JP2006145263A - Manufacturing method for pressure sensitive sensor panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method suitable for the mass production of a fingerprint sensor using an active matrix type TFT substrate. <P>SOLUTION: A large-sized substrate 100 has a surface on which a plurality of pressure sensitive sensor integrated circuits 50 are formed in a matrix. Before the large-sized substrate 100 is cut into individual sensor integrated circuit chips 50, using one rotation roller 140, a conductive sheet 2 is stuck every row so that a terminal group 30 is exposed. The stuck position of the conductive sheet 2 is fixed, and the large-sized substrate 100 is scanned. After that, the conductive sheet 2 is cut between two adjoining pressure sensitive sensor integrated circuit chips 50 and 50, thereby obtaining individual pressure sensitive sensor integrated circuit chips 50. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a pressure-sensitive sensor panel, and in particular, a pressure-sensitive sensor integrated circuit chip including a plurality of pressure-sensitive cells each including a contact electrode and a contact electrode selection thin film transistor that selects the contact electrode; The present invention relates to a method for manufacturing a pressure-sensitive sensor panel including a conductive sheet attached to the surface of a pressure-sensitive sensor integrated circuit chip and contacting the contact electrode by pressing.

  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, there has been little proposal for a method of manufacturing a fingerprint sensor using the active matrix TFT substrate described above. In particular, in order to mass-produce such fingerprint sensors, it is necessary to cut and divide the TFT substrate on which a large number of sensor integrated circuits are arranged into individual sensor chips. There is a possibility that foreign matter generated during the cutting enters between the conductive sheet and the conductive sheet, causing a sensing failure.

  Therefore, the main characteristic configuration of the present invention is as follows. That is, in the method of manufacturing a pressure-sensitive sensor panel according to the present invention, first, a plurality of pressure-sensitive cells including a contact electrode and a contact electrode selecting thin film transistor for selecting the contact electrode are arranged, and a detection signal from the pressure-sensitive cell is received. An insulating substrate having a plurality of pressure-sensitive sensor integrated circuits each having an output terminal group formed in a matrix on the surface thereof is prepared. Then, the insulating substrate is sequentially moved for each row of the pressure-sensitive sensor integrated circuit to a position where the conductive sheet is pasted.

  Thereafter, a belt-like conductive sheet is placed on the surface of the line of pressure-sensitive sensor integrated circuits moved to the position, and the conductive sheet is attached to the surface of the pressure-sensitive sensor integrated circuit so that the terminals are exposed. . Then, the insulating substrate is cut and separated into individual pressure-sensitive sensor integrated circuit chips.

  In addition, it is preferable that the conductive sheet is affixed to the surface of the pressure-sensitive sensor integrated circuit while applying tension to both ends of the conductive sheet so that the terminal group is exposed. Moreover, it is preferable to perform the process of affixing a conductive sheet, pressing the said conductive sheet with a rotating roller.

  Moreover, it is preferable that the conductive sheet is attached via an adhesive applied to the pressure-sensitive sensor integrated circuit chip. Furthermore, the adhesive preferably comprises a first adhesive ring and a second adhesive ring adjacent to the outside of the first adhesive ring. Furthermore, it is preferable that the first adhesive ring is made of a thermosetting resin and the second adhesive ring is made of an ultraviolet curable resin.

  According to the present invention, since the conductive sheet is attached to the chip surface before the large substrate is cut into individual sensor integrated circuit chips, foreign matter can be prevented from entering between the substrate and the conductive sheet, and sensing failure can be avoided. . In addition, the position where the conductive sheet is pasted is fixed and the large substrate is scanned, so a series of operations (placing the conductive sheet and pasting with a rotating roller) is always performed at the same position, so reproducibility and stability are excellent. A pressure-sensitive sensor panel can be provided.

  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 was 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, an ITO (indium tin oxide) contact electrode 14 by vapor deposition. The conductive 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, a method for manufacturing the pressure-sensitive sensor panel 1 will be described with reference to the drawings. First, as shown in FIG. 4, a plurality of pressure-sensitive sensor integrated circuits 50A (each of which becomes the above-described pressure-sensitive sensor integrated circuit chip 50 after cutting and separation) are formed on the surface thereof in rows and columns by a known TFT process. A large substrate 100 formed in a matrix is prepared.

  Next, as shown in FIG. 5A, along the edge of the surface of the pressure-sensitive sensor integrated circuit chip 50 (the surface on which the TFT 11 and the like are formed), a thermosetting epoxy resin is used as an adhesive to form a ring shape. Apply to form the first adhesive ring 130. The reason why the thermosetting epoxy resin is used is to improve the adhesion with the conductive sheet 2 described later. Thereafter, baking is performed at a temperature of 70 ° C. for about 15 minutes to cure the first adhesive ring 130 to some extent.

  Thereafter, as shown in FIG. 5B, along the edge of the pressure-sensitive sensor integrated circuit chip 50 adjacent to the outside of the first adhesive ring 130, an ultraviolet curable epoxy resin is used as an adhesive in a ring shape. Apply to form a second adhesive ring 131. As described above, the double ring structure is adopted for the first adhesive ring 130 and the second adhesive ring 131 because the first adhesive ring 130 is heat-cured to some extent, and the second adhesive ring 131 has the second adhesive ring. By blocking the adhesive, when the conductive sheet 2 to be described later is attached to the pressure-sensitive sensor integrated circuit chip 50, the adhesive infiltrates into the pressure-sensitive cell region of the pressure-sensitive sensor integrated circuit chip 50, thereby degrading the detection characteristics. This is to prevent it from occurring.

The first adhesive ring 130 may be formed of a thermosetting resin, but the second adhesive ring 131 is preferably formed of an ultraviolet curable resin having fast curing. As will be described later, since tension is applied to both ends of the conductive sheet 2 and the large-sized substrate 100 is sequentially moved, the pressure sensitive sensor integrated circuit chip 50 is attached to each row, so that the effect of applying the tension can be obtained. This is because the second adhesive ring 131 needs to be hardened quickly in order to obtain it. When the second adhesive ring 131 is formed of an ultraviolet curable resin, it can be cured under the conditions of an ultraviolet irradiation energy density of 100 mW / cm ² and an irradiation time of 20 seconds.

  Further, a gold paste 133 is applied on the potential setting pad electrode 132 formed at the corner of the pressure-sensitive sensor integrated circuit chip 50. This is because the conductive sheet 2 described later is electrically connected to the potential setting pad electrode 132 through the gold paste 133 to set the conductive sheet 2 to a predetermined potential. The potential setting pad electrode 132 is set to a ground potential, for example.

  Next, as shown in FIG. 6, the large substrate 100 is moved to a position where the conductive sheet 2 is pasted, and the strip-shaped conductive sheet 2 is placed on one row of the pressure-sensitive sensor integrated circuit chip 50. The pressure-sensitive sensor integrated circuit chip 50 is attached to the surface of the pressure-sensitive sensor integrated circuit chip 50 while being pressed by the rotating roller 140. Here, one row refers to one row of the pressure-sensitive sensor integrated circuit chips 50 arranged in the same direction as the rotational movement direction of the rotating roller 140 shown in FIG.

  Then, after the strip-shaped conductive sheet 2 is attached to one row of the pressure-sensitive sensor integrated circuit chips 50, the large substrate 100 is moved, and the strip-shaped conductive sheet is moved to the next row of the pressure-sensitive sensor integrated circuit chips 50 in the same manner. 2 is pasted. Thus, the movement of the large substrate 100 and the attachment of the conductive sheet 2 are repeated.

  At this time, in order to expose the terminal group 30 of the pressure-sensitive sensor integrated circuit chip 50, the conductive sheet 2 is cut in advance so that the width of the conductive sheet 2 is smaller than the width of the plurality of pressure-sensitive sensor integrated circuit chips 50. ing. This is because if the conductive sheet 2 is cut so that the terminal group 30 of the pressure-sensitive sensor integrated circuit chip 50 is exposed after the conductive sheet 2 is attached, the surface of the pressure-sensitive sensor integrated circuit chip 50 is damaged.

  In addition, when the conductive sheet 2 is pasted using the rotating roller 140, it is preferably performed while applying tension to both ends of the conductive sheet 2. This is because when the conductive sheet 2 is bent, it cannot be applied uniformly.

  In this embodiment, the position where the conductive sheet 2 is attached, that is, the position of the rotating roller 140 is fixed, and the large substrate 100 is sequentially scanned. Accordingly, the conductive sheet 2 can be always placed and pasted at the same position, and the conductive sheet 2 can be pasted with uniform pressing force for each row because one rotating roller 140 is used. Because it is possible, it is excellent in reproducibility and stability.

  Note that the conductive sheet 2 can be attached after the pressure-sensitive sensor integrated circuit chip 50 is individually cut as shown in FIG. However, foreign substances such as small glass fragments and dust are generated when the large substrate 100 is cut. Therefore, when the conductive sheet 2 is pasted thereafter, the foreign substances enter between the substrate and the conductive sheet 2 to cause sensing failure. there is a possibility. Therefore, in the present embodiment, the above problem is solved by attaching the conductive sheet 2 before cutting the large substrate 100.

  Thus, after the conductive sheet 2 is attached to the surface of the plurality of pressure-sensitive sensor integrated circuit chips 50, in this state, the baking process is performed again, and the first adhesive ring 130 and the second adhesive ring are performed. 131 is heat cured. This baking treatment is preferably performed in an N 2 atmosphere under conditions of 70 ° C. to 90 ° C. for about 30 minutes. Then, after the baking process, as shown in FIG. 8, the strip-shaped conductive sheet 2 is cut along the cutting line CL at the edge of the pressure-sensitive sensor integrated circuit chip 50 using a cutter, and the large substrate 100 is cut using a penet cutter. . Thereby, the individual pressure sensor integrated circuit chip 50 (pressure sensor panel 1) to which the conductive sheet 2 is attached is obtained.

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 top view which shows the manufacturing method of the pressure-sensitive sensor panel which concerns on embodiment of this invention. It is a top view which shows the manufacturing method of the pressure-sensitive sensor panel which concerns on embodiment of this invention. It is a top view which shows the manufacturing method of the pressure-sensitive sensor panel which concerns on embodiment of this invention. It is a top view which shows the manufacturing method of the pressure-sensitive sensor panel which concerns on a reference example. It is a top view which shows the manufacturing method of the pressure-sensitive sensor panel which concerns on embodiment of this invention.

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 50A Pressure-sensitive sensor integrated circuit 100 Large substrate
130 First adhesive ring 131 Second adhesive ring
132 Pad electrode for potential setting 133 Gold paste 140 Rotating roller

Claims (6)

A pressure-sensitive sensor integrated circuit 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 for outputting a detection signal from the pressure-sensitive cell. And preparing an insulating substrate formed in a matrix of rows and columns on the surface,
Sequentially moving the insulating substrate for each row of the pressure-sensitive sensor integrated circuit at a position where a conductive sheet is pasted;
Placing a strip-shaped conductive sheet on the surface of the pressure-sensitive sensor integrated circuit in a row moved to the position;
A step of affixing the conductive sheet on the surface of the pressure-sensitive sensor integrated circuit so that the terminal group is exposed;
And a step of cutting and separating the insulating substrate into individual pressure-sensitive sensor integrated circuit chips. 2. The step of attaching the conductive sheet to the surface of the pressure-sensitive sensor integrated circuit so that the terminal group is exposed is performed while applying tension to both ends of the conductive sheet. The manufacturing method of the pressure-sensitive sensor panel of description. The step of attaching the conductive sheet to the surface of the pressure-sensitive sensor integrated circuit so that the terminal group is exposed is performed while pressing the conductive sheet with a rotating roller. The manufacturing method of the pressure-sensitive sensor panel of Claim 2. 2. The method of manufacturing a pressure-sensitive sensor panel according to claim 1, wherein the conductive sheet is attached via an adhesive applied to the pressure-sensitive sensor integrated circuit chip. The pressure-sensitive sensor panel according to claim 4, wherein the adhesive comprises a first adhesive ring and a second adhesive ring adjacent to the outside of the first adhesive ring. Method. 6. The method of manufacturing a pressure-sensitive sensor panel according to claim 5, wherein the first adhesive ring is made of a thermosetting resin, and the second adhesive ring is made of an ultraviolet curable resin.

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