JP2008263183A - Film circuit substrate and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-precision film circuit substrate composed by connecting a superposing part at each end of each sheet flexible film substrate in a state of providing each cut between a plurality of lines of circuit patterns in the superposing part when obtaining an elongated film substrate by connecting and superposing each short-side end of each sheet flexible film substrate in which a plurality of lines of continuously-arranged circuit patterns are arrayed in parallel in the same face, and its manufacturing method. <P>SOLUTION: A strip-like flexible film substrate has two or more lines of circuit patterns which are arranged in plurality of pieces on one side. A plurality of strip-like flexible film substrates are aligned so as to form an elongated flexible film substrate. Short-side ends of the strip-like flexible film substrate are bonded to each other via an adhesive layer so that a wiring pattern is arranged at each short-side end of each strip-like flexible film substrate on the circuit-pattern-formation-face side. A cut is formed between the respective circuit patterns in the superposing part at each short-side end part to be superposed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a long film circuit corresponding to a reel-to-reel manufacturing apparatus in COF (Chip on Film) technology in order to increase the accuracy of a circuit pattern as the electronic product becomes lighter and smaller. In order to manufacture a board | substrate accurately, it is related with the film circuit board joined together in the state which has a notch between the circuit patterns of several rows in the overlapping part of an end part of a flexible film board | substrate, and its manufacturing method.

  As electronics products become lighter and smaller, printed circuit board patterning needs to be highly accurate. Since the flexible film substrate can be bent, three-dimensional wiring can be formed, and the flexible film substrate is suitable for downsizing of electronic products. The COF technology used for IC connection to a liquid crystal display panel can obtain the finest pattern as a resin substrate by processing a relatively narrow and long polyimide film substrate. Is approaching its limits.

  For miniaturization, there are an index represented by a line width and a space width between lines, and an index represented by a position of a pattern on a substrate. Although there are measures to further reduce the line width and space width, the positional accuracy, which is the latter index, is related to the alignment between the electrode pad and the circuit pattern when joining the electronic components such as the circuit board and IC. As the number of pins of ICs increases, it is becoming strict to meet the required accuracy.

  In the current COF technology, a lengthened film is generally used as a base substrate, and the conveyance method in the circuit pattern forming process flows in a reel-to-reel method. The advantage of the reel-to-reel method is that the film is easy to handle, so it can be mentioned that the productivity is good, but if you do chemical treatment or heat treatment with a flexible film alone without attaching a support etc., As the flexible film expands and contracts, the alignment between the electrode pad and the circuit pattern when joining the circuit pattern and the electronic component such as an IC becomes difficult as the miniaturization progresses. In addition, in order to cope with the recent cost reduction, the number of circuit pattern rows arranged on the flexible film handled by the reel-to-reel method increases, so it becomes more difficult to ensure the dimensional accuracy of the circuit pattern. .

  As a method for improving these, a flexible film coated with a slightly sticky adhesive on the surface opposite to the circuit pattern forming surface of the flexible film substrate is attached to the surface of the flexible film substrate so that the flexibility when passing through the process can be improved. A technique for reducing the expansion and contraction of the conductive film and ensuring the dimensional accuracy of the circuit pattern has been proposed (for example, see Patent Document 1). However, with regard to the progress of miniaturization in the future, the limit is approaching to meet the required dimensional accuracy required from IC mounting.

  On the other hand, it has been proposed to bond a flexible film substrate to a reinforcing plate to form a very fine circuit pattern while maintaining the dimensional accuracy of the circuit pattern (see, for example, Patent Document 2). . The flexible film substrate is made by peeling off a reinforcing plate after forming a circuit pattern. The proposal mainly uses a sheet-type reinforcing plate, and the flexible film substrate on which the circuit pattern is formed is also a sheet. On the other hand, in the current COF technology, handling of a flexible film substrate on which a circuit pattern is formed, such as electronic component connection, test, connection with an LCD panel, etc., has both a single wafer and a long case, There are many cases where long films are handled in a reel-to-reel system.

  In order to make use of existing reel-to-reel equipment, strip-shaped flexible film substrates with high dimensional accuracy produced by bonding to a reinforcing plate are aligned in the same direction, and the short edge of the film substrate is aligned. There is a proposal for producing a long film substrate by superimposing a film substrate on an adhesive layer formed in advance on the part and thermocompression bonding the adhesive layer (see, for example, Patent Document 3). In this proposal, when a circuit pattern is arranged in a row on a strip-shaped flexible film substrate, for example, by recognizing a feed hole called a sprocket hole formed outside the circuit pattern or the circuit pattern, The alignment accuracy and the connection accuracy can be increased.

  In response to demands for productivity improvement and cost reduction, it is effective to increase the size of the flexible film substrate and arrange more circuit patterns on the flexible film. In this case, a plurality of rows of circuit patterns can be made into a single row by a cutting step, and the strip-like flexible film substrates can be accurately joined through the adhesive layer, but can be arranged on a single flexible film. As the number of circuit pattern rows increases, the number of splicing devices increases. Therefore, not only the equipment cost burden increases, but also the work load such as attachment and removal of product reels to the splicing device increases, and the productivity decreases. . It is desirable to solve the above-mentioned problem by overlapping and connecting short-side ends of flexible film substrates on which a plurality of rows of circuit patterns are arranged.

  On the other hand, in order to reduce the area of the COF substrate, the circuit pattern interval arranged on one row of film substrates tends to be narrowed. Conventionally, the flexible film portions where the circuit pattern is not arranged are overlapped and connected to each other. However, in order to cope with the narrowing of the circuit pattern interval, it does not function as a part of the circuit pattern or the circuit pattern. There has been proposed a method of connecting using a part of a wiring pattern arranged to confirm the continuity of a circuit pattern (see, for example, Patent Document 4). In this case, since the circuit pattern or the wiring pattern is connected and, for example, an electrical inspection probe is pressed, high dimensional accuracy of the pattern is required.

In order to increase productivity, when overlapping and connecting the short side ends of the flexible film substrate having a plurality of rows of circuit patterns, the overlapping length in the short side direction of the flexible film substrate becomes long, It is difficult to ensure the dimensional accuracy of the joining portion due to film slack when the film circuit boards are stacked, film slipping during pressure bonding, and curing shrinkage of the adhesive layer.
JP-A-60-57697 JP 2003-298194 A JP 2006-295143 A International Publication WO06 / 038496 Pamphlet

  An object of the present invention is to provide a highly accurate film circuit board and a method of manufacturing the same for making maximum use of reel-to-reel equipment. In other words, the circuit pattern rows continuously arranged at equal intervals are connected by overlapping the short side end portions of the single-sided flexible film substrate in which a plurality of parallel arrangements are arranged in the same plane. A highly accurate film circuit board and a method for manufacturing the same are provided by connecting the plurality of circuit patterns with notches at the overlapping portion of the end portions of the flexible film substrate when obtaining the film substrate. There is.

In order to achieve the above object, the present invention has the following configuration. That is,
(1) Flexibility in which a plurality of strip-shaped flexible film substrates having at least two rows of circuit patterns arranged on one side are aligned, and the short side edges of each other are joined via an adhesive layer A film circuit board, wherein a cut portion is formed between circuit patterns in each row in the overlapped portion of the overlapped short side end portion.

  (2) Flexibility to align a plurality of strip-like flexible film substrates having at least two rows of circuit patterns arranged on one side and to bond the short side edges of each other via an adhesive layer A method for manufacturing a film circuit board, comprising: providing a notch between circuit patterns in each row in an overlapping portion at a short-side end portion to be overlapped before overlapping.

  (3) No wiring pattern is formed on the flexible film of the overlapping portion, and the wiring is formed on the flexible film of the overlapping portion on the first flexible film substrate on which the adhesive layer is formed. The second flexible film substrate on which the pattern is formed is superposed, and the adhesive layer is heated and pressed by pressing the heating and pressing means from the flexible film substrate side of the second flexible film substrate. The manufacturing method of the film circuit board as described in said (2).

  (4) The method for producing a film circuit board according to (3), wherein the adhesive layer is heated and pressurized by a heating and pressing means of a ceramic heater or an impulse heater.

  (5) The above (3) or characterized in that the same number of heating and pressing means as the number of circuit pattern rows arranged on the flexible film substrate are arranged in a zigzag shape, and the bonding is performed in two steps. The manufacturing method of the film circuit board as described in (4).

  (6) A plurality of strip-shaped flexible film substrates having at least two rows of circuit patterns arranged on one side are aligned, and the intervals at which the circuit patterns are arranged overlap each other at the short side ends. A method of manufacturing a film circuit board in which a circuit pattern is cut and separated into a single row or a predetermined plurality of rows after being overlapped and bonded via an adhesive layer so as to be the same as the arrangement interval of circuit patterns other than the portion. A method of manufacturing a film circuit board, comprising: providing a cut between each circuit pattern in an overlapping portion of the circuit patterns at the short side end portion to be overlapped before bonding.

  According to the present invention, the short-side end portions of the single-sided flexible film substrates in which a plurality of rows of circuit patterns arranged continuously at equal intervals are arranged in parallel on the same plane are connected by being overlapped. Therefore, when obtaining a long film substrate, a circuit pattern or a part of the wiring pattern is used for the overlapping portion so that the circuit pattern can be arranged to the maximum while maintaining connection and connection, and the high dimensional accuracy of the pattern is high. The secured lengthened film substrate can be manufactured. As a result, the precision of the patterning of the printed circuit board can be improved with the reduction in weight and size of the electronic product.

  Hereinafter, the present invention will be described in more detail based on embodiments shown in the drawings. FIG. 1 is a front view showing an example of flexible film substrate connection of the present invention. In FIG. 1, strip-shaped flexible film substrates (hereinafter referred to as strip-shaped film substrates) 1 and 2 in which five rows of circuit patterns are arranged in parallel in the surface of the flexible film are arranged. Yes, one overlapping portion of the strip-shaped film substrates 1 and 2 has a circuit pattern or a wiring pattern (hereinafter, the overlapping pattern of the strip-shaped flexible film substrate 2 has a wiring pattern, and the circuit pattern is also a wiring pattern. To be included). In order to separate each of the plurality of wiring patterns arranged in parallel in the overlapping portion of the strip-shaped film substrate 2, the notch 5 is formed so as to be parallel to the long side direction of the strip-shaped film substrate with at least the overlapping width. Has been. The long side direction of the strip-shaped film substrate is the same as the cutting direction when the strip-shaped film substrate having a plurality of rows of circuit patterns is connected and then cut and separated into a single row of circuit patterns.

  The number of rows arranged on the strip-shaped film substrate is the dimensional stability at the time of heating by the heating and pressurizing means for heating the adhesive, and the transport unit for superimposing the short side edges of the strip-shaped film substrate on each other. From the viewpoint of handling properties, the number of rows arranged with a film width of about 150 mm is preferable. In general, film substrate widths of 35 mm, 48 mm, and 70 mm are often used in the chip mounting process. Therefore, if the width of the film substrate is 35 mm, it is 2 to 4, if it is 48 mm, 2 to 3; If it is 70 mm, 2 is the preferable number of rows arranged on the strip-shaped film substrate.

  The notch 5 is preferably processed so as not to cut the circuit pattern and to damage the dimensional accuracy and quality of the circuit pattern. The cuts 5 are formed in the strip-shaped film substrate 2, but may be formed in the strip-shaped film substrate 1 in which the wiring pattern is not in the overlapping portion. The notch 5 has a step of forming a single row after connecting a plurality of rows of circuit patterns, but it is desirable not to provide an interval between the row of circuit patterns in order to reduce unnecessary removal portions at the time of cutting. For this reason, the length of the cut 5 is preferably equal to or greater than the overlapping width, and the width of the cut 5 is as small as possible when the tape width when the circuit pattern is made into a single row is reduced by the tape width reduction caused by forming the cut 5. It is preferable to make it as narrow as possible. The width of the cut 5 is preferably 1 mm or less, more preferably 0.5 mm or less.

  The notch 5 is formed outside the circuit pattern. After the circuit pattern is formed on the strip-like film, the notch 5 is formed by punching with a mold, or the circuit in the film substrate is attached to the reinforcing plate using a laser irradiation device. A method of making a cut with high relative position accuracy with respect to the pattern can be mentioned.

  If the transport direction of the strip-shaped film substrate is the direction of the arrow 8 in FIG. 1, before the strip-shaped film substrates 1 and 2 are overlapped, the adhesive layer 4 is formed on the short-side end of the strip-shaped film substrate 1, The short side end of the strip-shaped film substrate 2 is overlaid on the adhesive layer 4 of the strip-shaped film substrate 1. Thereafter, the strip-like film substrates 1 and 2 are joined together by melting and curing the adhesive layer 4 with a heating and pressing means such as a block heater, a ceramic heater, or an impulse heater.

  As the heating and pressing tool, a ceramic heater or an impulse heater is desirable.

A block heater can be used as the heating and pressurizing means. However, in order to reduce the connection time and achieve high-accuracy temperature control at the time of crimping, the temperature rise from normal temperature to the specified temperature, the shortness of the temperature drop time, the temperature The temperature chart at the time of rising and falling needs to be more rectangular. From this point, it is desirable to use a ceramic heater or an impulse heater.

An example of the connecting method of the present invention will be described with reference to FIGS. The joining device for realizing this joining method includes a positioning unit and a strip-like film that overlap an adhesive layer formed on the rear upstream-side strip-like film substrate on the short-side end portion of the adjacent downstream-side strip-like film substrate. A unit that heats and presses a portion where the short side edges of the substrate overlap each other is provided.

  The transport unit has a mechanism for accurately transporting the strip-shaped film substrate in the transport direction and transporting the strip-shaped film substrate flat. In order to accurately transport in the transport direction, for example, a feed hole formed at the end in the long side direction of the strip-shaped film substrate is used as a guide, a guide pin is inserted into the feed hole, and the strip-shaped film substrate is placed in a predetermined place. A mechanism that pulls out the guide pins after transporting and a mechanism that sucks and fixes the strip-shaped film to the transport stand are provided.The strip-shaped film substrate is lifted by the suction arm installed on the top of the strip-shaped film substrate, and placed in place. For example, a method of transporting the strip-shaped film substrate by lowering the suction arm after the movement and releasing the suction can be used. The connection method shown in FIGS. 2A to 2E uses a transport unit using a suction arm described later.

  The carriages 211 and 212 have an adsorption mechanism, and the position of the strip-shaped film substrate 201 and the strip-shaped film 202 at the end of the flexible film already connected and elongated on the upper surface of the carriage having a flat surface. Adsorbed and fixed well. Further, the position of the strip-shaped film substrates 201 and 202 is controlled so as to have a predetermined interval (FIG. 2A). An adhesive layer 213 is formed on the downstream short side end of the strip-shaped film substrate 201 in the connecting and conveying direction 220. Since the strip-shaped film substrates 201 and 202 are arranged so that the circuit pattern formed on the strip-shaped film substrate is on the lower surface, the adhesive layer 213 is formed on the lower surface of the strip-shaped film substrate 201. Adsorption arms 214 and 215 having a mechanism for adsorbing the strip-like film back and forth by heating and pressurizing means 216a for heating and pressurizing the adhesive layer 213 are arranged. When the strip-shaped film substrate 201 and the strip-shaped film substrate 202 at the end of the elongated film substrate are transported to a predetermined position, the suction arms 214 and 215 are lowered to fix the strip-shaped film substrates 201 and 202 by suction ( FIG. 2 (b)). After the strip-shaped film substrate 202 is lifted by lifting the suction arm 215, the suction arm 215 is moved downstream, then the suction arm 215 is lowered, and the short-side end of the strip-shaped film substrate 202 is heated and pressurized. It is moved so as to be positioned on 216a (FIG. 2 (c)). At this time, a circuit pattern or a part of the wiring pattern is disposed at the short side end of the strip-shaped film substrate 202. In order to avoid problems such as circuit pattern scratches and pattern chipping due to conveyance, air is blown from the lower side to the conveyance tables 211 and 212 so as not to contact the conveyance table when conveying the strip-shaped film substrate. It is preferable.

  Next, the strip-shaped film substrate 201 is lifted by raising the suction arm 214, and then the suction arm 214 is moved downstream, and then the suction arm 214 is lowered to heat the short side end of the strip-shaped film substrate 201. It is made to transfer so that the contact bonding layer 213 may be located on the pressurization means 216a (FIG.2 (d)). When the front short side end of the strip-shaped film substrate 201 is overlapped with the strip-shaped film substrate 202 via the adhesive layer 213, the heating and pressurizing means 216a and 216b heat and press the overlapping portion (FIG. 2 (e)). The adhesive layer 213 is cured. The conditions of the heating and pressurizing means 216b for melting and bonding the adhesive depend on the curing conditions of the adhesive layer to be used, but the heating temperature from 250 ° C. to 450 ° C., the pressure from 1 kPa to 20 kPa, and the heating from 1 second to 60 seconds Pressurization time can be used. In addition, a circuit pattern or a part of the wiring pattern is disposed at the short side end portion of the strip-shaped film substrate 202, and usually, tin plating or gold plating is applied to the copper wiring. It is difficult to set a high temperature condition, and the heating condition of the heating / pressurizing means 216a on the circuit pattern side is preferably 0 ° C. to 120 ° C. in order not to affect the tin plating or gold plating surface form.

  In addition, in order to reduce the variation in the pressure of the heating and pressurizing means when connecting, a circuit for measuring a spring or reaction force is attached between the heating and pressing means and the connecting device, and the circuit pattern or It is preferable to always apply a constant pressing pressure to all the wiring pattern rows.

  Thereafter, the heating and pressurizing means 216a and 216b are separated from the strip-shaped film substrates 201 and 202, and the suction arms 214 and 215 are raised to complete the connection. The strip-shaped film substrate is transported in the transport direction 220, the suction arms 214 and 215 are moved backward to return to FIG. 2A, and the process up to FIG. Can be manufactured.

  The above is a method of transporting and connecting the circuit pattern or adhesive layer formed on the strip-shaped film substrate with the bottom surface, but the circuit pattern or adhesive layer may be transported with the top surface of the strip-shaped film substrate. In this case, the downstream strip-shaped film substrate 202 was first lifted by the suction arm 215, and then the upstream strip-shaped film substrate 201 was transferred by the suction arm 214 onto the heating and pressurizing means 216a. Thereafter, the suction arm 215 is lowered and the short side end of the downstream strip-shaped film substrate 202 is overlaid on the short side end of the upstream strip-shaped film substrate 201.

  In consideration of productivity, the adhesive layer 213 is preferably used so that sufficient bonding strength can be obtained in a short time. However, in the case of heating and pressurizing in a short time, the heating and pressurizing means is often set to a high temperature. . Normally, the heat resistance temperature of polyimide used as a flexible film material is very high, around 400 ° C., and the dimensional change of the film substrate under a splicing condition is small. However, since the adhesive used for joining is cured and shrunk under the joining condition, it becomes a factor for changing the dimension of the circuit pattern or part of the wiring pattern arranged in the joining part in the short side direction. When the short side lengths of the strip-shaped film substrates to be joined are short, the dimensional change amount is small. However, when the circuit patterns are joined in a plurality of rows, that is, the longer the short side length is, the shorter the dimensional change amount by the adhesive layer 213 is. Since accumulation is performed in the side direction, as in the present invention, the accumulation of the dimensional change amount is reduced by cutting and separating the circuit patterns of a plurality of columns, so that the circuit pattern or wiring arranged in the overlapping portion is reduced. The dimensional accuracy of the pattern can be ensured.

  Having notches between a plurality of rows of circuit patterns is more effective in securing the dimensional accuracy of the circuit pattern or wiring pattern arranged in the overlapping portion from the following points.

  As the length of the short side end when the upstream side strip-shaped film substrate is overlapped with the short side end of the downstream side strip-shaped film substrate is longer, the strip-shaped film substrate 201 is moved to the strip-shaped film substrate by the suction arm 214 shown in FIG. When the heating and pressurizing means 216a and 216b are pressed against each other when the film substrate is bent and loosened when being sucked and transported to be superposed on the short side end portion of 202, a circuit pattern arranged in the superposed portion Or the dimensional accuracy of a wiring pattern will deteriorate. In some cases, the dimensional accuracy of all circuit pattern rows may be deteriorated, resulting in a decrease in yield.

  FIG. 3 shows a schematic cross-sectional view when the short-side end portions of the strip-shaped film substrate are overlapped and connected. Since it is a case where it connects by the connection method of FIG. 2, the circuit pattern or wiring pattern (code | symbol 15 in FIG. 3) of a superimposition part is arrange | positioned on the lower surface. In order from the top, the base film base material 10 of the strip-shaped film substrate 201, the adhesive layer 213, the base film base material 20 of the flexible film substrate 202, and the metal pattern 15 plated with Sn or Au are formed. Reference numeral 16 denotes a metal pattern of the strip-shaped film substrate 201, and 17 denotes a solder resist for protecting the wiring pattern.

  Another cause of lowering the dimensional accuracy of the circuit patterns when connecting a plurality of rows of circuit patterns at once is a decrease in flatness of the heating and pressurizing means 216a and 216b. When the heating / pressurizing means is curved downward, the heating / pressurizing means 216a comes into contact with the short-side end portion from the central portion of the flexible film substrate, and the short-side end portions of the film substrate. Is constrained last, so that the accumulation of dimensional deviations is reduced. However, when the heating / pressurizing means is curved upward, when the heating / pressurizing means 216a is lowered, it comes into contact with the central portion from the short side end of the flexible film substrate. Are brought close to the central portion of the flexible film substrate, and the circuit pattern in the central portion is stuck in an extended state, so that the dimensional accuracy of the circuit pattern is deteriorated.

  In order not to reduce the dimensional accuracy of the circuit pattern, it is important to press the short side width of the wide flexible film substrate with high flatness, but as the width of the flexible film substrate increases, the flatness of the circuit pattern increases. Adjustment becomes difficult. When a metal is used as the material for the heating and pressurizing means, the metal is deformed due to thermal expansion due to the heating temperature, so the metal is usually processed and maintained flat at the heating temperature at the time of joining. It is difficult to secure.

  Separating each circuit pattern row is effective even when the flatness of the heating and pressurizing means is reduced. This is because each circuit pattern is discontinuous, so that the expansion and contraction of the flexible film substrate does not propagate even when there is a time difference in the pressing of the heating and pressing means. Although it is preferable from the point of productivity that the heating and pressing tool can heat and press all circuit patterns at once, the flatness of the circuit pattern row is ensured as the number of circuit pattern rows increases, that is, the length of the heating and pressing means increases. In this case, the length of the heating and pressing means having the same length as each circuit pattern is desirable. In this case, it is desirable that the arrangement of the heating and pressurizing means is an alternating arrangement, that is, a staggered arrangement with respect to a plurality of circuit patterns.

  Regarding the staggered arrangement, it is desirable to arrange the heating and pressing means at a distance that is an integral multiple of the length of the strip-shaped flexible film substrate. From the viewpoint of shortening the apparatus length, 1 time is more preferable. For example, when the heating and pressurizing means for joining the odd-numbered strip-shaped flexible film substrates is arranged on the upstream side, the heating and pressurizing means for joining the even-numbered strip-shaped flexible film substrates is a strip-like shape. The length of the flexible film substrate is arranged on the downstream side. By arranging in this way, when the even-numbered strip-shaped flexible film substrates are heated and pressurized, the odd-numbered strip-shaped flexible film substrates on the upstream side can be simultaneously heated and pressurized. Therefore, the same productivity as the case where all the target strip-like flexible film substrates are heated and pressed at a time can be obtained.

  Next, although the manufacturing method of the flexible film board | substrate used for this invention is demonstrated below, it is not limited to this. Here, a strip-shaped film substrate is bonded to a reinforcing plate via a peelable adhesive layer, and after forming a high-definition circuit pattern, peeling from the reinforcing plate forms multiple rows of circuit patterns on at least one side. To do. The circuit pattern is preferably formed mainly of a copper film having a small resistance value, and known techniques such as a subtractive method, a semi-additive method, and a full additive method can be employed. Furthermore, tin plating and gold plating for solder bonding can be performed, and a solder resist film for protecting the metal layer can be formed as appropriate. Thereafter, an adhesive layer is formed on the upper surface of the downstream end conveyed in the joining step, and then peeled off from the reinforcing plate to obtain a strip-shaped film substrate.

  A plastic film is used as the flexible film. For example, films such as polycarbonate, polyether sulfide, polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyimide, polyamide, and liquid crystal polymer can be employed. Among these, a polyimide film is preferably used because it is excellent in heat resistance and chemical resistance. In addition, a liquid crystal polymer is preferably used in terms of excellent electrical characteristics such as low dielectric loss and low hygroscopicity. It is also possible to employ a flexible glass fiber reinforced resin plate. Moreover, these films may be laminated | stacked.

  Examples of the resin for the glass fiber reinforced resin plate include epoxy, polyphenylene sulfide, polyphenylene ether, maleimide (co) polymer resin, polyamide, and polyimide.

  The thickness of the flexible film is preferably thin for light weight, downsizing, or formation of fine via holes. On the other hand, the thickness of the flexible film is preferably thick for ensuring mechanical strength and maintaining flatness. From a preferable point, the range of 4 μm to 125 μm is preferable.

  As the sheet reinforcement plate, inorganic glass such as soda lime glass, borosilicate glass and quartz glass, ceramics such as alumina, silicon nitride and zirconia, stainless steel, invar alloy, titanium and other metals and glass fiber reinforced resin Those having a small linear expansion coefficient and hygroscopic expansion coefficient, such as a plate having the same, are preferable. Among these, inorganic glass and a metal plate are preferable in that appropriate flexibility can be easily obtained. The thickness of the inorganic glass substrate is preferably in the range of 0.3 mm to 1.1 mm in consideration of cracking prevention due to handling and handling properties.

  Examples of the peelable organic layer for bonding the reinforcing plate and the flexible film substrate include an adhesive called an acrylic or urethane re-peeling agent. Adhesive strength is sufficient during processing of flexible film substrate, it can be easily peeled off at the time of peeling, and it does not cause distortion in flexible film substrate. preferable. A silicone resin having tackiness can also be used. It is also possible to use an epoxy resin having tackiness.

  The thickness of the peelable organic material layer is preferably 0.1 μm or more, and more preferably 0.3 μm or more because the flatness becomes worse as the thickness becomes thinner and the unevenness of the peeling force due to the unevenness of the film thickness occurs. Further preferred. On the other hand, when the thickness of the peelable organic material layer is increased, the anchoring property of the organic material layer on the flexible film substrate is improved, so that the adhesive strength is increased. Therefore, it is preferably 20 μm or less, and more preferably 10 μm or less.

  For example, a peelable organic material is applied to soda lime glass having a thickness of 1.1 mm as a sheet-fed reinforcing plate using a spin coater, a blade coater, a roll coater, a bar coater, a die coater, screen printing, or the like. Use of a die coater is preferable in order to uniformly apply to a single-wafer substrate sent intermittently. After the peelable organic material is applied, the organic layer is dried by heat drying or vacuum drying to obtain a peelable organic material layer having a thickness of 2 μm, for example. An air barrier film made of a release film (a silicone resin layer is provided on a polyester film) is bonded onto the applied peelable organic layer and left at room temperature for 1 week. This period is called aging, and the cross-linking of the peelable organic substance proceeds and the adhesive force gradually decreases. The standing period and the storage temperature are selected so that a desired adhesive strength can be obtained. Instead of laminating the air blocking film, it can be stored in a nitrogen atmosphere or in a vacuum. It is also possible to apply a peelable organic substance to a long film substrate, dry it, and then transfer it to a reinforcing plate.

  Next, for example, a flexible film having a thickness of 25 μm is prepared. The air blocking film on the glass substrate is peeled off, and the flexible film is bonded to the glass substrate. A metal layer (which may be a circuit pattern on the bonding surface) may be formed in advance on one or both sides of the flexible film. The flexible film may be pasted in a cut sheet having a predetermined size, or may be pasted and cut while being unwound from a long roll. In such a pasting operation, the flexible film is held on the surface of the flexible planar body and then pressed against the glass substrate, so that the flexible film can be applied to the glass substrate side with low stress and high accuracy. A laminating method can be suitably employed. An example of a laminating apparatus used in the above method will be described with reference to FIG.

  FIG. 4 is a schematic front view of a laminating apparatus 400 that can be preferably used in the present invention. The flexible sheet 402 is charged by the electrostatic charging device 401 and the flexible film 403 is adsorbed. A flexible fabric or thin film can be used for the flexible planar body 402 and is fixed to the frame body 404. Further, the electrostatic charging device 401 is supported by a support column 406 on the base 405, and the support column 406 is electrostatically charged with the frame 404 and the mounting table 407 that move to the left and right in FIG. 4 by a vertical movement mechanism (not shown). The device 401 moves so as not to interfere. Next, the glass substrate 409 on which the peelable organic layer 408 is applied is held on the mounting table 407 by vacuum suction or the like. The squeegee 410 presses the flexible film 403 together with the flexible planar body 402 against the peelable organic material layer 408, and the flexible film 403 is transferred to the glass substrate 409 side. The squeegee 410 is held by a squeegee holder 411 and can move and move up and down. The mounting table 407 can be moved to the left and right in the figure by a rail 412, a guide 413, a nut 414, brackets 415 and 416, a ball screw 417, and a motor 418.

  As a method for forming a circuit pattern, when a metal layer is not provided on the surface opposite to the bonding surface of the flexible film, the metal layer is formed by a full additive method or a semi-additive method. Furthermore, if necessary, plating with gold, nickel, tin or the like is performed to obtain a circuit pattern.

  Next, a solder resist layer is formed on the circuit pattern. As the solder resist, a photosensitive solder resist or a thermosetting solder resist is preferable. Among these, it is more preferable to use a photosensitive solder resist for the fine circuit pattern. A photosensitive solder resist is applied onto the circuit pattern with a spin coater, blade coater, roll coater, bar coater, die coater, screen printing machine, etc., dried, and then exposed to ultraviolet rays through a predetermined photomask and developed. Thus, a solder resist pattern is obtained. Next, curing is performed at 100 ° C. to 200 ° C.

  When creating a circuit pattern, the processing is performed using a design in which the same circuit pattern is repeatedly arranged in two dimensions, and the circuit pattern is formed in a strip shape in which the circuit pattern is arranged one-dimensionally before the flexible film substrate is peeled off. A sheet-fed flexible film substrate can be produced by separating the attached flexible film substrate and then peeling the flexible film substrate from the glass substrate. The normal circuit pattern is arranged at a uniform interval in one dimension from the viewpoint of productivity in the next process for mounting the semiconductor chip. For cutting the flexible film substrate, a laser, a high-pressure water jet, a cutter, or the like can be used. The glass substrate is also cut into strips and then peeled off, which can reduce the size of the apparatus and is a preferable mode.

  The overlapping width of the short side edge of the strip-shaped film substrate is preferably 4.75 mm or less, which is a gap between feed holes, from the viewpoint of reducing the loss of the circuit pattern. It is preferable to make it smaller than the overlapping width of the flexible film so as not to protrude from the joint portion of the flexible film substrate. The adhesive used for the adhesive layer is preferably an adhesive that can obtain a high adhesive force with a small area and is less likely to cause thermal distortion during bonding. In addition, a short time required for bonding is also an important requirement for ensuring productivity. Therefore, although a hot-melt adhesive, a photocurable adhesive, etc. can be suitably employed for the adhesive layer in addition to the pressure-sensitive adhesive, a hot-melt adhesive is preferred in that a high adhesive force can be realized. If the thickness of the adhesive layer is too large, the level difference at the joining portion becomes large, and the flatness of the circuit pattern before and after the joining portion is impaired. This causes a vacuum suction failure and an electrical inspection probe contact failure. On the other hand, if the thickness of the adhesive layer is too small, sufficient strength cannot be obtained.

  Therefore, the thickness of the adhesive layer is preferably in the range of 1 μm to 20 μm, and more preferably in the range of 2 μm to 10 μm. The adhesive layer can be supplied in the form of a sheet or paste. The organic material in the form of paste can be applied directly to the flexible film circuit board with a nozzle or the like in terms of reducing processing steps and simplifying the equipment. It is preferable to do.

  From the above, the overlapping width of the short-side end portion of the strip-shaped film substrate is influenced by the employed adhesive layer, but is preferably 0.8 mm or more so that sufficient joining strength can be obtained.

  FIG. 5 is a schematic front view of a peeling apparatus 500 for explaining a preferred method of peeling a flexible film from a reinforcing plate. Using the apparatus shown in FIG. 5, the flexible film is peeled along a curved surface obtained by cutting a part of a cylindrical shape, and the peel angle formed by the reinforcing plate and the flexible film substrate is kept at an acute angle. The method of peeling a flexible film board | substrate from an edge part in the state which carried out can be mentioned.

  First, the flexible film substrate is set so that the reinforcing plate 501 side comes to the stage 505 (not shown). The stage 505 is raised by an air cylinder (not shown), and the peeling start position of the flexible film substrate 503 bonded to the reinforcing plate 501 via the peelable organic layer 502 and a predetermined position of the curved surface 504 (FIG. 5). The middle S). One end of the flexible film substrate 503 is held by a vacuum chuck or the like built in the curved surface 504, and then the movable body 506 holding the curved surface is rotated to bring the flexible film substrate along the curved surface 504. Peel off. At this time, in synchronization with the rotation of the movable body 506, the stage 505 moves rightward on the rail 508, and moves the peeling point leftward on the substrate. After the peeling is completed, the holding body 507 is moved rightward along the rail 508, and the flexible film substrate peeled off on the stage 509 is taken out to manufacture the single wafer flexible film substrate.

  The cut at the short side edge of the strip-shaped film substrate can be formed using, for example, a laser. The laser device has the function of measuring the position of multiple marks on the work piece and irradiating the predetermined position calculated from the position with high precision, so that the circuit pattern and wiring in the film substrate A notch can be formed by recognizing a plurality of patterns and irradiating a predetermined position with laser. By irradiating the laser in a state of being bonded to the reinforcing plate, the position of the circuit pattern in the film substrate can be recognized with high accuracy, and high cutting position accuracy can be realized. After the strip-shaped film substrate is peeled off from the reinforcing plate using the peeling device described below, for example, the film substrate is sucked to the suction stage and formed by laser irradiation, or by a rotary blade or a guillotine cutter. A cut can be formed at the short side edge of the film substrate.

  The cut length is preferably equal to or greater than the overlapping width of the short side edge of the strip-shaped film substrate. However, when the length is long, the circuit pattern at the short side end portion of the strip-shaped flexible film hangs down due to its own weight due to the cuts on both sides, and it becomes more difficult to transport the strip-shaped film substrate. Although it depends on the thickness and physical properties of the flexible film and the width of the circuit pattern, it is preferable that the width is not more than twice the overlapping width because sufficient handling can be performed.

  When the cut width is a strip-shaped film substrate having a plurality of rows of circuit patterns, and then cut into single rows, a positional shift occurs between the cut portions and the separated cut portions, and the single row film A wide width is set so that the film does not fall off due to misalignment from the outer edge of the substrate. However, if the cut width is set too wide, the length in the short side direction of the joint portion due to the adhesive layer is shortened, so that the joint strength is reduced and the film is liable to be twisted when the film substrate is transported after a single row. Therefore, it is not preferable. Since the general cutting accuracy in a single row separation cutting process using a slit device or the like is ± 0.15 mm to ± 0.2 mm, the minimum width of the cutting width can be determined in consideration of the cutting accuracy. Preferably, 0.3 mm to 0.4 mm is preferable.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to these.

Example 1
A long polyimide film (“Kapton” 100EN (trade name) manufactured by Toray DuPont Co., Ltd.) having a thickness of 25 μm was prepared as a flexible film substrate. A 150 nm thick chromium: nickel = 20: 80 (weight ratio) alloy film and a 850 nm thick copper film were laminated in this order on a polyimide film by a reel-to-reel type sputtering apparatus compatible with long films. .

  An ultraviolet curable adhesive “SK Dyne” SW-11A (manufactured by Soken Chemical Co., Ltd.) and a curing agent L45 (Soken Chemical Co., Ltd.) were applied to soda lime glass having a thickness of 1.1 mm and 320 × 350 mm as a reinforcing plate with a die coater. Co.) was mixed at 100: 3 (weight ratio) and dried at 80 ° C. for 2 minutes. The peelable organic layer thickness after drying was 2 μm. Next, an air blocking film (a film in which a silicone resin layer that can be easily released on a polyester film) was bonded to the organic layer, and left for one week.

A polyimide film provided with a metal layer was cut out to 320 × 350 mm. After the air blocking film on the glass was peeled off, a polyimide film provided with a metal layer on an organic material layer that can be peeled off with a laminator shown in FIG. 4 was bonded. The flexible sheet 402 made of polyester mesh was charged by the electrostatic charging device 401, and the flexible film substrate 403 was adsorbed. Next, the glass substrate 409 on which the peelable organic layer 408 was applied was held on the mounting table 407 by vacuum suction. The polyimide film was pressed against the peelable organic layer 408 together with the squeegee 410 together with the flexible planar body 402, and the polyimide film 403 was transferred to the glass substrate 409 side. Thereafter, the organic layer was cured by irradiating with 3000 mJ / cm ^{2 of} ultraviolet rays from the glass substrate side.

  A positive photoresist was applied onto the copper film with a spin coater and dried at 80 ° C. for 10 minutes. The photoresist was exposed and developed through a photomask to form a photoresist layer having a thickness of 12 μm in a portion where a plating film was unnecessary.

  The test photomask pattern had the following shape. On two long sides of a 19.3 mm × 2.5 mm rectangle, 772 wires (width 10 μm, length 5 mm) per side were arranged as inner leads at a pitch of 25 μm. 772 wirings (width 25 μm, width 25 μm, each side) at a pitch of 50 μm so that the outermost end is in contact with the two long sides of the rectangle 38.6 mm × 20 mm in the same center as the rectangle of 19.3 mm × 2.5 mm. 100 μm in length) were arranged as outer leads. One unit was formed by connecting the inner lead and the outer lead with a one-to-one wiring having a width of 10 μm. This unit was arranged with 6 rows of circuit patterns at a 48 mm pitch, equally distributed from the center in the direction in which the glass substrate had a length of 320 mm. The distance between the circuit pattern rows was 0 mm. Fourteen glass substrates were arranged at a pitch of 23.75 mm, equally spaced from the center in the 350 mm length direction.

  Next, a copper layer having a thickness of 8 μm was formed by electrolytic plating in a copper sulfate plating solution using the copper film as an electrode. The photoresist was stripped with a photoresist stripping solution, and then the copper film and the chromium-nickel alloy film that were under the resist layer were removed by soft etching with a hydrogen peroxide-sulfuric acid aqueous solution. Subsequently, a tin layer having a thickness of 0.4 μm was formed on the copper plating film by electroless plating to obtain a circuit pattern. Then, in order to protect a circuit pattern, solder resist SN-9000 (made by Hitachi Chemical Co., Ltd.) was formed on the circuit pattern with the screen printer. Cure at 120 ° C. for 90 minutes in an oven to obtain a 10 μm thick solder resist layer.

  Next, an adhesive layer was formed on the end of the short side in the connecting and conveying direction of the single-wafer flexible film substrate. The resin for the adhesive layer was prepared as follows. 1,1,3,3-tetramethyl-1,3-bis (3-aminopropyl) disiloxane was added to a reaction kettle equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device using hot water / cooling water and a stirring device. 24.9 g (0.1 mol) and 4,4′-diaminodiphenyl ether 180.2 g (0.9 mol) were charged with 2813 g of N, N-dimethylacetamide and dissolved, and then 3,3 ′, 4,4′- 291.3 g (0.99 mol) of biphenyltetracarboxylic dianhydride was added and reacted at room temperature for 1 hour and then at 70 ° C. for 5 hours to obtain an adhesive comprising a 15% by weight polyamic acid solution.

  Using the dispenser device FAD-320S manufactured by Musashi Engineering Co., Ltd., the center line of the adhesive layer having a width of 0.7 mm is positioned 2 mm inside from the short side edge of the flexible film substrate. After coating, it was semi-cured in a baking oven at 120 ° C. for 2 minutes. The thickness of the adhesive after semi-curing was 2 μm.

  Subsequently, the YAG laser was used to cut the overlapping portion of the short side end portion of the flexible film substrate and to externally process the 48 mm width circuit pattern into three rows and three rows. Since the overlapping width of the flexible film substrate is 1 mm, the adhesive layer is formed by cutting 0.1 × 1.5 mm (0.1 mm width, 1.5 mm is the length in the film longitudinal direction). It was formed between the circuit pattern rows formed at a 48 mm pitch at four places on the short side end portion. Then, the flexible film substrate was peeled from the glass substrate with the peeling apparatus shown in FIG. 5, and the single wafer flexible film substrate was produced.

  This single-wafer flexible film substrate is sequentially aligned on the carrier shown in FIG. 2, and adjacent flexible films are arranged so that an adhesive layer is disposed under the wiring pattern of the flexible film circuit board as shown in FIG. The heat resistant film circuit board is overlaid and heat-pressed from the side of the flexible film substrate on which the adhesive layer is formed using a ceramic heater having a length of 150 mm and a width of 1.5 mm as a heating and pressurizing means at 350 ° C. for 10 seconds. Flexible film circuit boards were joined together. This was repeated 30 times in order to produce a wide long film circuit board. Next, it cut | disconnected to the 48 mm width long film circuit board using the cutting device. In this case, a cut is present on the cut portion. At this time, when all the overlapping portions were visually confirmed, there was no film dropout at the outer edge portion of the flexible film circuit board due to the formation of the notches in the overlapping portions.

  After cutting out 90 mm before and after 50 mm in the longitudinal direction of the film substrate in the joining portion, each piece is sandwiched between two flat glasses to ensure flatness, and the length measuring machine SMIC-800 (manufactured by Sokkia Co., Ltd.) is used. Then, the distance between the center in the width direction (design value 29.3 mm) of the outermost inner leads arranged in the overlapping portion was measured. The dimensional accuracy was set to ± 0.02% so that the connection between the electrode pad and the probe for electrical connection inspection can be surely performed. In all the connecting portions, it was -1.3 μm to +3.4 μm (± 0.02%: ± 5.86 μm) with respect to the design value, and the positional accuracy was good.

  Moreover, the tensile test of 90 places of the joining parts after dimensional accuracy measurement was performed, and the tensile strength was measured. Tensile strength of 0.051 N or more, which does not cause a peeling failure during film transport after chip joining or chip mounting, was considered good. The tensile test apparatus used was Tensilon “ORINTEC” RTC-1250A, and the tensile test conditions were a load of 500 N and a tensile speed of 300 mm / min. As a result, the average value was 0.181N, the minimum value was 0.11N, and the tensile strength of all the joints was good.

Example 2
The flexible film circuit board was connected as shown in FIG. 3 as in Example 1 except that the cut was made 2 mm in the longitudinal direction with a rotary blade having a width of 0.5 mm, and the same evaluation as in Example 1 was performed. went. When all the overlapping portions of the 48 mm wide long film circuit board were visually confirmed, there was no film dropout at the outer edge of the flexible film circuit board due to the formation of the cuts in the overlapping portions.

  The dimension of the center distance in the width direction (design value 29.3 mm) of the outermost outer lead of the joint portion by a length measuring machine SMIC-800 (manufactured by Sokkia Co., Ltd.) is from -1.1 μm to +4 with respect to the design value. It was found to be 2 μm (± 0.02%: ± 5.86 μm), and the positional accuracy was good. Moreover, as for the result of the connection strength of the width of 48 mm, the average value was 0.104 N and the minimum value was 0.086 N, and the tensile strength of all the connection portions was good.

Example 3
A flexible film substrate was produced in the same manner as in Example 1 until an adhesive having a thickness after semi-curing of 2 μm was formed. Subsequently, a circuit pattern having a width of 48 mm was processed into three rows and three rows using a YAG laser. Then, the flexible film substrate was peeled from the glass substrate with the peeling apparatus shown in FIG. 5, and the single wafer flexible film substrate was produced.

  After that, using a die that can be cut into a width of 2 mm and a length of 2 mm, cuts were formed between the circuit pattern rows formed at 48 mm pitch at four locations on the short side end where the adhesive layer was not formed. .

  This single-wafer flexible film substrate is sequentially aligned on the carrier shown in FIG. 2, and adjacent flexible films are arranged so that an adhesive layer is disposed under the wiring pattern of the flexible film circuit board as shown in FIG. The heat resistant film circuit board is overlaid and heat-pressed from the side of the flexible film substrate on which the adhesive layer is formed using a ceramic heater having a length of 150 mm and a width of 1.5 mm as a heating and pressurizing means at 350 ° C. for 10 seconds. Flexible film circuit boards were joined together. This was repeated 30 times in order to produce a wide long film circuit board. Next, it cut | disconnected to the 48 mm width long film circuit board using the cutting device. In this case, a cut is present on the cut portion. At this time, when all the overlapping portions were visually confirmed, there was no film dropout at the outer edge portion of the flexible film circuit board due to the formation of the notches in the overlapping portions.

  The dimension of the center distance in the width direction (design value 29.3 mm) of the outermost outer lead of the joint portion by the length measuring machine SMIC-800 (manufactured by Sokkia Co., Ltd.) is from -1.6 μm to +4 with respect to the design value. The position accuracy was good at .6 μm (± 0.02%: ± 5.86 μm). Moreover, as for the result of the connection strength of the width of 48 mm, the average value was 0.124N, and the minimum value was 0.086N, and the tensile strength of all the connection portions was good.

Example 4
Ceramic heaters with a length of 48.5 mm and a width of 1.5 mm are connected in a staggered manner so that the first and third rows of heating and pressing means are upstream, the second row is downstream, and the distance between them is 50 mm. Except having used the apparatus, the flexible film circuit board was connected like FIG. 3 similarly to Example 1, and the same evaluation as Example 1 was performed. When all the overlapping portions of the 48 mm wide long film circuit board were visually confirmed, there was no film dropout at the outer edge of the flexible film circuit board due to the formation of the cuts in the overlapping portions.

  The dimension of the center distance in the width direction (design value 29.3 mm) of the outermost outer lead of the joint portion by the length measuring machine SMIC-800 (manufactured by Sokkia Co., Ltd.) is -1.0 μm to +3 with respect to the design value. It was found to be 2 μm (± 0.02%: ± 5.86 μm), and the positional accuracy was good. Moreover, as for the result of the connection strength of 48 mm width, the average value was 0.111 N and the minimum value was 0.093 N, and the tensile strength of all the connection portions was good.

Example 5
Similar to Example 1, except that a joining device using an impulse heater having a length of 150 mm and a width of 1.5 mm was used, flexible film circuit boards were joined as shown in FIG. Went. When all the overlapping portions of the 48 mm wide long film circuit board were visually confirmed, there was no film dropout at the outer edge of the flexible film circuit board due to the formation of the cuts in the overlapping portions.

The dimension of the center distance in the width direction (design value 29.3 mm) of the outermost outer lead of the joint portion by a length measuring machine SMIC-800 (manufactured by Sokkia Co., Ltd.) The positional accuracy was good, being 0.8 μm (± 0.02%: ± 5.86 μm). Moreover, as for the result of the connection strength of 48 mm width, the average value was 0.122N, the minimum value was 0.089N, and the tensile strength of all the connection portions was good.

Comparative Example 1
A flexible film circuit board is joined as shown in FIG. 3 in the same manner as in Example 1 except that the three rows of circuit patterns are not separated, that is, the cuts are not formed as in the present invention. The same evaluation was performed.

  The dimension of the center distance in the width direction (design value 29.3 mm) of the outermost outer lead of the joint portion by the length measuring machine SMIC-800 (manufactured by Sokkia Co., Ltd.) is +0.6 μm to +10. 6 μm and acceptance criteria ± 0.02% (± 5.86 μm) could not be satisfied. As for the joint strength, the average value was 0.146 N and the minimum value was 0.079 N, and the tensile strength of all joint portions was good.

It is a front view which shows an example of the flexible film board | substrate connection of this invention. It is the schematic which shows an example of the method of joining a flexible film. It is sectional drawing of a joining part. It is a conceptual diagram which shows an example of the sticking apparatus of the flexible film to a reinforcement board. It is a conceptual diagram which shows an example of the peeling apparatus of a flexible film from a reinforcement board.

Explanation of symbols

1, 2, 201, 202, 503: flexible film substrate 3: feed hole 4, 213: adhesive layer 5: notch 6: circuit pattern row 8, 220: splicing and conveying directions 10, 20, 403: flexible film 15, 16: Circuit pattern or wiring pattern 17: Solder resist 211, 212: Transport table 214, 215: Suction arm 216a, 216b: Heating and pressing means 400: Pasting (laminating) device 401: Electrostatic charging device 402: Flexible Property surface 404: frame 407: mounting table 408, 502: peelable organic layer 409, 501: glass substrate 410: squeegee 412: rail 500: peeling device 504: curved surface 505: stage 506: movable body 507: Holder 508: Rail

Claims (6)

A flexible film substrate in which a plurality of strip-shaped flexible film substrates having at least two rows of circuit patterns arranged on one side are aligned and the short side edges of each other are joined together via an adhesive layer. A film circuit board having a notch between the circuit patterns of each row in the overlapping portion of the overlapping short side end portion. A flexible film substrate in which a plurality of strip-shaped flexible film substrates having at least two rows of circuit patterns arranged on one side are aligned, and the short side edges of each other are joined together via an adhesive layer. A method of manufacturing a film circuit board, wherein a cut is provided between circuit patterns in each row in an overlapping portion at a short side end portion to be overlapped before overlapping. A wiring pattern is not formed on the flexible film in the overlapping portion, and a wiring pattern is formed on the flexible film in the overlapping portion on the first flexible film substrate on which the adhesive layer is formed. The second flexible film substrate is overlapped, and the adhesive layer is heated and pressed by pressing the heating and pressing means from the flexible film substrate side of the second flexible film substrate. Item 3. A method for producing a film circuit board according to Item 2. The method for producing a film circuit board according to claim 3, wherein the adhesive layer is heated and pressurized by a heating and pressing means of a ceramic heater or an impulse heater. 5. The heating and pressurizing means as many as the number of circuit pattern rows arranged on the flexible film substrate are arranged in a staggered shape, and bonding is performed in two times. 6. A method for producing a film circuit board. A plurality of strip-shaped flexible film substrates having at least two rows of circuit patterns arranged on one side are aligned, and the intervals between the circuit patterns arranged between the short side edges of each other than the overlapping portion A method of manufacturing a film circuit board in which a circuit pattern is cut and separated into a single row or a predetermined plurality of rows after being bonded with an adhesive layer so as to be the same as the arrangement interval of circuit patterns, and before the bonding A method for producing a film circuit board, comprising: forming a notch between each circuit pattern in an overlapping portion of the circuit pattern of the short side end portion to be overlapped with each other.

Images