JP2006145318A - Pressure sensitive sensor unit, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting technology suitable for a fingerprint sensor using an active matrix type TFT substrate. <P>SOLUTION: By inserting a packing 192 between a conductive sheet 2 and a pressure sensitive sensor integrated circuit chip 50, the conductive sheet 2 is stuck on the surface of the pressure sensitive sensor integrated circuit chip 50 while a certain gap is kept, and they are stored in a storage case 200. The packing 192 does not harden, contract, or expand differently from an adhesive, so that the certain distance is kept between the conductive sheet 2 and the pressure sensitive sensor integrated circuit chip 50. The reliability and strength of this pressure sensitive sensor unit 300 are improved by filling moisture proof resin 150 outside the packing 192 and between the conductive sheet 2 and the pressure sensitive sensor integrated circuit chip 50. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive sensor unit and a manufacturing method thereof, and more particularly, a pressure-sensitive sensor integrated circuit chip including a plurality of pressure-sensitive cells including a contact electrode and a thin film transistor for selecting a contact electrode for selecting the contact electrode; The present invention relates to a pressure-sensitive sensor unit including a conductive sheet attached to the surface of a pressure-sensitive sensor integrated circuit chip and brought into contact with the pressure of the contact electrode, and a manufacturing method thereof.

  In recent years, fingerprint sensors that detect human fingerprints have attracted attention as identity verification means when using electronic devices such as personal computers. A fingerprint sensor that is currently popular is an optical type in which a fingertip is pressed against the glass surface of a sensor panel, light is irradiated to the pressed fingertip portion, and the reflected light is read by a light receiving means such as a CCD. Most of the things. However, the optical fingerprint sensor is not only difficult to reduce in size and thickness, but also has a problem of high manufacturing cost.

Therefore, a flexible conductive sheet is affixed to the active matrix TFT substrate, and fingerprint detection is performed by converting the difference in pressing force between the peak and valley of the fingerprint when the finger is pressed against the conductive sheet into an electrical signal. An active matrix fingerprint sensor has been proposed.
JP-A-8-68704

  However, a mounting technology for a fingerprint sensor using the active matrix TFT substrate described above has not been proposed. In particular, it has not been proposed how to attach a conductive sheet to a TFT substrate.

  Therefore, the main characteristic configuration of the present invention is as follows. That is, the pressure-sensitive sensor unit of the present invention has a plurality of pressure-sensitive cells including a contact electrode and a contact electrode selection thin film transistor for selecting the contact electrode, and a terminal from which a detection signal is output from the pressure-sensitive cell. A pressure-sensitive sensor integrated circuit chip having a group, a conductive sheet that contacts the contact electrode when pressed, and an upper frame and a lower frame, and the pressure sensitivity is obtained by fitting the upper frame and the lower frame together A storage case in which a sensor integrated circuit chip and the conductive sheet are stored, and a packing inserted between the conductive sheet and the pressure-sensitive sensor integrated circuit chip are provided.

  The pressure-sensitive sensor unit according to the present invention is characterized in that a moisture-proof resin is filled between the conductive sheet and the pressure-sensitive sensor integrated circuit chip and outside the packing.

  In the method of manufacturing a pressure-sensitive sensor unit according to the present invention, a plurality of pressure-sensitive cells each including a contact electrode and a thin film transistor for selecting a contact electrode for selecting the contact electrode are arranged, and a detection signal is output from the pressure-sensitive cell. A pressure-sensitive sensor integrated circuit chip having a terminal group, a packing is disposed on the surface of the previous pressure-sensitive sensor integrated circuit chip, a conductive sheet is further disposed on the packing, and an upper frame and a lower frame Thus, the upper frame and the lower frame are fitted together with the conductive sheet, the packing, and the pressure-sensitive sensor integrated circuit chip interposed therebetween.

  The pressure-sensitive sensor unit manufacturing method of the present invention is characterized in that a moisture-proof resin is filled between the conductive sheet and the pressure-sensitive sensor integrated circuit chip and outside the packing.

  The pressure-sensitive sensor unit and the manufacturing method thereof according to the present invention are electrically conductive by inserting a packing between the pressure-sensitive sensor integrated circuit chip and the conductive sheet without using an adhesive, and fitting the upper frame and the lower frame. Since the sheet is bonded to the pressure-sensitive sensor integrated circuit chip, the manufacturing cost can be reduced. Moreover, since the complicated process for apply | coating and hardening an adhesive agent is reduced, manufacturing cost can be held down.

  Furthermore, since the packing does not cause curing shrinkage at the time of curing unlike an adhesive, the gap between the conductive sheet and the pressure-sensitive sensor integrated circuit chip can be maintained at a constant distance. That is, since the bending of the conductive sheet can be prevented, the reliability of the fingerprint sensor is improved.

  Further, the moisture resistance and strength of the pressure sensitive sensor unit can be improved by filling the outer side of the packing with the moisture-proof resin between the conductive sheet and the pressure sensitive sensor integrated circuit chip.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. First, the structure of the pressure-sensitive sensor panel according to the embodiment of the present invention will be described. FIG. 1 is an exploded perspective view of the pressure-sensitive sensor panel.

  The pressure sensitive sensor panel 1 forms an amorphous silicon film on an insulating substrate 10 such as glass or ceramic, and forms a number of TFTs (thin film transistors) 11, drain lines 12, and gate lines 13 by a known photolithography technique. Further, a conductive film 2a is deposited on the back surface of an insulating film such as PET (polyethylene terephthalate) on a pressure-sensitive sensor integrated circuit chip 50 formed by forming, for example, a contact electrode 14 of ITO (indium tin oxide) by vapor deposition. The sheet 2 is pasted.

  The drain line 12 and the gate line 13 are arranged in a direction crossing each other, and function as a scanning line when a scanning signal is applied as will be described later. The drain line 12 is connected to an X direction scanning circuit 20 that outputs an X direction scanning signal, and the gate line 13 is connected to a Y direction scanning circuit 21 that outputs a Y direction scanning signal.

  In the case of detecting a fingerprint pattern, the interval between the drain lines 12 and the interval between the gate lines 13 is about 50 to 60 μm. On the insulating substrate 10, a large number of pressure sensitive cells are formed in a matrix in which the drain of each TFT is connected to the drain line 12, the gate is connected to the gate line 13, and the source is connected to the contact electrode 14.

  Further, on the insulating substrate 10, as will be described later, a detector 22 for detecting a signal from each pressure sensitive cell, an output terminal for taking out an output signal from the detector 22, and an X-direction scanning circuit 20 In addition, input terminals for supplying power and a scanning clock to internal circuits such as the Y-direction scanning circuit 21 and the detector 22 are arranged in a line to form a terminal group 30, and this terminal group 30 is an edge of the insulating substrate 10. It is provided along one side.

FIG. 2 shows an enlarged view of the pressure sensitive cell of the pressure sensitive sensor panel 1 shown in FIG. The same reference numerals as those in FIG. 1 indicate the same components. In the TFT 11 of the pressure sensitive cell, the drain terminal D is connected to a part 12 a of the drain line 12, the source terminal S is connected to the contact electrode 14, and the gate terminal G is connected to a part 13 a of the gate line 13. The intersection of the drain line 12 and the gate line 13 is insulated by an insulating spacer 15 such as a SiO ₂ film formed by masking and vapor deposition.

FIG. 3 is an equivalent circuit diagram of the pressure-sensitive sensor panel 1 shown in FIG. The conductive film 2 a of the conductive sheet 2 of the pressure-sensitive sensor panel 1 is grounded via a resistor 16. The drain line 12 of the pressure-sensitive sensor panel 1 is connected to the X direction scanning circuit 20 via the resistor R, and the gate line 13 is connected to the Y direction scanning circuit 21. All the drain lines 12 are connected to the detector 22, and the detector 22 takes in the potentials of the detection points D ₁ , D ₂ , D ₃ ,... Of the drain line 12 and generates a fingerprint pattern based on these potentials. To detect.

  Now, when the finger F is put on the pressure-sensitive sensor panel 1 configured as described above and pressed lightly, the entire conductive sheet 2 is pushed down. Since the pressing force is different from that of the conductive sheet 2, the contact electrode 14 of the pressure-sensitive cell located directly under or near the peak portion is in electrical contact with the conductive film 2 a on the back surface of the conductive sheet 2. On the other hand, the contact electrode 14 of the pressure-sensitive cell located immediately below or near the valley of the fingerprint is not in electrical contact with the conductive film 2a.

  In the circuit shown in FIG. 3, the Y-direction scanning circuit 21 sequentially switches and outputs scanning signals to the gate lines 13 at a predetermined timing. While a certain potential (“H” level) is applied to the existing gate line 13, the scanning signal is sequentially switched and applied to the drain line 12 from the X-direction scanning circuit 20 at a predetermined timing.

  Then, the conductive sheet is formed at the portion where the contact electrode 14 of the pressure sensitive cell located near the intersection of the gate line 13 to which the potential is applied and the drain line 12 to which the scanning signal is applied is pressed at the peak portion of the fingerprint pattern. 2 is electrically in contact with the conductive film 2a, and the source terminal S of the TFT 11 of the pressure-sensitive cell is grounded via the contact electrode 14, the conductive film 2a, and the resistor 16, so that the drain terminal current flows and the resistance R A voltage drop due to.

The detector 22 takes in the potentials of the detection points D ₁ , D ₂ , D ₃ ,. By sequentially switching the scanning signals from the X-direction scanning circuit 20 and the Y-direction scanning circuit 21, the signals from all the pressure sensitive cells of the pressure sensitive sensor panel 1 are taken into the detector 22 in time series. A fingerprint pattern can be detected. The fingerprint pattern detection signal from the detector 22 is taken out of the pressure sensitive sensor panel 1 through the terminal group 30.

  Next, the pressure sensor unit 300 in which the pressure sensor panel 1 is mounted in a predetermined storage case 200 will be described. 4 is an exploded perspective view of the pressure-sensitive sensor unit 300, and FIG. 5 is a cross-sectional view of the completed pressure-sensitive sensor unit 300 along the line XX of FIG. Here, the storage case 200 includes an upper frame 190 and a lower frame 191 having a storage space. The upper frame 190 and the lower frame 191 are respectively in accordance with the shapes of the pressure-sensitive sensor unit 300 and the conductive sheet 2. The conductive sheet 2, the ring-shaped packing 192, and the pressure-sensitive sensor integrated circuit chip 50 are formed in a storage space that is composed of a rectangular bottom plate and side plates erected from each side of the bottom plate and is surrounded by the bottom plate and the side plate. It is comprised so that the laminated body which consists of may be inserted.

  The upper frame 190 is provided with an opening for exposing the pressure-sensitive sensor panel 1. Further, the upper frame 190 and the lower frame 191 are provided with outlets 195 for leading an FPC 170 (flexible printed circuit) which is a flexible printed circuit body to the outside of the storage case 200. The FPC 170 is pressure-bonded to the terminal group 30 of the pressure-sensitive sensor integrated circuit chip 50, and is connected to an external power supply circuit and a display device through the lead-out port 195.

  A ring-shaped packing 192 is disposed on the surface of the pressure-sensitive sensor integrated circuit chip 50 to which the FPC 170 is connected, and the conductive sheet 2 is disposed on the packing 192. The upper frame 190 and the lower frame 191 These layers are fitted together in a sandwiched state. By fitting the upper frame 190 and the lower frame 191 in this way, the conductive sheet 2 is stored in the storage case 200 in a state of being bonded to the pressure-sensitive sensor integrated circuit chip 50, and the pressure-sensitive sensor unit 300 is formed. The Here, the packing 192 is made of an elastic body such as rubber. The upper frame 190 and the lower frame 191 may be made of resin or metal. One of the upper frame 190 and the lower frame 191 may be made of resin, and the other may be made of metal.

  According to this embodiment, the distance (gap) between them can be kept constant by the ring-shaped packing 192 inserted between the conductive sheet 2 and the pressure-sensitive sensor integrated circuit chip 50.

  In addition, as shown in FIG. 6, a moisture-proof resin 150 may be filled between the conductive sheet 2 and the pressure-sensitive sensor integrated circuit chip 50 and outside the packing 192. By adopting a configuration in which the moisture-proof resin 150 is filled outside the packing 192 in this way, the moisture resistance of the pressure-sensitive sensor unit 300 is improved, and further, the conductive sheet 2 is connected to the packing 192 and the pressure-sensitive sensor integrated circuit chip 50. Strength increases due to close contact. Here, as the moisture-proof resin 150, for example, a fluid silicone resin can be used.

  In addition, since the distance (gap) between the conductive sheet 2 and the pressure-sensitive sensor integrated circuit chip 50 is kept constant by the packing 192, there is no influence even if the moisture-proof resin 150 undergoes curing shrinkage. 2 will not bend.

  The moisture-proof resin 150 is filled after the packing 192 is inserted and the conductive sheet 2 is bonded to the pressure-sensitive sensor integrated circuit chip 50, that is, after the pressure-sensitive sensor panel 1 is mounted on the storage case 200, This is preferable for improving the reliability and strength of the pressure-sensitive sensor unit 300. The filling of the moisture-proof resin 150 can be introduced, for example, through an opening 193 provided to face the terminal group 30 on the upper frame 190 of the storage case 200 as shown in FIG.

  Note that the pressure-sensitive sensor unit 300 may be configured to use an adhesive to attach the conductive sheet 2 to the pressure-sensitive sensor integrated circuit chip 50 as shown in FIG. However, when the adhesive 130 is used, it is necessary to apply the adhesive 130 along the edge of the pressure-sensitive sensor integrated circuit 50 as shown in FIG. .

  Furthermore, there is a problem that it is difficult to uniformly apply the adhesive 130 along the edge of the pressure-sensitive sensor integrated circuit 50. Further, after the adhesive 130 is applied, the adhesive 130 undergoes curing shrinkage and the conductive sheet 2 is bent, so that the gap (distance between the conductive sheet 2 and the pressure-sensitive sensor integrated circuit 50) is kept constant. Is difficult. Moreover, productivity is bad and production cost becomes high. Therefore, in the embodiment of the present invention, since the conductive sheet 2 and the pressure-sensitive sensor integrated circuit 50 are attached by inserting the packing 192 instead of the adhesive 130, the above problem is also solved.

It is a disassembled perspective view of the pressure-sensitive sensor panel which concerns on embodiment of this invention. It is an enlarged view of the pressure sensitive cell of the pressure sensitive sensor panel 1 shown in FIG. FIG. 2 is an equivalent circuit diagram of the pressure-sensitive sensor panel 1 shown in FIG. 1 according to the embodiment of the present invention. It is a disassembled perspective view of the pressure-sensitive sensor unit which concerns on embodiment of this invention. It is sectional drawing of the pressure-sensitive sensor unit which concerns on embodiment of this invention. It is sectional drawing of the pressure-sensitive sensor unit concerning a reference example. It is sectional drawing of the pressure-sensitive sensor unit concerning a reference example. It is a top view of the pressure-sensitive sensor unit concerning a reference example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure sensitive sensor panel 2 Conductive sheet 10 Insulating substrate 11 TFT 12 Drain line 13 Gate line 14 Contact electrode 15 Insulating spacer 16 Resistance 20 X direction scanning circuit 21 Y direction scanning circuit 22 Detector 30 Terminal group 50 Pressure sensitive sensor integrated circuit Chip 130 Adhesive 150 Moisture-proof resin 170 FPC (flexible printed circuit) 190 Upper frame 191 Lower frame 192 Packing 193 Opening 195 Outlet 200 Storage case 300 Pressure-sensitive sensor unit

Claims (4)

A pressure-sensitive sensor integrated circuit chip comprising a plurality of pressure-sensitive cells each including a contact electrode and a thin film transistor for selecting a contact electrode for selecting the contact electrode, and a terminal group from which a detection signal from the pressure-sensitive cell is output; ,
A conductive sheet that contacts the contact electrode by pressing;
A storage case for storing the pressure-sensitive sensor integrated circuit chip and the conductive sheet by fitting the upper frame and the lower frame;
A pressure-sensitive sensor unit comprising a packing inserted between the conductive sheet and the pressure-sensitive sensor integrated circuit chip. The pressure-sensitive sensor unit according to claim 1, wherein a moisture-proof resin is filled between the conductive sheet and the pressure-sensitive sensor integrated circuit chip and outside the packing. A pressure-sensitive sensor integrated circuit chip comprising a plurality of pressure-sensitive cells each having a contact electrode and a thin film transistor for selecting a contact electrode for selecting the contact electrode, and having a terminal group for outputting a detection signal from the pressure-sensitive cell. Prepare
Placing a packing on the surface of the pressure-sensitive sensor integrated circuit chip in the previous period, and further placing a conductive sheet on the packing,
A method of manufacturing a pressure-sensitive sensor unit, wherein the upper frame and the lower frame are fitted together with the upper frame and the lower frame sandwiching the conductive sheet, the packing, and the pressure-sensitive sensor integrated circuit chip. The method for manufacturing a pressure-sensitive sensor unit according to claim 3, wherein a moisture-proof resin is filled between the conductive sheet and the pressure-sensitive sensor integrated circuit chip and outside the packing.

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