JP2005109023A - Semiconductor chip and liquid crystal display with semiconductor chip mounted thereon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor chip which can be reduced in size and increased in the degree of integration by improving connection reliability in connection using an anisotropic conductive adhesive. <P>SOLUTION: The semiconductor chip 1 has a plurality of bumps 3 which are electrically connected to electrodes 12 of another member 11 using the anisotropic conductive adhesive 21. Between adjacent bumps 3A and 3B, an insulator 4A which is higher than these bumps is formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor chip having a plurality of bumps, and the bumps are connected to electrodes of other members by an anisotropic conductive adhesive, and a liquid crystal display device on which the semiconductor chip is mounted.

  A semiconductor chip is a semiconductor piece in which various circuits are formed as semiconductor elements cut out from a semiconductor wafer. Usually, a semiconductor chip is fixed to a lead frame, wire-bonded to the inner lead of the lead frame, and resin-sealed package, and then the outer lead of the lead frame is connected to an electrode of another member (for example, a circuit board). Had been implemented.

  In recent years, a method of mounting a semiconductor chip directly on another member without packaging it has been adopted. This method is advantageous in that the mounting size can be reduced, the electrical characteristics can be improved, and the number of materials and the number of processes can be reduced, so that it can be manufactured relatively inexpensively.

  In a method of mounting directly on another member, there is a method in which the bump of the semiconductor chip is opposed to the electrode of the other member, an anisotropic conductive material is interposed, and the mounting is performed by pressure bonding. This method has been adopted in a COG (Chip On Glass) type liquid crystal display device. Since the driving IC chip is directly mounted on the glass substrate of the liquid crystal panel, the COG type liquid crystal display device has advantages such as reduction in weight and thickness, fine pitch, and reduction in IC chip packaging process.

  The COG type liquid crystal display device has a liquid crystal panel and an IC chip. The liquid crystal panel has a structure in which a pair of substrates are opposed and surrounded by a seal, and the liquid crystal 7 is sealed between the substrates. One substrate of the liquid crystal panel has a terminal portion protruding from the other substrate, and an IC chip is mounted on the electrode pad formed on the terminal portion by an anisotropic conductive material.

  FIG. 3 is a schematic cross-sectional view showing a conventional IC chip 101 in a mounted state. The IC chip 101 has a plurality of bumps 102. A plurality of electrode pads 113 are provided on the terminal portion of the substrate 112 of the liquid crystal panel 111 so as to correspond to the plurality of bumps 102. The bumps 102 of the IC chip 101 and the electrode pads 113 of the liquid crystal panel are electrically connected by an anisotropic conductive material 121.

  The anisotropic conductive material 121 is a material in which conductive particles 122 are dispersed in a thermoplastic or thermosetting resin 123. The anisotropic conductive material 121 is interposed between the IC chip 101 and the liquid crystal panel 111 and bonded to the bump 102 and the electrode. The pad 113 is electrically connected through the conductive particles 122.

JP 2003-195335 A

  However, since the connection using the anisotropic conductive material applies pressure with the anisotropic conductive material interposed, the conductive particles existing between the bumps of the semiconductor chip and the electrodes of other members are outside. The density of the conductive particles that are pushed out (between the bumps) and exist in the thermoplastic or thermosetting resin between the bumps is increased. For this reason, the semiconductor chips connected by the anisotropic conductive material may cause a short circuit between adjacent bumps due to the conductive particles existing between the bumps, and there is a problem in terms of reliability.

  In the conventional semiconductor chip, in order to prevent the occurrence of a short circuit, the distance between adjacent bumps is increased to some extent so that the adjacent bumps are not electrically connected by conductive particles. For this reason, the conventional semiconductor chip cannot reduce the distance between the bumps, and has a limitation in size reduction and integration. Also, in the conventional semiconductor chip, when bump density increases by increasing the size and integration degree, the distance between the bumps is limited. Therefore, if the width of the bump itself is narrowed, the connection reliability decreases. There is a concern that

  Further, in the COG type liquid crystal display device, it is possible to reduce the size of the liquid crystal panel by making the terminal portion as narrow as possible, and the cost can be reduced by increasing the number of chamfers from the mother glass. In the chip, the distance between the bumps is limited, and the terminal portion cannot be narrowed because it cannot be miniaturized.

  Therefore, an object of the present invention is to provide a semiconductor chip capable of improving connection reliability, miniaturization and integration degree in connection using an anisotropic conductive adhesive. Furthermore, an object of the present invention is to provide a liquid crystal display device on which a semiconductor chip capable of narrowing a terminal portion is mounted.

  In order to achieve the above-described object, a semiconductor chip of the present invention has a plurality of bumps, and the bumps are electrically connected to electrodes of other members by anisotropic conductive adhesive. Between the adjacent bumps, an inter-bump insulator having a height projecting from the bump is formed.

  In the semiconductor chip of the present invention, the height of the insulator between the bumps protrudes by 20 to 70% of the diameter of the conductive particles contained in the anisotropic conductive adhesive than the bumps. It is particularly preferable that the height protrudes by a length corresponding to 30 to 60% of the diameter of the conductive particles.

  In the semiconductor chip of the present invention, the inter-bump insulator may be provided in contact with the bump.

  In the semiconductor chip of the present invention, it is preferable that the inter-bump insulator has heat resistance.

  Furthermore, the liquid crystal display device of the present invention is characterized in that the bumps of the semiconductor chip are electrically connected to electrode pads provided on the substrate of the liquid crystal panel by an anisotropic conductive adhesive.

  In the semiconductor chip of the present invention, since an inter-bump insulator protruding higher than the bump is formed between adjacent bumps, when adhering with an anisotropic conductive adhesive, adjacent bumps are It can prevent being electrically short-circuited by the conductive particles, and can improve the reliability of connection. Furthermore, since the semiconductor chip of the present invention can prevent a short circuit between adjacent bumps with an insulator between the bumps, the bump pitch distance can be shortened without reducing the bump width, and the size is reduced while maintaining the reliability. And the degree of integration can be increased.

  In the semiconductor chip of the present invention, the insulator between the bumps is higher than the bump by 20 to 70%, more preferably 30 to 60% of the diameter of the conductive particles contained in the anisotropic conductive adhesive. Thus, the short-circuit due to the conductive particles can be prevented while maintaining an appropriate distance for connection between the bumps of the semiconductor chip and the electrodes of other members.

  Moreover, the semiconductor chip of the present invention limits the extrusion of the conductive particles captured between the bumps of the semiconductor chip and the electrodes of other members by providing the inter-bump insulator in contact with the bumps. And the number of conductive particles contributing to the connection between the bump and the electrode can be increased. Furthermore, the effect that the conductive particles which existed in the anisotropic conductive adhesive between the bumps are pushed out by the inter-bump insulator and the number of conductive particles captured between the bumps and the electrodes is increased can be expected. And since the number of conductive particles contributing to the connection between the bumps of the semiconductor chip and the electrodes of other members increases, the reliability of the connection by the anisotropic conductive adhesive is further improved.

  In addition, the semiconductor chip of the present invention can be mounted by thermocompression bonding by adopting a thermosetting resin as the anisotropic conductive adhesive because the inter-bump insulator has heat resistance.

  Furthermore, in the liquid crystal display device of the present invention, since the bumps of the semiconductor chip are electrically connected to the electrode pads provided on the substrate of the liquid crystal panel by anisotropic conductive adhesive, the size of the semiconductor chip is reduced. By doing so, the liquid crystal display device can also be reduced in size.

  First, the semiconductor chip of the present invention will be described. FIG. 1 is a schematic sectional view showing a semiconductor chip 1 of the present invention in a mounted state. In FIG. 1, the semiconductor chip 1 is mounted on another member 11, and the bump 3 of the semiconductor chip 1 is electrically connected to the electrode 12 of the other member 11 by an anisotropic conductive adhesive 21.

  The semiconductor chip 1 is a semiconductor piece in which various circuits are formed as semiconductor elements on a semiconductor substrate 2, and has a plurality of bumps 3 protruding from the pattern surface on one surface (the lower surface in FIG. 1). Further, on one surface of the semiconductor chip 1, an inter-bump insulator 4 is formed between adjacent bumps, the height of which protrudes higher than that of the bump 3.

  The inter-bump insulator 4 prevents the adjacent bumps 3 from being electrically short-circuited by the conductive particles 22 when bonded by the anisotropic conductive adhesive 21. For this reason, if the inter-bump insulator 4 is lower than the bump 3, a short circuit due to the conductive particles 22 cannot be prevented. On the other hand, when the inter-bump insulator 4 is too higher than the bump 3, the bump 3 and the electrode 12 are separated from each other, and the connection by the conductive particles becomes unstable and the reliability may be lowered. In general, in the connection using the anisotropic conductive adhesive 21, the conductive particles 22 in the anisotropic conductive adhesive 21 are bonded in a pressurized state so that the diameter thereof is about 50%. Therefore, the height of the inter-bump insulator 4 protrudes from the bump 3 by a length of 20 to 70%, more preferably 30 to 60% of the diameter of the conductive particles 22 in the anisotropic conductive adhesive 21. Preferably it is. The diameter of the conductive particles 22 is the diameter of the conductive particles 22 before being deformed by pressurization, and indicates the average diameter in the anisotropic conductive adhesive 21.

  The inter-bump insulator 4 may be provided in contact with the adjacent bumps 3A and 3B like the inter-bump insulator 4A, or the adjacent bumps 3B and 3C like the inter-bump insulators 4B and 4C. , 3C and 3D may be separated.

  When the inter-bump insulator 4A is provided in contact with the adjacent bumps 3A and 3B, the conductive particles 22 captured between the bump 3 and the electrode 12 can be restricted from being pushed out. The number of conductive particles between the electrodes 12 can be increased. Similarly, even if the distance between the adjacent bumps 3B and 3C, such as the inter-bump insulator 4B, is shorter than the diameter of the conductive particles, the conductive particles captured between the bumps 3 and the electrodes 12 are the same. 22 can be pushed out, and the number of conductive particles between the bump 3 and the electrode 12 can be increased.

  Further, in the inter-bump insulator 4A and the inter-bump insulator 4B, the conductive particles present in the anisotropic conductive adhesive between the bumps are pushed out by the inter-bump insulators 4A and 4B, and the bump 3 and the electrode The effect of increasing the number of conductive particles trapped between 12 can also be expected. In this case, the inter-bump insulator 4 can extrude the conductive particles along the taper when the protruding tip has a tapered shape rather than the rectangular cross-sectional shape. Since it is extruded between the electrodes 12, it is preferable.

  Note that the inter-bump insulator 4 is not necessarily provided between all the adjacent bumps 3, and the distance between the bumps is separated like the adjacent bumps 3 </ b> D and 3 </ b> E in FIG. 1, and a short circuit occurs. It is not necessary to provide it at a place where the possibility is low.

  As the inter-bump insulator 4, an insulator such as an SOG (Spin On Glass) film or a synthetic resin can be used. In particular, photosensitive resin such as polyimide resin, silicone resin, epoxy resin, and acrylic resin is preferable as the inter-bump insulator 4. Furthermore, if the insulating material 4 between the bumps has a heat resistance of about 270 ° C., a thermosetting resin can be adopted as an adhesive for the anisotropic conductive adhesive, and mounting by thermocompression bonding is possible. It is preferable because it is possible. The inter-bump insulator 4 can be formed using a known lithography technique.

  Examples of the other member 11 include a substrate of a liquid crystal panel, but a circuit substrate, a film carrier, or the like can also be applied.

  The anisotropic conductive adhesive 21 is obtained by dispersing conductive particles 22 in an adhesive 23. The adhesive 23 may be solid or liquid, and a thermoplastic, thermosetting, ultraviolet curable resin, or the like can be used. When a thermosetting resin is used as the adhesive 23, it is necessary to use a material having heat resistance as the inter-bump insulator 4. As the conductive particles 22, particles whose surfaces are covered with a conductive material with particulate metal or resin particles can be used.

  The semiconductor chip 1 may be sealed with a protective resin after being mounted on the other member 11 to insulate the semiconductor chip and protect the semiconductor chip from external mechanical and environmental stresses.

  Next, a liquid crystal display device mounted with the semiconductor chip of the present invention will be described. FIG. 2 is a schematic cross-sectional view showing a liquid crystal display device 41 of the present invention. The liquid crystal display device 41 includes a liquid crystal panel 42 and the semiconductor chip 1. In the liquid crystal panel 42, the first substrate 44 on which the electrodes 43 are formed and the second substrate 46 on which the electrodes 45 are formed face each other so that the electrodes 43 and 45 are on the inside, and the substrates 44 and 46 are sealed. In this structure, a liquid crystal 48 is enclosed between the substrates 44 and 46. The liquid crystal panel 42 includes a display unit 51 positioned inside the seal 47, a seal unit 52 provided with the seal 47, and a terminal unit 53 positioned outside the seal 47.

  The electrode 43 formed on the first substrate 44 extends from the display unit 51 to the terminal unit 53 beyond the seal unit 52, and functions as an electrode pad 43 </ b> A for connecting to the IC chip 1 in the terminal unit 53. Yes. Further, the terminal portion 53 is provided with an external terminal 49 for connecting the IC chip 1 and an external circuit (not shown). The terminal portion 53 may be provided with an electrode pad for connecting the IC chip 1 and the electrode 45 of the second substrate 46.

  Although details of the IC chip 1 are not shown, as described above, there are inter-bump insulators whose height protrudes from the bumps between the plurality of bumps and the adjacent bumps. The bumps of the IC chip 1 are electrically connected to the electrode pads 45A and the external terminals 49 formed on the terminal portions 53 of the first substrate 44 of the liquid crystal panel 42 by an anisotropic conductive adhesive (not shown). It is connected.

  In this embodiment, a driving IC chip that drives liquid crystal is used as a semiconductor chip. The surface of the driving IC chip is provided with bumps and an inter-bump insulator in contact with the bumps. The bumps have a height of 15 μm from the pattern surface, and the inter-bump insulators have a height of 17 μm from the pattern surface. Therefore, in the present embodiment, the inter-bump insulator has a structure with a height of 2 μm protruding from the bump.

  If this driving IC chip is mounted on a liquid crystal panel using an anisotropic conductive material containing conductive particles having a diameter of 4 μm, a liquid crystal display device without a short circuit between bumps can be manufactured.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed. For example, the periphery of the bump may be surrounded by an insulator between the bumps.

Schematic sectional view showing the semiconductor chip of the present invention in a mounted state Schematic sectional view showing a liquid crystal display device of the present invention Schematic sectional view showing a conventional semiconductor chip in a mounted state

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor chip 3 Bump 4 Bump insulator 11 Other members 12 Electrode 21 Anisotropic conductive adhesive 22 Conductive particle

Claims (6)

  In a semiconductor chip having a plurality of bumps, and the bumps are electrically connected to electrodes of other members by anisotropic conductive adhesive, the height protrudes between the bumps adjacent to the bumps. A semiconductor chip characterized in that an insulating material between bumps is formed.   2. The semiconductor chip according to claim 1, wherein the inter-bump insulator protrudes from the bump by a length of 20 to 70% of the diameter of the conductive particles contained in the anisotropic conductive adhesive.   The semiconductor chip according to claim 2, wherein the inter-bump insulator protrudes from the bump by a length of 30 to 60% of the diameter of the conductive particles.   The semiconductor chip according to claim 1, wherein the inter-bump insulator is provided in contact with the bump.   The semiconductor chip according to claim 1, wherein the inter-bump insulator has heat resistance.   6. A liquid crystal display device, wherein the bumps of the semiconductor chip according to claim 1 are electrically connected to electrode pads provided on a substrate of a liquid crystal panel by an anisotropic conductive adhesive.