JP5228869B2 - Adhesive film for circuit connection and method for recognizing mark for position identification of circuit member - Google Patents

Description

  The present invention relates to an adhesive film for circuit connection and a method for recognizing a mark for position identification of a circuit member.

  In recent years, electronic components have been reduced in size, thickness, and performance, and economic high-density mounting technology has been actively developed. The connection between electronic components used for high-density mounting and fine circuit electrodes is difficult with conventional solders and rubber connectors, so anisotropic conductive adhesives or films with excellent resolution are often used. It has come to be. For example, an anisotropic conductive material which is an adhesive containing a predetermined amount of conductive particles when connecting a liquid crystal display (Liquid Crystal Display) glass and a fine electrode of TAB (Tape Automated Bonding) or FPC (Flexible Print Circuit). By sandwiching the adhesive adhesive film between the opposed electrodes and applying pressure in this state, both electrodes are electrically connected to each other, and both are bonded and fixed. At this time, insulation between adjacent electrodes is maintained.

  In order to cope with the connection of miniaturized circuits, for example, the insulation between adjacent electrodes is ensured by making the particle size of the conductive particles smaller than the width of the insulating portion between the adjacent electrodes. Furthermore, the conduction | electrical_connection in a connection part is obtained by making content of an electroconductive particle into the grade which does not contact electroconductive particles, and making an electroconductive particle exist reliably on an electrode.

By the way, in recent years, particularly in the mounting of a wiring board and a semiconductor wafer, an electrical connection may be obtained by bringing the electrodes into contact with each other without providing an electrical connection body such as conductive particles on the adhesive film itself. In this case, an electrically insulating adhesive for circuit connection is used.
Japanese Patent Laid-Open No. 06-290276

  At the time of circuit connection using the circuit connection adhesive, a position identification mark provided on the circuit member may be used for alignment of the circuit member to be connected. In this case, the position identification mark is recognized by an electromagnetic wave such as visible light that passes through the adhesive layer attached to the circuit member. In order to increase the mounting density and simplify the number of steps, it is desirable to attach an adhesive layer to the circuit member so as to cover the mark for position identification. For that purpose, it is necessary to recognize the mark with high accuracy by the electromagnetic wave transmitted through the adhesive layer.

  However, conventionally, the position identifying mark cannot always be sufficiently recognized by the electromagnetic wave transmitted through the adhesive layer, and it may be difficult to accurately align the circuit members.

  Accordingly, the present invention provides an adhesive film for circuit connection that makes it possible to sufficiently recognize a mark for position identification of a circuit member by electromagnetic waves transmitted through an adhesive layer attached to the circuit member. Objective. Another object of the present invention is to provide a method that makes it possible to recognize a position identification mark of a circuit member with high accuracy.

  The present invention relates to an adhesive film for circuit connection comprising a film-like support and an insulating adhesive layer provided in contact with the main surface of the support. The center line average roughness Ra of the main surface on the adhesive layer side of the support constituting the adhesive film according to the present invention is 0.3 μm or less.

  The main surface of the support on the adhesive layer side has high smoothness such that the center line average roughness Ra is within the above specified range, so that the adhesive layer attached to the circuit member is transmitted. Thus, the visible light can sufficiently recognize the position identification mark of the circuit member from the adhesive layer side. The surface of a support used for a conventional adhesive film having an insulating adhesive layer is conventionally subjected to a roughening treatment from the viewpoint of improving surface wettability and adhesion strength with the adhesive layer. There were many. Then, since the adhesive follows the roughened surface of the support, the surface of the adhesive layer after the support is peeled becomes rough. As a result, it is considered that the light transmittance of the adhesive layer was lowered and it was difficult to recognize the mark for position identification. For example, the surface of the main surface 2a on the side of the adhesive layer 3 of the support 2 like the conventional adhesive film 1 for circuit connection having the support 2 and the adhesive layer 3 shown in the sectional views of FIGS. When the roughness is large, the light transmittance of the adhesive layer 2 is low, and it is difficult to recognize the position identification mark by an electromagnetic wave such as visible light.

  In order to achieve the effects of the present invention more remarkably, the ten-point average roughness Rz of the main surface on the adhesive layer side of the support is preferably 1.5 μm or less. For the same reason, the maximum height Ry of the main surface of the support on the adhesive layer side is more preferably 2.0 μm or less.

  Furthermore, the light transmittance of the adhesive layer is preferably 15% to 100%.

  In another aspect, the present invention relates to a method for recognizing a position identification mark (position identification symbol) of a circuit member. In the method according to the present invention, the adhesive film for circuit connection according to the present invention is applied to the surface of the circuit member having the substrate and the mark for position identification provided on the substrate. The surface of the layer opposite to the support is in contact with the circuit member, and the adhesive layer is attached so that it covers the mark. Then, the support is removed from the attached adhesive film for circuit connection, and then the adhesive layer is transmitted. The mark is recognized by the electromagnetic wave.

  According to the method of the present invention, it is possible to recognize the position identification mark of the circuit member with high accuracy.

  According to the present invention, it is possible to sufficiently recognize the position identification mark of the circuit member from the adhesive layer side by the electromagnetic wave transmitted through the adhesive layer attached to the circuit member. Further, since the adhesive layer can be arranged at a position above the position identification mark, it is easy to increase the mounting density and simplify the number of steps. As a result, it is possible to provide a method for recognizing a position identification mark having a high degree of process freedom.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  In this specification, “center line average roughness Ra”, “ten-point average surface roughness Rz”, and “maximum height Ry” are values measured in accordance with JIS B0601: 1994. The measurement is performed using a 2CR as a filter with a measurement length of 2.8 mm, a measurement speed of 1 mm / s, and a cutoff value R + W.

  FIG. 1 is a cross-sectional view showing an embodiment of an adhesive film for circuit connection. An adhesive film for circuit connection 1 shown in FIG. 1 includes a film-like support 2 having main surfaces 2a and 2b, and an insulating adhesive layer 3 provided in contact with one main surface 2a of the support 2. Consists of

  The main surface 2a on the side of the adhesive layer 3 of the support 2 has a center line average roughness Ra of 0.3 μm or less. When the center line average roughness Ra exceeds 0.3 μm, irregular reflection of light increases, and the translucency of the adhesive layer 3 may not be kept sufficiently high. Although the minimum of centerline average roughness Ra is not specifically limited, It is preferable that centerline average roughness Ra is 0.01-0.3 micrometer.

  From the same viewpoint, the ten-point average surface roughness Rz of the main surface 2a is preferably 3 μm or less. The lower limit of the ten-point average surface roughness Rz is not particularly limited, but the ten-point average surface roughness Rz is more preferably 0.001 to 2 μm from the viewpoint of improving translucency, and 0.01 to 1.5 μm. More preferably, it is 0.01 to 1.3 μm.

  Furthermore, from the same viewpoint, the maximum height Ry of the main surface 2a is preferably 3 μm or less. The lower limit of the maximum height Ry is not particularly limited. The maximum height Ry is more preferably 0.001 to 2 μm, and further preferably 0.01 to 1.5 μm.

  A support having a main surface having Ra, Rz and Ry in the above range can be obtained by smoothing the support surface by a generally employed method.

  The main surface (back surface) 2b opposite to the adhesive layer 3 of the support 2 also has the same center line average roughness Ra, ten-point average surface roughness Rz, and maximum height Ry as the main surface 2a. preferable. However, the center line average roughness Ra of the main surface 2b may exceed 3 μm, and there is no particular problem even if it is about 20 μm or less. The ten-point average surface roughness Rz of the main surface 2b may exceed 3 μm, and there is no particular problem even if it is about 20 μm or less. The maximum height Ry of the main surface 2b may exceed 3 μm, and even if it is about 20 μm or less, there is no particular problem.

  The visible light transmittance of the adhesive layer 3 is preferably 15% to 100%.

  The thickness of the support 2 is preferably 5 to 200 μm, more preferably 10 to 100 μm, and even more preferably 25 to 75 μm. When the thickness of the support 2 is less than 25 μm, the support tends to be difficult to handle. In addition, there are not many effects obtained by increasing the thickness, and it is more preferable to keep the thickness to 150 μm or less in consideration of environmental problems.

  The material of the support 2 is not particularly limited, and can be appropriately selected from those used as a support for a film for electrical insulation or electrical connection. Specific examples of the support 2 include polyethylene terephthalate film, polyethylene naphthalate film, polyolefin film, polyethylene isophthalate film, polybutylene terephthalate film, polyacetate film, polycarbonate film, polyphenylene sulfide film, polyamide film, ethylene-acetic acid. Examples thereof include a vinyl copolymer film, a polyvinyl chloride film, a polyvinylidene chloride film, a synthetic rubber film, a liquid crystal polymer film, a polyimide film, and a low density polyethylene film. Among these, a polyethylene terephthalate film is preferable because it is excellent in dimensional stability at a temperature when producing a film for electrical insulation and the material cost is low.

  The main surface 2 a of the support 2 may be subjected to a peeling treatment in order to adjust the adhesion between the support 2 and the adhesive layer 3. The mold release treatment is performed, for example, by applying a mold release treatment agent to the main surface 2a of the support 2. Examples of the mold release treatment agent include silicone, silicone alkyd, amino alkyd, alkyl alkyd and melamine. These may be used alone or in combination of two or more. The main surface 2a and / or 2b of the support 2 may be coated with a polymer or the like. When the main surface 2a of the support is subjected to surface treatment such as mold release treatment or polymer coating, the main surface 2a after the surface treatment is subjected to the centerline average roughness Ra within the above range. , Ten-point average surface roughness Rz and maximum height Ry.

  The adhesive layer 3 is formed of a thermoplastic material used for an insulating sheet or the like, or a curable material that is cured by heat or light. A curable material is preferable because it is excellent in heat resistance and moisture resistance after circuit connection. Among the curable materials, epoxy adhesives can be preferably applied because they can be cured for a short time, have good connection workability, and have excellent adhesion in terms of molecular structure. Generally, an epoxy adhesive contains a high molecular weight epoxy resin, a solid epoxy resin, a liquid epoxy resin, a phenoxy resin, polyurethane, polyester, NBR, rubber, and the like as main components, and a curing agent, a coupling agent, and the like. It is a curable resin composition to which additives such as various modifiers and catalysts are added.

Examples of the epoxy resin used for the adhesive layer 3 include bisphenol-type epoxy resins derived from epichlorohydrin and bisphenol A, F or AD, epoxy novolac resins derived from epichlorohydrin and phenol novolac or cresol novolac, and naphthalene rings. Various epoxy compounds having two or more glycidyl groups in one molecule selected from naphthalene-based epoxy resins, glycidyl amines, glycidyl esters, biphenyl type epoxy resins, and alicyclic epoxy resins having an included skeleton are used. These can be used alone or in combination of two or more. These epoxy resins, impurity ions (Na ^+, C1 ^-, etc.) and / or the concentration of the hydrolyzable chlorine using a high purity product was reduced to 300ppm or less preferred in order to prevent electron migration.

  The curing agent is selected from, for example, imidazole series, hydrazide series, boron trifluoride-amine complex, sulfonium salt, amine imide, diaminomaleonitrile, melamine and derivatives thereof, polyamine salt, dicyandiamide, and modified products thereof. These may be used alone or in combination of two or more. These are anionic or cationic polymerizable catalyst-type curing agents, and are preferable because they can easily obtain immediate effects and require less chemical equivalent considerations. In addition, polyaddition types such as polyamines, polymercaptans, polyphenols, and acid anhydrides can be used as the curing agent. You may use these together with the said catalyst type hardening | curing agent.

  As an anionic polymerization type catalyst-type curing agent, secondary amines or imidazoles can be blended in the epoxy resin. By using these, the epoxy resin can be cured by heating at a medium temperature of about 160 ° C. to 200 ° C. for several tens of seconds to several hours, and a relatively long pot life (pot life) can be obtained. . As the cationic polymerization type catalyst-type curing agent, a photosensitive onium salt that cures the resin by energy ray irradiation, such as an aromatic diazonium salt and an aromatic sulfonium salt, is mainly used. In addition to irradiation with energy rays, there are aliphatic sulfonium salts and the like as curing agents that are activated by heating to cure the epoxy resin. This type of curing agent is preferred because it has the property of fast curing.

  It is preferable to use these hardeners coated with a polymer material such as polyurethane or polyester, a metal thin film such as Ni or Cu, and an inorganic material such as calcium silicate so that the pot life can be extended. .

  The adhesive layer 3 contains, for example, a filler, a softener, an accelerator, an anti-aging agent, a colorant, a flame retardant, a dielectric material, a thixotropic agent, a coupling agent, a phenol resin, and a melamine resin as additives. May be. Curing agents such as isocyanates can also be used.

  The adhesive film for circuit connection (circuit connection material) 1 is excellent in handleability because it is in the form of a film. The adhesive layer 3 preferably contains a film forming material. Examples of the film forming material include epoxy resin, polyurethane, and rubber.

  In order to obtain high reliability as a circuit connection material, a phenoxy resin can be suitably used as a film forming material. The phenoxy resin corresponds to a high molecular weight epoxy resin having a weight average molecular weight of 10,000 or more determined by high performance liquid chromatography (HLC). Similar to the epoxy resin, there are phenoxy resins such as bisphenol A type, AD type, and AF type. Since these are similar in structure to the epoxy resin, they have good compatibility with the epoxy resin and also provide good adhesion. As the molecular weight increases, film formability can be easily obtained, and the melt viscosity that affects the fluidity during connection can be set in a wide range. The weight average molecular weight of the phenoxy resin is preferably 10,000 to 80,000, more preferably 20000 to 60,000, from the viewpoint of melt viscosity and compatibility with other resins.

  The resin used as the film-forming material contains polar groups such as hydroxyl groups and carboxyl groups, so that compatibility with the epoxy resin is improved and a film having a uniform appearance and characteristics can be obtained. This is preferable from the viewpoint of obtaining a short time curing by promoting the reaction.

  It is preferable that the compounding quantity of a film forming material is 20-80 mass% with respect to the whole adhesive bond layer 3 from the point of acceleration | stimulation of film formation property or hardening reaction.

  In order to adjust the melt viscosity, the adhesive layer 3 may contain a styrene resin or an acrylic resin.

  The adhesive layer 3 may include conductive particles as long as the insulating property is maintained so that the insulation between adjacent electrodes can be sufficiently maintained, and the recognition of the mark for position identification is not significantly disturbed. Specifically, the adhesive layer 3 contains a metal selected from Au, Ag, Pt, Ni, Cu, W, Sb, Sn and solder, and a conductive filler (conductive particles) such as carbon. Also good. The shape of the filler is not particularly limited, and may be a sphere, a rectangle, a triangle, a star, or the like. From the viewpoint of resolution and dispersibility, a spherical filler can be preferably used. The diameter of the spherical filler is preferably 20 μm or less, more preferably 7 μm or less. The lower limit of the diameter is preferably 0.005 μm or more, more preferably 1 μm or more. In the case of a non-spherical filler, the maximum width of the cross-sectional area is preferably 20 μm or less, and more preferably 7 μm or less.

  The adhesive layer 3 may contain an insulating filler such as an inorganic material such as silica, silicone, or ceramic, or an organic material such as styrene or acrylic rubber. These shapes are not particularly limited, and may be a sphere, a rectangle, a triangle, a star, or the like. In view of resolution and dispersibility, spherical fillers are preferred. The diameter of the spherical filler is preferably 20 μm or less, more preferably 7 μm or less. The lower limit of the diameter is preferably 0.005 μm or more, more preferably 1 μm or more. In the case of a non-spherical filler, the maximum width of the cross-sectional area is preferably 20 μm or less, and more preferably 7 μm or less.

  The adhesive layer 3 can contain a plurality of types of fillers having different shapes, sizes and materials at the same time. Further, a conductive filler and an insulating filler can be used in combination.

  The adhesive film 1 for circuit connection is applied, for example, with a step of dissolving or dispersing the adhesive composition in a solvent to liquefy and applying the liquefied adhesive composition onto the main surface 2a of the support 2. And a step of removing the solvent from the adhesive composition. The liquefied adhesive composition may be an emulsion. The removal of the solvent is performed by heating to below the activation temperature of the curing agent.

  As the solvent, an aromatic hydrocarbon-based and oxygen-containing mixed solvent is preferable because the solubility of the material is improved. The SP value of the oxygen-containing solvent is preferably in the range of 8.1 to 10.7 in terms of protecting the latent curing agent. Acetic acid ester is preferable as the oxygen-based solvent. The boiling point of the solvent is preferably 150 ° C. or lower. When the boiling point exceeds 150 ° C., a high temperature is required for drying, and there is a tendency for the potential to be lowered because it is close to the activation temperature of the latent curing agent. Moreover, when the boiling point is too low, the workability during drying tends to decrease. For this reason, the boiling point is more preferably 60 to 150 ° C, and further preferably 70 to 130 ° C.

  The adhesive film for circuit connection (insulating adhesive film) 1 may be stored not only in the form of a single sheet but also in a roll or reel state by being wound around a winding core. In the adhesive film stored in a roll or reel state, the support 2 may be in direct contact with the adhesive layer 3 not only on the main surface 2a but also on the back main surface 2b. In order to prevent the adhesive layer 3 from being transferred to the main surface 2b side of the support when the circuit connection adhesive film wound in a roll shape or a reel shape is pulled out for use, the adhesive layer 3 and the main surface The adhesion strength with 2b is required to be lower than the adhesion strength between the adhesive layer 3 and the main surface 2a. Another protective film may be disposed on the side of the adhesive layer 3 opposite to the support 2. In this case, the peeling process of the main surface 2b of the support may be unnecessary.

  The adhesive layer of the adhesive film for circuit connection is not limited to a single layer as in the embodiment of FIG. 1, and may be composed of a plurality of layers as long as the recognition of the mark for position identification is not significantly prevented. For example, a plurality of adhesive layers having different compositions and physical properties may be laminated. Further, in consideration of adhesiveness with a circuit member as an adherend, two types of adhesive layers having high adhesiveness with respect to each circuit member to be connected may be laminated.

  FIG. 2 is a cross-sectional view showing an embodiment of a method for recognizing a mark for position identification of a circuit member. In the method shown in FIG. 2, a support is formed from an adhesive film for circuit connection attached to a surface of a circuit member 5 having a substrate 11 and a mark 10 for position identification provided on the substrate 11. 2 is removed. The adhesive film for circuit connection is bonded to the circuit member 5 so that the surface of the adhesive layer 3 opposite to the support 2 is in contact with the circuit member 5 and the adhesive layer 3 covers the mark 10.

  Thereafter, the mark 10 is recognized by the visible light 12 transmitted through the adhesive layer 3 while using the camera 13. Based on the position information of the mark 10, the circuit member to be connected is aligned. At this time, since the surface of the support 3 has the smooth surface as described above, the position of the mark 10 can be recognized with high accuracy.

  The recognition of the mark 10 can also be performed using visible light, electromagnetic waves such as ultraviolet rays and X-rays. However, visible light is preferable from the viewpoint of facilities and ease of introduction. Since the wavelength of visible light is about 1 μm, unevenness of 1 μm or more may significantly hinder the transparency.

  Examples of circuit members to be connected include electronic components that are active elements or passive elements, printed boards, flexible wiring boards, and glass boards. Active elements include semiconductor chips, transistors, diodes, thyristors, and the like. Passive elements include capacitors, resistors and coils. The flexible wiring board has, for example, polyimide or polyester as a base material. A circuit is formed of, for example, ITO on a glass substrate as a circuit member. The adhesive film for circuit connection according to the present invention is particularly useful as a film adhesive for bonding a liquid crystal panel or a semiconductor chip.

  Protruding electrodes such as bumps formed by plating or wire bumps may be provided on the electrode pads of the semiconductor chip or the substrate. This protruding electrode can be used as a connection terminal. The wire bump is formed by a method in which the tip of a gold wire is melted with a torch or the like to form a gold ball, the ball is pressed onto an electrode pad, and then the wire is cut.

  The circuit member has a connection terminal. Although there may be one connection terminal, usually a large number of connection terminals are provided. At least a part of the connection terminals provided on each of the at least one set of circuit members are arranged to face each other while being aligned based on the position information of the mark for position identification, and an adhesive layer is interposed between the connection terminals arranged to face each other. In this state, heating and pressurization are performed to electrically connect the connection terminals arranged opposite to each other. By heating and pressurizing the circuit member, the connection terminals arranged opposite to each other are in direct contact and are electrically connected.

  In the present invention, it is also assumed that the adhesive film is directly attached to the semiconductor wafer. In this case, an adhesive film cut into the same size as the wafer such as 12 inches or larger is laminated on the wafer. The wafer is divided into individual pieces by dicing in a state where the adhesive film is laminated on the wafer. Thereby, it becomes possible to laminate | stack an adhesive film in fewer frequency | counts than the case where an adhesive film is laminated | stacked per chip | tip or the board | substrate 1 sheet unit. This method not only simplifies the man-hours in this way, but also allows the adhesive film to be affixed with the same size as the chip size to be singulated, so that it is advantageous in terms of mounting density. Since the mark for position identification can be recognized with high accuracy via the adhesive layer, the arrangement position of the mark can be freely set.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these.

Example 1
A polyethylene terephthalate film (hereinafter referred to as “PET film”) was produced by a general method using an extrusion apparatus. A release treatment was performed on both sides of the obtained PET film using silicone as a release treatment agent. Supports PET film after release treatment (thickness: 50 μm, center line average roughness Ra: 0.1 μm, 10-point average surface roughness Rz: 0.8 μm, maximum height Ry: 1.4 μm) Used as a body.

  A 30% by mass ethyl acetate solution containing 20/80 (mass ratio) of a phenoxy resin (high molecular weight epoxy resin) and a liquid epoxy resin composition (epoxy equivalent 185) containing a microcapsule type latent curing agent Prepared. This solution was mixed to disperse the solid content to obtain a liquid adhesive composition.

  Next, the adhesive composition was applied to the main surface of the support using a coating apparatus. Then, the applied adhesive composition is dried at a temperature and time at which it does not cure to form an adhesive layer, and is composed of a support and an insulating adhesive layer formed thereon. An adhesive film was obtained. The thickness of the adhesive layer was 25 μm.

  The adhesive layer of the obtained adhesive film was transferred to a substrate having wiring having a height of 18 μm using a tool heated to 90 ° C. After the transfer, as shown in FIG. 2, when the position identification mark on the substrate was recognized using a visible light camera through the adhesive layer, the position of the substrate could be recognized with a high recognition rate of 99.9%.

(Example 2)
A PET film was prepared by a general method using an extrusion apparatus. A release treatment was performed on both sides of the obtained PET film using silicone as a release treatment agent. Supports PET film after release treatment (thickness: 50 μm, main surface centerline average roughness Ra: 0.1 μm, ten-point average surface roughness Rz: 0.1 μm, maximum height Ry: 1.5 μm) Using as a body, an adhesive film was produced in the same manner as in Example 1. The thickness of the adhesive layer was 25 μm.

  The adhesive layer of the obtained adhesive film was transferred to a substrate having wiring having a height of 18 μm using a tool heated to 90 ° C. After the transfer, as shown in FIG. 2, when the position identification mark on the substrate was recognized using a visible light camera through the adhesive layer, the position of the substrate could be recognized with a high recognition rate of 99.9%.

(Comparative Example 1)
A PET film was prepared by a general method using an extrusion apparatus. A release treatment was performed on both sides of the obtained PET film using silicone as a release treatment agent. Supports PET film after release treatment (thickness: 50 μm, center line average roughness Ra: 0.4 μm, ten-point average surface roughness Rz: 3.8 μm, maximum height Ry: 5.4 μm) Using as a body, an adhesive film was produced in the same manner as in Example 1. The thickness of the adhesive layer was 25 μm.

  The adhesive layer of the obtained adhesive film was transferred to a substrate having wiring having a height of 18 μm using a tool heated to 90 ° C. After the transfer, as shown in FIG. 2, when the mark for position identification on the substrate was recognized using a visible light camera through the adhesive layer, the recognition rate was as low as 32%, and the position of the substrate could hardly be recognized. It was.

(Comparative Example 2)
A PET film was prepared by a general method using an extrusion apparatus. A release treatment was performed on both sides of the obtained PET film using silicone as a release treatment agent. Supports PET film after release treatment (thickness: 50 μm, center line average roughness Ra: 1.5 μm, ten-point average surface roughness Rz: 11.6 μm, maximum height Ry: 15.1 μm) An insulating adhesive film was produced in the same manner as in Example 1 using the product as a body. The thickness of the adhesive layer was 25 μm.

  The adhesive layer of the obtained adhesive film was transferred to a substrate having wiring having a height of 18 μm using a tool heated to 90 ° C. After the transfer, as shown in FIG. 2, when the position identifying mark on the substrate was recognized using a visible light camera through the adhesive layer, the recognition rate was as low as 12%, and the position of the substrate could hardly be recognized. It was.

  Also from the above experimental results, according to the adhesive film of the present invention, when the adhesive layer is transferred to the circuit member, the position of the circuit member on the substrate is sufficiently recognized from the adhesive layer side using a visible light camera. It was confirmed that it was possible.

It is sectional drawing which shows one Embodiment of the adhesive film for circuit connections. It is sectional drawing which shows one Embodiment of the method of recognizing the mark for position identification of a circuit member. It is sectional drawing which shows the conventional adhesive film for circuit connection. It is sectional drawing which shows the conventional adhesive film for circuit connection.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Circuit-connecting adhesive film, 2 ... Support body, 2a ... Main surface of support body, 2b ... Main surface of support body, 3 ... Adhesive layer, 5 ... Circuit member, 10 ... Mark for position identification, 11 ... Substrate, 12 ... visible light, 13 ... camera.

Claims (4)

A film-like support and an insulating adhesive layer provided in contact with the main surface of the support, and the center line average roughness Ra of the main surface on the adhesive layer side of the support is An adhesive film for circuit connection having a thickness of 0.3 μm or less and a ten-point average roughness Rz of 1.5 μm or less . The maximum height Ry of the adhesive layer side main surface of the supporting body is 2.0μm or less, the adhesive film for circuit connection according to claim 1 Symbol placement. Light transmittance of the adhesive layer is 15% to 100%, the adhesive film for circuit connection according to claim 1 or 2, wherein. The adhesive film for circuit connection according to any one of claims 1 to 3 , wherein a surface of the circuit member having a substrate and a position identification mark provided on the substrate is provided with the mark. The surface opposite to the support of the adhesive layer is in contact with the circuit member and the adhesive layer is attached so as to cover the mark, and the support is removed from the attached adhesive film for circuit connection, Then, the method of recognizing a mark for identifying a position of a circuit member, wherein the mark is recognized by an electromagnetic wave transmitted through the adhesive layer.

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