at a fixed temperature of 50°C for two hours. Then add 32.02 g (0.1 mol) of TFMB to the solution. After complete dissolution, the reaction is stirred at a fixed temperature of 50°C for six hours to obtain polyimide precursor resin PAA-7 with a solid content of about 20 wt %. Preparation Example 13 : Synthesis of Polyimide Precursor Resin PAA-8 21.81 g (0.1 mol) of PMDA was dissolved in 200 g of γ-butyrolactone, heated to 50° C. and the reaction was stirred for two hours. 0.601 g (0.01 mol) of isopropyl alcohol was slowly added dropwise, and the reaction was stirred at a fixed temperature of 50°C for three hours. Then add 32.02 g (0.1 mol) of TFMB to the solution. After complete dissolution, the reaction is stirred at a fixed temperature of 50°C for six hours to obtain polyimide precursor resin PAA-8 with a solid content of about 21 wt %. Preparation Example 14 : Synthesis of carboxyl group (-COOH) soluble polyimide SPI-6 Weigh 43.62 g (0.2 mol) of PMDA and 30.43 g (0.2 mol) of DABA, add 300 mL of DMAc at room temperature The mixture was stirred for 1 hour, and then heated to 50°C and stirred for 4 hours. After 4 hours, 50 mL of toluene was added, and water was removed at 150° C. using a dean-stark device. After the water removal is complete, the toluene is removed to obtain a polyimide solution SPI-6 with a carboxyl group, with a solid content of about 20 wt %. Preparation of dry film to take the above Production Example 1 to 100 parts by weight of 14 prepared as a solution of polyimide precursor or soluble polyimide solution, the ratio in Table 1 to Table 5 (parts by weight) was added as needed or hydrophobic solvent Stabilizer, and add 2 parts by weight of hot alkali generator (

). In addition, if it is a photosensitive polyimide precursor solution or a photosensitive soluble polyimide solution (such as PAA-1 to PAA-4, SPI-2, SPI-4 and SPI-5), then add 1 part by weight of photoinitiator (2,4,6-trimethylbenzyl diphenylphosphine oxide and benzophenone, ratio is 1:1) to prepare a coating composition. Each coating composition was evenly coated on a polyethylene terephthalate (model: R310, manufactured by Mitsubishi) substrate with a doctor blade, and baked in an oven. The baking temperature and time are shown in the tables. Then, the surface coated with the aforementioned coating composition is covered with a release film (model: L150L, manufactured by South Asia) to obtain a dry film with a polyimide precursor coating or a soluble polyimide coating. The thickness is about 40 μm. The hydrophilic solvent content and hydrophobic solvent addition amount (parts by weight) before coating are based on 100 parts by weight of polyimide precursor solution or soluble polyimide solution, and the hydrophilic solvent and hydrophobic solvent after baking and drying The content (wt%) is based on the total weight of the resin layer. Dry film test Check the solvent content of the above dry film and test the physical properties of the dry film, such as adhesion, transfer integrity, water solubility, folding resistance and photosensitivity. The test details are as follows: 1. Solvent content test Take 0.01 grams of polyimide precursor coating or soluble polyimide coating (that is, without PET substrate and release film), dissolve in dimethyl sulfoxide (DMSO), use Agilent 7890GC gas Phase chromatograph, capillary (column) model: DB1701 (0.53mm, 30mm, 1.5μm), to perform quantitative analysis of gas chromatography. 2. Dry film stickiness detection Take the dry film of each example and comparative example, tear off the release film, and observe whether there is residual polyimide layer resin on the release film. No residue at all is 0, <10% residue is 1, 10%-20% residue is 2, and >20% residue is NG. 3. Transfer test Take a 20*20cm dry film, tear off the release film, and then press the dry film and the wet press method as follows to press the dry film film coated with the polyimide layer to the surface. On the copper foil substrate of the circuit (L/S=30/30μm; L/S is the line width/line distance): (a) Wet press on the surface of the copper foil substrate with the circuit, apply deionized water , Use a hot roller to press at 60°C and a downforce of 5kg. (b) Dry press lamination on the surface of the copper foil substrate with wiring, using a hot roller, and pressing at 60°C and a downforce of 5 kg. After standing for 10 minutes, tear off the PET film on the dry film, and observe whether the PET film has residual polyimide layer resin. No residue on the PET film is 0, <10% is 1, 10%~20% The residue is 2, and >20% remains in the PET film as NG. 4. Water solubility test Take a dry film of 20*20cm, press the side of the dry film coated with polyimide layer onto the surface of the copper foil substrate with the circuit by the above wet pressing method, let it stand and use Observe the time when the water on the copper foil substrate is completely absorbed by the microscope. Observe every 5 minutes during the first hour, and every 30 minutes thereafter. 5. Bubble test Take a 20*20cm dry film, and press the side of the dry film coated with polyimide layer to the surface of the copper foil substrate with the circuit by the above wet pressing and dry pressing methods. After standing for 10 minutes, observe the residual state of bubbles. Pass without bubbles, and NG with bubbles. 6. Physical property test ( bending resistance test 1) Take a dry film of 20*20cm, and press the side of the dry film coated with polyimide layer to the copper foil substrate by the above wet pressing and dry pressing methods respectively On the surface with the wire, after standing for 120 minutes, bake at 250 ^o C for 120 minutes, then cool to room temperature, and use a Measure Infect Turn (MIT) test machine (Jindehao company) equipment to bend The bending angle is 135 degrees, the bending radius R=0.38mm, and the load is 500g. The bending resistance test is performed, and the number of bending times the circuit board is subjected to when the circuit property fails is recorded. The greater the number of folding endurance tests, the better the physical properties of the polyimide layer formed. 7. Physical property test ( bending resistance test 2-for photosensitive materials ) Take a dry film of 20*20cm, and press the side of the dry film coated with polyimide layer by the above wet pressing and dry pressing methods respectively after the substrate having a copper foil bonded to the surface of the line was allowed to stand for 120 minutes exposure to UV exposure unit (exposure energy 400mJ / cm ^2), then baked to peel off the PET film 90 ^o C 10 min at a concentration of 1wt% of K ₂ CO ₃ aqueous solution pattern development, and then baked to 250 ^o C 120 minutes, with lowered to room temperature, and to verify folding machine (Measure Infect Turn (MIT) test machine, Jinde Hao Corporation) device to bend The bending angle is 135 degrees, the bending radius R=0.38mm, and the load is 500g. The bending resistance test is performed, and the number of bending times the circuit board is subjected to when the circuit property fails is recorded. The greater the number of folding endurance tests, the better the physical properties of the polyimide layer formed. 8. Physical property test ( bending resistance test 3) : take a dry film of 20*20cm (take 4 pieces in each example), place it at room temperature, and then use the above wet on the first, third, fifth, and seventh days, respectively. -Type press-fit method, the dry film coated with polyimide layer is attached to the surface of the copper foil substrate circuit, stand for 120 minutes, and bake at 250 ^o C for 120 minutes, after cooling to room temperature , Using the Measure Infect Turn (MIT) test machine (Jindehao company) equipment, with a bending angle of 135 degrees, a bending radius R = 0.38mm, a load of 500g to carry out the folding test, record the folding test less than 200 times Number of days left, the longer the number of days, the better the storage stability of the dry film. 9. Physical property test ( bending resistance test 4) : take a dry film of 20*20cm, and then apply the polyimide layer on the dry film to the copper foil substrate with the circuit by the above wet pressing method On the surface, then stand at room temperature, take 2*10cm of the pressed substrate every 6 hours and bake at 250 ^o C for 120 minutes. After cooling to room temperature, use a folding test machine (Measure Infect Turn (Measure Infect Turn ( MIT) test machine, Jindehao company) equipment, with a bending angle of 135 degrees, a bending radius R=0.38mm, a load of 500g for folding endurance test, record the folding endurance test less than 200 times of placement time, the longer the placement time indicates dry The better the stability of the membrane process. 10. Photosensitive test: take a 20*20cm dry film, and press the side of the dry film coated with polyimide layer to the surface of the copper foil substrate with the above wet pressing and dry pressing methods respectively After standing for 120 minutes, use a glass mask with an L/S of 60/60µm and a via size of 60µm, with different UV energy (50mJ/cm ² , 100mJ/cm ² , 150 J/cm ² , 200 J/cm ² , 250 J/cm ² ) exposure to the polyimide layer. After exposure of the PET film tearing, into oven at 90 ^o C Bake for 10 minutes, then ₂ CO ₃ concentration of 1wt% aqueous K for pattern development, and then the SEM to measure developing the polyimide layer L / S (µm) and via(µm) resolution, record the exposure energy that the resolution meets the requirements. A lower exposure energy means better sensitivity of the material. The test results of each example and comparative example are recorded in Table 1 to Table 7. Table 1 ＜Comparing the effects of different hydrophobic solvents＞

NA: Unable to measure Table 2 <Comparing the effects of different resins/different hydrophilic solvents>

Table 3 ＜Comparison effect of different hydrophilic/hydrophobic solvent ratio＞

Table 4 ＜Comparing the effect of adding stabilizers＞

Table 5 ＜Comparison of effects of different total solvents＞

Table 6 ＜Comparing the effects of different pressing methods＞

Table 7 <Photosensitive test>

Table 1 shows the effect of adding no hydrophobic solvent and adding different hydrophobic solvents. It can be seen from Table 1 that if only the common solvent (such as NMP) used in the preparation of conventional polyimide precursors or soluble polyimide is used, the polyimide resin is greatly adhered to the release film, which is difficult to apply to the subsequent Processing, adding hydrophobic solvent can improve the sticking phenomenon, and has good transfer ability and water solubility, suitable for wet lamination process. Table 2 shows that when a specific hydrophilic solvent is matched with a hydrophobic solvent and the ratio is controlled within the range described in the present invention, the resulting dry film is non-sticky, has good transferability and water solubility, and is suitable for wet lamination processes. Table 3 shows that when the weight ratio of the hydrophilic solvent and the hydrophobic solvent is too high (eg, more than 2), the dry film is too sticky and cannot be used, and the storage stability of the dry film is not good (bending resistance test 3); when the hydrophilic solvent If the weight ratio of the hydrophobic solvent is too low (eg, less than 0.05), the storage stability can be increased, but the dry film transfer ability and water solubility are poor at this time. The results in Table 3 show that the appropriate adjustment of the hydrophilic solvent and hydrophobic solvent The dry film obtained by weight ratio (eg, 0.05~2, preferably 0.1~1) has both anti-sticking property, excellent transfer ability and water solubility, and the storage stability of the dry film is good (bending resistance test 3), The subsequently formed polyimide layer also has excellent physical properties (bending resistance test 1). Table 4 shows that adding an appropriate amount of stabilizer helps to improve the process stability of the dry film (fold resistance test 4) and water solubility, and does not affect the physical properties of the subsequent polyimide layer (fold resistance test 1). Table 5 shows that when the total amount of dry film solvent is controlled between 30wt% and 70wt%, the dry film adhesion, transfer ability and water solubility are better, and even in the presence of water, the final polyimide layer prepared It also has good physical properties (folding resistance test 1). When the total amount of solvent is less than 30wt%, the dry film cannot pass the transfer test, the water solubility is poor, and the physical properties of the polyimide layer finally obtained are also poor (bending resistance test 1). When the total amount of solvent is higher than 70wt%, the dry film is too sticky and subsequent processing cannot be performed. Tables 6 and 7 show that the dry film of the present invention is suitable for a wet lamination method, which not only does not leave air bubbles between the patterned surface and the polyimide resin layer, but also has better physical properties. In addition, compared with the dry lamination method, the dry film and wet lamination method of the present invention can achieve the same resolution with a lower exposure energy.

A‧‧‧substrate roll B‧‧‧product roll 1‧‧‧dry film roll 2‧‧‧upper roller 3‧‧‧lower roller 10‧‧‧substrate 11‧‧‧surface to be pressed 20‧‧‧poly Acrylic imide dry film 21‧‧‧ Base material 22‧‧‧ Polyimide layer 30‧‧‧ Mask 40‧‧‧ Mask

Figure 1 is a schematic diagram of a roll-to-roll process. FIG. 2 is a schematic diagram of the dry film of the present invention applied to wet lamination. Fig. 3 is a related processing step of applying the dry film of the present invention to a cover film.

A‧‧‧ substrate roll

B‧‧‧Product Roll

1‧‧‧Dry film roll

2‧‧‧Up roller

3‧‧‧lower wheel

Claims (3)

A polyimide dry film for wet lamination, comprising a base material and a polyimide layer, wherein the polyimide layer comprises: (a) a polyimide precursor or a soluble polyimide; And (b) a solvent, wherein the solvent comprises a hydrophilic solvent and a hydrophobic solvent, and the weight ratio of the hydrophilic solvent to the hydrophobic solvent is between 0.53 and 0.72, wherein based on the total weight of the polyimide layer, the solvent The content is between about 30wt% and about 70wt%, wherein the hydrophilic solvent includes N,N-dimethylacetamide, N,N-diethylacetamide, N-methyl-2- Pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone or a mixture thereof, and wherein the hydrophobic solvent system includes:

, N,N-dimethyldecylamide or a combination thereof. The dry film according to claim 1, further comprising (c) additives, wherein the additives include: stabilizers, ring closure accelerators, pigments, leveling agents, defoamers, coupling agents, catalysis Agents, acrylic monomers, photoinitiators or combinations thereof. The dry film according to claim 2, wherein the stabilizer contains:

,

Or a combination thereof, wherein: R ₁₇ ", R ₁₈ ", R ₁₉ "and R ₂₀ " are each independently C ₁ -C ₄ alkyl, or R ₁₉ "and R ₂₀ " together with the oxygen atom to which they are attached form 5 to 6 Member heterocycle, or R ₁₉ "and R ₁₇ " or R ₂₀ "and R ₁₈ ", together with the oxygen and nitrogen atoms to which they are attached, form a 5 to 6 membered heterocycle; R ₂₁ " and R ₂₂ "are each independently C _1- C ₄ alkyl, or R ₂₁ "and R ₂₂ " together with the carbon atom to which they are attached form a 5 to 6 member carbocycle; and R ₂₃ "and R ₂₄ " are each independently C ₁ -C ₄ alkyl.

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