JP4473847B2 - Flexible printed circuit board and manufacturing method thereof - Google Patents

Description

  The present invention relates to a flexible printed circuit board and a manufacturing method thereof, and more particularly to a flexible printed circuit board on which electronic components are mounted and a manufacturing method thereof.

  In recent years, with the increase in the density of electronic components, fine pitches of conductor wiring patterns have been promoted in flexible printed circuit boards on which electronic components are mounted.

In order to form a conductor wiring pattern with a fine pitch with high accuracy, for example, in Japanese Patent Laid-Open No. 2000-124580 (Patent Document 1), (a) the bottom surface of the polyimide base film forming container corresponds to the wiring pattern. A resist pattern is formed, (b) Polyamic acid varnish is uniformly injected into a polyimide base film forming container, imidized to form a polyimide base film, and (c) Polyimide base film for forming a polyimide base film Remove from the container, (d) remove the resist pattern from the polyimide base film, form a wiring pattern groove, (e) form a wiring pattern by disposing a conductor in the wiring pattern groove, It has been proposed to manufacture flexible printed wiring boards.
JP 2000-124580 A

  However, according to such a method, there is a problem that man-hours are large and productivity cannot be improved.

  In addition, as fine pitches progress, defects such as short-circuiting between wirings are likely to occur due to, for example, the presence of even a small amount of foreign matter between the wirings of a conductor wiring pattern. There is a tendency for the yield of non-defective substrates (yield) to decrease, and the productivity to decrease.

  The present invention has been made in view of such circumstances, and the object thereof is to manufacture a flexible printed circuit board in which a conductor wiring pattern is formed at a fine pitch with a high yield rate and good productivity. An object of the present invention is to provide a flexible printed circuit board that can be manufactured and a flexible printed circuit board that is manufactured by the manufacturing method and on which electronic components are mounted.

In order to achieve the above object, a method for manufacturing a flexible printed circuit board according to the present invention includes a step of manufacturing a first flexible printed circuit board having a first connection terminal for connection to an electronic component, and a connection to the electronic component. A second flexible printed circuit board having a second connection terminal for making the second flexible printed circuit board as a separate member from the first flexible printed circuit board 2, the first flexible printed circuit board having no defect, and the second flexible printed circuit board A printed circuit board is selected, and the selected first flexible printed circuit board and the second flexible printed circuit board are connected to the same electronic component in which the first connection terminal and the second connection terminal are the same. to, adjacent to and placed on the support plate, it has been characterized by comprising a step of forming a flexible wired circuit board of the composite .

  In such a method for manufacturing a flexible printed circuit board, in the manufacturing process, the first flexible printed circuit board and the second flexible printed circuit board are divided and formed. By forming the conductive wiring pattern at a fine pitch, Even if the first flexible wiring circuit board or the second flexible wiring circuit board is likely to be defective, only the first flexible wiring circuit board or the second flexible wiring circuit board in which the defect has occurred is regarded as a defective product, and the defect-free first The first flexible printed circuit board and the second flexible printed circuit board can be selected and combined. Therefore, according to the method for manufacturing a flexible printed circuit board of the present invention, a conductor wiring pattern can be formed at a fine pitch, and a high yield rate and a good productivity can be obtained.

  In addition, in the method for manufacturing a flexible printed circuit board according to the present invention, the first flexible printed circuit board and the second flexible printed circuit board are disposed adjacent to each other on the support plate, whereby the first flexible printed circuit board and the second flexible printed circuit board are disposed. By connecting the first connection terminal and the second connection terminal to the same electronic component while securely supporting the flexible printed circuit board, the first flexible wiring circuit substrate and the second flexible wiring are connected via the electronic component. The circuit board can be electrically connected. Therefore, while simplifying the flexible printed circuit board, it is possible to simplify the configuration and reduce the number of manufacturing steps without requiring a direct connection between the first flexible printed circuit board and the second flexible printed circuit board. However, the reliability of the flexible printed circuit board can be improved by the reliable installation on the support plate.

  In the method for manufacturing a flexible printed circuit board according to the present invention, the step of producing the first flexible printed circuit board includes a step of preparing a first base insulating layer made of a resin having a thickness of 10 to 200 μm, and the first base. A step of forming a first conductor layer made of a metal foil having a thickness of 5 to 100 μm on the surface of the insulating layer, and a first cover insulating layer made of a resin having a thickness of 10 to 200 μm covering the first conductor layer And the step of producing the second flexible printed circuit board includes a step of preparing a second base insulating layer made of a resin having a thickness of 10 to 200 μm, and a surface of the second base insulating layer. A step of forming a second conductor layer made of a metal foil having a thickness of 5 to 100 μm, and a second cover insulating layer made of a resin having a thickness of 10 to 200 μm covering the second conductor layer. It is preferable that has a degree.

The flexible printed circuit board of the present invention is a composite flexible printed circuit board comprising a first flexible printed circuit board having no defect and a second flexible printed circuit board having no defect, and is connected to an electronic component. A first flexible wiring circuit board having a first connection terminal for connection, a second flexible wiring circuit board having a second connection terminal for connection to an electronic component, the first flexible wiring circuit board, and the second flexible wiring A support plate for supporting the circuit board from the side opposite to the side on which the electronic component is mounted, and the first flexible printed circuit board includes a first base insulating layer made of a resin having a thickness of 10 to 200 μm; A first conductor layer formed on a surface of the first insulating base layer and made of a metal foil having a thickness of 5 to 100 μm; and covering the first conductor layer. And a first cover insulating layer made of a resin having a thickness of 10 to 200 μm, and the second flexible printed circuit board includes a second base insulating layer made of a resin having a thickness of 10 to 200 μm and the second base insulating layer. A second conductor layer made of a metal foil having a thickness of 5 to 100 μm and a second cover insulating layer made of a resin having a thickness of 10 to 200 μm covering the second conductor layer. It is characterized by.

  In such a flexible printed circuit board, the first flexible printed circuit board and the second flexible printed circuit board are divided and formed. Therefore, in the manufacturing process, by forming the conductive wiring pattern at a fine pitch, Even if a defect is likely to occur in the first flexible printed circuit board or the second flexible printed circuit board, only the first flexible printed circuit board or the second flexible printed circuit board in which the defect has occurred is regarded as a defective product, and the first defect free. The flexible printed circuit board and the second flexible printed circuit board can be selected and combined. Therefore, the flexible printed circuit board of the present invention can be obtained with a high yield rate and good productivity while being able to form a conductor wiring pattern at a fine pitch.

  Moreover, in the flexible printed circuit board according to the present invention, the first flexible printed circuit board and the second flexible printed circuit board are installed adjacent to each other on the support plate. By connecting the first connection terminal and the second connection terminal to the same electronic component while securely supporting the substrate, the first flexible wiring circuit substrate and the second flexible wiring circuit substrate are connected to the electronic component via the electronic component. Can be electrically connected. Therefore, while simplifying the flexible printed circuit board, it is possible to simplify the configuration and reduce the number of manufacturing steps without requiring a direct connection between the first flexible printed circuit board and the second flexible printed circuit board. However, the reliability of the flexible printed circuit board can be improved by the reliable installation on the support plate.

  The flexible printed circuit board according to the present invention is suitable for the first flexible printed circuit board and / or the second flexible printed circuit board having a conductive wiring pattern formed at a pitch of 150 μm or less. It is said.

  In the flexible printed circuit board and the method for manufacturing the same of the present invention, the conductor wiring pattern can be formed with a fine pitch, but can be obtained at a high yield and good productivity. In addition, while simplifying the flexible printed circuit board, it is possible to simplify the configuration and reduce the number of manufacturing steps without requiring direct connection between the first flexible printed circuit board and the second flexible printed circuit board. However, the reliability of the flexible printed circuit board can be improved by the reliable installation on the support plate.

FIG. 1 is a plan view showing an embodiment of a flexible printed circuit board according to the present invention, and FIG. 2 is a side sectional view thereof.

  1 and 2, the flexible printed circuit board 1 is used for, for example, a flat panel display, and the first flexible printed circuit board 2 and the first flexible printed circuit board 2 are formed as separate members. 2 A flexible printed circuit board 3 and a support plate 4 are provided.

  The 1st flexible wiring circuit board 2 consists of a film which has flexibility, and as shown in FIG. 1, it comprises substantially trapezoid shape in planar view, and the 1st conductor wiring pattern part 5 and its 1st conductor wiring pattern part 5 is provided with a first inner terminal portion 6 and a first outer terminal portion 7 that are formed continuously on both sides.

  In the first conductor wiring pattern portion 5, a plurality (four) of first conductor wiring patterns 8 in which a plurality of wirings W1 are arranged in parallel at a fine pitch are formed in block units. The pitch of each first conductor wiring pattern 8 (the sum of the width of the wiring W1 and the interval between the wirings W1 adjacent to each other) is usually 150 μm or less, preferably 100 μm or less, and usually 20 μm or more. Yes. Further, the width of the wiring W1 in each first conductor wiring pattern 8 is preferably 10 to 80 μm, and the interval between the adjacent wirings W1 is preferably 10 to 80 μm.

  The first inner terminal portion 6 is a block at an inner end portion (an end portion facing the second flexible printed circuit board 3) in a direction in which the wiring W1 of the first conductor wiring pattern 8 extends (hereinafter referred to as a longitudinal direction). Corresponding to each first conductor wiring pattern 8 formed as a unit, a plurality (four) are formed along the width direction (direction orthogonal to the longitudinal direction). Each first inner terminal portion 6 includes a first connection terminal formed as a first connecting terminal formed by exposing a longitudinal inner end portion of the wiring W1 of the first conductor wiring pattern 8 from a first cover insulating layer 13 described later. The inner terminals 9 are provided in parallel with each other at a predetermined interval along the width direction. In addition, the 1st inner side terminal 9 is connected to the electronic component E mentioned later.

  In addition, as shown in FIG. 5, at the inner end in the longitudinal direction of the first flexible printed circuit board 2, a concave shape is formed outwardly in the longitudinal direction between the first inner terminal portions 6 adjacent to each other in the width direction. A recess 15 that is recessed is formed. Note that inclined portions 16 that are wider from the outside in the longitudinal direction to the inside are formed on both side portions in the width direction on the opening side of each recess 15.

  Further, at the inner end in the longitudinal direction of the first flexible printed circuit board 2, both sides in the width direction (the first inner terminal 6 on the outermost side in the width direction and the outer edge in the width direction of the first flexible printed circuit board 2). (Between), a projection 17 projecting inward in the longitudinal direction is formed. On each inner side in the width direction of each protrusion 17, an inclined portion 18 that is tapered toward the inner side in the longitudinal direction is formed.

  As shown in FIG. 1, the first outer terminal portion 7 has a width at the outer end in the longitudinal direction of the first conductor wiring pattern 8 (the end opposite to the end facing the second flexible printed circuit board 3). It is formed continuously over the entire direction. The first outer terminal portion 7 has a first outer terminal 10 formed by exposing a longitudinal outer end portion of the wiring W1 of the first conductor wiring pattern 8 from a first cover insulating layer 13 described later in the width direction. Are arranged in parallel with each other at a predetermined interval. The first outer terminal 10 is connected to, for example, a flat panel display device.

  In addition, the total number of the 1st inner side terminals 9 in the 1st inner side terminal part 6 and the total number of the 1st outer side terminals 10 in the 1st outer side terminal part 7 are the same number, Although it does not specifically limit, For example, about 100-1000 pieces It is.

  Further, as shown in FIG. 2, the first flexible printed circuit board 2 includes a first base insulating layer 11, a first conductor layer 12 formed on the surface of the first base insulating layer 11, and its first And a first insulating cover layer 13 that covers the one conductor layer 12.

  The first base insulating layer 11 is not particularly limited as long as it has insulating properties and flexibility. For example, polyimide resin, acrylic resin, polyether nitrile resin, polyether sulfone resin, polyethylene terephthalate resin, polyethylene Resin films such as naphthalate resin and polyvinyl chloride resin are used. Preferably, a polyimide resin film is used. In addition, it is preferable that the thickness of the 1st base insulating layer 11 is 10-200 micrometers normally, Furthermore, it is preferable that it is 10-75 micrometers.

  Moreover, as the 1st conductor layer 12, if it has electroconductivity, it will not restrict | limit in particular, For example, copper, chromium, nickel, aluminum, stainless steel, copper-beryllium, phosphor bronze, iron-nickel, and those A metal foil such as an alloy is used. Preferably, copper foil is used. Moreover, it is preferable that the thickness of the 1st conductor layer 12 is 5-100 micrometers normally, Furthermore, it is 5-18 micrometers.

  Further, as the first cover insulating layer 13, the same resin as that of the first base insulating layer 11 is used. Preferably, a polyimide resin is used, and the thickness is usually 10 to 200 μm, and further 10 to 75 μm. It is preferable that

  And such a 1st flexible wiring circuit board 2 is not specifically limited, For example, it can manufacture by the well-known method shown in FIG. In FIG. 3, the cross section along the longitudinal direction of the wiring W1 of the first conductor wiring pattern 8 is a side sectional view of the “X-axis direction” (direction indicated by the arrow X in FIG. 1), and the first flexible wiring circuit. Cross sections along the width direction of the substrate 2 are respectively shown as front sectional views of the “Y-axis direction” (the direction indicated by the arrow Y in FIG. 1).

  3, in this method, first, as shown in FIG. 3A, a first base insulating layer 11 is prepared, and as shown in FIG. 3B, on the first base insulating layer 11. The first conductor layer 12 is laminated. The first conductor layer 12 is laminated on the first base insulating layer 11 without any particular limitation. For example, the first base insulating layer 11 made of a film is interposed via a known adhesive layer (not shown). The first conductor layer 12 is laminated on the first base insulating layer 11 via the adhesive layer by sticking the conductor layer 12 made of metal foil, or the surface of the conductor layer 12 made of metal foil In addition, the first insulating base layer 11 is formed directly on the conductor layer 12 by applying a resin solution and drying, or the adhesive layer is formed on the surface of the conductor layer 12 made of metal foil. By directly attaching the first base insulating layer 11, the first conductor layer 12 may be directly laminated on the first base insulating layer 11 without using an adhesive layer. When providing said adhesive bond layer, the thickness has preferable 10-35 micrometers.

  In addition, this process can also be abbreviate | omitted using the 2 layer base material by which the 1st conductor layer 12 was laminated | stacked previously on the 1st base insulating layer 11. FIG.

  Next, in this method, as shown in FIG. 3C, the first conductor layer 12 is patterned to form the first conductor wiring pattern 8. The first conductor layer 12 may be patterned by a known method, for example, a subtractive method or the like. In the subtractive method, an etching resist made of a photoresist or the like is first laminated on the first conductor layer 12, and then the etching resist is exposed and developed to form a pattern corresponding to the first conductor wiring pattern 8. Then, after etching the first conductor layer 12 using the etching resist as a resist (wet etching), the etching resist may be removed.

  In addition to the subtractive method, the patterning of the 1st conductor layer 12 can use well-known patterning methods, such as an additive method and a semi-additive method, according to the objective and use, for example.

  In this method, as shown in FIG. 3D, the first insulating cover layer 13 is formed on the first insulating base layer 11 so as to cover the first conductive layer 12 formed on the first conductive wiring pattern 8. By forming the first flexible printed circuit board 2 is obtained.

  The formation of the first cover insulating layer 13 is not particularly limited. For example, the first cover insulating layer 13 made of a film is formed on the first base insulating layer 11 including the first conductor layer 12 with a known adhesive layer ( The first cover layer 13 is laminated on the first base insulating layer 11 including the first conductor layer 12 via the adhesive layer by sticking via the first conductor layer 12 or the first conductor layer. Whether the first cover insulating layer 13 is directly formed on the surface of the first base insulating layer 11 including the first conductor layer 12 by applying a resin solution on the first base insulating layer 11 including 12 and drying. Alternatively, the first cover insulating layer 13 made of an adhesive film is directly attached to the surface of the first base insulating layer 11 including the first conductor layer 12, so that the first cover insulating layer 13 is not interposed through the adhesive layer. On the first base insulating layer 11 including the one conductor layer 12, the first Bar insulating layer 13 may be laminated directly. When providing said adhesive bond layer, the thickness has preferable 10-35 micrometers. In addition, a photosensitive resin solution is applied on the first insulating base layer 11 including the first conductive layer 12, and then exposed and developed, whereby the first insulating base layer 11 including the first conductive layer 12 is exposed on the first insulating base layer 11. One cover insulating layer 13 may be formed as a pattern having a predetermined shape.

  Further, in the formation of the first cover insulating layer 13, without forming the first cover insulating layer 13 at both longitudinal ends (longitudinal inner end and outer end) of the first conductor wiring pattern 8, By exposing the first conductor wiring pattern 8, the first inner terminal 9 and the first outer terminal 10 are formed, and the exposed portions are respectively defined as the first inner terminal portion 6 and the first outer terminal portion 7. And

  More specifically, the first inner terminal portion 6 and the first outer terminal portion 7 are formed simultaneously with the formation of the first cover insulating layer 13 in the case of, for example, patterning of a photosensitive resin. In addition, when the resin solution is applied over the entire surface or when the first cover insulating layer 13 made of a film is adhered, for example, the first method is performed by a known method such as drilling, punching, laser processing, or etching. What is necessary is just to form by opening the longitudinal direction both ends of the cover insulating layer 13. FIG.

  The 2nd flexible wiring circuit board 3 consists of a film which has flexibility, and as shown in FIG. 1, it comprises substantially T shape in planar view, the 2nd conductor wiring pattern part 21, and its 2nd conductor wiring pattern A second inner terminal portion 22 and a second outer terminal portion 23 formed continuously on both sides of the portion 21 are provided.

  In the second conductor wiring pattern portion 21, a plurality of (four) second conductor wiring patterns 24 in which a plurality of wirings W2 are arranged in parallel at a pitch coarser than the pitch of the wiring W1 of the first conductor wiring pattern 8 are formed. Has been. The pitch of each second conductor wiring pattern 24 (the sum of the width of the wiring W2 and the interval between the wirings W2 adjacent to each other) is usually 80 to 500 μm, preferably 80 to 200 μm. Moreover, it is preferable that the width | variety of the wiring W2 in each 2nd conductor wiring pattern 24 is 40-100 micrometers, and it is preferable that the space | interval of each wiring W2 adjacent to each other is 40-100 micrometers.

  The second inner terminal portion 22 is a block at an inner end portion (an end portion facing the first flexible printed circuit board 2) in a direction in which the wiring W2 of the second conductor wiring pattern 24 extends (hereinafter referred to as a longitudinal direction). Corresponding to each second conductor wiring pattern 24 formed in units, a plurality (four) are formed along the width direction (direction orthogonal to the longitudinal direction of the wiring W2). Each second inner terminal portion 22 has a second connection terminal formed as a second connection terminal formed by exposing a longitudinal inner end portion of the wiring W2 of the second conductor wiring pattern 24 from a second cover insulating layer 29 described later. The inner terminals 25 are provided in parallel with each other at a predetermined interval along the width direction. In addition, the 2nd inner side terminal 25 is connected to the electronic component E mentioned later.

  Further, as shown in FIG. 5, at the inner end in the longitudinal direction of the second flexible printed circuit board 3, the second inner terminal portions 22 adjacent to each other in the width direction protrude inward in the longitudinal direction. The convex part 31 which protrudes in a shape is formed. Note that inclined portions 32 that are narrower from the outer side in the longitudinal direction toward the inner side are formed on both side portions in the width direction on the protruding side of each convex portion 31.

  Further, at the inner end of the second flexible printed circuit board 3 in the longitudinal direction, both sides in the width direction (the second inner terminal portion 22 on the outermost side in the width direction and the outer edge in the width direction of the second flexible printed circuit board 3) (Between), a protrusion 33 protruding inward in the longitudinal direction is formed. On the outer side in the width direction of each protrusion 33, an inclined portion 34 that tapers inward in the longitudinal direction is formed.

  As shown in FIG. 1, the second outer terminal portion 23 has a width at the outer end in the longitudinal direction of the second conductor wiring pattern 24 (the end opposite to the end facing the first flexible printed circuit board 2). It is formed continuously over the entire direction. The second outer terminal portion 23 is formed with a second outer terminal 26 formed by exposing a longitudinal outer end portion of the wiring W2 of the second conductor wiring pattern 24 from a second cover insulating layer 29 described later. Are arranged in parallel with each other at a predetermined interval. The second outer terminal 26 is connected to an external circuit such as a control circuit, for example.

  The total number of second inner terminals 25 in the second inner terminal portion 22 and the total number of second outer terminals 26 in the second outer terminal portion 23 are the same and are not particularly limited. For example, about 1 to 100 It is.

  As shown in FIG. 2, the second flexible printed circuit board 3 is formed on the second base insulating layer 27 and the surface of the second base insulating layer 27 in the same manner as the first flexible printed circuit board 2. A second conductor layer 28 and a second cover insulating layer 29 covering the second conductor layer 28.

  The second base insulating layer 27 and the second cover insulating layer 29 are not particularly limited as long as they have insulating properties and flexibility, and the same resin as the first base insulating layer 11 is used. A polyimide resin is used. In addition, the thickness of the second insulating base layer 27 is usually 10 to 200 μm, more preferably 10 to 75 μm, and the thickness of the second insulating cover layer 29 is usually 10 to 200 μm, and more preferably 10 to 10 μm. It is preferable that it is -75 micrometers.

  Moreover, the 2nd conductor layer 28 will not be restrict | limited especially if it has electroconductivity, The metal foil similar to the 1st conductor layer 12 is used, Preferably, copper foil is used. Moreover, it is preferable that the thickness of the 2nd conductor layer 28 is 5-100 micrometers normally, Furthermore, it is 5-18 micrometers.

  Such a second flexible printed circuit board 3 is not particularly limited, and can be manufactured by, for example, a known method shown in FIG. 4 in the same manner as the first flexible printed circuit board 2. In FIG. 4, the section along the longitudinal direction of the wiring W2 of the second conductor wiring pattern 24 is a side sectional view of “X-axis direction” (direction indicated by the arrow X in FIG. 1), and the second flexible wiring circuit Cross sections along the width direction of the substrate 3 are respectively shown as front sectional views of the “Y-axis direction” (the direction indicated by the arrow Y in FIG. 1).

  4, in this method, first, as shown in FIG. 4A, a second base insulating layer 27 is prepared, and as shown in FIG. 4B, on the second base insulating layer 27. The second conductor layer 28 is laminated. In order to laminate the second conductor layer 28 on the second insulating base layer 27, a method similar to the method of laminating the first conductor layer 12 on the first insulating base layer 11 is used.

  Next, in this method, as shown in FIG. 4C, the second conductor layer 28 is patterned to form the second conductor wiring pattern 24. The second conductor layer 28 may be patterned by a known method, and, like the first conductor layer 12, a subtractive method or the like is used. Depending on the purpose and application, for example, a known patterning method such as an additive method or a semi-additive method may be used.

  In this method, as shown in FIG. 4D, the second cover insulating layer 29 is formed on the second base insulating layer 27 so as to cover the second conductor layer 28 formed on the second conductor wiring pattern 24. By forming the second flexible printed circuit board 3, the second flexible printed circuit board 3 is obtained.

  The second cover insulating layer 29 is formed by a method similar to the method of forming the first cover insulating layer 13.

  In addition, the formation of the second cover insulating layer 29 is the same as the formation of the first cover insulating layer 13 at the second end portions in the longitudinal direction (longitudinal inner end portion and outer end portion) of the second conductor wiring pattern 24. By exposing the second conductor wiring pattern 24 without forming the insulating cover layer 29, the second inner terminal 25 and the second outer terminal 26 are respectively formed, and the portions where the second inner terminal 25 and the second outer terminal 26 are exposed are respectively defined as the second inner terminals. The terminal portion 22 and the second outer terminal portion 23 are used. The second inner terminal portion 22 and the second outer terminal portion 23 are formed using the same method as the first inner terminal portion 6 and the first outer terminal portion 7.

  As shown in FIG. 5, the flexible printed circuit board 1 includes a first flexible printed circuit board 2 and a second flexible printed circuit board 3 obtained as described above. The first inner terminal 9 and the second inner terminal 25 of each second inner terminal portion 22 are disposed adjacent to each other on the support plate 4 so as to be connected to the same (common) electronic component E.

  The support plate 4 has a substantially rectangular plate shape having substantially the same width as the longitudinal inner end of the first flexible printed circuit board 2 and the longitudinal inner end of the second flexible printed circuit board 3, and is not particularly limited. However, for example, a metal plate such as an aluminum plate or a stainless plate, a fiber reinforced resin plate such as a glass-epoxy plate, a resin plate such as a polyimide plate or a polyethylene terephthalate (PET) plate, or the like is used. From the viewpoint of improving the connection reliability of the electronic component E, a metal plate such as an aluminum plate or a stainless plate is preferably used. Moreover, the thickness of the support plate 4 is 50 micrometers-4 mm normally.

  The first flexible printed circuit board 2 and the second flexible printed circuit board 3 are connected to the first inner terminal 9 of each first inner terminal portion 6 and the second inner terminal 25 of each second inner terminal portion 22. In order to be installed adjacent to the support plate 4 so as to be connected to the same electronic component E, the inclined portions 16 of the concave portions 15 of the first flexible printed circuit board 2 and the second flexible plate are provided on the support plate 4. The inclined portions 32 of the convex portions 31 of the printed circuit board 3 face each other with a slight gap, and the inclined portions 18 of the protruding portions 17 of the first flexible printed circuit board 2 and the second flexible printed circuit. The first flexible wiring circuit board 2 and the second flexible wiring circuit board 3 are arranged so as to face each other so that the inclined portions 34 of the respective protrusions 33 of the substrate 3 face each other with a slight gap. As shown in 2, the adhesive 41 through, these first flexible wiring circuit board 2 and the second flexible wiring circuit board 3 may be stuck on the support plate 4.

  If the first flexible printed circuit board 2 and the second flexible printed circuit board 3 are arranged to face each other in this way, the first inner terminals 9 of the first inner terminal portions 6 and the second inner terminal portions 22 of the second inner terminals 22 are arranged. The first flexible wiring circuit board 2 and the second flexible wiring circuit board 3 can be installed on the support plate 4 while being easily and reliably positioned so that the inner terminal 25 is connected to the same electronic component E. it can.

  Although it does not specifically limit as an adhesive agent which forms the adhesive bond layer 41, For example, well-known adhesive agents, such as an epoxy-type adhesive agent and a polyimide-type adhesive agent, are used. In addition, the thickness of the adhesive bond layer 41 is 10-100 micrometers normally, Preferably, it is 10-50 micrometers.

  Moreover, although it does not specifically limit in order to stick the 1st flexible printed circuit board 2 and the 2nd flexible printed circuit board 3 on the support plate 4 via the adhesive bond layer 41, For example, a 1st flexible printed circuit board Adhesive agent is applied to the inner end portion of the second base insulating layer 11 and the inner end portion of the second base insulating layer 27 of the second flexible printed circuit board 3, and then adhered to the support plate 4, or After applying an adhesive to the surface of the support plate 4, the inner end of the first base insulating layer 11 of the first flexible printed circuit board 2 and the inner end of the second base insulating layer 27 of the second flexible printed circuit board 3 are used. What is necessary is just to adhere | attach a part on the support plate 4 to which the adhesive agent was apply | coated. FIG. 2 shows the former mode.

  As a result, the first inner terminal portions 6 of the first flexible printed circuit board 2 and the second inner terminal portions 22 of the second flexible printed circuit board 3 are arranged to face each other with a predetermined gap therebetween. The space formed in a substantially rectangular shape in plan view is an electronic component mounting portion 42 for mounting the electronic component E.

  In such a flexible printed circuit board 1, the first flexible printed circuit board 2 and the second flexible printed circuit board 3 are divided and formed with the electronic component mounting portion 42 interposed therebetween. By forming the first conductor wiring pattern 8 of the 1 flexible wiring circuit board 2 at a fine pitch, even if the first flexible wiring circuit board 2 is likely to be defective, the first flexible wiring circuit board 2 in which the defect is generated Only the first flexible printed circuit board 2 having no defect can be selected and combined with the second flexible printed circuit board 3 as a defective product.

  That is, for example, as shown in FIG. 6, in the integrated flexible printed circuit board 51 in which the electronic component mounting portion 42 is formed by punching, when the first conductor wiring pattern 8 is formed at a fine pitch, a defect occurs. Since the flexible printed circuit board 1 becomes a defective product as a whole, the yield rate (yield) is reduced, and as a result, the productivity is significantly reduced. In FIG. 6, the same members as those of the flexible printed circuit board 1 shown in FIG.

  However, since the flexible printed circuit board 1 is a composite flexible printed circuit board 1 in which the first flexible printed circuit board 2 and the second flexible printed circuit board 3 which are independent from each other are combined, the flexible printed circuit board 1 is formed at a fine pitch. Since the non-defective product of the first flexible printed circuit board 2 having the first conductor wiring pattern 8 can always be combined with the second flexible printed circuit board 3, the flexible printed circuit board 1 as a whole is highly productive with a high good product rate. Can get well.

  And the electronic component E is mounted in the electronic component mounting part 42 of the flexible printed circuit board 1 obtained in this way as shown by the virtual line of FIG.

  The electronic component E is appropriately selected depending on its purpose and application, such as a semiconductor chip, a capacitor, or a resistor. Such an electronic component E is installed, for example, in each electronic component mounting portion 42, and the first inner terminal 9 of the first flexible printed circuit board 2 and the second inner terminal 25 of the second flexible printed circuit board 3, for example, The flexible printed circuit board 1 is mounted by being connected by a known method such as wire bonding, bonding with a different direction conductive adhesive, or solder bonding.

  In this flexible printed circuit board 1, the first flexible printed circuit board 2 and the second flexible printed circuit board 3 are installed adjacent to each other on the support plate 4, and the first flexible printed circuit board 2 and the second flexible printed circuit board 3 are installed. While securely supporting the printed circuit board 3, the first inner terminal 9 of each inner terminal portion 6 and the second inner terminal 25 of each second inner terminal portion 22 that are opposed to each other are the same (common) electronic component E. The first flexible printed circuit board 2 and the second flexible printed circuit board 3 can be electrically connected via the electronic component E. Therefore, while simplifying the flexible printed circuit board 1, the direct connection between the first flexible printed circuit board 2 and the second flexible printed circuit board 3 is not required, and the configuration is simplified and the number of manufacturing steps is reduced. However, the reliability of the flexible printed circuit board 1 can be improved by the reliable installation on the support plate 4.

  Further, after the electronic component E is mounted in this way, the support plate 4 may be removed if unnecessary.

  In the above description, the first conductor wiring pattern 8 of the first flexible wiring circuit board 2 is formed at a fine pitch, while the second conductor wiring pattern 24 of the second flexible wiring circuit board 3 is changed to the first conductor wiring pattern 8. In the flexible printed circuit board of the present invention, for example, the reverse of the above, that is, the second conductor wiring pattern 24 of the second flexible printed circuit board 3 is formed at a fine pitch. The first conductor wiring pattern 8 of the first flexible wiring circuit board 2 may be formed at a pitch coarser than the fine pitch of the second conductor wiring pattern 24, and further, the first conductor of the first flexible wiring circuit board 2 may be formed. Both the wiring pattern 8 and the second conductor wiring pattern 24 of the second flexible printed circuit board 3 are, for example, 1 0μm may be formed below a fine pitch.

  In the above description, the total number (for example, about 100 to 1000) of the first inner terminals 9 in the first inner terminal portion 6 of the first flexible printed circuit board 2 is calculated as the second number of the second flexible printed circuit board 3. The number of the second inner terminals 25 in the inner terminal portion 22 is larger than the total number (for example, about 1 to 100), but the number of terminals is not particularly limited. For example, the total number of the first inner terminals 9 and the second inner terminals The total number of terminals 25 may be the same or different.

  In the above description, the first flexible printed circuit board 2 and the second flexible printed circuit board 3 are electrically connected via the electronic component E. However, if necessary, for example, by wire bonding or the like, These may be electrically connected via connection wiring.

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

Example 1
1) Production of first flexible printed circuit board First, a two-layer base material in which a first base insulating layer made of a polyimide resin film having a thickness of 25 μm and a first conductor layer made of a copper foil having a thickness of 18 μm are directly laminated. Was prepared (see FIG. 3B).

  Next, the first conductor layer was formed into a first conductor wiring pattern having a wiring width of 75 μm, a spacing of 50 μm, a pitch of 125 μm, and several 400 first inner terminals and first outer terminals by a subtractive method (see FIG. 3 (c)).

Thereafter, a first cover insulating layer in which a polyimide resin film having a thickness of 25 μm is pre-punched into a shape in which the first inner terminal and the first outer terminal are exposed is interposed through an adhesive layer made of an epoxy adhesive having a thickness of 15 μm. The first flexible printed circuit board was fabricated by sticking on the first base insulating layer including the first conductor layer (see FIG. 3D). The detailed shape of the first flexible printed circuit board is the same as that of the first flexible printed circuit board shown in FIG.
2) Production of second flexible printed circuit board First, a two-layer base material in which a second base insulating layer made of a polyimide resin film having a thickness of 25 μm and a second conductor layer made of a copper foil having a thickness of 18 μm are directly laminated. Was prepared (see FIG. 4B).

  Next, the second conductor layer was formed into a second conductor wiring pattern having a wiring width of 100 μm, a spacing of 100 μm, a pitch of 200 μm, and a number of 25 second inner terminals and second outer terminals by a subtractive method (see FIG. 4 (c)).

Thereafter, a second cover insulating layer in which a polyimide resin film having a thickness of 25 μm is pre-punched into a shape in which the second inner terminal and the second outer terminal are exposed is interposed through an adhesive layer made of an epoxy adhesive having a thickness of 15 μm. Then, the second flexible printed circuit board was fabricated by pasting on the second base insulating layer including the second conductor layer. The detailed shape of the second flexible printed circuit board is the same as that of the second flexible printed circuit board shown in FIG.
3) Production of composite type flexible printed circuit board An aluminum plate (100 mm × 30 mm) having a thickness of 2 mm is prepared as a support plate, and the inner end portion of the first base insulating layer of the first flexible printed circuit board obtained as described above and the first 2 An epoxy adhesive was applied to the inner end of the second base insulating layer of the flexible printed circuit board to a thickness of 50 μm. Next, on the support plate, the inclined portions of the concave portions of the first flexible printed circuit board and the inclined portions of the convex portions of the second flexible printed circuit board face each other with a slight gap therebetween, In addition, the first flexible printed circuit board is arranged such that the inclined portion of each protrusion of the first flexible printed circuit board and the inclined portion of each protruded part of the second flexible printed circuit board face each other with a slight gap therebetween. In a state where the second flexible printed circuit board and the second flexible printed circuit board are abutted (see FIG. 5), the composite flexible printed circuit board is obtained (see FIG. 1).

It is a top view which shows one Embodiment of the flexible wiring circuit board of this invention. It is a sectional side view of the flexible printed circuit board shown in FIG. It is process sectional drawing which shows one Embodiment of the manufacturing method of the 1st flexible printed circuit board of the flexible printed circuit board shown in FIG. 1, (a) is the process of preparing a 1st base insulating layer, (b) , A step of laminating the first conductor layer on the first insulating base layer, (c) a step of forming the first conductor layer in the first conductor wiring pattern, and (d) a first layer including the first conductor layer. A step of forming a first insulating cover layer on the insulating base layer is shown. It is process sectional drawing which shows one Embodiment of the manufacturing method of the 2nd flexible wiring circuit board of the flexible wiring circuit board shown in FIG. 1, (a) is the process of preparing a 2nd base insulating layer, (b) , A step of laminating the second conductor layer on the second base insulating layer, (c) a step of forming the second conductor layer in the second conductor wiring pattern, and (d) a second layer including the second conductor layer. A step of forming a second cover insulating layer on the base insulating layer is shown. It is a principal part top view of the flexible printed circuit board shown in FIG. It is a top view which shows an integrated flexible printed circuit board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flexible wiring circuit board 2 1st flexible wiring circuit board 3 2nd flexible wiring circuit board 4 Support plate 8 1st conductor wiring pattern 9 1st inner side terminal 25 2nd inner side terminal E Electronic component

Claims (4)

Producing a first flexible printed circuit board having a first connection terminal for connection to an electronic component;
Producing a second flexible printed circuit board having a second connection terminal for connecting to the electronic component as a separate member from the first flexible printed circuit board 2;
The first flexible printed circuit board and the second flexible printed circuit board having no defect are selected, and the selected first flexible printed circuit board and the second flexible printed circuit board are connected to the first connection terminal and the first flexible printed circuit board. And a step of forming a composite-type flexible printed circuit board so as to be connected to the same electronic component so that two connection terminals are connected to each other. A method for manufacturing a printed circuit board. The step of producing the first flexible printed circuit board includes:
Preparing a first base insulating layer made of a resin having a thickness of 10 to 200 μm;
Forming a first conductor layer made of a metal foil having a thickness of 5 to 100 μm on the surface of the first base insulating layer;
Covering the first conductor layer and forming a first cover insulating layer made of a resin having a thickness of 10 to 200 μm,
The step of producing the second flexible printed circuit board includes:
Preparing a second base insulating layer made of a resin having a thickness of 10 to 200 μm;
Forming a second conductor layer made of a metal foil having a thickness of 5 to 100 μm on the surface of the second insulating base layer;
The method for manufacturing a flexible printed circuit board according to claim 1, further comprising a step of covering the second conductor layer and forming a second cover insulating layer made of a resin having a thickness of 10 to 200 μm. A complex type flexible printed circuit board comprising a first flexible printed circuit board without defects and a second flexible printed circuit board without defects,
A first flexible wiring circuit board having a first connection terminal for connection to an electronic component; a second flexible wiring circuit board having a second connection terminal for connection to an electronic component; the first flexible wiring circuit board; A support plate for supporting the second flexible printed circuit board from a side opposite to the side on which the electronic component is mounted;
The first flexible printed circuit board includes a first base insulating layer made of a resin having a thickness of 10 to 200 μm, and a first conductor layer formed on a surface of the first base insulating layer and made of a metal foil having a thickness of 5 to 100 μm. And a first cover insulating layer that covers the first conductor layer and is made of a resin having a thickness of 10 to 200 μm,
The second flexible printed circuit board includes a second base insulating layer made of a resin having a thickness of 10 to 200 μm, and a second conductor layer formed on a surface of the second base insulating layer and made of a metal foil having a thickness of 5 to 100 μm. And a second cover insulating layer made of a resin having a thickness of 10 to 200 μm and covering the second conductor layer.   4. The flexible wiring according to claim 3, wherein the first flexible wiring circuit board and / or the second flexible wiring circuit board has a conductor wiring pattern formed at a pitch of 150 μm or less. 5. Circuit board.

Images