Display device including imperfect connection parts extending between printed circuit boards for bridging

• US 7,123,249 B2
• Filed: 07/23/2003
• Issued: 10/17/2006
• Est. Priority Date: 07/26/2002
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Device Engineering Co., Ltd. (Hitachi, Ltd.), Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Takenaka, Yuuichi
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): LUI, DONNA V
• Application Number:
  US10/624,601
• Publication Number:
  US 20040017536A1
• Time in Patent Office: 1,182 Days
• Field of Search: 349/150, 349/151, 345/206, 428/209, 428/194
• US Class Current: 345/206
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/0298 Multilayer circuits
• CPC Class Codes: H05K 1/0366 reinforced, e.g. by fibres, fabrics H05K1/036 takes precedence
• CPC Class Codes: H05K 1/147 at least one of the printed circuits being bent or folded, e.g. by using a flexible printed circuit H05K1/148 takes precedence
• CPC Class Codes: H05K 2203/0228 Cutting, sawing, milling or shearing
• CPC Class Codes: H05K 2203/1545 Continuous processing, i.e. involving rolls moving a band-like or solid carrier along a continuous production path

Abstract

In a display device including a display panel and a multi-layered printed circuit board which is arranged along one side of the display panel and is electrically connected to a plurality of leads of the display panel through a plurality of tape carrier packages, according to the present invention, a plurality of slits or notches are formed in a sheet fiber member which is impregnated with resin and constitutes a base sheet of the multi-layered printed circuit board along one side of the display panel. The discontinuity of the sheet fiber member formed by the slits or the notches absorbs the difference in thermal expansion of the multi-layered printed circuit board and the display panel due to the change of an ambient temperature of the display device and hence, it is possible to prevent peeling of the tape carrier package from the display panel or breaking of the tape carrier package per se.

Claims

1. A display device, comprising:

an insulating substrate which has a large number of electrodes, having an end periphery thereof on which a plurality of leads which supply signals for image display to the respective electrodes are formed;

a multi-layered printed circuit board which is arranged along the end periphery and includes wiring for transmitting the signals for image display along the end periphery; and

a plurality of printed circuit boards for bridging which are arranged in parallel along the end periphery of the insulating substrate, wherein for every one of a plurality of groups of leads formed by dividing the plurality of leads along the end periphery, each printed circuit board bridges the wiring of the multi-layered printed circuit board with one of the plurality of groups of leads, wherein

the multi-layered printed circuit board includes at least a unit which has at least one base sheet which is formed by impregnating an insulating sheet fiber member with resin and conductive layers which are stacked and fixed to the base sheet and are insulated from each other by the base sheet, and imperfect connection parts which attenuate an elongation and a shrinkage of the multi-layered printed circuit board in the longitudinal direction in a plane of the base sheet, the imperfect connection parts are formed at a portion of the sheet fiber member of the base sheet, and

the imperfect connection parts extend between the printed circuit boards for bridging in the direction which connects end peripheries of the printed circuit boards for bridging along the widthwise direction.

2. A display device according to claim 1, wherein a semiconductor chip is mounted on the printed circuit board for bridging.

3. A display device according to claim 1, wherein another insulating substrate is further arranged to face the insulating substrate, these insulating substrates have respective peripheries thereof adhered to each other, and liquid crystal is filled and sealed between the insulating substrate and another insulating substrate.

4. A display device, comprising:

an insulating substrate which has a large number of electrodes, having an end periphery thereof on which a plurality of leads which supply signals for image display to the respective electrodes are formed;

a multi-layered printed circuit board which is arranged along the end periphery and includes wiring for transmitting the signals for image display along the end periphery; and

a plurality of printed circuit boards for bridging which are arranged in parallel along the end periphery of the insulating substrate, wherein for every one of a plurality of groups of leads formed by dividing the plurality of leads along the end periphery, each printed circuit board bridges the wiring of the multi-layered printed circuit board with one of the plurality of groups of leads, wherein

the multi-layered printed circuit board includes at least a unit which has at least one base sheet which is formed by impregnating an insulating sheet fiber member with resin and conductive layers which are stacked and fixed to the base sheet and are insulated from each other by the base sheet, and imperfect connection parts which attenuate an elongation and a shrinkage of the multi-layered printed circuit board in the longitudinal direction in a plane of the base sheet, the imperfect connection parts are formed at a portion of the sheet fiber member of the base sheet,

the imperfect connection parts are constituted of an imperfect connection parts of a first row which are intermittently arranged in the longitudinal direction of the multi-layered printed circuit board and are positioned at the end periphery of a side remote from the insulating substrate, and an imperfect connection parts of a second row which are intermittently arranged in the longitudinal direction of the multi-layered printed circuit board and are positioned at the end periphery of a side close to the insulating substrate, and

the imperfect connection parts of the first row are formed between arrangements of the printed circuit boards for bridging and the imperfect connection parts of the second row are formed at positions where the printed circuit boards for bridging are overlapped to the multi-layered printed circuit board.

5. A display device according to claim 4, wherein between the imperfect connection parts of the first row and the imperfect connection parts of the second row along the longitudinal direction of the multi-layered printed circuit board, the insulating sheet fiber member is continued without being deformed.

6. A display device according to claim 4, wherein the imperfect connection parts of the first row and the imperfect connection parts of the second row are arranged in a staggered manner along the longitudinal direction of the multi-layered printed circuit board.

7. A display device according to claim 4, wherein between the imperfect connection parts of the first row and the end periphery of the multi-layered printed circuit board on a side remote from the insulating substrate, an area where the insulating sheet fiber member is formed continuously without being deformed is provided.

8. A display device, comprising:

an insulating substrate which has a main surface on which a plurality of electrodes contributing to an image display operation are formed, wherein a plurality of leads which supply signals to the plurality of respective electrodes are arranged in parallel along at least one side of the main surface of the insulating substrate;

a multi-layered printed circuit board which has wiring for transmitting the signals along at least one side of the main surface of the insulating substrate; and

a plurality of printed circuit boards which respectively bridge a distance between the multi-layered printed circuit board and at least one side of the main surface of the insulating substrate, and supply the signal to at least one of groups of the plurality of leads which are formed in a divided manner at least along one side of the main surface from the multi-layered printed circuit board, wherein

the multi-layered printed circuit board has a laminated structure which includes at least a base sheet formed of an insulating sheet fiber member impregnated with resin and a conductive layer formed on the base sheet and insulated from the base sheet,

the extension direction of the base sheet is arranged along at least one side of the main surface of the insulating substrate,

a plurality of discontinued areas in the extending direction of the base sheet are formed in the insulating sheet fiber member, and

the discontinued areas of the sheet fiber member which are formed in the base sheet of the multi-layered printed circuit board extend in the direction which traverses the extending direction of the base sheet so as to divide the sheet fiber member into sections.

9. A display device according to claim 8, wherein films made of the resin which extend along the extension direction of the base sheet are formed on the discontinued areas of the sheet fiber member formed in the base sheet of the multi-layered printed circuit board.

10. A display device according to claim 8, wherein the sheet fiber member formed in the base sheet of the multi-layered printed circuit board are not completely separated along the extending direction of the base sheet in the discontinued areas.