JP2009267109A - Flexible wiring board, flexible semiconductor device and liquid crystal display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible wiring board which can be easily manufactured without requiring complicated manufacturing processes, and which can efficiently discharge heat generated from the electronic component when an electronic component is mounted. <P>SOLUTION: The flexible wiring board includes a flexible insulating substrate where an outer lead forming area and an electronic component mounting area are adjacently formed through a first bending portion formed between both the areas, and a wiring pattern is formed on one surface of the flexible insulating substrate. One end portion of the wiring pattern formed on the flexible wiring board forms an outer lead, the other end forms an inner lead, and the flexible wiring board is formed so as to be bent to a predetermined shape. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flexible wiring board capable of efficiently releasing heat generated from an electronic component when the electronic component is mounted and energized, a flexible semiconductor device having a semiconductor mounted on the flexible wiring board, and the flexible semiconductor The present invention relates to a liquid crystal display device having the device.

  As is well known, the flexible wiring board is mounted on a display device such as a liquid crystal television, a plasma display, and an organic EL television, on which electronic components such as a driver IC for driving are mounted.

  Such flexible wiring boards include TAB (Tape Automated Bonding) tape, TCP (Tape Carrier Package), COF (Chip On Film), and the like, which are used so that their characteristics can be used effectively.

In addition, since the flexible substrate uses a flexible resin film as the insulating substrate, it has excellent flexibility, and can be used by changing its form, such as bending it. It is. Utilizing such characteristics, the flexible substrate is mounted with a semiconductor and is ACF-connected to a transparent electrode at the edge of a liquid crystal display device such as a liquid crystal television, a plasma display, or an organic EL television, and on the back side of the display device. It can be bent and incorporated in a display device, and is used for a display device in which the frame body of the display device is narrowed to make the display surface larger and the frame body narrower.

  In particular, COF has no device hole as compared to TAB tape having device holes, so there is no need to form flying leads, and all the formed wiring patterns are supported by the base film at the bottom of the wiring pattern. Therefore, the COF substrate is widely adopted as a flexible wiring substrate of a liquid crystal display device because it is relatively easy to make a fine pitch and has high bending reliability and mounting workability.

  However, thinning a wiring pattern such as COF is a very important technology for incorporating high-performance electronic components. On the other hand, a wiring pattern dissipates heat generated in electronic components. As the wiring pattern formed like a COF is thinned, the ability to release heat generated in the electronic component is decreasing. In addition, since the performance of electronic components is high and the size is reduced, the amount of heat generated from highly integrated electronic components generated by driving the electronic components tends to increase. In a flexible wiring board in which is thinned, from the viewpoint of heat dissipation efficiency, the thinning of the wiring pattern decreases the heat dissipation efficiency.

As shown in FIG. 10, for example, a conventional display device has an internal structure of a liquid crystal display device 40 in which a COF type flexible wiring substrate 39 on which an IC is mounted is incorporated. Here, the electronic component (IC) E serving as a heating element is disposed inside the arc of the flexible wiring board 39 bent in an arc. As shown in FIG. 10, in recent electronic devices, the flexible wiring board 39 on which an electronic component (IC) E incorporated in the device is mounted in an arc shape in order to reduce the size and size of the device. The bent electronic component (IC) E is arranged inside the arcuate shape of the flexible wiring board 39, and its periphery is surrounded by various structures such as the rigid wiring board (input means 34) and the display means 35. Therefore, it has become impossible to secure a special space for effectively radiating heat.

  Under such circumstances, when an electronic component such as a driver IC for driving is driven, the maximum temperature of the surface of the driver IC when energized may reach around 100 ° C. This heat generation may cause a failure of the electronic device.

  For this purpose, the electronic component is arranged so as to abut on the inner wall surface of the housing through an insulating substrate of a flexible wiring board made of polyimide film or the like, and heat generated by the electronic component is applied to the inner peripheral wall surface of the housing through the insulating substrate. There is known a method of transferring heat to a radiator made of a conductive metal that is disposed.

That is, as shown in FIG. 10, the transparent electrode of the liquid crystal display device 40 is disposed on the surface of the edge of the liquid crystal display device 40, and the output-side outer lead of the flexible wiring board of the present invention is connected to the transparent electrode. Anisotropic conductive bonding (ACF) is performed. In such a flexible wiring board, the wiring pattern is formed on the inner surface of the insulating substrate of the flexible wiring board in order to make an ACF connection with the transparent electrode, and the inner surface of the insulating substrate of the wiring pattern. That is, the inner leads 17a and 17b are formed in a wiring pattern on the surface on which the display means 35 is disposed.
The electronic component E is mounted on the board and bent along the housing 38 for use. Then, by bending and using the flexible wiring board in this way, the electronic component E is placed on the display means 35 side of the flexible wiring board mounted on the inner lead that is the tip of the wiring pattern, and the film carrier tape, display device 35. It is disposed at a position surrounded by various members such as input means (usually a rigid wiring board 34).

  Therefore, since the heat generated by driving the electronic component E is difficult to be released from the portion surrounded by the insulating substrate, the temperature of the portion where the electronic component E is disposed becomes very high. That is, as shown in FIG. 10, since each structure such as a flexible wiring board is close and dense inside the liquid crystal display device 40, the heat generated from the electronic component E tends to stay in the electronic component E. The temperature of the part where is mounted becomes high. In order to release the heat generated in the electronic component E by energizing the electronic component E in this way, a heat radiation metal plate 36 is provided between the back surface of the wiring pattern on which the electronic component E is mounted and the housing 38. Attempts have been made to dispose heat generated by energizing the electronic component E to the outside of the housing 38 by arranging a heat dissipating means. However, as shown in FIG. 10, when the heat generated from the electronic component is released through the heat radiating metal plate 36, the electronic component E and the heat radiating metal plate 36 are not in direct contact but are insulated. The electronic component E and the heat radiating metal plate 36 are in contact with each other through a polyimide film as a substrate. The insulating substrate such as polyimide has low thermal conductivity, and the heat generated in the electronic component E is sufficiently radiated. The heat could not be transmitted to the plate 36 and heat dissipation was insufficient. In particular, the density of electronic components is increased and the amount of heat generated per unit volume of the electronic components is increased, and the line width of the wiring pattern formed on the flexible wiring board is reduced, and the wiring pattern formed on the flexible wiring board is also reduced. It is no longer fully functioning as a heat dissipation means.

  In such a flexible wiring board, it is possible to increase the thickness of the conductive metal layer (wiring pattern or dummy wiring) and improve the heat dissipation of the flexible wiring board itself by using the wiring pattern as a heat dissipation means. Such an attempt is contrary to the reduction in size and weight of electronic devices. Even if such a flexible wiring board is actually manufactured and the temperature of the surface of the electronic component is measured, there are several improvements compared to the case before the improvement. The heat dissipation is still not improved to the expected extent.

Furthermore, regarding heat dissipation, as exemplified below, a printed circuit board that can dissipate heat through heat dissipation means such as a heat dissipation plate, a through hole, an inner layer circuit, an outermost layer circuit, and a heat dissipation metal plate has been proposed. .

  In Patent Document 1 (Japanese Patent Laid-Open No. 2001-284748), an electronic component having a heat dissipation plate such as aluminum or iron is surface-mounted on the surface of the substrate, and further on the back side of the substrate at a position corresponding to the electronic component, There is disclosed a printed circuit board in which heat radiating means is bonded and heat is radiated through the heat radiating plate and the heat radiating means.

  In Patent Document 2 (Japanese Patent Laid-Open No. 5-343821), a heat radiation land portion provided in a gap portion facing a component connecting conductor pattern portion on which an electronic component is mounted and a through hole provided in the heat radiation land portion are disclosed. A printed circuit board that can dissipate heat through a hole is disclosed.

  Patent Document 3 (Japanese Patent Laid-Open No. 11-274669) discloses a double-sided or multi-layer printed wiring board that dissipates heat through an inner layer circuit or an outermost layer circuit exposed at the end of the substrate and is formed at the end of the substrate. There is disclosed a printed wiring board characterized in that heat is radiated through a circuit, the inner layer circuit and the outermost layer circuit.

  In patent document 4 (Unexamined-Japanese-Patent No. 7-235737), it has the opening pierced in the base material, and the heat radiating metal plate inserted in the opening, and radiates heat through this heat radiating metal plate. A printed circuit board that can be used is disclosed.

  However, when the printed wiring board disclosed in these patent documents is to be bent, the bending position must avoid the above-described heat dissipation means. That is, the design flexibility of these printed wiring boards is remarkably restricted, and when these printed wiring boards are used in a liquid crystal display device, it is difficult to reduce the size and size of the device.

Although it depends on the shape, hardness, and thickness of the heat dissipation means, it is generally difficult to bend and is limited to application to a flat substrate such as a rigid type PCB.
Furthermore, these printed wiring boards require a process for forming a predetermined heat dissipation means during manufacturing, which complicates the manufacturing process and increases costs.

In other words, there is room for improvement in terms of both easy manufacture and compatibility between the flexibility of the flexible wiring board and the heat dissipation characteristics when incorporated in a display device.
JP 2001-284748 A JP-A-5-343821 Japanese Patent Laid-Open No. 11-274669 JP-A-7-235737

  The present invention provides a flexible wiring board that can be easily manufactured without going through a complicated manufacturing process and that can efficiently release heat generated from the electronic component when the electronic component is mounted. With the goal.

  In addition, by providing such a flexible wiring board, a flexible semiconductor device capable of efficiently releasing heat generated from an electronic component, and a liquid crystal display device with extremely high heat dissipation mounted with the flexible semiconductor device are provided. The purpose is to do.

The flexible wiring board of the present invention includes an outer lead forming region that occupies approximately half of the tape width direction perpendicular to the feeding direction of the flexible substrate, and the remaining tape width direction perpendicular to the feeding direction of the flexible substrate. An electronic component mounting area that occupies substantially half of the flexible insulating substrate that is adjacent to each other via a first bent portion formed between the two regions, and a wiring pattern on one surface of the flexible insulating substrate One end of the wiring pattern formed on the flexible wiring board is an outer lead composed of an input side outer lead and an output side outer lead, and the other end is an input side inner lead and A wiring pattern in which the input side inner lead and the input side outer lead are formed, and the output side The wiring pattern in which the inner lead and the output-side outer lead are formed is formed so as to be electrically connectable by mounting the electronic component on the electronic component mounting scheduled portion formed in the electronic component mounting region. The flexible wiring board is formed so that it can be bent approximately 180 degrees at the first bent portion so that the surface of the flexible insulating substrate on which the wiring pattern is not formed comes into contact and the wiring pattern is located outside. The flexible printed circuit board bent approximately 180 degrees is subjected to a second bend such that the outer lead faces in a direction perpendicular to the first bent portion bent approximately 180 degrees with the electronic component mounting area on the outside. It is characterized by being formed as possible.

  Further, the flexible wiring board is formed such that an input-side outer lead and an output-side outer lead are formed in the outer lead forming area so as to face the edge of the flexible wiring board. The wiring pattern for forming the outer outer lead is routed to form the input inner lead at the electronic component mounting planned portion in the electronic component mounting region beyond the first bent portion, and the output outer lead from the outer region. It is preferable that the output-side inner lead is formed at the electronic component mounting scheduled portion of the electronic component mounting planned portion beyond the first bent portion 13 by the wiring pattern being routed.

  In the flexible wiring board, the width of the flexible insulating board in the feeding direction of the flexible wiring board is formed to be the widest in the outer lead forming region, and the width of the flexible wiring board is set to be the first bent portion and the electronic In the component mounting area, the notch portions of the flexible insulating substrate are formed at the front and rear edges in the feed direction so as to decrease to 85 to 95% with respect to the width (100%) of the flexible wiring board in the outer lead formation region 10a. Preferably it is formed.

  Further, when the flexible substrate is bent at about 180 degrees at the first bent portion on the surface of the flexible wiring substrate on which the wiring pattern of the flexible insulating substrate is not formed, In order to maintain this bent state, it is preferable that an adhesive be formed on a part of the back surface of the flexible insulating substrate so as to be disposed.

The flexible semiconductor device according to the present invention includes an outer lead formation region that occupies substantially half of the tape width direction orthogonal to the feeding direction of the flexible substrate, and a tape width direction orthogonal to the feeding direction of the flexible substrate. An electronic component mounting area that occupies the remaining half is adjacent to a flexible insulating substrate via a first bent portion formed between the two regions, and wiring is provided on one surface of the flexible insulating substrate. A flexible wiring board on which a pattern is formed. One end of the wiring pattern formed on the flexible wiring board is an outer lead composed of an input-side outer lead and an output-side outer lead, and the other end is an input-side inner A wiring pattern in which the input side inner lead and the input side outer lead are formed, and an inner lead consisting of a lead and an output side inner lead; The wiring pattern in which the output side inner lead and the output side outer lead are formed is electrically connected by the electronic component mounted on the electronic component mounting planned portion formed in the electronic component mounting region. The mounted flexible wiring board is bent at approximately 180 degrees at the first bent portion so that the surface of the flexible insulating substrate on which the wiring pattern is not formed contacts and the wiring pattern is located outside. The flexible wiring board bent at about 180 degrees at the first bent portion so that the electronic component mounted on the electronic component mounting planned portion in the electronic component mounting area is positioned outside. However, the outer lead is bent again so as to face in a direction perpendicular to the first bent portion. That.

In the flexible semiconductor device, an adhesive is disposed on the back side of the flexible insulating substrate of the flexible wiring board that is bent by about 180 degrees so that the back side of the flexible insulating substrate is in contact with the first bent portion. It is preferable that at least a part of the abutting flexible insulating substrates is adhered to each other by the adhesive.
In addition, the display device according to the present invention includes an outer lead formation region that occupies substantially half of the tape width direction orthogonal to the flexible substrate feed direction, and a tape width direction orthogonal to the flexible substrate feed direction. An electronic component mounting area that occupies the remaining half is adjacent to a flexible insulating substrate via a first bent portion formed between the two regions, and wiring is provided on one surface of the flexible insulating substrate. A flexible wiring board on which a pattern is formed. One end of the wiring pattern formed on the flexible wiring board is an outer lead composed of an input-side outer lead and an output-side outer lead, and the other end is an input-side inner In addition to an inner lead composed of a lead and an output-side inner lead, a wiring pattern in which the input-side inner lead and the input-side outer lead are formed; The wiring pattern in which the outer lead and the output-side outer lead are formed is electrically connected by the electronic component mounted on the electronic component mounting planned portion formed in the electronic component mounting region, and the electronic component is mounted. The flexible wiring board is bent at approximately 180 degrees at the first bent portion so that the surface of the flexible insulating substrate on which the wiring pattern is not formed contacts and the wiring pattern is located on the outside. The flexible wiring board that is bent at the first bent portion at approximately 180 degrees so that the electronic component mounted on the electronic component mounting scheduled portion in the electronic component mounting area is located outside the bent flexible wiring board is A flexible semiconductor device is formed by being bent again so that the outer leads face each other in a direction perpendicular to the bent portion. The electrical connection between the output-side outer lead of the flexible semiconductor device and the transparent electrode formed on the display device is established by an anisotropic conductive adhesive, and the input-side outer lead is displayed. The semiconductor device is electrically connected to an electronic component circuit for driving the device, and a semiconductor mounted on the flexible semiconductor is in contact with a metal plate for heat dissipation.

  Further, in the display device, the heat radiating metal plate is disposed inside the edge of the housing of the display device, and heat generated from an electronic component in contact with the heat radiating metal plate is converted to heat of the heat radiating metal plate. It is preferable to discharge to the outside of the housing of the display device using conductivity.

  The display device is preferably a liquid crystal display device, a plasma display device, or an organic EL display device.

  According to the flexible wiring board of the present invention, it is easily manufactured without going through a complicated manufacturing process. And, by bending and using the flexible semiconductor with electronic parts mounted at a predetermined position, the electronic parts that become the heating elements can be positioned on the outermost side, and the heat dissipating metal disposed on the inner peripheral wall surface of the housing By directly contacting the plate, the heat generated in the electronic component can be released efficiently.

  In addition, by using the flexible semiconductor device and the display device of the present invention, even if a semiconductor device having a wiring pattern with a very narrow wiring width on which a lightweight and miniaturized electronic component is mounted is generated from the electronic component. Heat can be efficiently released out of the electronic device.

Next, the flexible wiring board, flexible semiconductor device, and display device of the present invention will be specifically described.
A plan view of the flexible wiring board of the present invention is shown in FIG. 1 (1), and reference numeral 10 is the upper surface of the flexible wiring board of the present invention. FIG. 1B is a cross-sectional view schematically showing a cross section of the flexible wiring board 10 indicated by a one-dot chain line from the arrow X to the arrow Y shown in FIG.

  As shown in FIG. 1 (1), a flexible wiring board 10 of the present invention is a sprocket formed at regular intervals on both side edges of a flexible insulating tape comprising a flexible insulating substrate 12 having a predetermined width. Between the holes 22, the outer lead formation region A and the electronic component mounting region B are adjacent to each other via the first bent portion D. In the electronic component mounting area B, an electronic component mounting bottom C for mounting the electronic component is formed.

  In the flexible wiring board 10 of the present invention, a wiring pattern 14 is formed on one surface of a flexible insulating substrate 12, one end of this wiring pattern forms an outer lead, and the other end is Inner leads are formed. One end of the wiring pattern 14 formed on the flexible wiring board 10 forms the outer lead 16 and the other end forms the inner lead 17.

The wiring pattern 14 includes an input side wiring pattern 14a and an output side wiring pattern 14b.
There is. In the outer lead formation region A, an input side outer lead 16a is formed at one end of the wiring pattern 14a.

The input-side wiring pattern 14a, one end of which forms the input-side outer lead 16a, is routed through the outer lead formation region A and is adjacent to the outer lead formation region A beyond the first bent portion D. It is routed to the mounting area B. In the electronic component mounting area B, an electronic component mounting scheduled portion C where the electronic component is to be mounted is formed, and the other end portion of the input side wiring pattern 14a is input by the electronic component mounting planned portion C. A side inner lead 17a is formed.

Similarly, in the outer lead formation region A, the output-side wiring pattern 14b, one end of which forms the output-side outer lead 16b, is routed around the outer lead region A so that the outer lead extends beyond the first bent portion D. The region A is routed to the adjacent electronic component mounting region B. In the electronic component mounting area B, the electronic component mounting scheduled portion C is formed as described above, and the other end of the output side wiring pattern 14b is connected to the output side inner lead 17b in the electronic component mounting planned portion C. Forming.

By mounting the electronic component E on the electronic component mounting scheduled portion B formed on the flexible wiring board 10 of the present invention, the input side wiring pattern 14a and the output side wiring pattern 14b are formed so as to be electrically connectable. Has been.

  Such a flexible wiring board can be formed, for example, by etching a conductive metal layer formed on the surface of a flexible insulating substrate into a desired shape, as shown in FIG.

That is, the flexible wiring board of the present invention is a resin film that forms a layer having the flexible insulating plate 12 and the conductive metal layer 20 shown in FIG.
Examples of the resin forming the flexible insulating substrate 12 used here include polyester, polyamide, polyamideimide, liquid crystal polymer, and glass fiber-containing epoxy resin in addition to the polyimide described above. . In the present invention, it is particularly preferable to use polyimide.

  Examples of the polyimide constituting the flexible insulating substrate 12 in the present invention include a wholly aromatic polyimide synthesized from pyromellitic dianhydride and aromatic diamine, biphenyltetracarboxylic dianhydride and aromatic diamine, And wholly aromatic polyimides having a biphenyl skeleton synthesized from In particular, in the present invention, a wholly aromatic polyimide having a biphenyl skeleton (eg, trade name: Upilex, manufactured by Ube Industries, Ltd.) is preferably used. A thin polyimide film having an average thickness of 8 to 50 μm, preferably 16 to 40 μm, is usually used. However, when using a polyimide film with such a thickness, it may be difficult to handle alone, so the back side of the polyimide film (the surface opposite to the surface on which the wiring pattern is formed) A composite substrate film obtained by laminating a PET film so as to be peelable can also be used as the reinforcing film. In addition to such a PET film, for example, such a reinforcing film can be used by releasably attaching a polyester film other than a polyimide film for a support and polyethylene terephthalate (PET).

  As a laminate that can be used here, a seed layer and a conductive metal layer are sequentially formed on the surface of a flexible insulating substrate. Here, the seed layer is usually a sputtering layer of a seed metal such as nickel, chromium, or copper, and the thickness thereof is usually in the range of 20 to 300A, preferably in the range of 30 to 250A. A conductive metal layer 20 made of a conductive metal is formed on the surface of the seed layer. The thickness of the conductive metal layer 20 is usually 0.1 to 2 μm, preferably 0.1 to 1.5 μm. It is in the range. Examples of such a flexible insulating substrate and a substrate having a seed layer include Esperflex (trade name: Sumitomo Metal Mining Co., Ltd.), Diafine (trade name: Mitsubishi Shindoh Co., Ltd.), and Macinas (trade name: Nikko Metal Co., Ltd.).

  The conductive metal that forms the conductive metal layer 20 may be the same as or different from the metal that forms the wiring pattern. Further, when the metal forming the conductive metal layer 20 and the metal forming the wiring pattern are the same, the conductive metal layer 20 is integrated into the wiring pattern, and the boundary between the two can be identified. Sometimes it disappears. Here, examples of the metal forming the conductive metal layer 20 include copper and a copper alloy.

  As shown in FIG. 2B, a conductive metal layer 20 made of a conductive metal such as copper or a copper alloy is formed on one surface of the flexible insulating substrate shown in FIG. The conductive metal layer 20 can be formed by various methods such as vapor deposition, sublimation-deposition, electrolytic plating, and electroless plating.

  Also, instead of forming a conductive metal layer on one surface of the flexible insulating substrate as described above, the polyimide precursor solution is applied to one surface of the copper foil, and then dried and cured to be flexible. It is also possible to form an insulating substrate layer and to form a laminate composed of the flexible insulating substrate 12 and the conductive metal layer 20. Thus, the laminated body (brand name: Espanex, Nippon Steel Chemical Co., Ltd.) marketed as a laminated body which has an electroconductive metal layer on one surface of copper foil can also be used.

Next, as shown in FIG. 2C, a sprocket hole 22 is formed through the conductive metal layer 20 and the flexible insulating substrate 12 by punching or the like. The sprocket holes 22 may be formed on the surface of the flexible insulating substrate 12 (on the conductive metal layer 20 side), or conversely, may be formed from the back surface of the flexible insulating substrate 12. The sprocket hole 22 may be formed in the flexible insulating substrate 12 in advance before forming the conductive metal layer 20 on the surface of the flexible insulating substrate 12. When the seed layer and the conductive metal layer 20 are produced by the sputtering method as described above, since it is advantageous that the sputtering area is somewhat large, the width is wider than the width of the film carrier tape for mounting electronic components to be formed. After performing sputtering using the flexible insulating substrate 12, it is preferable to slit so as to have a predetermined width.

  The above example is an example of a laminate in which a conductive metal layer is disposed on one surface of a flexible insulating substrate. However, the core material is a conductive metal on both surfaces of the flexible insulating substrate. A wiring pattern can be formed using a conductive metal layer formed on one surface of the two-layer laminate using the two-layer laminate in which the layers are arranged. Further, when such a two-layer laminate is left in the bent portion and the flexible wiring board is bent, it is possible to prevent the bending deformation from returning due to the elasticity of the board (spring back).

Next, as shown in FIGS. 2D to 2H, the conductive metal layer 20 is selectively etched using a general photolithography method to form the wiring pattern 14.
First, as shown in FIG. 2D, a photosensitive resin layer 24 is formed by applying, for example, a negative photoresist material coating solution over a region where the wiring pattern 14 is formed. At this time, a positive photoresist material may be used.

  Moreover, when forming this photosensitive resin layer 24, you may form by apply | coating the resin composition which consists of photosensitive resin and a solvent, or it punches out the sheet | seat (dry film) which consists of photosensitive resin, and this is formed. You may stick and form.

  When a resin composition composed of a photosensitive resin and a solvent is applied and formed, the solvent component can be removed and dried and cured by a known drying means such as a tunnel-type heating furnace. On the other hand, when a photosensitive resin layer is formed by laminating a dry film coated with a negative photoresist, the photosensitive resin layer 24 can be efficiently formed without requiring a solvent removal time or the like.

  The thickness of the photosensitive resin layer 24 can be appropriately set according to the thickness of the wiring pattern to be formed, but is usually in the range of 2 to 25 μm, preferably 4 to 20 μm in terms of dry thickness. .

  After forming the photosensitive resin layer 24, the flexible insulating substrate 12 is positioned by inserting positioning pins into the sprocket holes 22 as shown in FIG. A photomask 28 on which a predetermined circuit is drawn is arranged on the surface of the photosensitive resin layer 24, and the irradiation light 26 is irradiated from the light source to expose and image the photosensitive resin forming the photosensitive resin layer 24.

The irradiation light 26 used for exposure here can be exposed more sharply by using light having a relatively short wavelength, for example, ultraviolet rays. In general, a photosensitive resin that is exposed to ultraviolet light is easily exposed to visible light, so the exposure chamber must be kept in a UV-cut state. In the case of exposure using ultraviolet rays, the amount of ultraviolet rays to be irradiated varies depending on the photosensitive resin used, but is usually 50 to 3000 mJ / cm ² , preferably 80 to 2500.
It is in the range of mJ / cm ² . By irradiating with such an irradiation dose of ultraviolet rays, the photosensitive resin of the planned portion can be reliably cured.

  When the photosensitive resin is cured by exposure as described above, and developed with an aqueous solution of an alkali metal carbonate, for example, as shown in FIG. 2 (f), a cured body (masking material) 24a of the photosensitive resin is obtained. Remaining, a desired wiring pattern (a predetermined pattern made of a cured body of a photosensitive resin) is formed on the surface of the conductive metal layer 20.

Next, the conductive metal layer 20 not covered with the masking material is selectively dissolved with an etching solution and removed by using a predetermined pattern made of the cured photosensitive resin thus formed as a masking material (see FIG. 2 (g)). Examples of the etching solution that can be used here include an etching solution containing potassium persulfate (K ₂ S ₂ O ₈ ) as a main component and a concentration of, for example, 100 to 200 g / liter, and cupric chloride etching solution. .

  Further, as shown in FIG. 2 (h), the masking material having a predetermined pattern made of a cured product of the photosensitive resin is dissolved and removed with a release agent containing an alkali component such as an alkali metal hydroxide. Then, the wiring pattern 14 is formed. Here, the release agent to be used is an alkaline aqueous solution such as an aqueous sodium hydroxide solution.

  As shown in FIG. 2I, a solder resist layer 32 is formed on the wiring pattern thus formed so that the inner lead and the outer lead are exposed. The average thickness of the solder resist formed here is usually in the range of 5 to 45 μm, but the first bent portion is more easily bent so that the portion of the first bent portion D can be bent more easily. The coating thickness of the solder resist ink in D can also be made relatively thinner than other portions.

  Such a solder resist layer can be formed by applying a solder resist ink using a screen mask as described above, or can be formed by sticking a solder resist film punched into a predetermined shape in advance. You can also.

  Further, after forming a thin plating layer on the entire wiring pattern 14 without forming the solder resist layer 32, the solder resist layer is formed according to the above-described method, and the surfaces of the inner leads and outer leads exposed from the solder resist layer are formed. Alternatively, plating may be performed.

  Examples of the plating process performed here include various plating processes such as a tin plating process, a nickel plating process, a gold plating process, a nickel-gold plating process, a solder plating process, a lead-free solder plating process, and a silver plating process. . In particular, in the electronic component mounting region, when the bump electrode is a gold bump electrode, in order to form a eutectic material with gold and form a reliable electrical connection between the bump electrode and the inner lead, It is preferable to form a plating layer. Moreover, the plating layer does not need to be a single layer, and may be a multilayer plating layer made of the same metal, or may be a dissimilar metal multilayer plating layer in which different metals are laminated.

  As shown in FIG. 1 (1), the flexible wiring board 10 manufactured through such a process includes an inner lead side wiring pattern 14 a derived from the conductive metal layer 20 on the flexible insulating substrate 12 and an outer layer. Lead-side wiring pattern 14b is formed.

The tip of the input side wiring pattern 14a provided in the inner lead formation region A is exposed from the solder resist layer 32 to form the input side inner lead 17a. The input side wiring pattern 14a covered with the solder resist layer 32 is: After being routed through the inner lead formation region A, the region is routed to the electronic component mounting region B beyond the first bent portion D. In this electronic component mounting region B, an electronic component mounting scheduled portion C is formed.
The input-side wiring pattern 14a routed to the electronic component mounting region B across the bent portion D extends to face the electronic component mounting planned portion C to form the input-side inner lead 17a.

On the other hand, similarly to the input side wiring pattern 14a, an output side wiring pattern 14b is formed in the outer lead forming region 10a, and the output side is usually at a position facing the input side outer lead 16a. Outer leads 16b are formed. The output side wiring pattern 14b is routed around the surface of the outer lead formation region A, gets over the bent portion D, and is routed to the electronic component mounting region B. As described above, the electronic component mounting area B is formed with the electronic component mounting planned portion C, and the input-side inner lead 17a formed so as to protrude from the electronic component mounting planned portion C is formed. The edge portion of the planned mounting portion C and the edge portion of the electronic component mounting planned portion C where the output-side inner leads 17b are formed face each other.

  In this way, the input-side inner part 17a and the output-side inner part 17b are formed opposite to the electronic part mounting scheduled part C formed in the electronic part mounting region B, and the flexible wiring board of the present invention is formed. In FIG. 5, the input-side inner lead 17a and the output-side inner lead 17b are electrically insulated in the electronic component mounting scheduled portion 18.

In the flexible wiring board of the present invention, the output side outer lead 16b and the output side inner lead 17b of the output side wiring pattern 14b, and the input side wiring pattern 1
The surface of the wiring pattern is covered with a solder resist except for the upper surfaces of the input side outer leads 16a and the output side inner leads 17b.

The flexible wiring board of the present invention usually has the input side outer lead 16a and the output side outer lead 16b in the outer lead formation region A as described above. However, as shown in FIG. Outer lead 16a or output-side outer lead 16b
Any one of these may be formed in the electronic component mounting region B.

  FIG. 3 shows a mode in which the output-side outer lead 16b is formed in the electronic component mounting region B. FIG. 4 shows an example of the flexible semiconductor device of the present invention in which the electronic component E is mounted on the flexible wiring board shown in FIG.

As shown in FIG. 4, in the flexible semiconductor device of the present invention, an input-side outer lead 16a and an output-side outer lead 16b are formed in the outer lead formation region A, and the wiring pattern is connected to the outer leads 16a and 16b. 14a and 14b are routed around the outer lead formation region A, and then routed around the electronic component mounting region B where the electronic component mounting planned portion C is formed beyond the first bent portion D. An input-side inner lead 17a and an output-side inner lead 17b formed in the electronic component mounting portion C are formed. FIG. 4 shows an aspect in which a notch F is formed at the edge of the electronic component E and the electronic component mounting region B.

By mounting an electronic component on the electronic component mounting scheduled portion C of the printed wiring board of the present invention, the printed wiring board can be used as a flexible semiconductor device. That is, as described above, two series of wiring patterns having one end as an outer lead and the other end as an inner lead are formed, and a predetermined electronic component E is formed in an electronic component mounting planned portion C formed in the electronic component mounting region C. Is implemented. For mounting of this electronic component, a bonding tool is brought into contact with the lower surface of the flexible insulating substrate, heated and pressurized, and further subjected to ultrasonic waves as necessary. For example, the bump electrode of the electronic component is a gold bump electrode. Yes, when tin plating is applied to the surfaces of the inner leads 17a and 17b, a gold-tin eutectic is generated by heating and pressurization, and the inner leads 17a in the electronic component E and the electronic component mounting portion C, An electrical connection is formed with 17b.

The pressure at this time is usually set in the range of 5 to 50 mg / μm ² , preferably 10 to 40 mg / μm ² , and the temperature is usually in the range of 400 to 480 ° C., preferably 410 to 460 ° C. Set in. Moreover, when using an ultrasonic wave, an ultrasonic wave with an amplitude of 0.5 to 10 μm, preferably 0.8 to 8 μm is used. Under such conditions, mounting of the electronic component is completed in 0.1 to 1 second.

After mounting the electronic component on the flexible wiring board of the present invention as described above, the bonding portion is filled with a sealing resin made of a thermosetting resin in order to ensure the bonding state between the flexible wiring board and the electronic component. And cured by heating. The heating and curing temperature at this time varies depending on the sealing resin used, but is usually 80 to 170 ° C., preferably 90 to 160 ° C., and the heating time is usually 30 to 300 minutes at this temperature. Preferably it is in the range of 50 to 240 minutes.

  As described above, the flexible semiconductor device of the present invention has the input-side outer lead 16a and the output-side outer lead 16b in the outer lead forming region A, and the electronic component mounting region B is adjacent to the first bent portion D. In the electronic component mounting bottom C formed in the electronic component mounting region B, an electrical connection is formed between the inner lead and the bump electrode formed on the electronic component. And this junction part is normally sealed with sealing resin, and the electronic component and the flexible wiring board are integrated.

The semiconductor device having the above configuration is used by being bent by a method different from that of a normal semiconductor device.
First, as shown in FIG. 4, the semiconductor device of the present invention cuts out the outer peripheral portion including the sprocket hole used to form the flexible wiring board, and cuts the front and rear portions in the MD direction of the electronic component mounting region B. A notch F is formed. This notch width is normally set to 85 to 95% when the length of the longest portion of the flexible wiring board in the MD direction is 100%. By forming the notch F, the first bent portion D can be easily bent, and heat and pressure can be directly applied to the outer lead when performing anisotropic conductive bonding.

The notch F is usually in the range of 2 to 10 mm, preferably 3 to 8 mm. By forming the notch F with such a width, a jig used for anisotropic conductive bonding can be easily used, and anisotropic conductive bonding can be performed with higher accuracy.

FIG. 5 shows a state where the semiconductor (flexible wiring board) of the present invention is bent in two at the first bent portion D as described above. That is, in the present invention, the electronic component E, the wiring pattern 14a
, 14b, the input side outer lead 16a and the output side outer lead 16b are on the outside, and are bent approximately 180 °, that is, bent in two, so that the back surface of the insulating film on which no wiring pattern is formed abuts. At this time, since the outer lead formation region A and the electronic component mounting region B occupy substantially the same area, the bent pieces have substantially the same size. In this bending operation, the positions of the first bent portions D are made clear by forming the notches F on both sides of the electronic component mounting region B, and the first bending can be performed more stably. . Further, it can be easily connected to a display means such as a liquid crystal panel or a printed circuit board as input means.

As shown in FIG. 5, when the semiconductor (flexible wiring board) of the present invention is bent at the first bent portion D, the semiconductor of the present invention is also shown in FIG. 5 due to the elasticity of the flexible insulating film. May not be able to be fixed in any form. In this case, the semiconductor of the present invention can be held in the form shown in FIG. 5 by using, for example, a double-sided adhesive tape on the surface opposite to the surface on which the electronic component E is mounted. In addition, when a laminated body in which conductive metal foils on both sides of an insulating substrate are laminated is used, the second bent portion D is formed on the back surface of the first bent portion D, or in addition,
By leaving the conductive metal foil with a predetermined width on the back surface of the bent portion, the conductive metal foil on the back surface may bend and overcome the restoring force due to the elasticity of the flexible insulating film. The shape shown in FIG. 5 can be maintained.

After the first bent portion D is bent as described above, the input-side outer leads 14a and the output-side outer leads are placed on both sides of the electronic component E so that the electronic component E is located outside as shown in FIG. The second bend is performed 90 degrees at two positions so as to be perpendicular to the first bend portion D so that the leads are opposed to each other so as to form a gap approximating the width of the electronic component E. In this way, by performing the second bending at approximately 90 degrees in two places, the electronic component E is disposed so as to be exposed to the outside of the portion of the vertical line folded in the “U” shape, and thus disposed. There is nothing that hides the heat generated from the electronic component E around the electronic component E, and the heat can be radiated with high efficiency.

  After performing the first bending in this way, the semiconductor device subjected to the second bending can be incorporated into an electronic device as shown in FIG. 7, for example. FIG. 7 shows an example in which the semiconductor device of the present invention is used as a semiconductor for driving a display device.

That is, in FIG. 7, the semiconductor device 10 of the present invention formed in a “U” shape by bending the terminal portion of the input means 34 twice as shown in FIG. 6 is the input of the semiconductor device 10 of the present invention. The outer outer lead 16a and the electrode formed on the input means are arranged so that electrical connection can be formed, and in an ordinary case, anisotropic conductive bonding is performed. The electrical signal thus input to the input side outer lead 16a is supplied from the wiring pattern to the electronic component E via the input side inner lead 17a. The electronic signal input to the electronic component E is processed in the electronic component E, so that the electronic component E generates heat.

  On the other hand, a heat radiating metal plate 36 is disposed on the inner surface of the housing 38 of the display device, and the outer surface of the electronic component E is in contact with the heat radiating metal plate 36. In the display device, the heat radiating metal plate 36 is extended to a portion where the heat dissipation efficiency is better, and the heat collected by the contact with the electronic component E is, for example, the upper portion on the rear surface of the display device where the heat dissipation efficiency is good. Dissipate heat.

  On the other hand, the electrical signal processed by the electronic component E passes through the output-side inner lead 17b and reaches the output-side outer lead 16b via the wiring pattern 14b, and this electrical signal is transmitted to the output-side outer lead 16b and the display device 35. The transparent electrode made of ITO or the like is connected by, for example, anisotropic conductive bonding and introduced into the display device 35 to control the display device 35.

  The display device 35 is usually formed with pixels of 400,000 to 5 million pixels, and each pixel of the display device is a book placed in a housing at the bottom edge and a housing at the side edge of the display device. It is controlled by the semiconductor device of the invention.

  Further, the electronic component E may be brought into contact with the casing 38 via a high thermal conductive sheet without using the heat radiating metal plate 36. In this case, it is preferable to make contact between the high thermal conductivity sheet and the electronic component or the housing so that air does not enter.

In the description of the flexible wiring board, the semiconductor device, and the display device of the present invention, the solder resist layer, the plating layer, and the like are omitted where not particularly necessary.
Examples of the above display device include a liquid crystal display device, a plasma display device, an organic EL display device, and the like.

  As described above, by using the flexible wiring board of the present invention, the temperature in the vicinity of the electronic component for driving the display device can be suppressed to about 10 to 35 ° C., so that the malfunction of the display device due to the temperature rise is small and the display is performed. The apparatus can be used stably for a long time.

Next, although the Example of this invention and a comparative example are shown and the flexible wiring board of this invention is demonstrated concretely, this invention is not limited by these.
[Example 1]
After slitting a CCL substrate (Esperflex, manufactured by Sumitomo Metal Mining Co., Ltd.) consisting of a 35 μm thick polyimide layer and an 8 μm copper layer to a width of 70 mm, a mold is placed and a punching machine is used to sprocket holes (1 .981 mm square, 4.75 mm pitch).

  Next, a positive type photoresist solution (FR1000, manufactured by Rohm and Haas) is applied to the CCL substrate by a roll coater so as to have a thickness of 4 to 5 μm on the copper surface side of the CCL substrate. Then, the solvent component of the photoresist solution was evaporated at 100 ° C. for 1 minute, and the photoresist component was dried and cured to form a photosensitive resin layer. In addition, when apply | coating a photoresist solution, it apply | coated with the roll coater of width 60mm so that a photoresist solution may not be apply | coated on a sprocket hole.

  Thereafter, an outer lead forming area having a width of 30 mm provided with an output outer lead and an input outer lead, and a part having a width of 30 mm provided with a part for mounting an electronic component on the input inner lead and the output inner lead (part to be mounted). The area to be mounted is irradiated with ultraviolet rays by a UV exposure apparatus manufactured by USHIO INC. Through a drawn glass photomask (minimum pitch 30 μm), and the photosensitive resin layer formed on the substrate surface is imaged. .

  After exposure and imaging, development was performed to form a resist pattern. Thereafter, spray etching was performed with a cupric chloride etchant to form a wiring pattern, and the resist was stripped with a sodium hydroxide solution.

Next, it was immersed in an electroless plating solution to form a tin plating layer on the circuit pattern surface.
Finally, a solder resist was screen printed, and a solder resist layer was formed according to a conventional method to obtain a COF substrate.

  The prepared COF substrate can be bent between the outer lead formation region and the planned mounting region so that the flexible insulating substrate surface on which the wiring pattern is not formed contacts, and the flexible insulating substrate surface contacts. The COF substrate bent 180 degrees in this way is perpendicular to the bent portion formed by contacting the flexible insulating substrate, and is bent 90 degrees at two locations so that the mounting planned portion is located outside. I was able to.

  In this case, the electronic component does not have a structure surrounded by the flexible wiring board, the input unit connected to the input side outer lead, and the display unit connected to the output side outer lead, as shown in FIG. The electronic component could be brought into contact with the heat-dissipating metal plate directly or via a high thermal conductive sheet.

  Assuming this structure, a structure in which the heat generating element 42 is fixed to the metal plate 36 for heat release / radiation and the COF substrate 44 via the double-sided adhesive sheet 43 is formed by the following steps (FIG. 8 (1)), It used for the heat dissipation test.

First, a COF substrate, a heating element, a heat radiating metal plate, and a double-sided pressure-sensitive adhesive sheet as shown below were prepared.
COF substrate: Esperflex (manufactured by Sumitomo Metal Mining Co., Ltd.) with a thickness of 70 mm × 223 mm × 43 μm (polyimide layer 35 μm and copper layer 8 μm)
Heating element: 50 mm × 15 mm bottom width (10 mm upper width) × 10 mm height, resistance 15Ω heating element (manufactured by ARCOL)
Heat dissipation metal plate: 300 mm × 460 mm × 1.6 mm thickness, iron heat dissipation metal plate Double-sided adhesive sheet: 25 mm × 70 mm × 40 μm-thick double-sided adhesive sheet Next, as a part where the heating element is fixed on the COF substrate, The copper layer was removed by etching, and a 10 mm × 40 mm polyimide exposed portion was formed.

  Further, the heating element is fixed to the heat radiating metal plate via the double-sided adhesive sheet, and a surface different from the surface of the heating element to which the heat radiating metal plate is fixed is interposed via the similar double-sided adhesive sheet 43. The structure 1 as shown by the number 48a in FIG. 8 (1) was formed by fixing to the exposed portion of the polyimide on the COF substrate 44.

  A current of 1 A was applied to the heating element 42 of the produced structure 1 by a rectifier. The surface temperature of the heating element 42 was measured with an infrared thermometer (IR-100: manufactured by Custom) at a position 20 mm away from the side surface of the heating element every 5 minutes from energization to 30 minutes. In addition, the atmospheric temperature at the time of a measurement was 25 degreeC, and relative humidity (RH) was 28%.

The obtained result is shown in A (broken line part) of FIG.
Note that the heating element was used instead of the electronic component here because the amount of heat generated by the electronic component varies significantly depending on the type, processing signal, etc. Since the heat dissipation characteristic of the flexible wiring board of the invention cannot be measured with high accuracy, the flexible wiring board of the invention has the heat generating element that generates a constant amount of heat generated by flowing a constant current as an electronic component. This is to accurately measure the heat dissipation.
[Comparative Example 1]
Example except that a CCL substrate having a conductive metal layer is slit to a width of 35 mm, and an input side inner lead, an output side inner lead, and a portion to be mounted are formed between regions where the output side outer lead and the input side outer lead face each other. A COF substrate was produced in the same manner as in Example 1.

  As shown in FIG. 10, the COF substrate 2 on which the electronic component is mounted on the part to be mounted has the electronic component E surrounded by the polyimide substrate, the input unit 34, and the display unit 35. Further, the electronic component E was not in direct contact with the heat radiating metal plate 36, but was in contact with the polyimide film substrate constituting the COF substrate.

  Assuming this structure, the COF substrate 44 is disposed on the heat radiating metal plate 36 via the double-sided adhesive sheet 43 by the following steps, and the heating element 42 is attached to the polyimide film substrate of the COF substrate 44 by double-sided adhesive. A structure that was fixed through the sheet 43 and further covered with the upper surface of the heating element 42 on the copper surface side of the copper laminate 46 was formed (FIG. 8b) and subjected to a heat dissipation test.

First, the following coating copper laminated plates were prepared together with the same COF substrate, heating element, heat radiating metal plate and double-sided adhesive sheet as in Example 1.
The polyimide film surface of the COF substrate is fixed on the heat radiating metal plate 36 via the double-sided adhesive sheet, and the polyimide exposed portion previously formed by etching on the COF substrate (copper surface) is interposed via the double-sided adhesive sheet. The heating element was fixed.

  Further, the heating element and the COF substrate are coated with the copper layer surface of the coating copper laminate, and the contact portion between the coating copper laminate, the heating element and the COF substrate is fixed with a double-sided adhesive sheet of 10 mm × 40 mm, and FIG. The structure 2 as shown in the number 48b of (2) was obtained.

A current of 1 A was applied to the created heating element of the structure 2 by a rectifier, and the surface temperature of the heating element 42 was measured under the same conditions as in Example 1 every 5 minutes from the energization.
The obtained results are shown in FIG. 9B (solid line part).

  As shown in FIG. 9, in the structure 1, since the heating element fixed to the COF substrate is in direct contact with the heat radiating metal plate, it can efficiently dissipate heat immediately after the test (5 The surface temperature of the heating element was suppressed to less than 80 ° C. (maximum temperature: 76.8 ° C.), although a slight increase in surface temperature was observed from 30 minutes to 30 minutes later.

  On the other hand, in the case of the structure 2 assuming a conventional structure, the heating element had a surface temperature exceeding 80 ° C. immediately after the test (after 5 minutes). Furthermore, the surface temperature increased with time after the start of the test, and after 30 minutes from the start of the test, the surface temperature of the heating element in the structure 1 was higher by 20 ° C. or higher to 97.3 ° C. Had reached. The reason for this is that the heat generating element is surrounded by a flexible insulating substrate (polyimide film) with low thermal conductivity and other structures, and heat is retained, and further, heat is effectively applied to the metal plate for heat dissipation. This is thought to be because it was not able to be released.

  According to the flexible wiring board of the present invention, the flexible wiring board can be easily manufactured without going through a complicated manufacturing process, and the heat generated from the electronic component can be efficiently released when the electronic component is mounted. A wiring board can be provided.

  In addition, by providing such a flexible wiring board, it is possible to provide a flexible semiconductor device capable of efficiently releasing heat generated from electronic components and a liquid crystal display device with extremely high heat dissipation.

FIG. 1A is a view showing a state of the flexible wiring board of the present invention as viewed from above. Moreover, FIG.1 (2) is a figure which shows sectional drawing of the flexible wiring board in the arrow part of FIG.1 (1). 2 is a cross-sectional view showing an example of a process for manufacturing the flexible wiring board shown in FIG. FIG. 3 is a diagram showing another aspect of the flexible wiring board of the present invention. FIG. 4 is a perspective view showing an example of the flexible semiconductor device of the present invention in which electronic components are mounted on a flexible wiring board. FIG. 5 is a perspective view showing a state where the flexible semiconductor device shown in FIG. 4 is bent 180 degrees at the first bent portion. FIG. 6 shows the flexible semiconductor device of the present invention bent 180 degrees at the first bent portion shown in FIG. 5 at two positions 90 degrees beside the electronic component E so that the electronic component E faces outward. It is a perspective view which shows the example of the semiconductor device of this invention bent by FIG. FIG. 7 is a cross-sectional view showing a state in which the flexible semiconductor device of the present invention shown in FIG. 6 is incorporated in a display device. FIG. 8 (1) schematically shows a test apparatus (structure 1) for representing the relationship between the surface temperature and its change over time in the flexible semiconductor device of the present invention formed using the flexible wiring board of the present invention. FIG. 8 (2) shows the surface temperature of a conventional flexible wiring board on which a heating element used in FIG. 8 (1) is mounted instead of an electronic component, and its aging, similar to a conventional semiconductor device. It is a figure which shows typically the test device (structure 2) for expressing the relationship of a mechanical change. FIG. 9 is a graph showing a heat generation state when an electronic component is mounted on the flexible wiring board of the present invention and a heat generation state when the electronic component is mounted on a conventional conventional flexible wiring board. FIG. 10 is a diagram illustrating an installation state of a semiconductor device in a conventional display device.

Explanation of symbols

A: outer lead formation region B: electronic component mounting region C: electronic component mounting planned portion D: first bent portion E: electronic component F: notch portion 10: flexible wiring board 10c of the present invention: wiring pattern surface 11: Another embodiment of the flexible wiring board 12: flexible insulating board 14a: input side wiring pattern 14b: output side wiring pattern 16: outer lead 16a: input side outer lead 16b: output side outer lead 17: inner lead 17a : Input-side inner lead 17b: output-side inner lead 20: conductive metal layer 22: sprocket hole 24: photosensitive resin layer 24a: photosensitive resin cured body (masking material)
26: Irradiation light 28: Photomask 32: Solder resist layer 33: Liquid crystal device 34 equipped with the flexible wiring board of the present invention 34: Input means 35: Display means 36: Metal plate 38 for heat dissipation: Housing 39: Conventional flexible wiring Substrate 40: conventional liquid crystal display device 42: heating element 43: double-sided adhesive sheet 44: COF substrate 46: copper laminate 48a: structure 1
48b: Structure 2

Claims (9)

Outer lead formation region occupying approximately half of the tape width direction orthogonal to the feeding direction of the flexible substrate, and electronic component mounting occupying substantially the other half of the tape width direction orthogonal to the feeding direction of the flexible substrate A flexible insulating substrate adjacent to each other through a first bent portion formed between the two regions, and a flexible wiring substrate having a wiring pattern formed on one surface of the flexible insulating substrate ,
One end of the wiring pattern formed on the flexible wiring board is an outer lead composed of an input outer lead and an output outer lead, and the other end is an inner lead composed of an input inner lead and an output inner lead. And
The wiring pattern in which the input side inner lead and the input side outer lead are formed and the wiring pattern in which the output side inner lead and the output side outer lead are formed are formed on the electronic component mounting planned portion formed in the electronic component mounting region. By being mounted with electronic components, it is formed to be electrically connectable,
The flexible wiring board is formed so that it can be bent approximately 180 degrees at the first bent portion so that the surface of the flexible insulating substrate on which the wiring pattern is not formed comes into contact and the wiring pattern is located outside. The flexible printed circuit board bent approximately 180 degrees is subjected to a second bend such that the outer lead faces in a direction perpendicular to the first bent portion bent approximately 180 degrees with the electronic component mounting area on the outside. A flexible wiring board characterized by being formed as possible.   In the outer lead formation region, an input side outer lead and an output side outer lead are formed so as to face the edge of the flexible wiring board, and a wiring pattern for forming an input side outer lead from the outer lead region The input inner lead is formed in the electronic component mounting planned portion of the electronic component mounting region beyond the first bent portion, and the wiring pattern forming the output outer lead is routed from the outer lead region. 2. The flexible wiring board according to claim 1, wherein an output-side inner lead is formed at an electronic component mounting scheduled portion of the electronic component mounting planned portion beyond the first bent portion.   The length of the outer lead forming region in the feeding direction of the flexible wiring substrate is formed to be the widest, and the width of the flexible wiring substrate extends from the first bent portion to the electronic component mounting region in the outer lead forming region. 2. A notch portion of a flexible insulating substrate is formed at the front and rear edge portions in the feed direction so as to decrease to 85 to 95% with respect to the width (100%). The flexible wiring board as described.   In order to maintain this bent state when the flexible substrate is bent at approximately 180 degrees at the first bent portion on the surface of the flexible wiring substrate on which the wiring pattern of the flexible insulating substrate is not formed. 2. The flexible wiring board according to claim 1, wherein an adhesive is formed on a part of the back surface of the flexible insulating substrate so as to be disposed. Outer lead formation region occupying approximately half of the tape width direction orthogonal to the feeding direction of the flexible substrate, and electronic component mounting occupying substantially the other half of the tape width direction orthogonal to the feeding direction of the flexible substrate A flexible insulating substrate adjacent to each other through a first bent portion formed between the two regions, and a flexible wiring substrate having a wiring pattern formed on one surface of the flexible insulating substrate One end of the wiring pattern formed on the flexible wiring board is an outer lead composed of an input outer lead and an output outer lead, and the other end is an inner lead composed of an input inner lead and an output inner lead. And
The wiring pattern in which the input side inner lead and the input side outer lead are formed and the wiring pattern in which the output side inner lead and the output side outer lead are formed are formed on the electronic component mounting planned portion formed in the electronic component mounting region. Electrically connected by the mounted electronic components,
The flexible wiring board on which the electronic component is mounted is bent by approximately 180 degrees at the first bending portion so that the surface of the flexible insulating substrate on which the wiring pattern is not formed contacts and the wiring pattern is located outside. In addition, the flexible printed circuit board bent at about 180 degrees is bent at about 180 degrees at the first bent portion so that the electronic component mounted on the electronic component mounting planned portion in the electronic component mounting area is located outside. A flexible semiconductor device, wherein the flexible wiring board is bent again so that the outer leads face each other in a direction perpendicular to the first bent portion.   An adhesive is disposed on the back side of the flexible insulating substrate of the flexible wiring board that is bent at approximately 180 degrees so that the back side of the flexible insulating substrate abuts at the first bent portion. 6. The flexible semiconductor device according to claim 5, wherein at least a part of the flexible insulating substrates are attached to each other. Outer lead formation region occupying approximately half of the tape width direction orthogonal to the feeding direction of the flexible substrate, and electronic component mounting occupying substantially the other half of the tape width direction orthogonal to the feeding direction of the flexible substrate A flexible insulating substrate adjacent to each other through a first bent portion formed between the two regions, and a flexible wiring substrate having a wiring pattern formed on one surface of the flexible insulating substrate One end of the wiring pattern formed on the flexible wiring board is an outer lead composed of an input outer lead and an output outer lead, and the other end is an inner lead composed of an input inner lead and an output inner lead. A wiring pattern formed with the input inner lead and the input outer lead, and the output inner lead and the output outer. -The wiring pattern on which the lead is formed is electrically connected by the electronic component mounted on the electronic component mounting planned portion formed in the electronic component mounting region,
The flexible wiring board on which the electronic component is mounted is bent by approximately 180 degrees at the first bending portion so that the surface of the flexible insulating substrate on which the wiring pattern is not formed contacts and the wiring pattern is located outside. In addition, the flexible printed circuit board bent at about 180 degrees is bent at about 180 degrees at the first bent portion so that the electronic component mounted on the electronic component mounting planned portion in the electronic component mounting area is located outside. The flexible printed circuit board is bent again so that the outer leads face each other in a direction perpendicular to the first bent portion to form a flexible semiconductor device,
An electrical connection is established with an anisotropic conductive adhesive between the output-side outer lead of the flexible semiconductor device and the transparent electrode formed on the display device, and the input-side outer lead is connected to the display device. It is electrically connected to the electronic component circuit to be driven,
A display device, wherein a semiconductor mounted on the flexible semiconductor is in contact with a metal plate for heat dissipation.   The heat dissipating metal plate is disposed inside the edge of the housing of the display device, and heat generated from electronic components in contact with the heat dissipating metal plate is utilized using the thermal conductivity of the heat dissipating metal plate, The display device according to claim 7, wherein the display device is discharged outside the housing of the display device.   8. The display device according to claim 7, wherein the display device is a liquid crystal display device, a plasma display device, or an organic EL display device.

Images