JP2006210831A - Ic chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower occurrence of leak between adjacent bumps or electrodes by lowering the density of conductive particles in a bump forming region. <P>SOLUTION: On the entire circuit forming surface 9 in the substrate 8 of a driving IC chip 7, a nonconducting adhesive material 13 not containing conductive particles is arranged to cover a bump 10, and a conducting adhesive material 14 containing conductive particles 14a is arranged on the nonconducting adhesive material 13 in the bump forming region 11 on the circuit forming surface 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an IC chip, and more particularly, to an IC chip that connects a bump of an IC chip and an electrode of an external wiring through a conductive adhesive containing a plurality of conductive particles.

  Conventionally, for example, an IC chip for directly driving a panel on a substrate of a display panel that displays information such as specific figures and characters by selectively applying an electric field to a predetermined portion of a pair of substrates filled with liquid crystal in the middle. A COG (Chip on Glass) type display device on which an IC chip such as the above is mounted is used as a display means for a mobile phone or the like.

  5A, 5B, and 5C are schematic cross-sectional views showing a connection structure between a conventional display panel and a panel driving IC chip.

  As shown in FIGS. 5A, 5B, and 5C, in the display panel 21, transparent electrodes 23 are provided on the mutually opposing surfaces of the pair of substrates 22, respectively. The both terminals 22 are extended to the terminal portion 24 of one of the substrates 22 that is formed to be large in plan view, thereby forming electrode terminals 25. In the panel driving IC chip 27, bumps 30 connected to electrodes of a circuit (not shown) are provided at each edge portion of the circuit forming surface 29 of the substrate 28.

  When the electrode terminals 25 of the display panel 21 and the bumps 30 of the panel driving IC chip 27 are connected, as shown in FIG. 5A, first, the panel on the electrode terminals 25 of the display panel 21 is displayed. A conductive adhesive 34 such as an anisotropic conductive film (ACF) made of a thermosetting resin 34b containing a plurality of conductive particles 34a, for example, is disposed in the pressure-bonding region of the driving IC chip 27. Next, as shown in FIG. 5B, the electrode terminals 25 of the display panel 21 and the bumps 30 of the panel driving IC chip 27 are aligned on the display panel 21 via the conductive adhesive 34. A panel driving IC chip 27 is placed. Then, as shown in FIG. 5C, by pressing the panel driving IC chip 27, the bumps 30 and the electrode terminals 25 are connected via the plurality of conductive particles 34a, and the display panel 21 and the panel driving chip are connected. The IC chip 27 is electrically connected.

  However, according to the method for connecting the display panel 21 and the panel driving IC chip 27 described above, when the panel driving IC chip 27 is pressed in the direction of the electrode terminal 25 via the conductive adhesive 34, it is shown in FIG. Thus, the thermosetting resin 34 b of the conductive adhesive 34 flows toward the outer edge of the substrate of the panel driving IC chip 27. Then, the respective conductive particles 34a originally arranged on the inner side of the bump forming region 31 which is an edge portion where the respective bumps 30 are formed on the substrate 28 flow in the outer edge direction on the substrate 28 together with the thermosetting resin 34b. As a result, the inner edge of the bump formation region 31 or between the adjacent bumps 30 may remain, and the density of the conductive particles 34 a may increase in the bump formation region 31. As a result, there is a problem in that leakage may occur between the adjacent bumps 30 or between the electrode terminals 25 due to the accumulated conductive particles 34a.

  In addition, the conductive area between the electrode terminals 25 and the bumps 30 has become narrow due to the miniaturization of the electrode terminals 25 accompanying the recent high definition of the display on the display panel 21. For this reason, it is considered that the number of the conductive particles 34a contained in the conductive adhesive 34 is increased so that the electrode terminals 25 and the bumps 30 are reliably connected. The density of the particles 34a is further increased, and there is a possibility that more leakage between the bumps 30 or between the electrode terminals 25 may occur. Furthermore, there is a problem that leakage is more likely to occur between the bumps 30 or between the electrode terminals 25 due to the narrowing of the pitch of each electrode terminal 25.

  The present invention has been made in view of these points, and by reducing the density of each conductive particle in the bump formation region, an IC chip that can reduce the occurrence of leakage between adjacent bumps or electrodes. The purpose is to provide.

  In order to achieve the above object, an IC chip according to the present invention is characterized in that a plurality of bumps are provided on a circuit forming surface of a substrate, and each bump is connected to each electrode of an external wiring. A non-conductive adhesive containing no conductive particles is disposed on the circuit forming surface so as to cover the conductive layer, and a conductive adhesive containing conductive particles is disposed on the non-conductive adhesive in the bump formation region. There is in point.

  The conductive adhesive may be disposed only on the non-conductive adhesive on the bump, and the thickness of the conductive adhesive is 2 to 3 times the diameter of the conductive particles. It may be.

  According to the present invention, a nonconductive adhesive is disposed on the circuit forming surface of the substrate of the IC chip so as to cover the bumps, and the conductive adhesive is disposed on the nonconductive adhesive in the bump forming region. It is like that. Here, when the IC chip is pressed and connected to the electrode of the external wiring via the non-conductive adhesive and the conductive adhesive, the non-conductive adhesive flows in the direction of the outer edge of the substrate. Since particles are not contained, it is possible to prevent the conductive particles from staying between the inner edge of the bump formation region, between the bumps, and between the electrodes.

  As described above, according to the IC chip according to the present invention, it is possible to prevent the staying of each conductive particle at the inner edge of the bump forming region or the like, so that between each bump generated by each staying conductive particle or Leakage between the electrodes can be prevented.

  Hereinafter, an embodiment of an IC chip according to the present invention will be described with reference to FIGS. Here, in the present embodiment, a case where a panel driving IC chip as an IC chip is connected to a display panel as external wiring will be described, but the present embodiment is not limited to this. For example, it may be used when an IC chip is connected to a wiring board such as a flexible wiring board as external wiring.

  FIG. 1 is a schematic plan view showing one connection process of the IC chip and the display panel according to the present embodiment. As shown in FIG. 1, the display panel 1 includes a pair of transparent substrates 2 made of glass or the like. The transparent electrodes 3 are provided on the surfaces facing each other. These transparent electrodes 3 are extended to the terminal portion 4 of one transparent substrate 2 which is formed to be large in the planar shape out of the two transparent substrates 2, and serve as electrode terminals 5.

  In the panel driving IC chip 7, a circuit is formed on one surface of the substrate 8, and bumps 10 connected to circuit electrodes (not shown) are formed on each edge portion of the circuit forming surface 9 of the substrate 8. Projecting from the substrate 8 is provided. And the edge part of the board | substrate 8 in which each bump 10 in the circuit formation surface 9 was formed is made into the bump formation area 11. FIG.

  On the circuit forming surface 9 of the panel driving IC chip 7, a non-conductive adhesive material 13 made of a thermosetting resin 13 a not containing conductive particles is disposed so as to cover the bumps 10. On the non-conductive adhesive 13, a conductive adhesive 14 in which a plurality of conductive particles 14a are contained in a thermosetting resin 14b is disposed.

  Next, a method of connecting the display panel 1 and the panel driving IC chip 7 will be described with reference to FIG.

  As shown in FIG. 2A, first, a non-conductive adhesive 13 having a predetermined thickness is applied to one surface of the circuit forming surface 9 of the substrate 8 of the panel driving IC chip 7 so as to cover each bump 10. To do. The non-conductive adhesive 13 is applied in an appropriate amount for reliable crimping between the display panel 1 and the panel driving IC chip 7. In this embodiment, the non-conductive adhesive 13 is used as a bump. It is applied so as to be higher by about 5 to 10 μm than the height dimension of 10.

  Next, as shown in FIGS. 2B and 3, the conductive adhesive 14 is applied to the entire bump forming region 11 on the circuit forming surface 9 of the substrate 8 from above the nonconductive adhesive 13. The conductive adhesive 14 is preferably applied to a thickness dimension equal to or larger than the diameter dimension of the conductive particles 14a. In the present embodiment, the conductive adhesive 14 is used by using conductive particles 14a having a diameter of 4 to 10 μm. It applies so that it may become a thickness dimension of about 10-15 micrometers. Moreover, as resin which comprises the electrically conductive adhesive material 14, in order to prevent the flow of the electrically-conductive particle 14a, it is desirable to use a highly viscous thing.

  In the present embodiment, the non-conductive adhesive 13 and the conductive adhesive 14 made of thermosetting resin are used. However, the present invention is not limited to this, and the non-conductive adhesive 13 and the conductive adhesive 14 are used. As long as materials of the same quality are used, for example, various resins such as a thermoplastic resin and an ultraviolet curable resin can be used.

  Thus, the panel driving IC chip 7 in which the nonconductive adhesive 13 and the conductive adhesive 14 are disposed at predetermined positions on the circuit forming surface 9 is completed.

  Subsequently, as shown in FIG. 2C, the panel driving IC is interposed through the non-conductive adhesive 13 and the conductive adhesive 14 while aligning the electrode terminals 5 and the bumps 10 of the display panel 1. The chip 7 is placed on the terminal portion 4 of the display panel 1.

  Then, as shown in FIG. 2D, a predetermined pressure and temperature are applied to the non-conductive adhesive 13 and the conductive adhesive 14 in the direction from the panel driving IC chip 7 to the electrode terminal 5. Then, first, each bump 10 and each electrode terminal 5 come into contact with each other through each conductive particle 14 a by pressurization from above the panel driving IC chip 7, and each conductive particle 14 a is in contact with each bump 10 and each electrode terminal 5. And the non-conductive adhesive 13 flows in the direction of the outer edge of the substrate 8 of the panel driving IC chip 7. Further, the bumps 10 and the electrode terminals 5 are electrically connected through the conductive particles 14a by curing the thermosetting resins 13a and 14b of the non-conductive adhesive 13 and the conductive adhesive 14 by heating. The display panel 1 and the panel driving IC chip 7 are connected through the non-conductive adhesive 13 and the conductive adhesive 14.

  According to the present embodiment, the non-conductive adhesive 13 is applied to the circuit forming surface 9 of the substrate 8 of the panel driving IC chip 7 so as to cover the bumps 10, and the conductive adhesive 14 is placed on the bump forming region 11. It is applied only on the non-conductive adhesive 13. When the panel driving IC chip 7 is pressed and connected in the direction of the electrode terminal 5 through the non-conductive adhesive 13 and the conductive adhesive 14, the thermosetting resin 13 a of the non-conductive adhesive 13 is attached to the outer edge of the substrate 8. Although the non-conductive adhesive 13 does not contain the conductive particles 14a, the conductive particles 14a are prevented from staying between the inner edge of the bump forming region 11, the bumps 10, and the electrode terminals 5. Can be prevented.

  Further, when the panel driving IC chip 7 is pressure-connected to the electrode terminal 5 via the non-conductive adhesive 13 and the conductive adhesive 14, the conductive particles 14 a of the conductive adhesive 14 are formed so as to protrude from the substrate 8. The bumps 10 are first pressurized and sandwiched between the bumps 10 and the electrode terminals 5. For this reason, each conductive particle 14a does not flow in the direction of the outer edge of the substrate 8 due to the flow of each thermosetting resin 13a, 14b of the non-conductive adhesive 13 and the conductive adhesive 14, and each conductive particle 14a is connected to each bump 10. It can be interposed between each electrode terminal 5.

  Therefore, according to the connection method between the display panel 1 and the panel driving IC chip 7 in the present embodiment, it is possible to prevent the conductive particles 14a from staying at the inner edge or the like of the bump forming region 11, and thus stayed. Leakage between the bumps 10 or between the electrode terminals 5 generated by the conductive particles 14a can be prevented. At the same time, each bump 10 and each electrode terminal 5 can be reliably conducted by each conductive particle 14 a interposed between each bump 10 and each electrode terminal 5.

  Moreover, even if the density of the conductive particles 14a in the conductive adhesive 14 is increased in response to the miniaturization of the electrode terminals 5 accompanying the refinement of the display in the display panel 1, the bump formation region 11 on the circuit formation surface 9 is increased. Since the conductive adhesive 14 is not applied to the inside, it is possible to prevent the stagnation of the conductive particles 14a from occurring at the inner edge of the bump forming region 11 on the circuit forming surface 9 or between the bumps 10. As a result, since the content density of the conductive particles 14a in the conductive adhesive 14 can be increased, each bump 10 and each electrode terminal 5 can be more reliably conducted.

  Furthermore, by using the non-conductive adhesive 13, the number of conductive particles 14a that do not contribute to the connection between the display panel 1 and the panel driving IC chip 7 can be reduced, so that the cost can be reduced. .

  Furthermore, conventionally, due to the problem of accuracy of the application position of the conductive adhesive 14, the application area of the conductive adhesive 14 applied on each electrode terminal 5 is larger than the area of the substrate 8 of the panel driving IC chip 7. Had to set. On the other hand, according to the present embodiment, since the non-conductive adhesive 13 and the conductive adhesive 14 are applied to the panel driving IC chip 7, the application region of the conductive adhesive 14 and the like is larger than the area of the substrate 8. There is no. As described above, since the application region of the conductive adhesive 14 or the like can be made narrower than in the conventional case, the area of the terminal portion 4 of the display panel 1 to which the panel driving IC chip 7 is connected can be reduced. As a result, the frame of the display panel 1 can be narrowed.

  In addition, this invention is not limited to the said embodiment, A various change is possible as needed.

  For example, in the present embodiment, the conductive adhesive 14 is continuously applied to the entire bump forming region 11. However, the present invention is not limited to this, and as shown in FIG. The conductive adhesive 14 may be applied to the substrate. Thereby, the density of each electroconductive particle 14a located between each bump 10 or between each electrode terminal 5 can be reduced, and the leak between each bump 10 and between each electrode terminal 5 can be prevented more reliably. .

Schematic plan view showing one connection process with external wiring in the IC chip according to the present invention (A) is a schematic cross-sectional view showing one connection step in AA of FIG. 1, (b) is a schematic cross-sectional view showing the next connection step of FIG. 2 (a), and (c) is a diagram. 2 (b) is a schematic cross-sectional view showing the next connection step, and (d) is a schematic cross-sectional view showing the next connection step in FIG. 2 (c). Typical sectional drawing which shows one connection process in BB of FIG. Typical sectional drawing which shows one connection process with the external wiring in the other IC chip concerning this invention (A) is a schematic cross-sectional view showing one connection process between a conventional IC chip and external wiring, (b) is a schematic cross-sectional view showing the next connection process of FIG. 5 (a), and (c) is , A schematic cross-sectional view showing the next connection step of FIG. Schematic plan view showing one connection step of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display panel 2 Transparent substrate 3 Transparent electrode 4 Terminal part 5 Electrode terminal 7 Panel drive IC chip 8 Substrate 9 Circuit formation surface 10 Bump 11 Bump formation area 13 Non-conductive adhesive 13a Thermosetting resin 14 Conductive adhesive 14a Conductive particle 14b thermosetting resin

Claims (3)

In an IC chip in which a plurality of bumps are provided on the circuit forming surface of the substrate, and each bump is connected to each electrode of external wiring.
A non-conductive adhesive containing no conductive particles is disposed on the circuit forming surface so as to cover the bumps, and a conductive adhesive containing conductive particles is disposed on the non-conductive adhesive in the bump formation region. An IC chip characterized by being provided.   The IC chip according to claim 1, wherein the conductive adhesive is disposed only on the nonconductive adhesive on the bump.   The IC chip according to claim 1 or 2, wherein the thickness of the conductive adhesive is 2 to 3 times the diameter of the conductive particles.

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