JP2006171601A - Package structure, manufacturing method for electro-optical device, the electro-optical device, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package structure where a semiconductor chip and a wiring board are packaged in a smaller space through a simplified process, a manufacturing method for an electro-optical device with the package structure, the electro-optical device, and electronic equipment. <P>SOLUTION: A liquid crystal display device 1 as the package structure includes a driver IC 8 which has bump electrodes 11a and 11b for connection on an active surface 8a, an FPC 20 having a terminal part for connection on a jointing surface 22, and a substrate 2 which has input/output terminal parts 5a and 5b, corresponding to the bump electrodes 11a and 11b and terminal part for connection at a terminal part 2a of a liquid crystal display panel 12; and at least the active surface 8a of the driver IC 8, the jointing surface 22 of the FPC 20, the input/output terminal parts 5a and 5b, and a wiring part 5c connected thereto are filled with an adhesive 9 and the bump electrodes 11a and 11b and the terminal part for connection are electrically jointed to the corresponding input/output terminal parts 5a and 5b and mounted on the substrate 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mounting structure on which a semiconductor chip is mounted, an electro-optical device manufacturing method including the mounting structure, an electro-optical device, and an electronic apparatus.

  As a typical display device used for a mobile phone which is a small information terminal, there is an electro-optical device including a liquid crystal display panel and a semiconductor chip for driving the liquid crystal display panel. As a mounting structure of such an electro-optical device, Patent Documents 1 and 2 disclose that the semiconductor chip is mounted on at least one substrate of a liquid crystal display panel by COG (Chip on glass).

  In the COG mounting described above, the input / output electrodes (bumps) formed on the active surface of the semiconductor chip and the input / output terminal portions formed on the substrate of the liquid crystal display panel are connected to an ACF (Anisotropic Conductive Film). It is made to join through. Further, it is necessary to connect a flexible wiring board (FPC) for supplying a driving signal to the semiconductor chip, and an input terminal portion of the input / output terminal portion is extended to a connection portion provided through an ACF. FPC is joined.

JP 2003-249525 A Japanese Patent Laid-Open No. 2004-61979

  However, in the above conventional mounting structure, the ACF for the semiconductor chip and the ACF for the FPC are separately attached to the corresponding input / output terminal portions, and the semiconductor chip and the FPC are joined to the substrate of the liquid crystal panel. is there. If the ACF for the semiconductor chip is attached to the region where the ACF for the FPC is attached with a displacement, the thickness of the ACF increases at that portion, and there is a possibility that a bonding failure may occur when the FPC is joined later. is there. For this purpose, the design of the input / output terminal portion in consideration of the ACF attachment tolerance is required, and an extra space where the ACF for the semiconductor chip and the ACF for the FPC do not overlap is required. Therefore, there is a problem that space-saving design of the input / output terminal portion is difficult.

  In addition, in order to prevent the bonding reliability from being lowered due to foreign matter intrusion and contamination after the semiconductor chip and the FPC are mounted on the substrate of the liquid crystal panel and changes in the temperature and humidity environment, the semiconductor chip and the FPC are included. The mounting area may be covered with a molding material made of resin or the like. Therefore, there is a problem that the mounting process becomes more complicated.

  The present invention has been made in consideration of the above-described problems, and a mounting structure in which a semiconductor chip and a wiring board are mounted in a more space-saving and simplified process, and an electro-optical device including the mounting structure An object of the present invention is to provide a device manufacturing method, an electro-optical device, and an electronic apparatus.

  The mounting structure of the present invention includes a semiconductor chip having a connection electrode on an active surface, a wiring board having a connection terminal portion on an end joint surface, and a connection electrode and a connection terminal portion on the same mounting surface. A circuit board having a corresponding joint terminal portion, and at least the active surface of the semiconductor chip, the joint surface of the wiring board, and the joint terminal portion and the wiring portion connected to the joint terminal portion are buried in an adhesive, The electrode and the connecting terminal portion are electrically joined to the corresponding joining terminal portion and mounted on the circuit board.

  According to this configuration, at least the active surface of the semiconductor chip and the bonding surface of the wiring board, and the bonding terminal portion of the circuit board and the wiring portion connected to the bonding terminal portion are embedded in the adhesive, and the connection electrode of the semiconductor chip And the connection terminal portion of the wiring board are joined to the corresponding joint terminal portion of the circuit board. Therefore, compared with the case where the semiconductor chip and the wiring substrate are bonded to the junction terminal portion of the circuit board through different anisotropic conductive films, the labor and time of attaching the anisotropic conductive film to the circuit board separately are different. Extra space on the circuit board in consideration of the mounting tolerance can be saved. In addition, a process of covering the mounting region including the semiconductor chip and the wiring board with a molding material made of resin or the like can be eliminated in order to prevent foreign matter from entering and contamination of the bonded portion. Therefore, it is possible to provide a mounting structure including a circuit board on which a semiconductor chip and a wiring board are mounted in a space-saving and simplified process.

  The wiring board is a flexible wiring board.

  According to this configuration, since the wiring board is a flexible wiring board, if the mounting structure is joined to the mounting destination using the other end other than the joining surface of the joined flexible wiring board, the flexible wiring board is flexible. The mounting structure can be positioned freely with respect to the mounting destination within the range having

  The adhesive is made of a thermosetting resin or a photocurable resin.

  According to this configuration, since the adhesive is made of a thermosetting resin or a photocurable resin, after the adhesive is applied, the connection electrode of the semiconductor chip and the connection terminal of the wiring board are connected to the connection terminal of the circuit board. If it heats or light-irradiates after crimping | bonding to, an adhesive agent will harden | cure and it can join a connecting electrode and a connecting terminal part with a corresponding joining terminal part.

  The adhesive may include any one of an epoxy-based, acrylic-based, urethane-based, silicon-based, and polyimide-based binder.

  According to this configuration, since the adhesive includes any one of epoxy, acrylic, urethane, silicon, and polyimide binders, the cured adhesive has electrical insulation and temperature and humidity. Therefore, a mounting structure having high connection reliability can be provided. Therefore, in order to ensure connection reliability, it is possible to omit the step of molding using resin or the like.

The adhesive preferably has a moisture permeability of 100 g / m ² · 24H or less after curing.

According to this configuration, since the moisture permeability of the adhesive after curing is 100 g / m ² · 24H or less, moisture and the like enter the inside through the adhesive after curing, and the insulation is impaired, resulting in poor bonding. Can be reduced. Therefore, a mounting structure having higher connection reliability can be provided.

  In the adhesive, fine particles having conductivity are dispersed.

  According to this configuration, since the conductive fine particles are dispersed in the adhesive, after the adhesive is cured, the connection electrodes of the semiconductor chip and the connection terminal portions of the wiring board are interposed via the fine particles. The joining portion between the joined terminal portions is electrically connected, and can be joined to the adjacent joined terminal portions while maintaining insulation. Therefore, as compared with the case where the fine particles are not dispersed, the unevenness and the variation in the parallelism at the joining portion are absorbed by the presence of the fine particles, and a mounting structure having a stable conduction resistance can be provided.

  An electro-optical device according to the present invention includes the mounting structure according to the present invention, and the circuit board is a substrate of a display panel having pixels.

  According to this configuration, since the mounting structure according to the invention is provided, the driving semiconductor chip and the wiring substrate for inputting an electric signal to the semiconductor chip are provided on the substrate of the display panel having the pixels as the circuit board. It is possible to provide an electro-optical device mounted in a space-saving and simplified process. That is, since a semiconductor chip and a wiring board are mounted on the substrate of the display panel in a space-saving manner, it is possible to provide a more miniaturized electro-optical device.

  In the electro-optical device according to the aspect of the invention, the circuit board may be at least one of two substrates of a liquid crystal display panel in which a liquid crystal as an electro-optical material is sandwiched.

  According to this configuration, since the mounting structure according to the present invention is provided, the semiconductor chip and the wiring board are more compactly mounted in a space-saving manner on at least one of the two substrates of the liquid crystal display panel as the circuit board. A liquid crystal display device as an electro-optical device can be provided.

  The method for manufacturing an electro-optical device according to the present invention is a method for manufacturing an electro-optical device including a display panel having a joining terminal portion, and covers at least a part of the wiring portion connected to the joining terminal portion and the joining terminal portion. An application step of applying an adhesive having fluidity, a crimping step of crimping the semiconductor chip and a wiring board for inputting an electric signal to the semiconductor chip after the adhesive is applied to the joining terminal portion, and an adhesive. And a curing step for curing.

  According to this method, in the coating process, the adhesive having fluidity is applied so as to cover at least a part of the wiring portion connected to the bonding terminal portion and the bonding terminal portion, that is, the mounting region, and in the subsequent crimping step, the semiconductor chip and A wiring board for inputting an electric signal to the semiconductor chip is crimped to the joining terminal portion. In order to cure the adhesive in the curing process, the anisotropic conductive film is separated from the case where the semiconductor chip and the wiring board are bonded to the bonding terminal portion of the display panel via different anisotropic conductive films. In addition, it is possible to eliminate the extra space of the joining terminal portion in consideration of the labor and pasting tolerances applied to the joining terminal portion. Further, it is desirable to cure the adhesive in a state where at least the active surface of the semiconductor chip and the bonding portion of the wiring board are embedded in a fluid adhesive. In this way, the step of covering the mounting region including the semiconductor chip and the wiring board with the molding material made of resin or the like can be eliminated in order to prevent foreign matter from entering and contamination of the joined portion. Therefore, an electro-optical device having a display panel in which a semiconductor chip and a wiring board are mounted in a more space-saving and simplified process can be manufactured.

  In the coating step, it is preferable that the coating amount be adjusted so that the adhesive pushed away by the mounted semiconductor chip and the wiring board does not protrude from the outer shape of the display panel.

  According to this method, in the coating process, the amount of adhesive applied is adjusted so that the adhesive pushed away by the mounted semiconductor chip and wiring board does not protrude from the outer shape of the display panel. The adhesive that protrudes from the outer shape when it is disposed at a predetermined position of the apparatus is later cured to reduce a defective outer shape in which the display panel cannot be disposed at the correct position.

  In the curing step, the adhesive is cured by heating or light irradiation.

  According to this method, a thermosetting or photocurable resin material is used as an adhesive, and in the curing process, the adhesive is cured by heating or light irradiation. Compared to the above, the chemical reaction can be accelerated and cured quickly by heating or light irradiation.

  Another electro-optical device of the present invention is manufactured using the method for manufacturing an electro-optical device according to the above invention.

  According to this configuration, since the electro-optical device is manufactured using the method for manufacturing the electro-optical device according to the invention, the electro-optical device having the display panel in which the semiconductor chip and the wiring board are mounted in a more space-saving and simplified process. Can be provided. That is, since a semiconductor chip and a wiring board are mounted in the joint terminal portion of the display panel in a space-saving manner, it is possible to provide a more miniaturized electro-optical device.

  An electronic apparatus according to the present invention includes the electro-optical device according to the present invention.

  According to this configuration, an electro-optic having a display panel in which a semiconductor chip capable of driving the display panel and a wiring board for inputting an electric signal for driving the semiconductor chip are mounted in a more space-saving and simplified process. Since the device is mounted, a more miniaturized electronic device can be provided.

  Embodiments of the present invention include a mounting structure in which a driver IC, which is a driving semiconductor device (semiconductor chip), is mounted on a liquid crystal display panel by COG (Chip on Glass), and an electro-optical device including the mounting structure. A liquid crystal display device will be described as an example.

  FIG. 1 is a schematic perspective view showing a liquid crystal display device. The liquid crystal display device 1 is a thin film transistor (TFT) active matrix liquid crystal display device, and a pair of substrates 2 and 3 bonded so as to face each other with a sealant 4 therebetween, and a gap between the substrates 2 and 3. And a liquid crystal layer 7 (see FIG. 2) as an electro-optical material sealed with a sealing material 4. A lighting device such as a backlight and other incidental devices are attached as necessary. The liquid crystal display device 1 on which the driver IC 8 is mounted is not limited to the TFT active matrix type, but may be a TFD (Thin Film Diode) active matrix type or a passive matrix type.

  The substrate 2 and the substrate 3 are plate-like members made of a light-transmitting material such as glass or synthetic resin. On the inner (liquid crystal side) surface of the substrate 2, a gate electrode 5 is formed in the Y direction, and a source electrode 6 is formed in the X direction. A pixel electrode (not shown) is formed for each pixel. The gate electrode 5 and the source electrode 6 are formed of a transparent conductive material such as ITO (Indium Tin Oxide). The source electrode 6 is formed, for example, as shown in FIG. 1, with the upper half routed to the left side and the lower half routed to the right side. Further, for each pixel, a thin film transistor T in which each of three terminals is connected to the gate electrode 5, the source electrode 6, and the pixel electrode is provided. On the other hand, a common electrode 3 a is formed on the inner surface of the substrate 3.

  In addition, the substrate 2 has a terminal portion 2 a that protrudes from the outer peripheral edge of the substrate 3. On the surface of the terminal portion 2a, output terminal portions 5a and 6a (see FIG. 2) and input terminal portions 5b and 6b corresponding to the plurality of bump electrodes 11a and 11b (see FIG. 2) of the driver IC 8 are formed. A driver IC 8 for driving is mounted. The gate electrode 5 and the output terminal portion 5a are connected by a wiring portion 5c extending from the output terminal portion 5a, and the source electrode 6 and the output terminal portion 6a are extended from the output terminal portion 6a. They are connected by the turned wiring part 6c. The wiring portions 5c and 6c are arranged with an interval of 13 μm to 15 μm, for example. An FPC (flexible wiring board) 20 for inputting an electric signal for driving the driver IC 8 is mounted on the input terminal portions 5b and 6b. One side of the FPC 20 is connected to a circuit board or the like of an external device (not shown).

  2 is a cross-sectional view of the liquid crystal display device taken along line AA in FIG. Specifically, it is a cross-sectional view showing a state where the driver IC 8 and the FPC 20 are mounted on the terminal portion 2 a of the liquid crystal display panel 12.

  On the back surface (active surface) 8a of the driver IC 8, a plurality of output bump electrodes 11a and input bump electrodes 11b are provided. The driver IC 8 and the FPC 20 are disposed on the terminal portion 2a of the substrate 2 via an adhesive 9 in which conductive fine particles 10 are dispersed in a resin mainly composed of a thermosetting epoxy binder. Yes. The bump electrode 11a is electrically connected to the output terminal portion 5a, and the bump electrode 11b is electrically connected to the input terminal portion 5b via the fine particles 10, respectively. Similarly, the connection terminal portion 21 (see FIG. 7) formed on the joint surface 22 of the FPC 20 is electrically connected to the input terminal portion 5b through the fine particles 10.

The conductive fine particles 10 have a particle diameter of 3 to 5 μm with Ni or Au plating around a spherical resin core, and are dispersed in the adhesive 9 with a distribution density of 100000 to 4000000 pcs / m ^3. ing.

As the adhesive 9, it is desirable that the elastic modulus after curing is 2.0 GPa or more. The moisture permeability after curing is preferably 100 g / m ² · 24H or less. According to this, connection reliability comparable to that in the case of using an ACF (Anisotropic Conductive Film) as a bonding material in a high temperature and high humidity durability test can be obtained. Therefore, as the adhesive 9, it is desirable to use a resin whose main component is any one of thermosetting or photocurable epoxy, acrylic, urethane, silicon, and polyimide binders. These resins have high electrical insulation after curing, and have properties that are physically stable against environmental changes such as temperature and humidity.

  FIG. 3 is a graph showing the relationship with the moisture permeability of the adhesive in the durability test. In the durability test in the present embodiment, a plurality of glass substrates on which transparent electrodes made of skewed ITO arranged at predetermined intervals as test pieces are formed are covered with an adhesive 9 having different moisture permeability and cured. Samples were used. Then, a DC (direct current voltage) of 2.5 V is applied between two terminals connected to every other electrode of these test pieces while being left in a constant temperature and high humidity bath at 60 ° C. and 90% for 96 hours. It is to test how much (number) of the electrode of the electrode is corroded by the moisture that has passed through the adhesive 9. In this case, the electrode pitch is about 100 μm, the width is about 95 μm, and the gap is about 5 μm.

As shown in FIG. 3, it can be seen that when the moisture permeability of the adhesive 9 exceeds 100 g / m ² · 24H, the number of corroded portions increases rapidly. Since the distance between the wiring portions 5c and 6c of the actual liquid crystal display panel 12 is several times wider than that of the test piece, the moisture permeability of the adhesive 9 is 100 g / m ² · 24H or less. If this is the case, it can be considered that the reliability quality can be sufficiently satisfied.

  Polarizing plates 12 a and 12 b are attached to the upper surface of the substrate 3 and the lower surface of the substrate 2 of the liquid crystal display panel 12 to deflect light incident on the liquid crystal layer in a predetermined direction. Note that an optical functional film such as a retardation plate may be laminated on these polarizing plates 12a and 12b for the purpose of improving viewing angle characteristics and compensating for birefringence.

  An alignment film for aligning liquid crystal molecules in a predetermined direction is provided so as to cover the pixel electrode formed on the substrate 2 and the common electrode 3a formed on the substrate 3, but is omitted in FIG.

  The liquid crystal display device 1 outputs a scanning signal from the driver IC 8 to the gate electrode 5 and a data signal to the source electrode 6 by the electric signal input to the driver IC 8 via the FPC 20 to turn on and off the thin film transistor T. Thus, the display is performed by applying an electric field to the liquid crystal layer 7 sandwiched between the desired pixel electrode and the common electrode 3a.

  Next, a method for manufacturing a liquid crystal display device as an electro-optical device will be described with reference to FIGS. 4 is a flowchart showing a method for manufacturing a liquid crystal display device, FIGS. 5A to 5F are schematic views showing states of respective steps corresponding to the flowchart of FIG. 4, and FIG. 6 is a schematic showing an adhesive application range. FIG. 7 is a schematic plan view showing a joint portion of the flexible wiring board.

  As shown in FIG. 4, the manufacturing method of the liquid crystal display device according to the present embodiment includes a step S <b> 1 as an application process for applying the adhesive 9 to the terminal portion 2 a of the liquid crystal display panel 12, and a semiconductor chip after applying the adhesive 9. Crimping process for crimping the driver IC 8 to the output terminal portions 5a and 6a and the input terminal portions 5b and 6b and crimping the FPC 20 as a wiring board for inputting an electric signal to the driver IC 8 to the input terminal portions 5b and 6b Steps S2 to S5, and Step S6 as a curing process for thermally curing the adhesive 9.

  Step S <b> 1 in FIG. 4 is an application process for applying the adhesive 9 to the terminal portion 2 a of the liquid crystal display panel 12. As shown in FIG. 6, the application range of the adhesive 9 is such that the output terminal portions 5a and 6a and the input terminal portions 5b and 6b as the joining terminal portions formed on the terminal portion 2a and the wiring portions 5c and 6c connected thereto. It is applied so as to cover the length direction L1 and the width direction L2. A chain line area 8b in FIG. 6 indicates an outer position when the driver IC 8 is mounted.

  In this case, the active surface 8a of the driver IC 8 to be mounted later and the bonding surface 22 of the FPC 20 are buried in the adhesive 9, and the adhesive 9 pushed away by the driver IC 8 and the FPC 20 is the outer shape of the liquid crystal display panel 12. The coating amount is adjusted so that it does not stick out. If it does in this way, the foreign material penetration | invasion and contamination to the joining site | part covered with the adhesive agent 9 can be prevented. Or the external appearance defect of the liquid crystal display panel 12 by the protruding adhesive 9 can be prevented.

  As shown in FIG. 5 (a), the adhesive 9 is applied by filling the syringe 40 with the adhesive 9 and adjusting the application amount in advance as described above using the dispensing technique to determine the amount on the surface of the terminal portion 2a. The method of discharging is mentioned. Then, the process proceeds to step S2.

  Step S2 in FIG. 4 is a temporary press-bonding step for positioning the driver IC 8. In step S2, as shown in FIG. 5B, the driver IC 8 is sucked and held at the tip of the temporary crimping tool 41, and the output terminal portions 5a and 6a and the input terminal portions 5b and 6b to which the plurality of bump electrodes 11a and 11b correspond. The driver IC 8 is temporarily fixed to the terminal portion 2a by positioning and pressing so as to face each other via the adhesive 9.

  As a method for positioning the driver IC 8, the active surface 8a of the driver IC 8 held by the temporary crimping tool 41 is imaged in advance to recognize the positions of the plurality of bump electrodes 11a and 11b. On the other hand, the alignment mark 13 (see FIG. 6) formed on the terminal portion 2a of the liquid crystal display panel 12 placed on the temporary pressure bonding table 42 is recognized, and the relative position is calculated by image processing. The provisional crimping table 42 is moved by a moving means (not shown) using the difference from the calculated relative position as a movement distance with respect to a predetermined position where the driver IC 8 is positioned. Thereafter, the temporary crimping tool 41 holding the driver IC 8 is lowered from above the terminal portion 2a to which the adhesive 9 has been applied, and crimped with a predetermined pressure.

  The temporary pressure bonding conditions of the driver IC 8 are room temperature, a pressure of about 8 MPa, and a pressure bonding time of 0.3 seconds. It should be noted that the temporary pressure bonding tool 41 or the temporary pressure bonding table 42 may be heated to about 60 ° C. according to the initial viscosity of the adhesive 9 to temporarily reduce the viscosity of the adhesive 9 to be temporarily pressure bonded. According to this, even if air bubbles are caught between the adhesive 9 and the adhesive 9 touched by the active surface 8a of the driver IC 8 during temporary pressure bonding, the air bubbles can be easily driven out due to a decrease in viscosity. That is, it is possible to prevent the adhesive 9 from being hard-bonded with air bubbles being involved and the adhesive 9 being cured to cause poor bonding.

  Next, step S3 in FIG. 4 is a main press-bonding step for thermo-compression of the driver IC 8. In step S3, as shown in FIG. 5C, the liquid crystal display panel 12 to which the driver IC 8 is temporarily fixed is placed on the main pressure bonding table 45 so that the terminal portion 2a protrudes. And after supporting the back surface part of the terminal part 2a in which the temporarily fixed driver IC8 is located with the support tool 44, it is thermocompression bonded with the main pressure bonding tool 43 from the upper surface (opposite surface of the active surface 8a) of the driver IC8. The crimping tool 43 is equipped with a heater (not shown). The support tool 44 may also be provided with a heater that can be preheated.

  The main pressure bonding conditions of the driver IC 8 are a temperature of about 200 ° C., a pressure of about 100 MPa, and a pressure bonding time of 10 seconds. Note that the main pressure bonding conditions are appropriately set in consideration of the size of the driver IC 8 to be mounted, the number and height of the plurality of bump electrodes 11a and 11b, the thermosetting characteristics of the adhesive 9, and the like. At this time, only a part of the adhesive 9 near the active surface 8a of the driver IC 8 is thermally cured, and the joining region of the FPC 20 is in an uncured state. Then, the process proceeds to step S4.

  Step S4 in FIG. 4 is a temporary press-bonding step for positioning the FPC 20 on the terminal portion 2a of the liquid crystal display panel 12 to which the driver IC 8 is finally press-bonded. In step S4, the liquid crystal display panel 12 is placed on the temporary crimping table 47 for FPC as shown in FIG. Next, the FPC 20 is sucked and held by the temporary crimping tool 46 for FPC, and the FPC 20 is positioned and pressed so that the connection terminal portion 21 of the FPC 20 faces the corresponding input terminal portions 5b and 6b via the adhesive 9. Is temporarily fixed to the terminal portion 2a. As shown in FIG. 7, the connection terminal portion 21 of the FPC 20 is routed in the same direction and connected to the other connection terminal portion 24. The surface of the FPC 20 other than the joint surface 23 on which the joint surface 22 and the other connection terminal portion 24 are formed is covered with an insulating resist or cover film. Therefore, the positioning of the FPC 20 is performed so that the resist or the cover film does not cover the input terminal portions 5b and 6b.

  As for the positioning method of the FPC 20, as in the case of the driver IC 8, the joint surface 22 of the FPC 20 held by the temporary crimping tool 46 is imaged in advance to recognize the position of the connection terminal portion 21. On the other hand, the alignment mark 14 (see FIG. 6) formed on the terminal portion 2a of the liquid crystal display panel 12 placed on the temporary pressure bonding table 47 is recognized, and the relative position is calculated by image processing. The provisional crimping table 47 is moved by a moving means (not shown) with the difference from the calculated relative position to a predetermined position where the FPC 20 is positioned as a moving distance. Thereafter, the temporary crimping tool 46 holding the FPC 20 is lowered from above the terminal portion 2a to which the adhesive 9 is applied, and crimped with a predetermined pressure. Then, the process proceeds to step S5.

  Step S5 in FIG. 4 is a main press-bonding step for thermo-compressing the FPC 20. In step S5, as shown in FIG. 5E, the liquid crystal display panel 12 to which the FPC 20 is temporarily fixed is placed on the main crimping table 50 for FPC so that the terminal portion 2a protrudes. And after supporting the back surface part of the terminal part 2a in which the joint surface 22 of the temporarily fixed FPC 20 is located by the support tool 49, thermocompression bonding is performed from the upper surface of the FPC 20 (opposite surface of the joint surface 22) with a main crimping tool 48 for FPC. To do. The crimping tool 48 is equipped with a heater (not shown). The support tool 49 may also be provided with a preheatable heater.

  The main pressure bonding conditions of the FPC 20 are a temperature of about 200 ° C., a pressure of 2 to 6 MPa, and a pressure bonding time of 10 seconds. The main crimping conditions are appropriately set in consideration of the size of the joint surface 22 of the FPC 20 to be mounted, the number of connection terminal portions 21, the length and thickness of the conductor portions, the thermosetting characteristics of the adhesive 9, and the like. Is. The uncured portion of the adhesive 9 exists also in the main press bonding process of the FPC 20. Then, the process proceeds to step S6.

  Step S6 in FIG. 4 is a curing process in which the adhesive 9 is thermally cured. In step S6, as shown in FIG. 5 (f), the liquid crystal display panel 12 in which the driver IC 8 and the FPC 20 are finally bonded to the terminal portion 2a is left in a thermostatic chamber set at a temperature of about 80 ° C. for 2 hours. The adhesive 9 in the cured part is cured. In the present embodiment, the adhesive 9 is cured off-line. However, on-line curing is also possible if a heater capable of heating the liquid crystal display panel 12 placed on the main crimping table 50 is provided. The liquid crystal display device 1 is completed through the above steps.

  The liquid crystal display device 1 thus completed has a terminal portion 2a in consideration of the ACF attachment tolerance, as compared with the case where the ACF for the driver IC 8 and the ACF for the FPC 20 are separately attached to the terminal portion 2a. The extra space could be eliminated. Specifically, it is necessary to consider the width tolerance of about ± 0.05 mm and the pasting tolerance of ± 0.2 mm of the conventional ACF itself. As a result, as shown in FIG. 2, the dimension 2b from the end face of the substrate 3 to the end face of the driver IC 8 is about 0.5 mm to 0.2 mm, and the dimension 2c from the end face of the driver IC 8 to the end face of the FPC 20 is 0.4 mm to 0. It was shortened to 2 mm. Therefore, the length of the terminal portion 2a can be shortened by a total of 0.5 mm.

  Next, a liquid crystal display module equipped with a lighting device in the liquid crystal display device will be described. The liquid crystal display device 1 described in the present embodiment is a transmissive display device. Therefore, for example, when mounted on a mobile phone or the like as an electronic device, a lighting device is provided.

  FIG. 8 is a schematic cross-sectional view showing a liquid crystal display module equipped with a lighting device. As shown in FIG. 8, the liquid crystal display module 110 has a structure in which the circuit board 32, the light guide plate 31, and the liquid crystal display device 1 are stacked in this order. Further, an LED element 30 as a light source is provided between the terminal portion 2a of the liquid crystal display panel 12 and the circuit board 32, and the side surface of the light guide plate 31 and the light emitting surface are opposed to each other.

  The LED board 34 on which the LED elements 30 are mounted is electrically connected to the circuit board 32 by a flexible wiring board (not shown). The number of LED elements 30 is determined according to the size of the pixel area of the liquid crystal display device 1 to be illuminated.

  The liquid crystal display panel 12 is fixed to the upper surface of the light guide plate 31 using a fixing material 33 such as a double-sided tape. Light emitted from the LED element 30 is emitted to the back side of the liquid crystal display panel 12 via the light guide plate 31, and passes through the polarizing plate 12b, the liquid crystal layer 7, and the polarizing plate 12a. Therefore, the liquid crystal display device 1 confirms the display as viewed from the direction of the arrow A. On the surface of the light guide plate 31 on which the liquid crystal display panel 12 is fixed, a translucent diffusion plate 35 made of an optical functional film or the like is laminated so that the emitted light is not uneven. A reflective plate 36 is laminated on the other surface of the light guide plate 31 so that the light guided from the LED element 30 does not leak. Further, a light-shielding plate 37 is attached to the back surface of the terminal portion 2a so that light emission of the LED element 30 enters the active surface 8a of the driver IC 8 from the back surface of the terminal portion 2a and no optical malfunction occurs.

  The liquid crystal display device 1 and the circuit board 32 are electrically connected by mounting the connection terminal portion 24 of the FPC 20 on the circuit board 32. Such a liquid crystal display module 110 is used in this state or in a state of being housed in a case (not shown) or the like. In the liquid crystal display device 1, since the driver IC 8 and the FPC 20 for driving are mounted in a space-saving manner on the terminal portion 2a of the liquid crystal display panel 12, the liquid crystal display module 110 equipped with the illumination device can be further downsized. .

  In the present embodiment, the electro-optical device has been described by taking a liquid crystal display device as an example, but the present invention is not limited to this, and the electroluminescence device, in particular, an organic electroluminescence device, an inorganic electroluminescence device, etc. , Plasma display devices, FED (Field Emission Display) devices, SED (Surface Conduction Electron Emitter Display) devices, LED (Light Emitting Diode) display devices, electrophoretic display devices, thin cathode ray tubes, small televisions using liquid crystal shutters, digital TV The present invention can be applied to various electro-optical devices such as a device using a micromirror device (DMD).

  Next, a mobile phone as an electronic apparatus according to an embodiment of the present invention will be described. FIG. 9 is an external view of a mobile phone equipped with a liquid crystal display module. A cellular phone 100 shown here includes a main body 101 and a display body 102 that can be opened and closed. Operation buttons 103 are arranged on the front surface of the main body 101. An antenna 104 is attached from one end of the display body 102 so as to be extendable and contractible. A speaker is disposed inside the receiver unit 105, and a microphone is incorporated inside the transmitter unit 106.

  The liquid crystal display module 110 is disposed so as to be positioned on the front side of the mobile phone 100. Various displays relating to telephone communication are displayed by the liquid crystal display module 110. The liquid crystal display module 110 contributes to the miniaturization of the mobile phone 100.

  In addition to the mobile phone 100 described above, the electronic device to which the liquid crystal display module 110 according to the present invention can be applied includes, for example, a portable information device called PDA (Personal Digital Assistants), a portable personal computer, a personal computer, Digital still camera, in-vehicle monitor, digital video camera, LCD TV, viewfinder type, monitor direct-view type video tape recorder, car navigation device, pager, electronic notebook, calculator, word processor, workstation, video phone, POS terminal, etc. And an apparatus using a liquid crystal display module which is an electro-optical device. Therefore, it goes without saying that the present invention is applicable even to a mounting structure in these electronic devices.

  The effect of this embodiment is as follows.

  (1) In the liquid crystal display device 1 as a mounting structure, the active surface 8a of the driver IC 8 and the joint surface 22 of the FPC 20 are connected to the input / output terminal portions 5a, 5b, 6a, 6b and the wiring portions 5c, 6c connected thereto. The adhesive 9 is hardened in a state where it is buried in the fluid adhesive 9 applied so as to cover the surface. The bump electrodes 11a, 11b and the connection terminal portion 21 are joined to the corresponding input / output terminal portions 5a, 5b, 6a, 6b, and the driver IC 8 and the FPC 20 are mounted on the surface of the terminal portion 2a of the liquid crystal display panel 12. ing. Therefore, the anisotropic conductive film is separately provided as compared with the case where the driver IC 8 and the FPC 20 are joined to the input / output terminal portions 5a, 5b, 6a, 6b of the terminal portion 2a through different anisotropic conductive films. The extra space of the terminal part 2a in consideration of the labor and pasting tolerance applied to the terminal part 2a can be saved. Further, the step of covering the mounting area including the driver IC 8 and the FPC 20 with a molding material made of a resin or the like can be eliminated in order to prevent foreign matter from entering and contamination of the joined portion. Therefore, it is possible to provide the liquid crystal display device 1 including the liquid crystal display panel 12 in which the driver IC 8 and the FPC 20 are mounted in a more space-saving and simplified process.

  (2) Since the FPC 20 which is a flexible wiring board is mounted on the liquid crystal display device 1, the FPC 20 can be bent and joined to the circuit board 32 and positioned within a flexible range.

  (3) Since the adhesive 9 is made of a resin containing a thermosetting epoxy binder, the bump electrodes 11a and 11b of the driver IC 8 and the connection terminal portion 21 of the FPC 20 are connected to the terminal portion after the adhesive 9 is applied. When the adhesive 9 is heated after being crimped to the input / output terminal portions 5a, 5b, 6a and 6b of 2a, the adhesive 9 is cured, and the corresponding input / output terminal portions 5a, 5b, 6a, 6b can be joined.

(4) The adhesive 9 has an elastic modulus of 2.0 GPa or more and a moisture permeability of 100 g / m ² · 24H or less after curing. Accordingly, the liquid crystal display device 1 has electrical insulation and has a high connection reliability with reduced bonding failure because the change (deformation, etc.) of physical characteristics due to environmental changes such as temperature and humidity is stable. can do.

(5) In the adhesive 9, fine particles 10 having a particle size of 3 to 5 [mu] m having conductivity are dispersed with a distribution density of 100000 to 4000000 pcs / m < ³ >, so that the bump electrodes 11a and 11b of the driver IC 8 and the FPC 20 are connected. Even if the terminal portions 21 are arranged at a high density, the fine particles 10 can be interposed in a stable quantity at the joint portions between the corresponding input / output terminal portions 5a, 5b, 6a, 6b. That is, it is possible to provide the liquid crystal display device 1 having a more stable conduction resistance at the bonding portion.

  (6) In the manufacturing method of the liquid crystal display device 1 of the present embodiment, in the coating process, an adhesive having fluidity so as to cover the input / output terminal portions 5a, 5b, 6a, 6b and the wiring portions 5c, 6c connected thereto. 9 is applied, and the driver IC 8 and the FPC 20 are crimped to the input / output terminal portions 5a, 5b, 6a and 6b in the subsequent crimping process. Since the adhesive 9 is thermally cured in the curing process, the driver IC 8 and the FPC 20 are different from the case where the driver IC 8 and the FPC 20 are joined to the input / output terminal portions 5a, 5b, 6a, and 6b through different anisotropic conductive films. It is possible to save an extra space of the terminal portion 2a in consideration of the trouble of attaching the anisotropic conductive film separately and the attaching tolerance. Therefore, the liquid crystal display device 1 having the liquid crystal display panel 12 mounted on the terminal portion 2a can be manufactured through a process in which the driver IC 8 and the FPC 20 are more space-saving and simplified. Therefore, it is possible to provide a liquid crystal display device 1 that is further downsized.

  (7) In the application process of the adhesive 9, since the application amount is adjusted so that the adhesive 9 pushed away by the driver IC 8 and the FPC 20 to be mounted later does not protrude from the outer shape of the liquid crystal display panel 12, the liquid crystal display panel When disposing 12 at a predetermined position of the liquid crystal display module 110, it is possible to reduce the external defect that the adhesive 9 protruding from the external shape is hardened later and cannot be disposed at the correct position.

  (8) In the curing step, the adhesive 9 is cured while the active surface 8a of the driver IC 8 and the bonding surface 22 of the FPC 20 that are crimped in the crimping step are buried in the adhesive 9, so that the driver IC 8 and the FPC 20 are joined. In addition to preventing foreign matter from entering and contaminating the bonded portion, the molding process for this purpose can be eliminated.

  (9) A mobile phone 100 as an electronic device includes a liquid crystal display module 110 in which a driver IC 8 and an FPC 20 are mounted on the terminal portion 2a of the liquid crystal display panel 12 in a space-saving manner and the liquid crystal display module 110 provided with an illumination device. Therefore, the mobile phone 100 with a smaller size can be provided.

  Modifications other than the present embodiment are as follows.

  (Modification 1) In the liquid crystal display device 1, the driver IC 8 and the FPC 20 mounted on the terminal portion 2 a of the liquid crystal display panel 12 are not limited to one each. For example, a plurality of driver ICs that output driving electric signals are mounted on the gate electrode 5 and the source electrode 6, respectively, and a plurality of FPCs that input driving electric signals are mounted corresponding to the driver ICs. It is also applicable to cases.

  (Modification 2) The adhesive 9 does not necessarily have to disperse the conductive fine particles 10. For example, when the degree of integration of the plurality of bump electrodes 11a and 11b of the driver IC 8 and the connection terminal portion 21 of the FPC 20 is low, a sufficient bonding area can be secured with the corresponding input / output terminal portions 5a, 5b, 6a, and 6b. Even in a state where 10 is not included, stable bonding is possible.

  (Modification 3) The adhesive 9 is not limited to a resin containing a thermosetting binder. For example, if the driver IC 8 and the FPC 20 are positioned using a photo-curing resin and then the driver IC 8 and the FPC 20 are pressed and irradiated with light from the back surface of the terminal portion 2a, the adhesive 9 is cured to form a plurality of bumps. It is possible to provide the liquid crystal display device 1 in which the electrodes 11a and 11b and the connection terminal portion 21 are joined to the corresponding input / output terminal portions 5a, 5b, 6a, and 6b.

  (Modification 4) In the manufacturing method of the liquid crystal display device 1, in the application step of the adhesive 9, it is not necessary to cover all the input / output terminal portions 5a, 5b, 6a, 6b and the wiring portions 5c, 6c connected thereto. . For example, when the wiring portions 5c and 6c are covered with an insulating material in advance, a part of the insulating material is taken into consideration for variations in the insulating material covering the input / output terminal portions 5a, 5b, 6a and 6b and the wiring portions 5c and 6c. If the adhesive 9 is applied so as to overlap with each other, it is possible to prevent foreign matter from entering and joining the joined portion.

  (Modification 5) In the manufacturing method of the liquid crystal display device 1, the crimping process for crimping the driver IC 8 and the FPC 20 to the input / output terminal parts 5a, 5b, 6a, 6b of the terminal part 2a is the temporary crimping process for positioning and the thermocompression bonding. It is not necessary to divide into two stages of the main press-bonding process. For example, if a mechanism capable of holding components is provided in the main crimping tools 43 and 48, thermocompression bonding can be performed following positioning.

  (Modification 6) In the manufacturing method of the liquid crystal display device 1, the positioning and pressure bonding are not limited to the driver IC 8. The FPC 20 may be positioned and pressure-bonded first.

  (Modification 7) In the manufacturing method of the liquid crystal display device 1, the driver IC 8 and the FPC 20 do not have to be subjected to the main pressure bonding in separate steps. For example, the main crimping tables 45 and 50 may be sized to support the back surface of the terminal portion 2 a, and the driver IC 8 positioned in the temporary crimping process may be thermocompression bonded by the main crimping tool 43 and simultaneously the FPC 20 may be thermocompression bonded by the main crimping tool 48. Is possible.

  The technical idea grasped from this embodiment and the modification is as follows.

  The mounting structure of the present invention corresponds to a semiconductor chip having a connection electrode on an active surface, a wiring board having a connection terminal portion on an end joint surface, and a connection electrode and a connection terminal portion on the same mounting surface. A circuit board having a joining terminal portion to be applied, and at least an active surface of the semiconductor chip and a joining surface of the wiring substrate are applied so as to cover the joining terminal portion and at least a part of the wiring portion connected to the joining terminal portion. The adhesive is cured in a state where the adhesive is buried in the adhesive, and the connection electrodes and the connection terminal portions are bonded to the corresponding connection terminal portions and mounted on the circuit board.

The schematic perspective view which shows the structure of a liquid crystal display device. Sectional drawing of the liquid crystal display device cut | disconnected by the AA line of FIG. The graph which shows the relationship with the water vapor transmission rate of the adhesive agent in a durability test. 5 is a flowchart showing a method for manufacturing a liquid crystal display device. (A)-(f) Schematic which shows the state of each process corresponding to the flowchart of FIG. The schematic plan view which shows the application | coating range of an adhesive agent. The schematic plan view which shows the junction part of a flexible wiring board. The schematic sectional drawing which shows the liquid crystal display module equipped with the illuminating device. 1 is an external view of a mobile phone equipped with a liquid crystal display module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device as an electro-optical device, 2 ... Board | substrate as a circuit board, 2a ... Terminal part as the same mounting surface, 5a, 5b ... Input / output terminal part as a joining terminal part, 6a, 6b ... Joining terminal part Input / output terminal section, 5c, 6c ... wiring section, 7 ... liquid crystal layer as liquid crystal, 8 ... driver IC as semiconductor chip, 9 ... adhesive, 10 ... fine particles, 11a, 11b ... bump as connection electrodes Electrode, 12 ... Liquid crystal display panel as display panel, 20 ... FPC (flexible wiring board) as wiring board, 21 ... Connection terminal, 22 ... Bonding surface, 100 ... Mobile phone as electronic device, 110 ... Electro-optical Liquid crystal display module as a device.

Claims (13)

A semiconductor chip having connection electrodes on the active surface;
A wiring board having a connecting terminal portion on the joint surface of the end portion;
A circuit board having a connection terminal portion corresponding to the connection electrode and the connection terminal portion on the same mounting surface;
At least the active surface of the semiconductor chip, the joint surface of the wiring board, the joint terminal portion, and the wiring portion connected to the joint terminal portion are buried in an adhesive, and the connection electrode and the connection terminal The mounting structure is characterized in that a portion is mounted on the circuit board by being electrically bonded to the corresponding connecting terminal portion.   The mounting structure according to claim 1, wherein the wiring board is a flexible wiring board.   The mounting structure according to claim 1, wherein the adhesive is made of a thermosetting resin or a photocurable resin.   The mounting structure according to any one of claims 1 to 3, wherein the adhesive includes any one of epoxy, acrylic, urethane, silicon, and polyimide binders. The mounting structure according to any one of claims 1 to 4, wherein the adhesive has a moisture permeability of 100 g / m ² · 24H or less after curing.   The mounting structure according to any one of claims 1 to 5, wherein conductive particles are dispersed in the adhesive. A mounting structure according to any one of claims 1 to 6,
The electro-optical device, wherein the circuit board is a substrate of a display panel having pixels.   8. The electro-optical device according to claim 7, wherein the circuit board is at least one of two substrates of a liquid crystal display panel in which liquid crystal as an electro-optical material is sandwiched. A method of manufacturing an electro-optical device including a display panel having a junction terminal portion,
An application step of applying an adhesive having fluidity so as to cover at least a part of the wiring portion connected to the bonding terminal portion and the bonding terminal portion;
A crimping step of crimping a semiconductor chip and a wiring board for inputting an electrical signal to the semiconductor chip after the adhesive is applied to the joining terminal portion;
A method for manufacturing an electro-optical device, comprising: a curing step for curing the adhesive.   10. The coating step is performed by adjusting a coating amount so that the adhesive pushed away by a mounted semiconductor chip and a wiring board does not protrude from the outer shape of the display panel. Manufacturing method of the electro-optical device.   The method of manufacturing an electro-optical device according to claim 9, wherein, in the curing step, the adhesive is cured by heating or light irradiation.   An electro-optical device manufactured using the method for manufacturing an electro-optical device according to claim 9. An electronic apparatus comprising the electro-optical device according to any one of claims 7, 8, and 12.

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