JP5678726B2 - Flexible substrate for electro-optical device and electro-optical device - Google Patents

Description

  The present invention relates to a flexible substrate for an electro-optical device and an electro-optical device including the same.

  Conventionally, a flexible substrate has been used to connect an electro-optical panel such as a liquid crystal display panel or an organic EL (Electro-Luminescence) display panel to a power supply circuit and a control circuit. In a flexible substrate for such applications, it is desirable to suppress as much as possible the occurrence of noise due to electromagnetic interference in the signal flowing through the wiring. In particular, when a signal having a high frequency is transmitted through a flexible substrate, such noise suppression is important. For this reason, in the flexible substrate, a ground wiring for electromagnetic shielding is provided in the vicinity of the wiring. For example, Patent Document 1 discloses that two wirings positioned at both ends of wirings provided in the electrical connection means of the tape carrier package are ground potential wirings.

Japanese Patent Laid-Open No. 10-10565

  However, in the technique described in Patent Document 1, since only two wires at both ends are used as ground potential wires, when many wires are provided, the effect of electromagnetic shielding on these wires is not so great. I can't expect it. In addition, the wiring should be shielded from electromagnetic waves generated by these electrical components at and near the location where the wiring and other electrical components (power supply circuit or control circuit) are connected. In the technique described in Patent Document 1, however, The effect of electromagnetic shielding at such a location and its vicinity is not high.

  This invention is made | formed in view of the said subject, and makes it a solution subject to improve the effect of the electromagnetic shielding with respect to wiring.

In order to solve the above-described problems, the present invention provides a substrate material having a first surface and a second surface opposite to the first surface, and the substrate material is disposed on the first surface, each of which is another A pair of power supply wirings having terminals connected to the electrical components, at least a pair of differential wirings arranged on the first surface, each having terminals connected to other electrical components, and the base The first member disposed on the first surface so as to surround both of the pair of terminals of the pair of power supply wirings and to surround both of the pair of terminals of the pair of differential wirings at one end of the plate member. A ground pattern, a second ground pattern disposed on the second surface so as to overlap the power supply wiring and the differential wiring on the first surface, the first ground pattern, and the second ground pattern. Multiple through to electrically connect the ground pattern of The first ground pattern includes a parallel portion extending alongside the power supply wiring and the differential wiring, and an outer portion connected to the parallel portion and outside the power supply wiring and the differential wiring. The parallel portion and the outer portion surround both of the pair of terminals of the pair of power supply wirings from three directions, and surround both of the pair of terminals of the pair of differential wirings from three directions. The plurality of through holes electrically connect the outer portion of the first ground pattern and the second ground pattern outside the terminal of the power supply wiring and the terminal of the differential wiring. A flexible substrate for an electro-optical device is provided.

  In this flexible substrate for an electro-optical device, the first ground pattern surrounds both the pair of terminals of the pair of power supply wirings and surrounds the pair of terminals of the pair of differential wirings at one end of the substrate material. Further, a second ground pattern is arranged on the second surface of the substrate material so as to overlap the power supply wiring and the differential wiring on the first surface of the substrate material. Thus, the pair of power supply wirings are surrounded by the first ground pattern and further overlapped with the second ground pattern, and the pair of differential wirings are also surrounded by the first ground pattern, and further the second ground pattern. Overlapping. Therefore, the effect of electromagnetic shielding on the power supply wiring and the differential wiring is high, the stability of the power supply voltage is improved, and the noise suppression effect on the high-speed signal flowing through the differential wiring can be enhanced. In particular, since the first ground pattern surrounds a terminal connected to another electrical component, the effect of electromagnetic shielding at the terminal and its vicinity can be enhanced.

In the above-described flexible substrate for an electro-optical device, the first ground pattern includes a parallel part extending alongside the power supply wiring and the differential wiring, and is connected to the parallel part and more than the power supply wiring and the differential wiring. An outside portion on the outside, and the parallel portion and the outside portion surround both of the pair of terminals of the pair of power supply wirings from three directions, and both of the pair of terminals of the pair of differential wirings are 3 enclose from the direction. As described above, the first ground pattern surrounds the terminal from three directions, so that the effect of electromagnetic shielding at the terminal and the vicinity thereof can be enhanced. In particular, since the first ground pattern has an outer portion outside the power supply wiring and the differential wiring, the first ground pattern has a high effect of shielding electromagnetic waves acting from outside the flexible substrate. The stability can be improved and the noise suppression effect on the high-speed signal flowing through the differential wiring can be enhanced.

In the above-described flexible substrate for an electro-optical device, the plurality of through holes are formed on the outer side of the terminal of the power supply wiring and the terminal of the differential wiring, and the second portion of the first ground pattern and the second portion. Electrically connect the ground pattern . In this electro-optic device flexible substrate, the first ground pattern on the first surface of the substrate material and the second ground pattern on the second surface are electrically connected by a plurality of through holes, and these through holes Is outside of the terminals of the power supply wiring and the differential wiring, the impedance of the end of the first ground pattern (that is, the outer portion) and the end of the second ground pattern can be kept low. Accordingly, the electromagnetic wave acting from outside the flexible substrate for the electro-optical device is highly effective in shielding the end portions of the first ground pattern and the second ground pattern, so that noise to signals flowing through the power supply wiring and the differential wiring is high. The suppression effect is also high.

  An electro-optical device according to the present invention includes the above-described flexible substrate for an electro-optical device, and an electro-optical panel that is driven by power supplied from the power supply wiring and controlled by a signal supplied from the differential wiring. Prepare. The electro-optical panel includes a liquid crystal display panel, an organic EL display panel, or other image display panel, and further, a liquid crystal system that emits light to write an electrostatic latent image on a photosensitive drum of an electrophotographic printer. There are organic EL type or other light emission type exposure heads.

1 is a schematic plan view of an electro-optical device according to an embodiment. It is a top view which shows the detail of the edge part of the flexible substrate for electro-optical apparatuses. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is a perspective view which shows the example of the electronic device with which the electro-optical apparatus was utilized. It is a perspective view which shows the other example of the electronic device using the electro-optical apparatus.

  FIG. 1 is a schematic plan view of an electro-optical device 1 according to an embodiment of the present invention. The electro-optical device 1 includes a liquid crystal display panel 2 that is an example of an electro-optical panel, and a flexible substrate 10 for an electro-optical device that is electrically connected to the liquid crystal display panel 2. The electro-optical device 1 is a component or module incorporated in a housing (not shown), but a completed electro-optical device including the housing and other components is also within the scope of the present invention.

  As shown in FIG. 1, an IC chip 12 having, for example, a data line driving circuit for driving the liquid crystal display panel 2 is mounted on one surface of the flexible substrate 10. The upper end portion of the flexible substrate 10 in the figure is attached to the liquid crystal display panel 2 and the IC chip 12 is electrically connected to the liquid crystal display panel 2, but the IC chip 12 and the liquid crystal display panel 2 are electrically connected. Illustration of wiring connected to is omitted.

  Also, on one surface of the flexible substrate 10, a pair of power supply wirings 14a and 14b, a pair of differential wirings 15a and 15b, another pair of differential wirings 16a and 16b, and a pair of control wirings 17a and 17b are arranged. ing. The power supply wirings 14a and 14b supply a power supply voltage for driving them to the IC chip 12 and the liquid crystal display panel 2. The differential wirings 15a, 15b, 16a, 16b are wirings for high-speed signal transmission conforming to, for example, LVDS (Low Voltage Differential Signaling), and the liquid crystal display panel 2 is controlled by signals supplied through these wirings. . In FIG. 1, two pairs of differential wirings 15a and 15b and differential wirings 16a and 16b are shown. However, the number of differential wiring pairs is not limited to that shown in FIG. The control wirings 17a and 17b supply a target control signal different from the differential wirings 15a, 15b, 16a and 16b to the IC chip 12, and the liquid crystal display panel 2 is controlled by signals supplied through these wirings. The control wirings 17a and 17b may or may not be differential lines.

  In FIG. 1, an LC circuit connected to the power supply wirings 14 a and 14 b can be arranged in the region 18 on one surface of the flexible substrate 10 for the purpose of stabilizing the power supply voltage. When the power supply wirings 14 a and 14 b are provided on the left side of the drawing in the flexible substrate 10, such an LC circuit may be arranged in the region 19. Thus, in the flexible substrate 10, a circuit can be arranged in a region where no wiring is provided.

  A first ground pattern 21 is disposed at the end of the flexible substrate 10 opposite to the liquid crystal display panel 2. The first ground pattern 21 is made of a conductive material, and is connected to the parallel portions 21a that extend alongside the wirings 14a, 14b, 15a, 15b, 16a, 16b, 17a, and 17b. 14 a, 14 b, 15 a, 15 b, 16 a, 16 b, 17 a, and 17 b, an outer portion 21 b that is located outside the 17 b. The ends of the pair of power supply wires 14a and 14b are arranged between two adjacent parallel portions 21a. The ends of the paired differential wires 15a and 15b are arranged between two adjacent parallel portions 21a. The ends of the paired differential wirings 16a and 16b are arranged between two adjacent parallel portions 21a. The ends of the paired control wirings 17a and 17b are disposed between two adjacent parallel portions 21a.

  2 is a plan view showing details of the end portion of the flexible substrate 10, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. As shown in FIG. 3, the flexible substrate 10 includes a flat thin resin-made substrate material 20. The wirings 14a, 14b, 15a, 15b, 16a, 16b, 17a, 17b and the first ground pattern 21 are arranged on the upper surface of the substrate material 20, that is, the first surface. These wirings 14a, 14b, 15a, 15b, 16a, 16b, 17a, 17b and the first ground pattern 21 are covered with a protective layer made of a non-conductive material, that is, a resist layer 25.

  A second ground pattern 22 is disposed on the lower surface of the substrate material 20, that is, the second surface. The second ground pattern 22 covers the entire lower surface of the substrate material 20 and supplies a ground potential to the liquid crystal display panel 2. Since the second ground pattern 22 covers the entire lower surface of the substrate material 20, the second ground pattern 22 overlaps the wirings 14a, 14b, 15a, 15b, 16a, 16b, 17a, and 17b on the upper surface of the substrate material 20. The second ground pattern 22 is covered with a protective layer made of a non-conductive material, that is, a resist layer 26.

  As shown in FIG. 2, a terminal T connected to another electrical component is provided at each end of the wirings 14a, 14b, 15a, 15b, 16a, 16b, 17a, and 17b. More precisely, a portion corresponding to the terminal T is opened in the resist layer 25, and the terminal T can be electrically connected to another electric component such as a power supply device through the opening.

  The outer portion 21b of the first ground pattern 21 is provided with a contact C that is connected to a connector that supplies a ground potential. More precisely, a portion corresponding to the contact C in the resist layer 26 is opened, and the contact C can be electrically connected to the connector through the opening.

  The flexible substrate 10 is provided with a large number of through holes 23, and a conductive material is disposed in the through holes 23. The first ground pattern 21 on the front side and the second ground pattern 22 on the back side are formed. Electrically connected. Some of these through holes 23 are arranged in the parallel portion 21 a of the first ground pattern 21, and others are the outer portions 21 b of the first ground pattern 21, that is, the wirings 14 a, 14 b, 15 a, 15b, 16a, 16b, 17a, 17b are arranged on the outer part. Accordingly, the ground potential applied to the first ground pattern 21 through the contact C is applied to the second ground pattern 22 through the through-hole 23, and as a result, applied to the liquid crystal display panel 2.

  In the flexible substrate 10, both of the pair of terminals T of the pair of power supply wirings 14 a and 14 b are surrounded by the two adjacent parallel portions 21 a and the outer portion 21 b of the first ground pattern 21 from three directions. Further, both of the pair of terminals T of the pair of differential wirings 15 a and 15 b are surrounded from three directions by two adjacent parallel portions 21 a and the outer portion 21 b of the first ground pattern 21. Similarly, both of the pair of terminals T of the pair of differential wirings 16 a and 16 b are surrounded from the three directions by the two adjacent parallel portions 21 a and the outer portion 21 b of the first ground pattern 21. Further, both of the pair of terminals T of the pair of control wirings 17 a and 17 b are surrounded from the three directions by the two adjacent parallel portions 21 a and the outer portion 21 b of the first ground pattern 21.

  Further, a second ground pattern 22 is disposed on the lower surface of the substrate material 20 so as to overlap the wirings 14a, 14b, 15a, 15b, 16a, 16b, 17a, and 17b on the upper surface of the substrate material 20. Thus, the pair of power supply wirings 14 a and 14 b is surrounded by the first ground pattern 21 from three directions and further overlaps the second ground pattern 22. The pair of differential wirings 15 a and 15 b are also surrounded by the first ground pattern 21 from three directions and further overlap the second ground pattern 22. The same applies to the differential wirings 16a and 16b and the control wirings 17a and 17b. Therefore, the effect of electromagnetic shielding on the power supply lines 14a and 14b, the differential lines 15a, 15b, 16a and 16b, and the control lines 17a and 17b is high. In particular, since the first ground pattern 21 surrounds the terminal T connected to other electrical components, the effect of electromagnetic shielding at the terminal T and its vicinity can be enhanced. Furthermore, since the first ground pattern 21 has an outer portion 21b outside the wirings 14a, 14b, 15a, 15b, 16a, 16b, 17a, and 17b, electromagnetic waves acting from the outside of the flexible substrate 10 are transmitted to the first ground pattern 21. Since the effect of shielding the ground pattern 21 is high, the stability of the power supply voltage is improved, and the noise suppression effect on the signals flowing through the wirings 15a, 15b, 16a, 16b, 17a, and 17b is also high.

  In the flexible substrate 10, the first ground pattern 21 on the upper surface of the substrate material 20 and the second ground pattern 22 on the lower surface are electrically connected by a plurality of through holes 23. Is located outside the terminal T of the wirings 14a, 14b, 15a, 15b, 16a, 16b, 17a, 17b, the end of the first ground pattern 21 (that is, the outer portion 21b) and the second ground pattern. The impedance at the end of 22 can be kept low. Therefore, the electromagnetic wave acting from the outside of the flexible substrate 10 is highly effective in shielding the ends of the first ground pattern 21 and the second ground pattern 22, so that the stability of the power supply voltage is improved and the high-speed signal flowing through the wiring The noise suppression effect can be enhanced.

  The electro-optical device according to the present invention is driven by the electric power supplied from the above-described flexible substrate 10 and the power supply wirings 14a and 14b and controlled by signals supplied from the differential wirings 15a, 15b, 16a and 16b. And an electro-optic panel. In addition to the liquid crystal display panel 2, the electro-optical panel includes an organic EL display panel or other image display panel. Furthermore, light is irradiated to write an electrostatic latent image on a photosensitive drum of an electrophotographic printer. There are liquid crystal type, organic EL type or other light emitting type exposure heads.

  Next, an electronic apparatus using the electro-optical device 1 according to the present invention will be described. FIG. 4 is a perspective view illustrating a configuration of a laptop personal computer that employs the electro-optical device 1 according to the embodiment described above as a display device. The personal computer 2000 includes a light emitting device 1 as a display device and a main body 2010. The main body 2010 is provided with a power switch 2001 and a keyboard 2002.

  FIG. 5 shows a configuration of a mobile phone that employs the electro-optical device 1 according to the embodiment described above as a display device. The cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and the electro-optical device 1. By operating the scroll button 3002, the screen displayed on the electro-optical device 1 is scrolled.

  Note that electronic devices to which the electro-optical device 1 according to the present invention is applied include those shown in FIGS. 4 and 5, digital still cameras, televisions, video cameras, car navigation devices, pagers, electronic notebooks, and electronic papers. Calculators, word processors, workstations, videophones, POS terminals, tablet computers, printers, scanners, copiers, video players, display devices with touch panels, and the like.

DESCRIPTION OF SYMBOLS 1 ... Electro-optical device, 2 ... Liquid crystal display panel, 10 ... Flexible board for electro-optical devices, 12 ... IC chip, 14a, 14b ... Power supply wiring, 15a, 15b ... Differential wiring, 16a, 16b ... Differential wiring, 17a , 17b ... control wiring, 18 ... region, 19 ... region, 20 ... substrate material, 21 ... first ground pattern, 21a ... parallel portion, 21b ... outer portion, 22 ... second ground pattern, 23 ... through hole, 25 ... resist layer, 26 ... resist layer, 2000 ... personal computer, 2001 ... power switch, 2002 ... keyboard, 2010 ... main body, 3000 ... mobile phone, 3001 ... operation buttons, 3002 ... scroll buttons, T ... terminals, C ... contact.

Claims (2)

A substrate material comprising a first surface and a second surface opposite the first surface;
A pair of power supply wirings disposed on the first surface, each having a terminal connected to another electrical component;
At least a pair of differential wirings disposed on the first surface, each having a terminal connected to another electrical component;
The one end portion of the substrate material is disposed on the first surface so as to surround both of the pair of terminals of the pair of power supply wirings and to surround both of the pair of terminals of the pair of differential wirings. A first ground pattern;
A second ground pattern disposed on the second surface so as to overlap the power supply wiring and the differential wiring on the first surface;
A plurality of through holes electrically connecting the first ground pattern and the second ground pattern ;
The first ground pattern includes a parallel portion extending alongside the power supply wiring and the differential wiring, and an outer portion connected to the parallel portion and outside the power supply wiring and the differential wiring,
The parallel portion and the outer portion surround both of the pair of terminals of the pair of power supply wirings from three directions, and surround both of the pair of terminals of the pair of differential wirings from three directions,
The plurality of through holes electrically connect the outer portion of the first ground pattern and the second ground pattern outside the terminal of the power supply wiring and the terminal of the differential wiring. A flexible substrate for an electro-optical device. The flexible substrate for an electro-optical device according to claim 1 ,
An electro-optical panel that is driven by power supplied by the power supply wiring and controlled by a signal supplied by the differential wiring;
An electro-optical device.

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