JP4559367B2 - Substrate connecting tape and printed circuit board manufacturing method using the substrate connecting tape - Google Patents

Description

  The present invention relates to a substrate connecting tape and a method of manufacturing a printed circuit board using the same. More specifically, the present invention relates to a substrate connection tape that can be electrically connected to a sheet-like substrate material, and can be electroplated, electrodeposited, and the like, and then easily separated into a sheet-like substrate material, and a method for manufacturing a printed board.

  In recent years, flexible substrates (flexible printed wiring boards) have been used in mobile phones, liquid crystal displays, digital cameras, hard disks, and many other electronic devices. Because of its flexibility, it is indispensable for use in hinges and movable parts, or for compactly storing a wiring board in equipment. However, due to its flexibility, when a flexible substrate is manufactured by a conveying means using a sheet-like flexible substrate material, conveyance troubles such as winding, dropping, and skewing frequently occur. The sheet-like substrate material cannot be transferred by a simple transfer mechanism as can be seen.

  A typical configuration of the flexible substrate material is a so-called three-layer material of insulating film / adhesive layer / copper foil such as polyimide or liquid crystal polymer (in the case of double-sided board, copper foil / adhesive layer / insulating film / adhesive layer). / Copper foil) is the mainstream, but in recent years two-layer materials without an adhesive layer are increasing, but the flexibility becomes higher and the conveyance trouble is more serious than the three-layer material. Further, the thickness of copper foil and insulating film is expected to become thinner in the future, and roll-to-roll processing is preferable in order to ensure transportability.

  However, roll-to-roll processing requires enormous capital investment, so some processes are processed with sheet-like materials, and then sheet-like materials are connected and processed into roll-like materials. There is a request. For example, laser drilling a sheet-like material, then plating it into a roll-like material, laminating or applying a photoresist, and after pattern exposure, after alkali development, etching, resist removal process, it is separated into a sheet-like material Flow is a typical workflow. In this flow, when electrolytic plating is performed, it is necessary to electrically connect between the sheet-like substrate materials using a jig or using a conductive tape (for example, a metal tape). In addition, because of excellent uniformity, a photosensitive resin composition having an ion-forming group may be electrodeposited. In this case as well, a jig is used or a conductive tape is used to conduct a conductive material between sheet-like substrate materials. Need to connect. The attachment and detachment of the jig is a very time-consuming operation, which is not preferable in terms of work efficiency. Further, when the conductive tape is separated into a sheet-like material, a process of cutting or peeling the tape is required. At that time, in the case of the flexible substrate material, there are problems such as deformation, elongation, tearing, or dust generation.

By connecting the substrates with a substrate connecting tape in which a layer that dissolves in the etching solution, a layer that dissolves in the resist removal solution and has etching resistance, and a layer that dissolves in the resist removal solution and has adhesiveness are laminated. In addition, a technique for eliminating the non-uniform phenomenon of etching is disclosed, and at the same time, the transportability in the alkali development / etching process is greatly improved, and the sheet material is deformed, stretched, and torn. In addition, harmful effects such as dust generation have been improved. However, when the sheet-like substrate material is connected with these substrate-connecting tapes, the sheet-like substrate material is insulated, and a new technique for conducting conductive connection has been demanded (for example, see Patent Document 1).
JP 2004-43848 A

  The object of the present invention is to provide a printed circuit board connecting tape that can be electrically connected to a sheet-like board material, and can be electroplated, electrodeposited, etc., and then easily separated into a sheet-like board material, and a method for producing the printed board. There is to do.

  As a result of investigations by the inventors, at least a metal layer that dissolves in the etching solution, a layer that dissolves in the resist removal solution and has etching resistance, and a layer that dissolves in the resist removal solution and has adhesiveness are sequentially stacked. A substrate connecting tape, comprising: a region having both a layer that dissolves in a resist removing solution and has etching resistance and a layer that dissolves in a resist removing solution and has no adhesive layer It has been found that the above problems can be solved with a tape.

  Alternatively, a substrate connecting tape in which at least a metal layer that dissolves in an etching solution, a layer that dissolves in a resist removal solution and has etching resistance, and a layer that dissolves in a resist removal solution and has adhesive properties are sequentially laminated. In a method of manufacturing a printed circuit board in which edges in the transport direction of a sheet-like substrate material are connected to each other and transported, the layer is dissolved in a resist removal solution and has an etching resistance and is dissolved in a resist removal solution and has adhesiveness. It has been found that the above-mentioned problems can be solved by a method for producing a printed circuit board characterized in that conductive connection is made between sheet-like board materials with a board-connecting tape having a region where both layers are absent.

  As a preferred embodiment, the region having neither the layer that dissolves in the resist removing solution and has etching resistance and the layer that dissolves in the resist removing solution and has no adhesive layer has a size that can include a circle having a diameter of 2 mm. Has found that the above-mentioned problems can be solved.

  According to the present invention, there is provided a printed circuit board connecting tape that can be electrically connected to a sheet substrate material, and can be electroplated, electrodeposited, etc., and then easily separated into a sheet substrate material, and a method for manufacturing the printed circuit board. can do.

  The best mode for carrying out the present invention will be described in detail below. In the present invention, the metal layer dissolved in the etching solution of the substrate connecting tape is made of a metal material such as copper, silver, aluminum, stainless steel, nichrome, iron and tungsten, copper, iron, chromium, zinc, tin or the like. Any conductive metal such as an alloy can be used. For example, if it is a printed circuit board for forming a copper wiring circuit, it is easier to use the same metal and solubility as the circuit, so copper can be used suitably. The thickness of the metal layer dissolved in the etching solution is 1 to 200 μm, preferably 5 to 50 μm.

  In the present invention, the layer that dissolves in the resist removal solution and has etching resistance has at least a property of not dissolving or swelling in the etching solution, and has a strength that can withstand those spray pressures. All of this layer is removed in the middle of the resist removal section. Examples of the layer that dissolves in such a resist removing solution and has etching resistance include, for example, a dry film resist film obtained by curing a photosensitive layer from which a support film and a protective film are peeled off by heat or ultraviolet irradiation, or a liquid photoresist. And a film cured by heat or ultraviolet irradiation after drying. In addition, films and polyvinyls having a carboxylic acid group, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, a sulfonimide group, and a phosphonic acid group, which are soluble in a strong alkali made of acrylic resin, epoxy resin, urethane resin, phenol resin, etc. Alcohol etc. are mentioned. The thickness of the layer dissolved in the resist removing solution and having etching resistance is 1 to 200 μm, preferably 5 to 100 μm.

  In the present invention, the layer that is dissolved in the resist removing solution and has adhesiveness plays a role of adhering the substrate connecting tape and the substrate, and is quickly removed by the resist removing unit when etching is no longer necessary. The If necessary, the adhesiveness may be increased by heating. Examples of such a layer include an adhesive resin mainly composed of an acrylic resin, an epoxy resin, a urethane resin, a phenol resin, and the like. These adhesive resins contain a monomer having a carboxylic acid group, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, a sulfonimide group, or a phosphonic acid group because they need to be dissolved or swelled in the resist removing solution. Specific examples of the adhesive resin include styrene / maleic acid monoalkyl ester copolymer, methacrylic acid / methacrylic acid ester copolymer, styrene / methacrylic acid / methacrylic acid ester copolymer, acrylic acid / methacrylic acid ester copolymer. , Methacrylic acid / methacrylic acid ester / acrylic acid ester copolymer, styrene / methacrylic acid / acrylic acid ester copolymer, styrene / acrylic acid / methacrylic acid ester copolymer, vinyl acetate / crotonic acid copolymer, vinyl acetate Styrene, acrylic acid ester, methacrylic acid ester, vinyl acetate, vinyl benzoate, etc., and carboxylic acid-containing monomers such as / crotonic acid / methacrylic acid ester copolymer, vinyl benzoate / acrylic acid / methacrylic acid ester copolymer And a copolymer thereof. Moreover, you may contain plasticizers, such as polyethyleneglycol, polypropylene glycol, diethyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, tributyl citrate, triethyl citrate, acetyl triethyl citrate. Moreover, in order to improve visibility, you may contain dye and a pigment. Moreover, you may use the dry film resist which consists of an unhardened photosensitive layer which peeled the support film and the protective film as a layer which melt | dissolves in a resist removal liquid and has adhesiveness. As a general resist film, for example, Liston from DuPont MRC Dry Film Co., Ltd., Fotec from Hitachi Chemical Co., Ltd., Sunfort from Asahi Kasei Electronics Co., Ltd. can be used. The thickness of the layer that dissolves in the resist removal solution and has adhesiveness is 1 to 200 μm, preferably 5 to 100 μm.

  In a preferred embodiment of the present invention, the substrate connecting tape is a region (referred to as region A) in which both the layer that dissolves in the resist removing solution and has etching resistance and the layer that dissolves in the resist removing solution and has adhesive properties are not present. And region A may include a 2 mm diameter circle. The shape of the region A may be any shape as long as a circle with a diameter of 2 mm is included in the region A. If a circle having a diameter of 2 mm is not included in the region A, a conductive connection may not be obtained. 1-3 show an example of a region A in which a circle with a diameter of 2 mm is included. Furthermore, in the present invention, the region A is preferably included in a circle having a diameter of 10 mm. When the region A is large and is not included in a circle having a diameter of 10 mm, the conductive connection may be lost if the conductive connection portion is strongly bent. 1-3 shows an example in which the region A is included in a circle having a diameter of 10 mm. In the region A, in order to obtain a conductive connection in a stable and reproducible manner by bringing the metal layer of the sheet-like substrate material into contact with the metal layer of the substrate connection tape in the region A, the region A is a specific region. I found out that it needs to be large.

  A configuration example of the substrate connecting tape in the present invention is shown in FIG. A substrate connecting tape 4 in which a metal layer 5 dissolved in an etching solution, a layer 6 dissolved in a resist removing solution and having etching resistance, and a layer 7 dissolved in a resist removing solution and having an adhesive property are sequentially laminated. The layer having the same function may be composed of a plurality of layers. Moreover, as long as the subject of this invention is solved, the other layer may be contained.

  The substrate connecting tape of the present invention can be manufactured by any method as long as the above-described configuration is obtained. However, a layer that dissolves in a resist removing solution and has etching resistance is coated on or laminated on a metal foil. It is most convenient to manufacture by laminating or laminating an adhesive layer that is dissolved in the resist removing solution. In order to obtain the region A, it is necessary to coat or laminate both layers in a pattern. Any method known to those skilled in the art can be used as a method of coating or laminating in a pattern. A gravure printing method is simple as a method of coating in a pattern. As a method of laminating in a pattern, it is convenient to punch a film-like layer such as a dry film resist into a pattern by punching in advance, and then laminate.

  In order to obtain the region A, there is a method in which both layers are aligned as much as possible in the same pattern (for example, a pattern in which circles of 3 mm in diameter are arranged at equal intervals on a 15 mm wide tape) as shown in FIG. In the case of continuous production due to problems in accuracy of the apparatus and expansion / contraction of the material, positional displacement may occur. In addition, as shown in FIG. 6, the method of obtaining the region A by changing the shape, size, and spacing in both layers is not displaced due to expansion / contraction, but is dissolved in the resist removal solution and dissolved in the etching resistant layer or resist removal solution. However, there are many areas where either one of the layers having adhesiveness does not exist, and there is a risk of hindering the function of the substrate connecting tape. However, the area A has a size that can include a circle having a diameter of 2 mm. Any method can be used. Any other method may be used to manufacture a substrate connecting tape having a region in which both the layer that is dissolved in the resist removing solution and has etching resistance and the layer that is dissolved in the resist removing solution and has no adhesive layer.

  In this invention, the board | substrate connection tape connects the edge parts of the conveyance direction of sheet-like board | substrate material mutually with a board | substrate connection tape. The tape may be affixed on both sides or only on one side. 7 to 8 show a cross-sectional structure of a portion in which a sheet-like substrate material is connected to both sides or one side with a substrate connecting tape 4 and conductively connected. In the region A, the metal layer of the sheet-like substrate material and the metal layer of the substrate connection tape are in contact with each other to be conductively connected. 9 to 11 show examples of tape application. In the present invention, the edges of the sheet-like substrate material in the carrying direction, that is, the front and rear sides in the carrying direction are connected to each other with a substrate connecting tape. Any attachment method may be used as long as no conveyance failure occurs due to cutting, deformation, twisting, distortion, or the like during conveyance. The sheet-like substrate materials are preferably connected so as not to overlap. In actual production, it is difficult to align the edges without gaps, and it is preferable to connect the sheet-like substrate materials with an interval. The interval varies depending on the length, width, sticking method, adhesion to the material, process, etc. of the tape, and thus cannot be defined unconditionally. Preferably it is 5 mm or less. More preferably, it is 0.5 mm to 3 mm. Any method and apparatus may be used for connecting the sheet-like substrate materials with the substrate connecting tape as long as the materials can be reliably connected. In FIG. 9, the width of the sheet-like substrate material 11 is longer than the length of the substrate connecting tape 4, but in the present invention, there is no particular limitation on the relationship between the width of the sheet-like substrate material and the length of the substrate connecting tape. Absent.

  In the present invention, the substrate connecting tape is preferably applied by applying pressure while heating. Since it varies depending on the configuration and components of the substrate connecting tape, the material of the substrate, the size and shape of the region A, etc., the pasting conditions cannot be specified in general, but the temperature is 40 to 140 ° C. and 0.01 to 0.6 MPa. It is better to pressurize. When the temperature exceeds 140 ° C. or / and the pressure exceeds 0.6 MPa, the layer having the adhesive property and the adhesive layer flows, and the metal layer of the sheet-like substrate material and the metal layer of the substrate connecting tape May not be in contact with each other and a conductive connection may not be obtained. When the temperature is less than 140 ° C. or / and the pressure is less than 0.01 MPa, the bonding of the substrate connecting tape to the sheet-like substrate material may be insufficient, and the joined sheet-like substrate material may be separated. .

  When two sheet-like substrate materials are joined with one substrate joining tape as shown in FIG. 9, as shown in FIG. 12, the region A includes two sheet-like substrate materials to be joined and a substrate joining tape. It is sufficient if there are at least one place for each of the two bonding portions, but a plurality of places is more reliable. When two sheet-like substrate materials are joined with a plurality of substrate joining tapes as shown in FIGS. 10 to 11, at least one substrate joining tape includes two sheet-like substrate materials to be joined and a substrate joining tape. It is sufficient if there are at least one place for each of the two bonding portions, but a plurality of places is more reliable.

  In at least one of the two bonding portions, when the region A is at the edge of the board connecting tape as shown in FIG. 13 or when the region A is at the edge of the sheet-like substrate material as shown in FIG. Since a gas / liquid may enter or it may be susceptible to environmental changes, and conductive connection may not be obtained. As shown in FIG. 12, a layer that dissolves in a resist removal solution and has etching resistance and a resist removal solution It is preferable to have a region A that is surrounded by the region 10 in which both the layer dissolved and the adhesive layer are present and that is not on the edge portion of the substrate connecting tape and the sheet-like substrate material.

  In the present invention, the metal layer dissolved in the etching liquid of the substrate connecting tape is completely removed during the etching process, dissolved in the resist removing liquid and has etching resistance, and dissolved in the resist removing liquid and adhered. The layer having the property is completely removed in the course of the resist removal process, so that the substance constituting the substrate connecting tape is completely eliminated in the resist removal process and separated into a sheet-like substrate material. Therefore, a simple transport mechanism can be used in the process before the resist removal process, and if the transportability of only the resist removal process is improved, a flexible material can be transported stably and a printed circuit board can be manufactured. Can do.

  A commercially available dry film resist (resin film thickness 25 μm) is punched with circular holes having the diameters shown in Table 1 at equal intervals in the X and Y directions perpendicular to each other at a 50 mm pitch, and the protective film is peeled off to obtain a thickness of 18 μm. The resist film was cured by laminating on a copper foil and irradiating with ultraviolet rays. After the support film was peeled off, the protective film was peeled off from the dry film resist, which was similarly perforated, on the cured resist, and the holes were aligned (lamination error within 0.2 mm). This was cut into a rectangle with a width of 15 mm and a length of 480 mm to obtain a substrate connecting tape. At that time, the long side (480 mm side) was cut so as to be inclined by 1 ° from the Y direction.

  The tape for connecting substrates is used so that the distance between the long sides (500 mm sides) of the sheet-like substrate material (500 mm × 250 mm, copper foil thickness 12 μm, polyimide base material thickness 25 μm) having copper foil on one side is about 1 mm. After peeling off the support film, as shown in FIG. 9, the sheet-like substrate material is attached to the edge of the copper foil surface of the flexible substrate material by applying pressure at 0.1 MPa with a hot roll heated to 90 ° C. It connected and obtained the connection board | substrate (samples 2-5). Moreover, the connection board | substrate (sample 1) was obtained by the same method except not making the hole with the punch. In addition, the board | substrate connection tape was affixed only on one side like FIG.

  Using an electrometer 617 model manufactured by Keithley Instruments Co., Ltd., the electrical resistance between the sheet-like substrate materials adjacent to the connection substrate was measured at an applied voltage of 1V. Ten identical samples were prepared for each sample in Table 1, and the ratio (%) of the samples having an electrical resistance of less than 1Ω was defined as the conductive connection rate. The results are shown in Table 1. Note that the substrate connection tape of Sample 3 had a region A having a size capable of including a circle having a diameter of 2 mm. According to the present invention, it has been confirmed that the sheet-like substrate material can be reliably conductively connected.

  When the material was inserted into a processing machine that continued etching, resist stripping, washing with water, and drying the above connection board, the copper foil of the substrate connecting tape was dissolved and removed during the etching process, but the substrate material was strong. It was connected to. In the next resist stripping step, the substrate connecting tape was completely dissolved and removed, and the flexible substrate material was separated into a sheet and discharged from the processing machine.

  Open a square hole with the sides shown in Table 2 in a commercially available dry film resist (resin film thickness 25 μm), peel off the protective film, laminate it on a 12 μm thick copper foil, and irradiate with ultraviolet rays. The resist film was cured. After the support film was peeled off, the protective film was peeled off from the dry film resist which was similarly perforated on the cured resist, and laminated so that the holes overlapped (position error within 0.2 mm). The tape was cut into a circle with a diameter of 50 mm so that the hole was in the center, and a substrate connecting tape was obtained.

  At approximately the center of the sheet-like substrate material (100 mm × 100 mm, copper foil thickness 12 μm, polyimide base material thickness 25 μm) having copper foil on one side, the substrate connecting tape is peeled off and heated to 60 ° C. The applied hot roll was pressurized at 0.1 MPa and pasted on the copper foil surface to obtain pasted samples (samples 7 to 11). A pasted sample (sample 6) was obtained in the same manner except that no hole was formed.

  The electrical resistance between the sheet-like substrate material of the attached sample and the substrate connecting tape was measured with an applied voltage of 1 V using an electrometer type 617 manufactured by Keithley Instruments Co., Ltd. Ten identical samples were prepared for each sample in Table 2, and the ratio (%) of the samples with an electrical resistance of less than 1Ω was defined as the conductive connection rate. Next, for all samples for which the conductive connection ratio was measured, one side of the sample was supported and rocked vigorously for 5 minutes, and then the electrical resistance between the sheet substrate material and the substrate connecting tape was measured, The ratio (%) of the sample with a resistance of less than 1Ω was defined as the conductive connection rate after the forced test. The results are shown in Table 2. The region A of the substrate connecting tape of Sample 8 could include a circle with a diameter of 2 mm. According to the present invention, it has been confirmed that the sheet-like substrate material can be reliably conductively connected. The region A of the sample 10 was included in a circle with a diameter of 10 mm, but the region A of the sample 11 was not included in a circle with a diameter of 10 mm.

The top view of the area | region which does not have both the layer which melt | dissolves in the resist removal liquid of a board | substrate connection tape, and has etching resistance, and the layer which melt | dissolves in a resist removal liquid, and has adhesiveness. The top view of the area | region which does not have both the layer which melt | dissolves in the resist removal liquid of a board | substrate connection tape, and has etching resistance, and the layer which melt | dissolves in a resist removal liquid, and has adhesiveness. The top view of the area | region which does not have both the layer which melt | dissolves in the resist removal liquid of a board | substrate connection tape, and has etching resistance, and the layer which melt | dissolves in a resist removal liquid, and has adhesiveness. Sectional drawing of the tape for board | substrate connection. The top view of the board | substrate connection tape which has an area | region which does not have both the layer which melt | dissolves in a resist removal liquid, and has etching resistance, and the layer which melt | dissolves in a resist removal liquid, and has adhesiveness. The top view of the board | substrate connection tape which has an area | region which does not have both the layer which melt | dissolves in a resist removal liquid, and has etching resistance, and the layer which melt | dissolves in a resist removal liquid, and has adhesiveness. Sectional drawing of the part which connected the sheet-like board | substrate material with the tape for board | substrate connection on both surfaces. Sectional drawing of the part which connected the sheet-like board | substrate material with the tape for board | substrate connection on the single side | surface. The top view of the board | substrate connected with the tape for board | substrate connection. The top view of the board | substrate connected with the tape for board | substrate connection. The top view of the board | substrate connected with the tape for board | substrate connection. The top view of the board | substrate connected with the tape for board | substrate connection. The top view of the board | substrate connected with the tape for board | substrate connection. The top view of the board | substrate connected with the tape for board | substrate connection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circle with a diameter of 2 mm 2 Circle with a diameter of 10 mm 3 Region having both a layer that is dissolved in a resist removing solution of a substrate connecting tape and has etching resistance, and a layer that is dissolved in a resist removing solution and has an adhesive property Connecting tape 5 Metal layer dissolved in etching solution 6 Layer dissolved in resist removing solution and having etching resistance 7 Layer dissolved in resist removing solution and having adhesiveness 8 Dissolved in resist removing solution of substrate connecting tape In addition, there is a layer having an etching resistance, which is dissolved in the resist removing solution and there is no adhesive layer. 9 There is a layer which is dissolved in the resist removing solution and has an adhesive property, and is dissolved in the resist removing solution and is resistant to etching. 10 A region that does not have a property layer 10 A layer that dissolves in the resist removal solution of the substrate connecting tape and has an etching resistance, and a solution in the resist removal solution Area where both the undissolved and adhesive layers are present 11 Sheet-like substrate material 12 Metal layer of sheet-like substrate material 13 Insulating layer of sheet-like substrate material

Claims (4)

  In a tape for connecting substrates, in which at least a metal layer that is dissolved in an etching solution, a layer that is dissolved in a resist removal solution and has etching resistance, and a layer that is dissolved in a resist removal solution and has adhesiveness are sequentially laminated. A tape for connecting a substrate, characterized in that it has a region free from both a layer that dissolves in a resist removing solution and has etching resistance and a layer that dissolves in a resist removing solution and has an adhesive property.   At least a metal layer that dissolves in an etching solution, a layer that dissolves in a resist removal solution and has etching resistance, and a substrate connection tape in which a layer that dissolves in a resist removal solution and has adhesive properties is sequentially laminated. In a printed circuit board manufacturing method in which edges in the transport direction of a substrate-like substrate material are connected to each other and transported, a layer that dissolves in a resist removal solution and has etching resistance and a layer that dissolves in a resist removal solution and has adhesiveness A method for producing a printed circuit board comprising conducting conductive connection between sheet-like board materials with a board-connecting tape having a region in which both are absent.   The region in which both the layer that dissolves in the resist removing solution and has etching resistance and the layer that dissolves in the resist removing solution and does not have the adhesive layer has a size capable of including a circle having a diameter of 2 mm. Item 2. A substrate connecting tape according to Item 1.   The region in which both the layer that dissolves in the resist removing solution and has etching resistance and the layer that dissolves in the resist removing solution and does not have the adhesive layer has a size capable of including a circle having a diameter of 2 mm. Item 3. A printed circuit board manufacturing method according to Item 2.

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