TWI550650B - Conductive sheet and electonic parts - Google Patents
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Description
本發明是有關於一種例如可貼附於印刷配線板等的被黏體而使用的導電性片及其製造方法。而且，本發明是有關於一種包括上述導電性片的電子零件。 The present invention relates to a conductive sheet which can be used, for example, to be adhered to an adherend such as a printed wiring board, and a method for producing the same. Moreover, the present invention relates to an electronic component including the above conductive sheet.
伴隨近年來的電子機器的輕薄短小化，除印刷配線板的小型化外，多使用可撓性印刷配線板。這些配線板中為了實現高功能化而使用各種導電性片。 In recent years, in addition to the miniaturization of printed wiring boards, flexible printed wiring boards have been used in addition to the reduction in size and thickness of electronic equipment. In these wiring boards, various conductive sheets are used in order to achieve high functionality.
例如，專利文獻1中，揭示了一種導電層由包含熱硬化性黏接劑的黏接層夾持的3層構造的熱硬化型導電性黏接片。構成該黏接片的導電層具有向表面方向***的突起部。該導電層的突起部藉由將黏接層加熱壓接至被黏體而貫通黏接層從而與被黏體電性直接接觸。藉此，作為導電性黏接性片而發揮功能。 For example, Patent Document 1 discloses a thermosetting conductive adhesive sheet having a three-layer structure in which a conductive layer is sandwiched by an adhesive layer containing a thermosetting adhesive. The conductive layer constituting the adhesive sheet has a projection that is raised in the surface direction. The protruding portion of the conductive layer is electrically connected to the adherend by directly pressing and bonding the adhesive layer to the adherend to penetrate the adhesive layer. Thereby, it functions as a conductive adhesive sheet.
而且，專利文獻2中，揭示了一種含有玻璃轉移溫度為-10℃以上、50℃以下的熱可塑性樹脂、及銀粉的導電性黏接膜。關於銀粉，通常記載從霧化(atomized)銀粉、球狀、微細球狀、薄片狀中至少組合使用2種以上。 Further, Patent Document 2 discloses a conductive adhesive film containing a thermoplastic resin having a glass transition temperature of -10 ° C or more and 50 ° C or less and silver powder. The silver powder is generally used in combination of at least two kinds of atomized silver powder, spherical, fine spherical, and flake.
專利文獻3中，揭示了一種含有聚胺基甲酸酯聚脲(polyurethane polyurea)樹脂、具有2個以上的環氧基的環氧樹脂、及導電性填料的電磁波屏蔽性黏接膜。 Patent Document 3 discloses an electromagnetic wave shielding adhesive film containing a polyurethane polyurea resin, an epoxy resin having two or more epoxy groups, and a conductive filler.
[專利文獻1]日本專利特開2002-97424號公報 [Patent Document 1] Japanese Patent Laid-Open Publication No. 2002-97424
[專利文獻2]日本專利特開2004-288560號公報 [Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-288560
[專利文獻3]WO2006/088127號公報 [Patent Document 3] WO2006/088127
然而，專利文獻1中所揭示的導電性黏接片採用將包含銅、鐵、鋁等的金屬箔的導電層藉由黏接劑層而夾持的構造，因而存在不適合於使印刷配線板的厚度變薄的情況的問題。而且，金屬箔因彎曲性差，故難以用於將導電性黏接片重複彎曲的可撓性印刷配線板。 However, the conductive adhesive sheet disclosed in Patent Document 1 has a structure in which a conductive layer containing a metal foil of copper, iron, aluminum or the like is sandwiched by an adhesive layer, and thus it is not suitable for a printed wiring board. The problem of the case where the thickness is thin. Further, since the metal foil is inferior in flexibility, it is difficult to use it for a flexible printed wiring board in which the conductive adhesive sheet is repeatedly bent.
而且，專利文獻2中所揭示的導電性黏接膜因熱可塑性樹脂的耐熱性低，故不適合於高溫環境下的使用。 Further, the conductive adhesive film disclosed in Patent Document 2 is not suitable for use in a high-temperature environment because the thermoplastic resin has low heat resistance.
而且，在將導電性片貼附於印刷配線板等的情況下，若導電層滲出則會對電子裝置的電性特性造成大的影響。因此，市場上對導電性片的滲出的要求嚴格，對專利文獻2或專利文獻3等的先前的導電性的片，要求對導電層的滲出的進一步改良。 Further, when the conductive sheet is attached to a printed wiring board or the like, if the conductive layer bleeds out, the electrical characteristics of the electronic device are greatly affected. Therefore, there is a strict demand for bleed out of the conductive sheet on the market, and further improvement of the bleed out of the conductive layer is required for the previously conductive sheet of Patent Document 2 or Patent Document 3.
本發明鑒於上述背景而完成，其目的在於提供一種在將導電性片貼附於印刷配線板等的被黏體的加熱壓製步驟中，可將導電層的滲出降低至最小限度的加工性良好的導電性片及其製造方法以及電子零件。 The present invention has been made in view of the above-described background, and an object of the invention is to provide a method of heating and pressing a conductive sheet such as a printed wiring board, which can reduce the bleeding of the conductive layer to a minimum. A conductive sheet, a method for producing the same, and an electronic component.
本發明的導電性片包括導電層，該導電層至少含有熱硬化性樹脂(A)、及枝晶(dendrite)狀導電性微粒子(B)，上述導電層的厚度滿足下述(i)與(ii)的至少一者：(i)150℃、2MPa、30分鐘的條件下加熱壓製後的厚度，在將 加熱壓製前的該導電層的厚度設為100時為30以上、95以下的範圍；(ii)上述枝晶狀導電性微粒子(B)的平均粒徑D90相對於該導電層的厚度為0.5倍以上、3倍以下的範圍；上述枝晶狀導電性微粒子(B)的平均粒徑D50為3μm以上、50μm以下，且，上述導電層中在50重量%以上、90重量%以下的範圍內含有上述枝晶狀導電性微粒子(B)。 The conductive sheet of the present invention includes a conductive layer containing at least a thermosetting resin (A) and dendritic conductive fine particles (B), and the thickness of the conductive layer satisfies the following (i) and ( At least one of ii): (i) a thickness after heating and pressing under conditions of 150 ° C, 2 MPa, and 30 minutes, and a range of 30 or more and 95 or less when the thickness of the conductive layer before heat pressing is 100; (ii) The average particle diameter D 90 of the dendritic conductive fine particles (B) is in a range of 0.5 times or more and 3 times or less with respect to the thickness of the conductive layer; and the average particle of the dendritic conductive fine particles (B) The diameter D 50 is 3 μm or more and 50 μm or less, and the dendritic conductive fine particles (B) are contained in the conductive layer in a range of 50% by weight or more and 90% by weight or less.
本發明的電子零件貼附著上述態樣的導電性片。 The electronic component of the present invention is adhered to the conductive sheet of the above aspect.
本發明的導電性片的製造方法包括下述步驟：將含有平均粒徑D50為3μm以上、50μm以下的枝晶狀導電性微粒子(B)、及熱硬化性樹脂(A)的導電性樹脂組成物塗佈於剝離性片上，形成在50重量%以上、90重量%以下的範圍內含有上述枝晶狀導電性微粒子(B)的導電層，對上述導電層施加2.5MPa以上、50MPa以下的壓力。 The method for producing a conductive sheet of the present invention includes the step of: conducting a conductive resin containing dendritic conductive fine particles (B) having an average particle diameter D 50 of 3 μm or more and 50 μm or less and a thermosetting resin (A). The composition is applied to the release sheet, and a conductive layer containing the dendritic conductive fine particles (B) in a range of 50% by weight or more and 90% by weight or less is formed, and 2.5 MPa or more and 50 MPa or less are applied to the conductive layer. pressure.
根據本發明，藉由使用枝晶狀導電性微粒子，在加熱壓製前形成包含較多的空隙的導電層，因而例如可由該空隙吸收在將導電性片加熱壓製到印刷配線板時所流動的熱硬化性樹脂等。藉此，可防止導電層的滲出，從而可改善加工性。其結果，使用了該導電性片的印刷配線板等的電子零件中，因滲出而引起的次品大幅減少從而良率良好。進而，可大幅地減少印刷配線板等的電子零件的電路的短路或離子遷移(ionic migration)。 According to the present invention, by using the dendritic conductive fine particles, a conductive layer containing a large number of voids is formed before the heat pressing, and thus, for example, the heat which flows when the conductive sheet is heated and pressed onto the printed wiring board can be absorbed by the void. Curable resin, etc. Thereby, the bleeding of the conductive layer can be prevented, and the workability can be improved. As a result, in the electronic component such as a printed wiring board using the conductive sheet, the defective product due to bleeding is greatly reduced, and the yield is good. Further, it is possible to greatly reduce short circuits or ionic migration of circuits of electronic components such as printed wiring boards.
根據本發明，具有如下效果：可提供一種在將導電性 片貼附於印刷配線板等的被黏體的加熱壓製步驟中，可將導電層的滲出降低至最小限度的加工性良好的導電性片、及其製造方法以及電子零件。 According to the present invention, there is an effect that conductivity can be provided The sheet is attached to a conductive pressing step of a adherend such as a printed wiring board, and the conductive sheet can be reduced to a minimum of excellent workability, a conductive sheet, a method for producing the same, and an electronic component.
以下，對本發明的實施形態進行詳細說明。另外，只要符合本發明的主旨，則其他實施形態亦可屬於本發明的範疇。而且，以下的實施形態可彼此適當組合。而且，本說明書中「任意的數A~任意的數B」的記載表示數A及比數A大的範圍、且數B及比數B小的範圍。 Hereinafter, embodiments of the present invention will be described in detail. Further, other embodiments may fall within the scope of the present invention as long as they conform to the gist of the present invention. Further, the following embodiments can be combined as appropriate with each other. In the present specification, the description of the "arbitrary number A to the arbitrary number B" indicates a range in which the number A and the ratio A are large, and the number B and the number B are smaller.
本發明的導電性片至少具有導電層。導電性片可包含一層的導電層，亦可積層有多個導電層，而且，還可積層有導電層以外的層(例如，支持層、絕緣層、保護層、黏接層)等。另外，本說明書中提及的導電性片並非必須片整體具有導電特性，至少導電層具有導電特性即可。導電層的導電特性可根據用途或需求來適當設定，並無特別限定。 The conductive sheet of the present invention has at least a conductive layer. The conductive sheet may include a conductive layer of one layer, or a plurality of conductive layers may be laminated, and a layer other than the conductive layer (for example, a support layer, an insulating layer, a protective layer, an adhesive layer) may be laminated. Further, the conductive sheet referred to in the present specification does not necessarily have to have conductive characteristics as a whole, and at least the conductive layer may have conductive characteristics. The conductive property of the conductive layer can be appropriately set depending on the use or demand, and is not particularly limited.
對第1實施形態中，作為導電性片的一實施態樣之包含1層的導電層的示例進行說明。第1實施形態的導電性片的導電層將熱硬化性樹脂(A)、與枝晶狀導電性微粒子(B)作為必要構成而包含。導電層的厚度如下：在150℃、2MPa、30分鐘的條件下，且在進行了與被黏體的加熱壓製的情況下，在將加熱壓製前的導電層的厚度設為100時，加熱壓製後的厚度為30以上、95以下的範圍。另外， 「加熱壓製前的導電層」是指即將要貼附於印刷配線板等的被黏體前的導電層。而且，被黏體是指貼附導電性片的對象物整體，例如可列舉印刷配線基板、可撓性基板等。 In the first embodiment, an example of a conductive layer including one layer as an embodiment of the conductive sheet will be described. The conductive layer of the conductive sheet of the first embodiment contains the thermosetting resin (A) and the dendritic conductive fine particles (B) as essential structures. The thickness of the conductive layer is as follows: under the conditions of 150 ° C, 2 MPa, 30 minutes, and in the case where the pressing with the adherend is performed, the thickness of the conductive layer before the heat pressing is set to 100, and the heating is pressed. The thickness after the thickness is in the range of 30 or more and 95 or less. In addition, The "conductive layer before heating and pressing" refers to a conductive layer that is to be attached to a surface of a member such as a printed wiring board. In addition, the adherend means the entire object to which the conductive sheet is attached, and examples thereof include a printed wiring board and a flexible board.
導電性片的導電層的上述條件下的加熱壓製後的導電層的厚度更佳為40以上，進而較佳為45以上。而且，該加熱壓製後的導電層的厚度更佳為90以下，進而較佳為85以下。尤佳為60~80的範圍。在加熱壓製後的厚度大於95的情況下，推想在加熱壓製前的導電層中空隙少，因此在加熱壓製前後厚度變化少，且有在加熱壓製時向水平方向的熱硬化性樹脂(A)的滲出增大之虞。另一方面，在加熱壓製後的厚度小於30的情況下，推想導電層中空隙過多，因此存在如下傾向：加熱壓製前後的厚度變化大，藉由加熱壓製亦殘留空隙，難以達成所期望的導電性。另外，本說明書中所提及的「滲出」包括低分子量成分滲出及導電層流動的露出。 The thickness of the conductive layer after heat pressing under the above-described conditions of the conductive layer of the conductive sheet is more preferably 40 or more, still more preferably 45 or more. Further, the thickness of the conductive layer after the heat pressing is more preferably 90 or less, further preferably 85 or less. Especially good for the range of 60~80. In the case where the thickness after the heat pressing is more than 95, it is conceivable that the number of voids in the conductive layer before the heat pressing is small, so that the thickness variation is small before and after the heating pressing, and the thermosetting resin (A) which is horizontally oriented during the heating pressing is used. The oozing is increased. On the other hand, in the case where the thickness after the heat pressing is less than 30, it is assumed that there are too many voids in the conductive layer, and therefore there is a tendency that the thickness variation before and after the heating press is large, and voids remain by heating and pressing, and it is difficult to achieve desired conductivity. Sex. In addition, "exudation" as referred to in the specification includes exudation of a low molecular weight component and exposure of a flow of a conductive layer.
第1實施形態的導電性片在溫度150℃、時間30分鐘、壓力2MPa的條件下進行加熱壓製，藉此可填埋在導電層中使用枝晶狀導電性微粒子(B)所形成的空隙。另外，第1實施形態的導電性片貼附於印刷配線板等的被黏體時的條件是以在上述加熱壓製條件下進行的示例進行說明，但亦可採用不同的加熱壓製步驟來將導電性片貼附於印刷配線板等的被黏體。例如，可根據所使用的熱硬化性樹脂的種類來調整加熱條件、壓製條件等。 The conductive sheet of the first embodiment is heated and pressed under the conditions of a temperature of 150 ° C, a time of 30 minutes, and a pressure of 2 MPa, whereby the voids formed by the dendritic conductive fine particles (B) can be filled in the conductive layer. In addition, the conditions when the conductive sheet of the first embodiment is attached to a adherend such as a printed wiring board are described below under the above-described heating and pressing conditions, but different heating and pressing steps may be employed to conduct the conductive material. The sheet is attached to a adherend such as a printed wiring board. For example, heating conditions, pressing conditions, and the like can be adjusted depending on the type of the thermosetting resin to be used.
第1實施形態的導電性片是以第1實施形態的導電性 片的導電層側與印刷配線板等的被黏體接觸的方式進行積層，並經過上述加熱壓製步驟，藉此可將導電性片貼附於被黏體。根據第1實施形態的導電性片，因含有熱硬化性樹脂，故可良好地保持與被黏體的黏接性。另外，已說明了將導電層接合於被黏體的示例，根據用途或需求而亦可設為在導電性片上設置與導電層不同的另外的黏接劑層，並將黏接劑層與被黏體接合的態樣。 The conductive sheet according to the first embodiment is the conductivity of the first embodiment. The conductive layer side of the sheet is laminated so as to be in contact with the adherend such as a printed wiring board, and is subjected to the above-described heat pressing step, whereby the conductive sheet can be attached to the adherend. According to the conductive sheet of the first embodiment, since the thermosetting resin is contained, the adhesion to the adherend can be favorably maintained. Further, an example in which a conductive layer is bonded to an adherend has been described, and depending on the use or demand, an additional adhesive layer different from the conductive layer may be provided on the conductive sheet, and the adhesive layer may be The state of adhesion of the body.
第1實施形態中所使用的熱硬化性樹脂(A)在不脫離本發明的主旨的範圍內並無特別限定，但較佳為丙烯酸系、酚系、環氧系、胺基甲酸酯系(urethane)、三聚氰胺系(melamine)、醇酸系等的樹脂。進而，在如可撓性印刷配線板般藉由加熱壓製步驟黏接、貼附後彎曲而使用的情況下，更佳為兼具備耐熱性與彎曲性的丙烯酸系樹脂、胺基甲酸酯系樹脂。另外，熱硬化性樹脂(A)可使用1種，亦可混合使用2種以上。 The thermosetting resin (A) used in the first embodiment is not particularly limited as long as it does not deviate from the gist of the present invention, but is preferably an acrylic, phenol, epoxy or urethane system. A resin such as urethane, melamine or alkyd. Further, when it is used by being bonded and adhered by a heating and pressing step as in a flexible printed wiring board, it is more preferably an acrylic resin or a urethane resin having heat resistance and flexibility. . In addition, one type of the thermosetting resin (A) may be used, or two or more types may be used in combination.
導電層中較佳為與熱硬化性樹脂(A)併用而使用硬化劑。硬化劑可使用與所使用的樹脂的官能基相對應的公知的化合物。例如，在樹脂含有羧基的情況下，較佳為環氧硬化劑、氮丙啶(aziridine)硬化劑等。而且，在樹脂含有羥基的情況下，較佳為異氰酸酯硬化劑或含有酸酐基的化合物等。 Among the conductive layers, it is preferred to use a curing agent in combination with the thermosetting resin (A). As the hardener, a known compound corresponding to the functional group of the resin to be used can be used. For example, when the resin contains a carboxyl group, an epoxy hardener, an aziridine hardener or the like is preferable. Further, when the resin contains a hydroxyl group, an isocyanate curing agent or an acid anhydride group-containing compound or the like is preferable.
圖1A表示對於第1實施形態的導電層而言適合的枝晶狀導電性微粒子(B)的一例的掃描式電子顯微鏡(Scanning Electron Microscope，SEM)像。枝晶狀一般而 言是指樹枝狀，如樹木的枝般的形狀。枝晶狀導電性微粒子(B)的素材可例示金、銀、銅、鎳、鋅或鐵等的導電性金屬或其合金、聚苯胺(polyaniline)、聚噻吩(polythiophene)、聚乙炔(polyacetylene)等的導電性有機化合物、或者將這些複合而成的導電性化合物。或者，以金屬或有機化合物或無機化合物為核心且該核心的表面由導電性的素材被覆的導電性微粒子也可作為較佳例而列舉。 FIG. 1A shows a scanning electron microscope (SEM) image of an example of the dendritic conductive fine particles (B) suitable for the conductive layer of the first embodiment. Dendritic Words refer to dendrites, such as the shape of branches of trees. The material of the dendritic conductive fine particles (B) may, for example, be a conductive metal such as gold, silver, copper, nickel, zinc or iron or an alloy thereof, polyaniline, polythiophene or polyacetylene. A conductive organic compound or the like, or a conductive compound obtained by combining these. Alternatively, conductive fine particles having a metal or an organic compound or an inorganic compound as a core and having a surface coated with a conductive material may be cited as a preferred example.
具有導電性的被覆層的導電性微粒子中，對於成為芯(core)的核心的表面形成有被覆層的粒子作為較佳例而列舉。作為核心，可列舉銅、鎳、鎘(cadmium)等的金屬及其合金，聚苯胺、聚噻吩、聚乙炔等的導電性有機化合物，或者通常的非導電性的有機化合物等。而且，作為被覆層，可列舉金、銀、銅等的導電性優異的金屬。而且，以銅作為核心且由銀形成被覆層的導電性微粒子作為更佳例而列舉。另外，枝晶狀導電性微粒子(B)可使用單一種類，亦可混合使用多種。 Among the conductive fine particles of the conductive coating layer, particles having a coating layer formed on the surface of the core of the core are exemplified as preferred examples. The core may be a metal such as copper, nickel or cadmium or an alloy thereof, a conductive organic compound such as polyaniline, polythiophene or polyacetylene, or a general non-conductive organic compound. Further, examples of the coating layer include metals having excellent conductivity such as gold, silver, and copper. Further, conductive fine particles having copper as a core and a coating layer formed of silver are exemplified as a more preferable example. Further, the dendritic conductive fine particles (B) may be used singly or in combination of a plurality of types.
具有導電性的被覆層的導電性微粒子中的被覆層的比例，在枝晶狀導電性微粒子(B)100重量%中，較佳為1重量%~40重量%，更佳為5重量%~20重量%。藉由使用所被覆的導電性微粒子，可因高價的銀的使用量的減少而降低成本，或抑制使用了銅的導電性微粒子的情況下的銅的氧化所引起的導電性降低。 The proportion of the coating layer in the conductive fine particles of the conductive coating layer is preferably from 1% by weight to 40% by weight, and more preferably 5% by weight, based on 100% by weight of the dendritic conductive fine particles (B). 20% by weight. By using the conductive fine particles to be coated, it is possible to reduce the cost due to the reduction in the amount of expensive silver used, or to suppress the decrease in conductivity due to oxidation of copper in the case where conductive fine particles of copper are used.
加熱壓製前後導電性片的厚度發生變化，推測主要是 因體積大的枝晶狀導電性微粒子(B)的存在而導電層中容易存在空隙，藉由加熱壓製而熱硬化性樹脂(A)流動從而填埋該空隙所導致。枝晶狀導電性微粒子(B)的空隙因所使用的枝晶狀導電性微粒子(B)的平均粒徑D50與平均粒徑D90的關係，而更容易受到影響。而且，加熱壓製前的導電層中空隙越多則厚度變化越大。即，認為在將加熱壓製前的厚度設為100情況下，加熱壓製後的厚度的值越小則導電層中空隙越多。 The thickness of the conductive sheet changes before and after the heating and pressing, and it is presumed that the void is easily formed in the conductive layer due to the presence of the bulky dendritic conductive fine particles (B), and the thermosetting resin (A) flows by heat pressing. Thereby causing the void to be filled. The voids of the dendritic conductive fine particles (B) are more susceptible to the relationship between the average particle diameter D 50 and the average particle diameter D 90 of the dendritic conductive fine particles (B) to be used. Moreover, the more the voids in the conductive layer before the heat pressing, the greater the thickness variation. That is, it is considered that when the thickness before the heat pressing is set to 100, the smaller the value of the thickness after the heat pressing, the larger the number of voids in the conductive layer.
枝晶狀導電性微粒子(B)的平均粒徑D50較佳為3μm~50μm，且平均粒徑D90較佳為平均粒徑D50的1.5倍~5倍。而且，平均粒徑D50更佳為3μm~40μm，進而較佳為5μm~25μm。平均粒徑D50為3μm以上，藉此導電層中容易產生空隙，可減少滲出。另一方面，平均粒徑D50為50μm以下，藉此容易形成適當的厚度的導電層。 The average particle diameter D 50 of the dendritic conductive fine particles (B) is preferably from 3 μm to 50 μm, and the average particle diameter D 90 is preferably from 1.5 to 5 times the average particle diameter D 50 . Further, the average particle diameter D 50 is more preferably from 3 μm to 40 μm, still more preferably from 5 μm to 25 μm. The average particle diameter D 50 is 3 μm or more, whereby voids are easily generated in the conductive layer, and bleeding can be reduced. On the other hand, the average particle diameter D 50 is 50 μm or less, whereby it is easy to form a conductive layer having an appropriate thickness.
枝晶狀導電性微粒子(B)的平均粒徑D90較佳為平均粒徑D50的1.5倍~5倍，更佳為2倍~3.5倍。平均粒徑D90的值具有依存於平均粒徑D50的平均粒徑的傾向，較佳為4.5μm~250μm。平均粒徑D90為平均粒徑D50的1.5倍以上，藉此粒徑分布的範圍變廣，因此具有導電層中容易產生空隙的傾向。另一方面，平均粒徑D90為平均粒徑D50的5倍以下，藉此具有粒徑分布的範圍不會過廣，從而具有導電層中的枝晶狀導電性微粒子(B)的填充變得適當的傾向。進而，因巨大的枝晶狀粒子的存在，而不易引起在加熱壓製後該巨大的枝晶狀粒子從導電層突出的現 象。 The average particle diameter D 90 of the dendritic conductive fine particles (B) is preferably 1.5 to 5 times, more preferably 2 to 3.5 times the average particle diameter D 50 . The value of the average particle diameter D 90 tends to depend on the average particle diameter of the average particle diameter D 50 , and is preferably from 4.5 μm to 250 μm. Since the average particle diameter D 90 is 1.5 times or more of the average particle diameter D 50 , the range of the particle diameter distribution is broadened, and thus the conductive layer tends to be likely to generate voids. On the other hand, the average particle diameter D 90 is not more than 5 times the average particle diameter D 50 , whereby the range of the particle diameter distribution is not excessively wide, and the filling of the dendritic conductive fine particles (B) in the conductive layer is provided. The tendency to become appropriate. Further, due to the presence of the large dendritic particles, the phenomenon that the large dendritic particles protrude from the conductive layer after the heat pressing is less likely to occur.
枝晶狀導電性微粒子(B)較佳為敲緊密度(tap density)(以下稱作「TD」)為0.8g/cm3~2.5g/cm3。藉由TD為0.8g/cm3以上，可使導電層中的導電性微粒子的填充更緊密。另一方面，藉由TD為2.5g/cm3以下，有如下傾向：導電層中的導電性微粒子的填充不易變得過密，且可維持加熱壓製前後的膜厚變化大的狀態，因而可進一步減少滲出。 The dendritic conductive fine particles (B) preferably have a tap density (hereinafter referred to as "TD") of 0.8 g/cm 3 to 2.5 g/cm 3 . By the TD being 0.8 g/cm 3 or more, the filling of the conductive fine particles in the conductive layer can be made closer. On the other hand, when TD is 2.5 g/cm 3 or less, there is a tendency that the filling of the conductive fine particles in the conductive layer is less likely to be excessively dense, and the film thickness change before and after the heating press can be maintained large, and thus further Reduce oozing.
而且，枝晶狀導電性微粒子(B)較佳為表觀密度(apparent density)(以下稱作「AD」)為0.4g/cm3~1.5g/cm3。藉由AD為0.4g/cm3以上，可使導電層中的導電性微粒子的填充更緊密。另一方面，藉由TD為1.5g/cm3以下，具有如下傾向：導電層中的導電性微粒子的填充不易變得過密，可維持加熱壓製前後的膜厚變化大的狀態，因而可進一步減少滲出。 Further, the dendritic conductive fine particles (B) preferably have an apparent density (hereinafter referred to as "AD") of 0.4 g/cm 3 to 1.5 g/cm 3 . When AD is 0.4 g/cm 3 or more, the filling of the conductive fine particles in the conductive layer can be made closer. On the other hand, when TD is 1.5 g/cm 3 or less, the filling of the conductive fine particles in the conductive layer is less likely to become too dense, and the change in film thickness before and after the heating press can be maintained, so that the film thickness can be further reduced. Exudation.
藉由將枝晶狀導電性微粒子(B)的表觀密度AD與敲緊密度TD的值設為適當值，可更適當地在導電層中形成空隙。亦即，枝晶狀導電性微粒子(B)的AD與TD的比率(AD/TD)更佳為0.3~0.9。藉由將AD/TD設為0.3以上，具有AD與TD的數值變得更適當，且加熱壓製後的膜厚變化不會變得過大的傾向。另一方面，藉由將AD/TD設為0.9以下，具有AD與TD的數值變得更適當，加熱壓製後的膜厚變化不會過小的傾向。 By setting the values of the apparent density AD and the knock tightness TD of the dendritic conductive fine particles (B) to appropriate values, it is possible to form voids more appropriately in the conductive layer. That is, the ratio of AD to TD (AD/TD) of the dendritic conductive fine particles (B) is more preferably from 0.3 to 0.9. By setting AD/TD to 0.3 or more, the values of AD and TD are more appropriate, and the film thickness change after heat pressing does not tend to become excessive. On the other hand, by setting AD/TD to 0.9 or less, the values of AD and TD are more appropriate, and the film thickness change after heat pressing tends not to be too small.
導電層中使用枝晶狀導電性微粒子(B)的比例，在 導電層100重量%中，較佳為50重量%~90重量%，更佳為60重量%~80重量%。藉由使用量為50重量%以上而具有容易獲得所期望的導電性的傾向。另一方面，藉由使用量為90重量%以下而具有容易確保用以片化的樹脂量的傾向。 The ratio of dendritic conductive fine particles (B) used in the conductive layer is The conductive layer is preferably 50% by weight to 90% by weight, more preferably 60% by weight to 80% by weight, based on 100% by weight of the conductive layer. The use amount is preferably 50% by weight or more, and tends to easily obtain desired conductivity. On the other hand, since the amount used is 90% by weight or less, there is a tendency to easily secure the amount of resin used for sheeting.
枝晶狀導電性微粒子(B)若與球狀導電性微粒子或薄片狀(flake)導電性微粒子(參照圖1B)相比較，則因形成如樹枝般的形狀，故容易在各個粒子間形成間隙。因此，若使用枝晶狀導電性微粒子(B)來形成導電層，則容易產生空隙。藉由使用枝晶狀導電性微粒子(B)，與將使用以球狀導電性粒子或薄片狀導電性微粒子作為主成分的導電性片在同一條件下加熱壓製的情況相比，可進一步減少向橫方向的滲出。 When the dendritic conductive fine particles (B) are compared with the spherical conductive fine particles or the flake conductive fine particles (see FIG. 1B), since a shape like a branch is formed, it is easy to form a gap between the respective particles. . Therefore, when the conductive layer is formed using the dendritic conductive fine particles (B), voids are likely to occur. By using the dendritic conductive fine particles (B), it is possible to further reduce the amount of the conductive sheet using the spherical conductive particles or the sheet-like conductive fine particles as a main component under the same conditions. Exudation in the transverse direction.
導電層中除熱硬化性樹脂(A)與枝晶狀導電性微粒子(B)之外，在不脫離本發明的主旨的範圍內可添加其他添加劑。例如，可包含矽烷偶合劑、抗氧化劑、顏料、染料、增黏樹脂、可塑劑、紫外線吸收劑、消泡劑、均化調整劑、填充劑、阻燃劑等。 In addition to the thermosetting resin (A) and the dendritic conductive fine particles (B) in the conductive layer, other additives may be added without departing from the gist of the invention. For example, a decane coupling agent, an antioxidant, a pigment, a dye, a tackifying resin, a plasticizer, a UV absorber, an antifoaming agent, a leveling agent, a filler, a flame retardant, and the like may be contained.
然後，對第1實施形態的導電性片的製造方法進行說明。首先，藉由至少混合熱硬化性樹脂(A)與枝晶狀導電性微粒子(B)來調合導電性樹脂組成物(C)。混合方法並無特別限定，作為較佳例，可列舉使用混合器(mixer)、溶解器(dissolver)、胡佛研磨機(hoover muller)、3輥研磨機(3 roll mill)、砂磨機等的方法。 Next, a method of producing the conductive sheet of the first embodiment will be described. First, the conductive resin composition (C) is blended by mixing at least the thermosetting resin (A) and the dendritic conductive fine particles (B). The mixing method is not particularly limited, and a preferred example thereof includes a mixer, a dissolver, a hoover muller, a 3-roll mill, a sand mill, and the like. Methods.
使用導電性樹脂組成物(C)，例如於剝離片上塗佈而形成導電層的塗膜。塗佈方法並無特別限定，可不作限制地使用先前公知的方法。例如，可藉由凹板印刷塗佈(gravure coating)方式、吻合塗佈(kiss coating)方式、模塗(die coating)方式、唇塗(lip coating)方式、刮刀塗佈(comma coating)方式、刮塗(blade coating)方式、輥塗(roll coating)方式、刀塗(knife coating)方式、噴塗(spray coating)方式、棒塗(bar coating)方式、旋塗(spin coating)方式、浸塗(dip coating)方式等來形成塗膜。 The conductive resin composition (C) is applied, for example, to a release sheet to form a coating film of a conductive layer. The coating method is not particularly limited, and a conventionally known method can be used without limitation. For example, it may be a gravure coating method, a kiss coating method, a die coating method, a lip coating method, a comma coating method, or the like. Blade coating method, roll coating method, knife coating method, spray coating method, bar coating method, spin coating method, dip coating ( A coating film is formed by a dip coating method or the like.
導電層的進行加熱壓製前的厚度可根據用途來適當設定，但較佳為5μm~100μm。另外，厚度為依據JISB7503(針盤量軌(dial gauge))測定的值。 The thickness of the conductive layer before the heat pressing can be appropriately set depending on the application, but is preferably 5 μm to 100 μm. Further, the thickness is a value measured in accordance with JIS B7503 (dial gauge).
第1實施形態的導電性片的加熱壓製後的膜厚較佳為枝晶狀導電性微粒子(B)的平均粒徑D50的0.25倍~10倍，更佳為0.5倍~5倍。 The film thickness after the heat pressing of the conductive sheet of the first embodiment is preferably 0.25 to 10 times, more preferably 0.5 to 5 times the average particle diameter D 50 of the dendritic conductive fine particles (B).
第1實施形態的導電性片的用途並無特別限定，可用於欲貼附導電性片而使用的所有用途中。例如，以貼附於印刷配線板來進行電磁波屏蔽的目的而使用，或者為了獲取形成在印刷配線板的電路的接地而使用。而且，可貼附於以微波爐等的家電為首的各種電子機器等而使用。 The use of the conductive sheet of the first embodiment is not particularly limited, and can be used in all applications in which a conductive sheet is to be attached. For example, it is used for the purpose of shielding electromagnetic waves from being attached to a printed wiring board, or used to obtain grounding of a circuit formed on a printed wiring board. In addition, it can be attached to various electronic devices such as home appliances such as microwave ovens.
根據第1實施形態的導電性片，如專利文獻1般，即便未設置3層構造而僅設為1層，亦可因使用熱硬化性樹脂而表現出對被黏體的黏接力。其結果，具有亦可用於薄 膜用途的優異的優點。而且，因為不使用如專利文獻1般的金屬箔，而使用以熱硬化性樹脂與枝晶狀導電性微粒子作為必要構成成分的導電層，故可撓性優異。因此，可較佳地適用於可撓性印刷配線板等中。而且，使用枝晶狀的導電性微粒子來作為導電性微粒子，藉此可在導電層內形成空隙等而利用空隙來吸收加熱壓製時的滲出。其結果，可將導電層的滲出限制在最小限度。而且，即使在高溫環境下難以使用的耐熱性低的樹脂等中，藉由使用枝晶狀導電性微粒子，亦可有效地抑制導電層的滲出。根據本發明的導電性片，可較佳地用作在高溫、高濕等的嚴酷條件下使用的用途。 According to the conductive sheet of the first embodiment, as long as the three-layer structure is not provided and only one layer is provided, the adhesion to the adherend can be exhibited by using the thermosetting resin. As a result, it can also be used for thin Excellent advantages of membrane use. In addition, since a metal foil such as Patent Document 1 is not used, and a conductive layer containing a thermosetting resin and dendritic conductive fine particles as essential constituent components is used, flexibility is excellent. Therefore, it can be suitably applied to a flexible printed wiring board or the like. In addition, dendritic conductive fine particles are used as the conductive fine particles, whereby voids or the like can be formed in the conductive layer, and voids can be absorbed by the voids during heat pressing. As a result, the bleed out of the conductive layer can be minimized. Further, even in a resin having low heat resistance which is difficult to use in a high-temperature environment, by using dendritic conductive fine particles, bleeding of the conductive layer can be effectively suppressed. The conductive sheet according to the present invention can be preferably used as a use under severe conditions such as high temperature and high humidity.
其次，對與上述第1實施形態不同的導電性片的一例進行說明。第2實施形態的導電性片是積層有絕緣層、上述第1實施形態的導電層的附有絕緣層的導電性片。 Next, an example of a conductive sheet different from the above-described first embodiment will be described. The conductive sheet of the second embodiment is an electrically conductive sheet having an insulating layer and an insulating layer in which the insulating layer of the first embodiment is laminated.
第2實施形態的導電性片中所使用的絕緣層在不脫離本發明的主旨的範圍內不作特別限定。絕緣層的素材並無特別限定，例如，較佳為使用導電層中可使用的熱硬化性樹脂(A)等具有絕緣性的樹脂。而且，亦可使用聚酯、聚碳酸酯、聚醯亞胺、聚苯硫醚等的塑膠膜。 The insulating layer used in the conductive sheet of the second embodiment is not particularly limited as long as it does not deviate from the gist of the invention. The material of the insulating layer is not particularly limited, and for example, an insulating resin such as a thermosetting resin (A) which can be used in the conductive layer is preferably used. Further, a plastic film such as polyester, polycarbonate, polyimide or polyphenylene sulfide can also be used.
而且，絕緣層中可視需要而包含矽烷偶合劑、抗氧化劑、顏料、染料、增黏樹脂、可塑劑、紫外線吸收劑、消泡劑、均化調整劑、填充劑、阻燃劑等。 Further, the insulating layer may optionally contain a decane coupling agent, an antioxidant, a pigment, a dye, a tackifying resin, a plasticizer, an ultraviolet absorber, an antifoaming agent, a leveling adjuster, a filler, a flame retardant, and the like.
第2實施形態的導電性片的用途並無特別限定，例如 可將導電層側貼附於印刷配線板的外側主面而用作電磁波屏蔽膜。 The use of the conductive sheet of the second embodiment is not particularly limited, and for example, The conductive layer side can be attached to the outer main surface of the printed wiring board to serve as an electromagnetic wave shielding film.
第2實施形態的導電性片的絕緣層的形成方法、及導電層與絕緣層的積層方法可不作限制地使用公知的方法。例如，可在預先形成的絕緣層上形成導電層，或者藉由與在第1實施形態中說明的導電層相同的製造方法而形成在絕緣層上。絕緣層的厚度可根據用途而不同，例如較佳為5μm~50μm。 The method for forming the insulating layer of the conductive sheet of the second embodiment and the method for laminating the conductive layer and the insulating layer can be carried out without any limitation. For example, a conductive layer may be formed on a previously formed insulating layer, or may be formed on the insulating layer by the same manufacturing method as the conductive layer described in the first embodiment. The thickness of the insulating layer may vary depending on the application, and is, for example, preferably 5 μm to 50 μm.
根據第2實施形態，因具有與第1實施形態相同的導電層，故可獲得與第1實施形態同樣的效果。而且，藉由製成與絕緣層的積層體，可提高導電性片的機械強度，或者可對表面賦予絕緣特性。 According to the second embodiment, since the conductive layer is the same as that of the first embodiment, the same effects as those of the first embodiment can be obtained. Further, by forming a laminate with the insulating layer, the mechanical strength of the conductive sheet can be improved, or the surface can be provided with insulating properties.
另外，第2實施形態中，已說明將絕緣層與導電層進行積層而成的導電性片的示例，但與導電層進行積層的層並無特別限定，可根據目的而積層具有各種功能的層。例如，亦可為將支持層或半導體層、保護膜、抗反射膜等的光學膜等積層而成的導電性片。 In the second embodiment, an example of a conductive sheet in which an insulating layer and a conductive layer are laminated is described. However, the layer to be laminated with the conductive layer is not particularly limited, and a layer having various functions can be laminated depending on the purpose. . For example, it may be a conductive sheet in which an optical film such as a support layer, a semiconductor layer, a protective film, or an antireflection film is laminated.
其次，對藉由與上述第1實施形態不同的製造方法製造的導電性片的示例進行說明。第3實施形態的導電性片的製造方法，在第1實施形態所說明的加熱壓製前包含加壓步驟的方面與第1實施形態的導電性片的製造方法不同。關於除此以外的方面，與第1實施形態所說明的步驟相同，所使用的導電層的構成亦相同。 Next, an example of a conductive sheet produced by a manufacturing method different from the above-described first embodiment will be described. The method for producing a conductive sheet according to the third embodiment differs from the method for producing a conductive sheet according to the first embodiment in that the pressurization step is included before the hot press described in the first embodiment. Regarding the other points, the configuration of the conductive layer used is the same as in the steps described in the first embodiment.
第3實施形態的導電性片在塗佈而形成導電層後，在與被黏體黏接時進行加熱壓製前，藉由進行加壓步驟(以下，為了與對被黏體與導電性片加熱壓製的步驟區分而稱作「預加壓步驟」)而製造而成。預加壓步驟可根據用途而適當變更，較佳為施加2.5MPa~50MPa(25k g/cm2~510k g/cm2)的壓力。就預加壓步驟而言，並不排除進行加熱，但因為並非是引起枝晶狀導電性微粒子(B)的變形或折斷，而促進熱硬化性樹脂的流動的目的，故不進行加熱，或者，較佳為設為促進熱硬化性樹脂的流動的溫度以下的加熱。 After the conductive sheet of the third embodiment is applied to form a conductive layer, it is subjected to a pressurization step (hereinafter, in order to heat the adherend and the conductive sheet before heating and pressing when adhering to the adherend). The step of pressing is divided and referred to as "pre-pressurization step"). The pre-pressurization step can be appropriately changed depending on the use, and it is preferred to apply a pressure of 2.5 MPa to 50 MPa ( 25 k g/cm 2 to 510 k g/cm 2 ). In the pre-pressurization step, heating is not excluded, but the purpose of promoting the flow of the thermosetting resin is not caused by deformation or breakage of the dendritic conductive fine particles (B), so heating is not performed, or It is preferable to set it as heating below the temperature which accelerates the flow of a thermosetting resin.
在將被黏體與導電性片接合前預先對導電性片施加壓力而使枝晶狀導電性微粒子(B)變形，或者將枝晶狀的粒子折斷，藉此枝晶狀導電性微粒子(B)彼此的接觸變緊密，從而可進一步提高導電層的導電特性。 Before the adherend and the conductive sheet are joined, pressure is applied to the conductive sheet to deform the dendritic conductive fine particles (B), or the dendritic particles are broken, whereby the dendritic conductive fine particles (B) The contact with each other becomes tight, so that the conductive characteristics of the conductive layer can be further improved.
作為對導電性片施加壓力的方法，有使用平板壓製機、輥壓製機等的方法。這些之中較佳為容易提高壓力的(提高線壓)輥壓製機。所使用的輥，可使用金屬輥及樹脂輥等的表面硬度不同的輥。使用該加壓後的導電性片，並與印刷配線板等的被黏體接合而進行加熱壓製，藉此可更有效地抑制導電層的滲出。 As a method of applying pressure to the conductive sheet, there is a method using a flat press, a roll press, or the like. Among these, a (pressurizing line pressure) roll press which is easy to increase the pressure is preferable. As the roll to be used, a roll having a different surface hardness such as a metal roll or a resin roll can be used. By using the pressed conductive sheet and bonding it to a adherend such as a printed wiring board, it is possible to more effectively suppress the bleeding of the conductive layer.
第3實施形態的導電層是進行預加壓步驟的導電層，但在將被黏體與導電性片接合時如第1實施形態所述般，在150℃、2MPa、30分鐘的條件下加熱壓製後的厚度，在將加熱壓製前的該導電層的厚度設為100時，必須為30 以上、95以下的範圍。亦即，相對於經過預加壓步驟後的與被黏體接合前的導電層的厚度，以上述條件進行了加熱壓製(在150℃、2MPa、30分鐘的條件下加熱壓製)的情況下的厚度變化必須包含在上述範圍(導電層的厚度設為100時，30以上、95以下的範圍)內。另外，只要滿足上述條件即可，亦可在預加壓步驟中膜厚發生變化。這是因為，即便在預加壓步驟中膜厚發生變化，只要存在用於吸收熱硬化性樹脂組成物或漏出的低分子量成分的移動的空隙，則即便在將被黏體與導電性片接合時進行加熱壓製，亦可有效地抑制導電層的滲出。 The conductive layer of the third embodiment is a conductive layer that is subjected to a pre-pressurization step. However, when the adherend is bonded to the conductive sheet, it is heated at 150 ° C, 2 MPa, and 30 minutes as described in the first embodiment. The thickness after pressing must be 30 when the thickness of the conductive layer before heat pressing is set to 100. Above and below 95. That is, in the case where the thickness of the conductive layer before bonding with the adherend after the pre-pressurization step is heated and pressed under the above conditions (heat-pressed under conditions of 150 ° C, 2 MPa, and 30 minutes) The thickness change must be included in the above range (the thickness of the conductive layer is set to 100, and is in the range of 30 or more and 95 or less). Further, as long as the above conditions are satisfied, the film thickness may be changed in the pre-pressurization step. This is because, even if the film thickness changes in the pre-pressurization step, there is a gap for moving the thermosetting resin composition or the leaked low-molecular weight component, even if the adherend is bonded to the conductive sheet. When the heating is performed, the bleeding of the conductive layer can be effectively suppressed.
根據第3實施形態，因使用具有與第1實施形態相同的導電層的導電性片，故可獲得與第1實施形態相同的效果。而且，在將印刷配線板等與導電性片加熱壓製前預先加壓導電層而壓碎枝晶狀導電性微粒子(B)，因而具有可有效地提取導電特性的優點。 According to the third embodiment, since the conductive sheet having the same conductive layer as that of the first embodiment is used, the same effects as those of the first embodiment can be obtained. Further, the printed wiring board or the like is pressed against the conductive layer before the conductive sheet is heated and pressed, and the dendritic conductive fine particles (B) are crushed, so that the conductive property can be efficiently extracted.
另外，第3實施形態中，已對具有1層導電層的導電性片的示例進行了說明，但如第2實施形態般附有絕緣層的導電性片或積層著其他層的導電性片中亦可適當地附加第3實施形態的預加壓步驟。在將導電性片設為附有絕緣層的導電性片的情況下，進行預加壓步驟的時期未作限制，更佳為在積層絕緣層前進行預加壓步驟。若對導電層進行預加壓步驟則導電層的表面變得更平滑，因此進而在積層絕緣層的情況下，絕緣層的厚度精度提高，因此即便絕緣層的厚度變薄亦可容易地獲得所期望的絕緣特性。 Further, in the third embodiment, an example of a conductive sheet having one conductive layer has been described. However, in the conductive sheet having an insulating layer or a conductive sheet in which another layer is laminated as in the second embodiment, The pre-pressurization step of the third embodiment may be added as appropriate. In the case where the conductive sheet is a conductive sheet with an insulating layer, the period in which the pre-pressurization step is performed is not limited, and it is more preferable to perform a pre-pressurization step before laminating the insulating layer. When the conductive layer is pre-pressurized, the surface of the conductive layer becomes smoother. Therefore, in the case of the laminated insulating layer, the thickness precision of the insulating layer is improved, so that the thickness of the insulating layer can be easily obtained even if the thickness of the insulating layer is reduced. Desired insulation properties.
其次，對與上述第1實施形態不同的導電性片的一例進行說明。第4實施形態的導電性片包含1層的導電層。第4實施形態的導電性片的導電層將熱硬化性樹脂(A)、及枝晶狀導電性微粒子(B)作為必要構成而包含，導電層中的枝晶狀導電性微粒子(B)的平均粒徑D90相對於導電層的膜厚為0.5倍~3倍的範圍內。 Next, an example of a conductive sheet different from the above-described first embodiment will be described. The conductive sheet of the fourth embodiment includes one conductive layer. The conductive layer of the conductive sheet of the fourth embodiment contains the thermosetting resin (A) and the dendritic conductive fine particles (B) as essential structures, and the dendritic conductive fine particles (B) in the conductive layer The average particle diameter D 90 is in the range of 0.5 to 3 times the film thickness of the conductive layer.
另外，第1實施形態中被特定的導電層的厚度並非必須為如下：150℃、2MPa、30分鐘的條件下加熱壓製後的厚度，在將加熱壓製前的該導電層的厚度設為100時為30以上、95以下的範圍。這是因為，藉由將枝晶狀導電微粒子(B)的平均粒徑D90設為相對於導電層的膜厚為3倍以下，而具有微粒子的前端在進行加熱壓製時不易從導電層突出的傾向。而且，這是因為，藉由將平均粒徑D90設為0.5倍以上，導電層中不易過多地產生空隙。其中，從更有效地防止導電層的滲出的觀點而言，更佳為亦滿足如下條件：150℃、2MPa、30分鐘的條件下加熱壓製後的厚度，在將加熱壓製前的該導電層的厚度設為100時為30以上、95以下的範圍。 Further, the thickness of the specific conductive layer in the first embodiment is not necessarily the following: the thickness after heat pressing under the conditions of 150 ° C, 2 MPa, and 30 minutes, and the thickness of the conductive layer before the heat pressing is set to 100. It is a range of 30 or more and 95 or less. This is because the average particle diameter D 90 of the dendritic conductive fine particles (B) is set to be 3 times or less with respect to the thickness of the conductive layer, and the front end having the fine particles is less likely to protrude from the conductive layer when subjected to heat pressing. Propensity. Further, this is because, by setting the average particle diameter D 90 to 0.5 or more, it is not easy to excessively generate voids in the conductive layer. Among them, from the viewpoint of more effectively preventing the bleeding of the conductive layer, it is more preferable to satisfy the following conditions: the thickness after heating and pressing under the conditions of 150 ° C, 2 MPa, and 30 minutes, the conductive layer before the heat pressing When the thickness is 100, it is in the range of 30 or more and 95 or less.
第4實施形態的導電性片以第4實施形態的導電性片的導電層側與印刷配線板等的被黏體接觸的方式積層，並經過第1實施形態中所說明的加熱壓製步驟，藉此可將導電性片貼附於被黏體。根據第4實施形態的導電性片，因在導電層中含有熱硬化性樹脂，故可使與被黏體的黏接性 保持為良好。另外，加熱壓製的條件可根據導電層的用途或需求(例如根據所求出的導電特性或空隙的比例等)而任意設定。 The conductive sheet of the fourth embodiment is laminated on the conductive layer side of the conductive sheet of the fourth embodiment so as to be in contact with the adherend such as a printed wiring board, and is subjected to the heating and pressing step described in the first embodiment. This attaches the conductive sheet to the adherend. According to the conductive sheet of the fourth embodiment, since the conductive layer contains a thermosetting resin, adhesion to the adherend can be obtained. Keep it good. Further, the conditions of the heat pressing may be arbitrarily set depending on the use or demand of the conductive layer (for example, based on the obtained conductive characteristics or the ratio of the voids, etc.).
第4實施形態的導電性片較佳為在導電層中藉由加熱壓製而填埋枝晶狀導電性微粒子(B)的空隙，但亦可不填埋而作為空隙加以利用。例如，不進行加熱壓製步驟，例如經由黏接劑層而將被黏體與導電性片接合亦可。經由黏接劑層的方法並無特別限定，例如，可列舉將與導電層不同的黏接劑層設置於導電性片上，或者將黏接劑層設置於被黏體側而經由黏接劑層接合被黏體的方法。 In the conductive sheet of the fourth embodiment, the voids of the dendritic conductive fine particles (B) are preferably filled in the conductive layer by heat pressing, but they may be used as voids without being filled. For example, the heat-pressing step may not be performed, and the adherend may be bonded to the conductive sheet via the adhesive layer, for example. The method of passing the adhesive layer is not particularly limited, and for example, an adhesive layer different from the conductive layer may be provided on the conductive sheet, or the adhesive layer may be provided on the adherend side via the adhesive layer. The method of joining the adherends.
構成導電層的熱硬化性樹脂(A)的較佳例如第1實施形態所述。而且，導電層中較佳為與熱硬化性樹脂(A)併用而使用硬化劑。關於硬化劑的示例亦如第1實施形態中所述。 The thermosetting resin (A) constituting the conductive layer is preferably as described in the first embodiment. Further, it is preferable to use a curing agent in combination with the thermosetting resin (A) in the conductive layer. Examples of the curing agent are also as described in the first embodiment.
枝晶狀導電性微粒子(B)的較佳態樣、素材可較佳地使用第1實施形態中所述的態樣、素材。 In the preferred embodiment and material of the dendritic conductive fine particles (B), the aspect and material described in the first embodiment can be preferably used.
枝晶狀導電性微粒子(B)較佳為平均粒徑D50為3μm~50μm，且平均粒徑D90為平均粒徑D50的1.5倍~5倍。而且，平均粒徑D50更佳為3μm~40μm，進而較佳為5μm~25μm。藉由平均粒徑D50為3μm以上，導電層中容易產生空隙，可減少滲出。另一方面，藉由平均粒徑D50為50μm以下，容易形成適當厚度的導電層。 The dendritic conductive fine particles (B) preferably have an average particle diameter D 50 of from 3 μm to 50 μm, and an average particle diameter D 90 of from 1.5 to 5 times the average particle diameter D 50 . Further, the average particle diameter D 50 is more preferably from 3 μm to 40 μm, still more preferably from 5 μm to 25 μm. When the average particle diameter D 50 is 3 μm or more, voids are easily generated in the conductive layer, and bleeding can be reduced. On the other hand, when the average particle diameter D 50 is 50 μm or less, it is easy to form a conductive layer having an appropriate thickness.
枝晶狀導電性微粒子(B)的平均粒徑D90較佳為平均粒徑D50的1.5倍~5倍，更佳為2倍~3.5倍。平均粒徑 D90的值具有依存於平均粒徑D50的平均粒徑的傾向，但較佳為4.5μm~250μm。其理由如第1實施形態中所述。 The average particle diameter D 90 of the dendritic conductive fine particles (B) is preferably 1.5 to 5 times, more preferably 2 to 3.5 times the average particle diameter D 50 . The value of the average particle diameter D 90 tends to depend on the average particle diameter of the average particle diameter D 50 , but is preferably 4.5 μm to 250 μm. The reason is as described in the first embodiment.
枝晶狀導電性微粒子(B)的敲緊密度(以下亦稱作「TD」)較佳為0.8g/cm3~2.5g/cm3。而且，枝晶狀導電性微粒子(B)的表觀密度(以下稱作「AD」)較佳為0.4g/cm3~1.5g/cm3。進而，枝晶狀導電性微粒子(B)的AD與TD的比率(AD/TD)更佳為0.3~0.9。這些的理由如第1實施形態中所述。 The knocking degree of the dendritic conductive fine particles (B) (hereinafter also referred to as "TD") is preferably 0.8 g/cm 3 to 2.5 g/cm 3 . Further, the apparent density (hereinafter referred to as "AD") of the dendritic conductive fine particles (B) is preferably 0.4 g/cm 3 to 1.5 g/cm 3 . Further, the ratio of AD to TD (AD/TD) of the dendritic conductive fine particles (B) is more preferably from 0.3 to 0.9. The reason for these is as described in the first embodiment.
第4實施形態的導電性片的厚度並無特別限定，較佳為5μm~100μm，更佳為10μm~50μm。另外，厚度為依據JISB7503(針盤量軌)測定的值。若導電層的厚度為5μm以上則容易獲得導電性。而且，若成為100μm以下則容易獲取彎曲性的平衡。 The thickness of the conductive sheet of the fourth embodiment is not particularly limited, but is preferably 5 μm to 100 μm, and more preferably 10 μm to 50 μm. Further, the thickness is a value measured in accordance with JIS B7503 (needle gauge). When the thickness of the conductive layer is 5 μm or more, conductivity is easily obtained. Further, when it is 100 μm or less, it is easy to obtain a balance of bendability.
導電層中使用枝晶狀導電性微粒子(B)的比例，在導電層100重量%中，較佳為50重量%~90重量%，更佳為60重量%~80重量%。其理由如第1實施形態中所述。而且，第4實施形態的導電層中，亦可視需要而添加添加劑，作為其一例，可列舉第1實施形態中所述的添加劑。而且，導電性片的製造方法如第1實施形態中所述。 The proportion of the dendritic conductive fine particles (B) used in the conductive layer is preferably from 50% by weight to 90% by weight, more preferably from 60% by weight to 80% by weight, based on 100% by weight of the conductive layer. The reason is as described in the first embodiment. Further, in the conductive layer of the fourth embodiment, an additive may be added as needed, and as an example thereof, the additive described in the first embodiment may be mentioned. Further, the method for producing a conductive sheet is as described in the first embodiment.
根據第4實施形態，可獲得與上述第1實施形態相同的效果。而且，具有可提供可靠性高的導電性片的優點，所述可靠性高的導電性片是藉由使用如下的導電層，並且藉由設計導電層的膜厚與平均粒徑D90，而可將導電層的滲出限制在最小限度。上述導電層中作為導電層的厚度， 導電層中的枝晶狀導電性微粒子(B)的平均粒徑D90相對於導電層的膜厚為0.5倍~3倍的範圍內。 According to the fourth embodiment, the same effects as those of the first embodiment described above can be obtained. Moreover, there is an advantage that a highly reliable conductive sheet can be provided by using a conductive layer as follows, and by designing a film thickness and an average particle diameter D 90 of the conductive layer, The bleed out of the conductive layer can be minimized. The thickness of the conductive layer in the conductive layer is such that the average particle diameter D 90 of the dendritic conductive fine particles (B) in the conductive layer is in the range of 0.5 to 3 times the film thickness of the conductive layer.
其次，對適用於作為第5實施形態的導電性片的電磁波屏蔽膜的示例進行說明。第5實施形態的導電性片積層有絕緣層與第4實施形態的導電層。作為用途，例如可用作貼附於印刷配線板等的電子零件的電磁波屏蔽膜。另外，電磁波屏蔽膜亦可積層有絕緣層與導電層以外的其他層(例如，保護層、黏接層)。 Next, an example of an electromagnetic wave shielding film which is applied to the conductive sheet of the fifth embodiment will be described. The conductive laminated layer of the fifth embodiment has an insulating layer and a conductive layer of the fourth embodiment. As the application, for example, it can be used as an electromagnetic wave shielding film attached to an electronic component such as a printed wiring board. Further, the electromagnetic wave shielding film may be laminated with an insulating layer and other layers (for example, a protective layer or an adhesive layer) other than the conductive layer.
絕緣層中使用的材料並無特別限定，作為較佳例，可列舉第2實施形態中所述的材料。而且，絕緣層中，可視需要而包含矽烷偶合劑、抗氧化劑、顏料、染料、增黏樹脂、可塑劑、紫外線吸收劑、消泡劑、均化調整劑、填充劑、阻燃劑等。關於絕緣層的形成方法，如第2實施形態中所述。 The material used in the insulating layer is not particularly limited, and a preferred embodiment is a material described in the second embodiment. Further, the insulating layer may optionally contain a decane coupling agent, an antioxidant, a pigment, a dye, a tackifying resin, a plasticizer, an ultraviolet absorber, an antifoaming agent, a leveling adjuster, a filler, a flame retardant, and the like. The method of forming the insulating layer is as described in the second embodiment.
而且，絕緣層的厚度在將導電層的厚度設為100時，較佳為50~200的比例。藉由設為上述範圍內的厚度，而容易獲取電磁波屏蔽膜的物性平衡。另外，第5實施形態的導電性片的導電層並非必須經過加熱製程，上述導電層的膜厚顯示實際利用時的膜厚，可為加熱製程前的膜厚，亦可為加熱製程後的膜厚。 Further, when the thickness of the insulating layer is set to 100, the thickness of the insulating layer is preferably a ratio of 50 to 200. By setting the thickness within the above range, the physical property balance of the electromagnetic wave shielding film can be easily obtained. Further, the conductive layer of the conductive sheet of the fifth embodiment does not have to be subjected to a heating process, and the film thickness of the conductive layer shows the film thickness at the time of actual use, and may be a film thickness before the heating process or a film after the heating process. thick.
作為可貼附電磁波屏蔽膜的被黏體，並無特別限定，例如，可列舉受到重複彎曲的可撓性印刷配線板為代表例。當然，可適用於以剛性印刷配線板為首的各種基板、 要求電磁波屏蔽的微波爐等的家電或所有電子機器、欲屏蔽電磁波的所有構件。 The adherend to which the electromagnetic wave shielding film can be attached is not particularly limited, and for example, a flexible printed wiring board subjected to repeated bending is exemplified. Of course, it can be applied to various substrates including rigid printed wiring boards. Home appliances such as microwave ovens that require electromagnetic wave shielding, all electronic devices, and all components that are intended to shield electromagnetic waves.
根據第5實施形態的電磁波屏蔽膜而獲得與上述實施形態相同的效果。 According to the electromagnetic wave shielding film of the fifth embodiment, the same effects as those of the above embodiment are obtained.
以下，列舉實例、比較例對本發明進行詳細說明，但本發明並不僅限定於以下的實例。另外，以下的「份」及「%」分別為基於「重量份」及「重量%」的值。 Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited to the following examples. In addition, the following "parts" and "%" are values based on "parts by weight" and "% by weight", respectively.
平均粒徑D50及平均粒徑D90使用日機裝公司製造的Microtrac MT3300而測定。表觀密度藉由利用JIS Z 2504：2000而規定的金屬粉的表觀密度試驗方法而求出。敲緊密度藉由JIS Z 2512：金屬粉-敲緊密度測定方法而求出。 The average measured particle diameter and the average particle diameter D 50 D 90 using Microtrac MT3300 manufactured by Nikkiso. The apparent density was determined by the apparent density test method of the metal powder specified by JIS Z 2504:2000. The knocking degree was determined by JIS Z 2512: Metal powder-knocking tightness measuring method.
<實例1~實例5> <Example 1 to Example 5>
作為枝晶狀導電性微粒子，使用表1A的材料，作為熱硬化性樹脂，使用胺基甲酸酯樹脂(toyo-chem公司製造)來製作導電性片。枝晶狀導電性微粒子(B)與熱硬化性樹脂(A)的比率相對於樹脂固形份100重量份而將枝晶狀導電性微粒子(B)設為250重量份。而且，以乾燥膜厚為10μm的方式，在對表面進行剝離處理後的厚度為100μm的聚對苯二甲酸乙二酯膜上，使用棒式塗佈機進行塗佈，以100℃乾燥3分鐘從而獲得導電性片。 As the dendritic conductive fine particles, a conductive sheet was produced using a urethane resin (manufactured by Toyo-Chem Co., Ltd.) as a thermosetting resin. The ratio of the dendritic conductive fine particles (B) to the thermosetting resin (A) was 250 parts by weight with respect to 100 parts by weight of the resin solid content, and the dendritic conductive fine particles (B). Further, the polyethylene terephthalate film having a thickness of 100 μm after being subjected to a release treatment on the surface was applied by a bar coater at a dry film thickness of 10 μm, and dried at 100 ° C for 3 minutes. Thereby, a conductive sheet was obtained.
<實例6~實例10> <Example 6 to Example 10>
在實例1~實例5中獲得的導電性片的單面上使用作為絕緣層的胺基甲酸酯樹脂(toyo-chem公司製造)，以乾 燥膜厚為10μm的方式進行塗佈、乾燥，從而獲得總厚20μm的附有絕緣層的導電性片。 A urethane resin (manufactured by Toyo-Chem Co., Ltd.) as an insulating layer was used on one surface of the conductive sheet obtained in Examples 1 to 5 to dry The dried film was coated and dried so as to have a thickness of 10 μm, thereby obtaining a conductive sheet with an insulating layer having a total thickness of 20 μm.
<實例11> <Example 11>
使用輥壓製機以對實例2中獲得的導電性片表面施加3MPa的壓力的方式進行預加壓。其後在經預加壓的導電性片的面上，以乾燥膜厚為10μm的方式將作為絕緣層的胺基甲酸酯樹脂(toyo-chem公司製造)進行塗佈、乾燥，藉此獲得總厚20μm的附有絕緣層的導電性片。 Pre-pressurization was carried out by applying a pressure of 3 MPa to the surface of the electroconductive sheet obtained in Example 2 using a roll press. Then, a urethane resin (manufactured by Toyo-Chem Co., Ltd.) as an insulating layer was applied and dried on the surface of the pre-pressurized conductive sheet so as to have a dry film thickness of 10 μm. A conductive sheet with an insulating layer and a total thickness of 20 μm.
<實例12、實例13> <Example 12, Example 13>
除將預加壓的壓力分別變更為10MPa、40MPa以外，與實例11同樣的方式進行，而獲得附有絕緣層的導電性片。 A conductive sheet with an insulating layer was obtained in the same manner as in Example 11 except that the pressure of the pre-pressurization was changed to 10 MPa and 40 MPa, respectively.
<比較例1~比較例2> <Comparative Example 1 to Comparative Example 2>
使用表1B所示的導電性微粒子，利用與實例1~實例5相同的方法獲得導電性片。 Using the conductive fine particles shown in Table 1B, a conductive sheet was obtained by the same method as in Examples 1 to 5.
<比較例3~比較例4> <Comparative Example 3 to Comparative Example 4>
使用表1B所示的導電性微粒子，利用與實例6~實例10相同的方法，獲得附有絕緣層的導電性片。 Using the conductive fine particles shown in Table 1B, a conductive sheet with an insulating layer was obtained by the same method as in Examples 6 to 10.
<滲出性評估> <Exudency assessment>
藉由層壓將各實例及各比較例的導電性片貼附於厚度為50μm的聚醯亞胺膜(Du Pont-Toray公司製造「kapton 200EN」)的一面上，利用開孔機貫通出直徑5mm的孔。 The conductive sheets of the respective examples and the comparative examples were attached to one surface of a polyimine film ("kapton 200EN" manufactured by Du Pont-Toray Co., Ltd.) having a thickness of 50 μm by lamination, and the diameter was made through a perforator. 5mm hole.
另外，準備厚度為50μm的聚醯亞胺膜(Du Pont-Toray公司製造「kapton 200EN」)，與上述導電性片在150℃、 30分鐘、2.0MPa的條件下進行加熱壓製處理，藉此獲得由聚醯亞胺膜夾持的導電性片的樣品。在加熱壓製處理後，使用放大鏡觀察導電性片的孔部分，從而測定滲出量。評估基準為以下所示。 Further, a polyimide film having a thickness of 50 μm ("kapton 200EN" manufactured by Du Pont-Toray Co., Ltd.) was prepared, and the above-mentioned conductive sheet was at 150 ° C, A heat pressing treatment was carried out under the conditions of 30 minutes and 2.0 MPa, whereby a sample of the conductive sheet held by the polyimide film was obtained. After the heat pressing treatment, the pore portion of the conductive sheet was observed with a magnifying glass to measure the amount of bleeding. The evaluation criteria are as follows.
○：導電性片的滲出量小於0.01mm ○: The amount of exudation of the conductive sheet is less than 0.01 mm
△：導電性片的滲出量為0.01mm以上且小於0.05mm △: The amount of exudation of the conductive sheet is 0.01 mm or more and less than 0.05 mm.
×：導電性片的滲出量為0.05mm以上 ×: The amount of exudation of the conductive sheet is 0.05 mm or more
<連接電阻值A的測定> <Measurement of connection resistance value A>
對於實例1~實例5及比較例1、比較例2的導電性片，準備寬度20mm、長度50mm的樣品，使用另外製作的可撓性印刷配線板來測定連接電阻值A。具體而言，如圖2A~圖2F所示，準備如下的可撓性印刷配線板，即，在厚度12.5μm的聚醯亞胺膜1上，形成包含厚度18μm的銅箔且未電性連接的電路2，在電路2上，積層附有黏接劑的具有厚度37.5μm、直徑0.8mm的通孔4的覆蓋膜3。然後，在覆蓋膜3上載置導電性片5，在該導電性片5上載置表面經厚度0.1μm的鎳處理過的厚度200μm的不鏽鋼板6，且在150℃、30分鐘、2.0MPa的條件下進行加熱壓製。之後，使用三菱化學公司製造「loresta GP」的四點探針(four-point probe)對電路2與不鏽鋼板6間的縱方向的電阻值進行測定。評估基準為以下。 For the conductive sheets of Examples 1 to 5 and Comparative Examples 1 and 2, samples having a width of 20 mm and a length of 50 mm were prepared, and the connection resistance value A was measured using a separately manufactured flexible printed wiring board. Specifically, as shown in FIG. 2A to FIG. 2F, a flexible printed wiring board having a copper foil having a thickness of 18 μm and a non-electrical connection was formed on the polyimide film 1 having a thickness of 12.5 μm. In the circuit 2, on the circuit 2, a cover film 3 having a through hole 4 having a thickness of 37.5 μm and a diameter of 0.8 mm with an adhesive is laminated. Then, the conductive sheet 5 was placed on the cover film 3, and a stainless steel plate 6 having a thickness of 200 μm which had been treated with nickel having a thickness of 0.1 μm was placed on the conductive sheet 5, and the conditions were 150 ° C, 30 minutes, and 2.0 MPa. The heat is pressed under. Thereafter, the resistance value in the longitudinal direction between the circuit 2 and the stainless steel plate 6 was measured using a four-point probe of "Losta GP" manufactured by Mitsubishi Chemical Corporation. The evaluation criteria are as follows.
○：小於200mΩ ○: less than 200mΩ
△：200mΩ以上且小於500mΩ △: 200mΩ or more and less than 500mΩ
×：500mΩ以上 ×: 500mΩ or more
<連接電阻值B的測定> <Measurement of connection resistance value B>
對於實例6~實例13及比較例3、4的附有絕緣層的導電性片，準備寬度20mm、長度50mm的樣品，使用另外製作的可撓性印刷配線板來測定連接電限值B。具體來說，如圖3A~圖3F所示，準備如下的可撓性印刷配線板，即，在厚度12.5μm的聚醯亞胺膜1上，形成包含厚度18μm的銅箔且未電性連接的電路2A、電路2B，在電路2A上積層附有黏接劑的具有厚度37.5μm、直徑0.8mm的通孔4的覆蓋膜3。然後，將導電性片5載置於覆蓋膜3上，在該導電性片5上載置表面經厚度0.1μm的鎳處理過的厚度200μm的絕緣層7，在150℃、30分鐘、2.0MPa的條件下進行加熱壓製，使用三菱化學公司製造「loresta GP」的四點探針來對電路2A與電路2B間的電阻值進行測定。評估基準為以下所示。 For the conductive sheets with insulating layers of Examples 6 to 13 and Comparative Examples 3 and 4, samples having a width of 20 mm and a length of 50 mm were prepared, and the connection electrical limit B was measured using a separately produced flexible printed wiring board. Specifically, as shown in FIG. 3A to FIG. 3F, a flexible printed wiring board having a copper foil having a thickness of 18 μm and a non-electrical connection was formed on the polyimide film 1 having a thickness of 12.5 μm. In the circuit 2A and the circuit 2B, a cover film 3 having a via hole 4 having a thickness of 37.5 μm and a diameter of 0.8 mm with an adhesive is laminated on the circuit 2A. Then, the conductive sheet 5 is placed on the cover film 3, and an insulating layer 7 having a thickness of 200 μm which has been treated with nickel having a thickness of 0.1 μm is placed on the conductive sheet 5 at 150 ° C, 30 minutes, and 2.0 MPa. The heating was pressed under the conditions, and the resistance between the circuit 2A and the circuit 2B was measured using a four-point probe manufactured by Mitsubishi Chemical Corporation "loresta GP". The evaluation criteria are as follows.
○：小於300mΩ ○: less than 300mΩ
△：300mΩ以上且小於500mΩ △: 300 mΩ or more and less than 500 mΩ
×：500mΩ以上 ×: 500mΩ or more
<彎曲性> <bending>
將寬度6mm、長度120mm的實例、及比較例的導電性片，在150℃、30分鐘、2.0MPa的條件下壓接至另外製作的可撓性印刷配線板(在厚度25μm的聚醯亞胺膜上，形成有包含厚度12μm的銅箔的電路圖案，進而在電路圖案上積層有附黏接劑的厚度40μm的覆蓋膜而成的配線板)的覆蓋膜面上。然後，在曲率半徑0.38mm、負載 500g、速度180次/分鐘的條件下設置在MIT彎曲試驗機上，根據電路圖案斷線為止的次數來評估耐彎曲性。評估基準為以下所示。 The conductive sheet having a width of 6 mm and a length of 120 mm and a comparative example were pressure-bonded to a separately prepared flexible printed wiring board under conditions of 150 ° C, 30 minutes, and 2.0 MPa (polyimine at a thickness of 25 μm) On the film, a circuit pattern including a copper foil having a thickness of 12 μm was formed, and a cover film surface on which a cover film having a thickness of 40 μm with an adhesive was laminated on the circuit pattern was formed. Then, at a radius of curvature of 0.38 mm, the load The bending resistance was evaluated on the MIT bending tester under conditions of 500 g and a speed of 180 times/min, and the number of times the circuit pattern was broken. The evaluation criteria are as follows.
○：3000次以上 ○: 3,000 times or more
△：2500次以上、且小於3000次 △: 2500 times or more and less than 3000 times
×：小於2500次 ×: less than 2500 times
根據表1A、表1B的結果可知，藉由使用枝晶狀導電性微粒子，比起先前形狀的導電性微粒子，加熱壓製後的朝向橫方向的滲出較少。而且可知，朝向縱方向的連接電阻A與先前形狀的導電性微粒子相比，藉由使用枝晶狀導電性微粒子而特性更優異。進而可確認，使用了枝晶狀導電性微粒子的導電性片彎曲性優異。 As is clear from the results of Tables 1A and 1B, by using the dendritic conductive fine particles, the amount of bleeding in the lateral direction after the heat pressing is smaller than that of the conductive fine particles having the previous shape. Further, it is understood that the connection resistance A in the longitudinal direction is superior in characteristics to the conductive fine particles of the prior shape by using the dendritic conductive fine particles. Further, it was confirmed that the conductive sheet using the dendritic conductive fine particles is excellent in flexibility.
<實例14> <Example 14>
使用平均粒徑D90為25μm、平均粒徑D50為13μm的銀作為枝晶狀導電性微粒子而製作導電層。使用胺基甲酸酯樹脂(toyo-chem公司製造)作為熱硬化性樹脂，而且枝晶狀導電性微粒子(B)與熱硬化性樹脂的比率相對於樹脂100重量份而將枝晶狀導電性微粒子設為250重量份，以乾燥膜厚為10μm的方式，在厚度100μm的表面經過剝離處理的聚對苯二甲酸乙二酯膜上，使用棒式塗佈 機進行塗佈，在100℃下乾燥3分鐘而獲得導電層。在上述導電層的單面使用作為絕緣層的胺基甲酸酯樹脂(toyo-chem公司製造)，以乾燥膜厚為15μm的方式進行塗佈、乾燥，從而獲得總厚25μm的具有絕緣層的電磁波屏蔽膜。 A conductive layer was produced by using silver having an average particle diameter D 90 of 25 μm and an average particle diameter D 50 of 13 μm as dendritic conductive fine particles. A urethane resin (manufactured by Toyo-Chem Co., Ltd.) is used as the thermosetting resin, and the ratio of the dendritic conductive fine particles (B) to the thermosetting resin is dendritic conductivity with respect to 100 parts by weight of the resin. The microparticles were used in an amount of 250 parts by weight, and were coated on a polyethylene terephthalate film having a thickness of 100 μm on a surface having a thickness of 100 μm by a bar coater at 100 ° C. Drying was carried out for 3 minutes to obtain a conductive layer. A urethane resin (manufactured by Toyo-Chem Co., Ltd.) as an insulating layer was used for one surface of the above-mentioned conductive layer, and dried and coated to have a dry film thickness of 15 μm to obtain an insulating layer having a total thickness of 25 μm. Electromagnetic wave shielding film.
<實例15~實例17> <Example 15~Example 17>
實例15~實例17中，除將導電性微粒子與平均粒徑D90及平均粒徑D50的部分代替為表2A所示的原料之外，其他與實例1同樣地進行，從而獲得電磁波屏蔽膜。 In Examples 15 to 17, except that the conductive fine particles, the portion having the average particle diameter D 90 and the average particle diameter D 50 were replaced with the raw materials shown in Table 2A, the same procedure as in Example 1 was carried out to obtain an electromagnetic wave shielding film. .
<實例18> <Example 18>
作為枝晶狀導電性微粒子(B)，使用表2A的材料，作為熱硬化性樹脂(A)，使用胺基甲酸酯樹脂(toyo-chem公司製造)來製作導電層。枝晶狀導電性微粒子(B)與熱硬化性樹脂(A)的比率相對於樹脂100重量份而將枝晶狀導電性微粒子設為250重量份，以乾燥膜厚為10μm的方式，在將厚度100μm的表面經過剝離處理的聚對苯二甲酸乙二酯膜上，使用棒式塗佈機塗佈，以100℃乾燥3分鐘而獲得導電性片。在上述導電性片的單面使用作為絕緣層的胺基甲酸酯樹脂(toyo-chem公司製造)，以乾燥膜厚為8μm的方式進行塗佈、乾燥，從而獲得總厚18μm的具有絕緣層的電磁波屏蔽膜。 As the dendritic conductive fine particles (B), a material of Table 2A was used, and as the thermosetting resin (A), a conductive layer was produced using a urethane resin (manufactured by Toyo-Chem Co., Ltd.). The ratio of the dendritic conductive fine particles (B) to the thermosetting resin (A) is 250 parts by weight of the dendritic conductive fine particles with respect to 100 parts by weight of the resin, and the dry film thickness is 10 μm. The surface having a thickness of 100 μm was subjected to a release-treated polyethylene terephthalate film, coated with a bar coater, and dried at 100 ° C for 3 minutes to obtain a conductive sheet. On the one surface of the above-mentioned conductive sheet, a urethane resin (manufactured by Toyo-Chem Co., Ltd.) as an insulating layer was used, and dried and coated to have a dry film thickness of 8 μm to obtain an insulating layer having a total thickness of 18 μm. Electromagnetic wave shielding film.
<實例19> <Example 19>
使用表2A的材料作為枝晶狀導電性微粒子而製作導電性片。使用胺基甲酸酯樹脂(toyo-chem公司製造)作 為熱硬化性樹脂，而且枝晶狀導電性微粒子(B)與熱硬化性樹脂的比率相對於樹脂100重量份而將枝晶狀導電性微粒子設為250重量份，並且以乾燥膜厚為10μm的方式，在厚度100μm的表面經過剝離處理的聚對苯二甲酸乙二酯膜上，使用棒式塗佈機進行塗佈，在100℃下乾燥3分鐘而獲得導電性片。在上述導電性片的單面使用作為絕緣層的胺基甲酸酯樹脂(toyo-chem公司製造)，以乾燥膜厚為25μm的方式設置，從而獲得總厚35μm的具有絕緣層的電磁波屏蔽膜。 A conductive sheet was produced using the material of Table 2A as dendritic conductive fine particles. Using a urethane resin (manufactured by Toyo-Chem Co., Ltd.) The thermosetting resin, and the ratio of the dendritic conductive fine particles (B) to the thermosetting resin is 250 parts by weight with respect to 100 parts by weight of the resin, and the dried film thickness is 10 μm. In the manner of coating on a polyethylene terephthalate film having a surface of 100 μm in thickness, which was subjected to a release treatment using a bar coater, it was dried at 100 ° C for 3 minutes to obtain a conductive sheet. A urethane resin (manufactured by Toyo-Chem Co., Ltd.) as an insulating layer was used as one surface of the above-mentioned conductive sheet, and a dry film thickness of 25 μm was used to obtain an electromagnetic wave shielding film having an insulating layer having a total thickness of 35 μm. .
<實例20> <Example 20>
使用輥壓製機以對實例18中獲得的導電性片表面施加3MPa的壓力的方式進行預加壓。然後，在經預加壓的導電性片的面上，將作為絕緣層的胺基甲酸酯樹脂(toyo-chem公司製造)以乾燥膜厚為8μm的方式進行塗佈、乾燥，藉此獲得總厚20μm的具有絕緣層的電磁波屏蔽膜。 Pre-pressurization was carried out by applying a pressure of 3 MPa to the surface of the electroconductive sheet obtained in Example 18 using a roll press. Then, on the surface of the pre-pressurized conductive sheet, a urethane resin (manufactured by Toyo-Chem Co., Ltd.) as an insulating layer was applied and dried to have a dry film thickness of 8 μm, thereby obtaining An electromagnetic wave shielding film having an insulating layer with a total thickness of 20 μm.
<實例21、實例22> <Example 21, Example 22>
除將預加壓的壓力分別變更為10MPa、40MPa以外，與實例20同樣地獲得具有絕緣層的電磁波屏蔽膜。 An electromagnetic wave shielding film having an insulating layer was obtained in the same manner as in Example 20 except that the pressure of the pre-pressing was changed to 10 MPa and 40 MPa, respectively.
<比較例11~比較例15> <Comparative Example 11 to Comparative Example 15>
使用表2B所示的導電性微粒子，利用與實例14~實例18相同的方法，獲得具有導電層與絕緣層的電磁波屏蔽膜。 Using the conductive fine particles shown in Table 2B, an electromagnetic wave shielding film having a conductive layer and an insulating layer was obtained by the same method as in Example 14 to Example 18.
關於表2A、表2B的枝晶銀、枝晶銅粉、薄片狀銀、 球狀銀，是使用福田金屬箔粉工業公司製造的枝晶銀、枝晶銅粉、薄片狀銀、球狀銀。 Regarding the dendritic silver, dendritic copper powder, flaky silver of Table 2A and Table 2B, The spherical silver is dendritic silver, dendritic copper powder, flaky silver, and spherical silver manufactured by Fukuda Metal Foil Powder Industrial Co., Ltd.
表2A、表2B的枝晶塗銀的銅粉使用的是福田金屬箔粉工業公司製造的枝晶銅粉，在以下的條件下進行銀被覆處理，藉此獲得銅的核心90重量%、銀被覆層10重量%的枝晶塗銀的銅粉。 The dendritic silver-coated copper powder of Table 2A and Table 2B is a dendritic copper powder manufactured by Fukuda Metal Foil Powder Co., Ltd., and subjected to silver coating treatment under the following conditions, thereby obtaining 90% by weight of silver core and silver. The coating layer was 10% by weight of dendritic silver-coated copper powder.
<滲出性評估> <Exudency assessment>
各實例及各比較例中將電磁波屏蔽膜藉由與實例1~實例13、比較例1~比較例4相同的方法來測定滲出量。評估基準與上述基準相同。 In each of the examples and the comparative examples, the electromagnetic wave shielding film was measured for the amount of bleeding by the same methods as those of Examples 1 to 13 and Comparative Examples 1 to 4. The evaluation criteria are the same as the above benchmarks.
<彎曲性> <bending>
將寬度6mm、長度120mm的實例、及比較例的電磁波屏蔽膜，藉由與實例1~實例13、比較例1~比較例4中說明的折射性評估相同的方法來進行評估。評估基準與上述基準相同。且為以下所示。 The electromagnetic wave shielding film having a width of 6 mm and a length of 120 mm and a comparative example were evaluated by the same method as the refractive index evaluations described in Examples 1 to 13 and Comparative Examples 1 to 4. The evaluation criteria are the same as the above benchmarks. And it is shown below.
<絕緣可靠性> <Insulation reliability>
準備寬度100mm、長度100mm的實例14~實例22及比較例11~比較例15的電磁波屏蔽膜，在150℃、30分鐘、2.0MPa的條件下進行加熱壓製處理。對使用三菱化學公司製造的Hiresta-UP(MCP-HT450)的表面電阻試驗機的TYPE URS，在施壓電壓100V的條件下接觸絕緣層1分鐘時的1分鐘後的絕緣可靠性進行評估。評估基準為以下所示。 The electromagnetic wave shielding films of Examples 14 to 22 and Comparative Examples 11 to 15 having a width of 100 mm and a length of 100 mm were prepared and subjected to heat pressing treatment under conditions of 150 ° C, 30 minutes, and 2.0 MPa. The insulation reliability of the TYPE URS using a surface resistance tester of Hiresta-UP (MCP-HT450) manufactured by Mitsubishi Chemical Corporation under the condition of a voltage of 100 V for 1 minute after contact with the insulating layer was evaluated. The evaluation criteria are as follows.
◎：1×107Ω/□以上 ◎: 1 × 10 7 Ω / □ or more
○：小於1×107Ω/□且為1×104Ω/□以上 ○: less than 1 × 10 7 Ω / □ and 1 × 10 4 Ω / □ or more
×：小於1×104Ω/□ ×: less than 1 × 10 4 Ω / □
根據表2A、表2B的結果可知，藉由將枝晶狀導電性微粒子的平均粒徑D90相對於導電層的膜厚而特定在0.5倍~3倍的範圍內，比起先前形狀的導電性微粒子，加熱壓製後的朝向橫方向的導電層的滲出較少。而且確認：顯示出優異的彎曲性，並且亦可實現高絕緣可靠性。 According to the results of Table 2A and Table 2B, it is understood that the average particle diameter D 90 of the dendritic conductive fine particles is specified to be in the range of 0.5 times to 3 times with respect to the film thickness of the conductive layer, and is more conductive than the previous shape. The fine particles have less bleed out of the conductive layer in the transverse direction after the heat pressing. Moreover, it was confirmed that excellent bending property was exhibited and high insulation reliability was also achieved.
關於包含以上的實例的實施形態，進而揭示以下的附記。 The following supplementary notes are further disclosed in the embodiment including the above examples.
(附記1) (Note 1)
一種導電性片，包括導電層，該導電層至少含有熱硬化性樹脂(A)、及枝晶狀導電性微粒子(B)，其特徵在於：在150℃、2Mpa、30分鐘的條件下加熱壓製上述導電性片後的厚度，在將加熱壓製前的厚度設為100時為30~95。 A conductive sheet comprising a conductive layer containing at least a thermosetting resin (A) and dendritic conductive fine particles (B), characterized by heating and pressing at 150 ° C, 2 MPa, 30 minutes The thickness of the conductive sheet is 30 to 95 when the thickness before the heat pressing is 100.
(附記2) (Note 2)
一種電磁波屏蔽膜，至少包括絕緣層及導電層，其特徵在於：上述導電層至少含有熱硬化性樹脂(A)及枝晶狀導電性微粒子(B)，枝晶狀導電性微粒子(B)的平均粒徑 D90相對於導電層的膜厚為0.5倍~3倍的範圍內。 An electromagnetic wave shielding film comprising at least an insulating layer and a conductive layer, wherein the conductive layer contains at least a thermosetting resin (A) and dendritic conductive fine particles (B), and dendritic conductive fine particles (B) The average particle size The film thickness of D90 with respect to the conductive layer is in the range of 0.5 to 3 times.
(附記3) (Note 3)
如附記2所述的電磁波屏蔽膜，其中枝晶狀導電性微粒子(B)的平均粒徑D50為3μm~50μm。 The electromagnetic wave shielding film according to the second aspect, wherein the dendritic conductive fine particles (B) have an average particle diameter D50 of from 3 μm to 50 μm.
(附記4) (Note 4)
如附記2或3所述的電磁波屏蔽膜，其中枝晶狀導電性微粒子(B)包括含有銅的核心、及銀被覆層；上述銀被覆層在枝晶狀導電性微粒子(B)100重量%中，為1重量%~40重量%的比例。 The electromagnetic wave shielding film according to the above 2 or 3, wherein the dendritic conductive fine particles (B) comprise a core containing copper and a silver coating layer; and the silver coating layer is 100% by weight of the dendritic conductive fine particles (B) The ratio is from 1% by weight to 40% by weight.
(附記5) (Note 5)
如附記2至4中任一項所述的電磁波屏蔽膜，其中在將導電層的厚度設為100時，絕緣層的厚度為50~200。 The electromagnetic wave shielding film according to any one of the items 2 to 4, wherein, when the thickness of the conductive layer is set to 100, the thickness of the insulating layer is 50 to 200.
該申請案主張以2011年5月31日提出申請的日本申請特願2011-121188、及2011年10月25日提出申請日本申請特願2011-233528為基礎的優先權，其揭示的全部內容引用於此。 The priority of the Japanese Patent Application No. 2011-121188 filed on May 31, 2011, and the Japanese Patent Application No. 2011-233528, filed on Oct. 25, 2011, the entire disclosure of which is incorporated by reference. herein.
本發明的導電性片在加熱製程等的製程中，可將導電層的滲出降低至最小限度，因而可較佳地適用於貼附於以印刷配線板或可撓性印刷板為首的基板等的整個被黏體而加以利用的用途中。特別是在導電性片的滲出成為問題的電子零件用途的貼附中可尤其發揮效力。本發明的導電性片亦可與絕緣層、支持層、黏接層、或者具有其他功能的膜等積層而加以利用。 The conductive sheet of the present invention can minimize the bleeding of the conductive layer in a process such as a heating process, and thus can be preferably applied to a substrate such as a printed wiring board or a flexible printed board. The use of the entire body for use. In particular, it is particularly effective in attaching an electronic component to which the bleeding of the conductive sheet is a problem. The conductive sheet of the present invention may be used by laminating an insulating layer, a support layer, an adhesive layer, or a film having other functions.
1‧‧‧聚醯亞胺膜 1‧‧‧ Polyimine film
2‧‧‧銅箔電路 2‧‧‧copper circuit
2A、2B‧‧‧電路 2A, 2B‧‧‧ circuits
3‧‧‧覆蓋膜 3‧‧‧ Cover film
4‧‧‧通孔 4‧‧‧through hole
5‧‧‧導電性片 5‧‧‧Electrical film
6‧‧‧不鏽鋼 6‧‧‧Stainless steel
7‧‧‧絕緣層 7‧‧‧Insulation
圖1A是表示枝晶狀導電性微粒子的一例的SEM像。 Fig. 1A is an SEM image showing an example of dendritic conductive fine particles.
圖1B是表示薄片狀導電性微粒子的一例的SEM像。 FIG. 1B is an SEM image showing an example of the sheet-like conductive fine particles.
圖2A是用以測定連接電阻值A的電路的說明圖，且是積層有覆蓋膜的可撓性印刷配線板的模式性平面圖。 2A is an explanatory view of a circuit for measuring a connection resistance value A, and is a schematic plan view of a flexible printed wiring board in which a cover film is laminated.
圖2B是圖2A的IIB-IIB切斷部剖面圖。 Fig. 2B is a cross-sectional view of the cut portion of IIB-IIB of Fig. 2A.
圖2C是圖2A的IIC-IIC切斷部剖面圖。 Fig. 2C is a cross-sectional view of the IIC-IIC cutting portion of Fig. 2A.
圖2D是用以測定連接電阻值A的電路的說明圖，且是將導電性片與不鏽鋼板重疊並加熱壓製後的可撓性印刷配線板的模式性平面圖。 2D is an explanatory view of a circuit for measuring the connection resistance value A, and is a schematic plan view of a flexible printed wiring board in which a conductive sheet is superposed on a stainless steel plate and heated and pressed.
圖2E是圖2D的IIE-IIE切斷部剖面圖。 Fig. 2E is a cross-sectional view of the cut portion of the IIE-IIE of Fig. 2D.
圖2F是圖2D的IIF-IIF切斷部剖面圖。 Fig. 2F is a cross-sectional view of the IIF-IIF cut portion of Fig. 2D.
圖3A是用以測定連接電阻值B的電路的說明圖，且是積層有覆蓋膜的可撓性印刷配線板的模式性平面圖。 3A is an explanatory view of a circuit for measuring a connection resistance value B, and is a schematic plan view of a flexible printed wiring board in which a cover film is laminated.
圖3B是圖3A的IIIB-IIIB切斷部剖面圖。 Fig. 3B is a cross-sectional view of the cut portion of IIIB-IIIB of Fig. 3A.
圖3C是圖3A的IIIC-IIIC切斷部剖面圖。 Fig. 3C is a cross-sectional view of the cut portion of IIIC-IIIC of Fig. 3A.
圖3D是用以測定連接電阻值B的電路的說明圖，且是將導電性片與不鏽鋼板重疊並加熱壓製後的模式性平面圖。 3D is an explanatory view of a circuit for measuring the connection resistance value B, and is a schematic plan view in which a conductive sheet is superposed on a stainless steel plate and heated and pressed.
圖3E是圖3D的IIIE-IIIE切斷部剖面圖。 Fig. 3E is a cross-sectional view of the cut portion of IIIE-IIIE of Fig. 3D.
圖3F是圖3D的IIIF-IIIF切斷部剖面圖。 Fig. 3F is a cross-sectional view of the IIIF-IIIF cut portion of Fig. 3D.
1‧‧‧聚醯亞胺膜 1‧‧‧ Polyimine film
2‧‧‧銅箔電路 2‧‧‧copper circuit
3‧‧‧覆蓋膜 3‧‧‧ Cover film
4‧‧‧通孔 4‧‧‧through hole
Claims (12)
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| KR20190068351A (en) * | 2017-12-08 | 2019-06-18 | 삼성에스디아이 주식회사 | Solar cell |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6167702A (en) * | 1984-09-07 | 1986-04-07 | Mitsui Mining & Smelting Co Ltd | Electrically conductive powder and electrically conductive composition using said powder |
| JPH08199109A (en) * | 1995-01-23 | 1996-08-06 | Tokuyama Corp | Copper paste and its production |
| TW561266B (en) * | 1999-09-17 | 2003-11-11 | Jsr Corp | Anisotropic conductive sheet, its manufacturing method, and connector |
| JP2005236153A (en) * | 2004-02-23 | 2005-09-02 | Sumitomo Bakelite Co Ltd | Multilayer circuit board, and manufacturing method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6167702A (en) * | 1984-09-07 | 1986-04-07 | Mitsui Mining & Smelting Co Ltd | Electrically conductive powder and electrically conductive composition using said powder |
| JPH08199109A (en) * | 1995-01-23 | 1996-08-06 | Tokuyama Corp | Copper paste and its production |
| TW561266B (en) * | 1999-09-17 | 2003-11-11 | Jsr Corp | Anisotropic conductive sheet, its manufacturing method, and connector |
| JP2005236153A (en) * | 2004-02-23 | 2005-09-02 | Sumitomo Bakelite Co Ltd | Multilayer circuit board, and manufacturing method thereof |
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