TW201706784A - Touch pad and circuit board of the touch pad - Google Patents

Abstract

A touch pad is composed of a circuit board and a cover board, wherein multiple sensing electrodes and an electrostatic protection electrode are formed on a surface of the circuit board. The electrostatic protection electrode is configured to surround a fingerprint sensor on the circuit board. The cover board has an opening corresponding to the fingerprint sensor. When the cover board is attached to the circuit board, a center of the opening aligns a center of the fingerprint sensor, and a gap is formed between the fingerprint sensor and the opening, wherein the electrostatic protection electrode corresponds to the gap. In the case that electrostatic discharge (ESD) occurs near the gap, the electrostatic protection electrode conducts the static electricity to a ground terminal so as to protect the fingerprint sensor and the sensing electrodes on the circuit board from being damaged by the static electricity.

Description

Touchpad and its circuit board

The present invention relates to a touch pad, and more particularly to a touch pad having a fingerprint sensor.

7 and 8 show a schematic view and a cross-sectional view of a touch panel 90 having a fingerprint sensor, which mainly includes a circuit board 91 and a cover 92. A fingerprint sensor 93 is mounted on the surface of the circuit board 91. The cover 92 can be used to sense and identify the fingerprint of the user. The cover 92 forms a pair of openings 94 for the fingerprint sensor 93. When the cover 92 is attached to the surface of the circuit board 91, the opening 94 can accommodate the fingerprint. The sensor 93 is exposed and the surface of the fingerprint sensor 93 is exposed for user manipulation.

In the process of fitting the cover plate 92, the positioning mark on the periphery of the cover plate 92 and the positioning mark on the periphery of the circuit board 91 are used as the alignment reference, and the positioning marks of the two are aligned and bonded. However, when the fingerprint sensor 93 is soldered to the circuit board 91, a slight positional error may occur, and when the opening 94 is formed on the cover 92, the opening position may be displaced, so when the cover 92 is When the circuit board 91 is bonded, the fingerprint sensor 93 may not be accommodated in the opening 94.

To avoid that the fingerprint sensor 93 cannot be placed in the opening 94, a larger size opening 94 can be preset to compensate for the error offset. However, after the opening 94 is enlarged, a significant gap is formed between the fingerprint sensor 93 and the opening 94. One method of solving the gap is to insert a colloid into the gap between the fingerprint sensor 93 and the opening 94 to form a rubber ring 95 as shown in FIG. 8, but the disadvantage is that the appearance of the finished product is not good, and the colloid is protruded. The surface of the cover 92 affects the user's operational touch.

FIG. 9 shows another way of filling the gap by directly inserting a ring cover 96 into the interior of the gap. The top of the ring cover 96 protrudes from the surface of the cover plate 92. When the gap is filled by the ring cover 96, in order to ensure that the gap has a sufficient width to fill the ring cover 96, the size of the opening 94 must be intentionally increased. The disadvantage is that the cost of additionally providing the ring cover 96 is increased, and the surface of the ring cover 96 still protrudes on the surface of the cover plate 92, which may affect the operation of the user and hinder the appearance of the finished touch panel 90.

The invention provides a touch panel, which does not need to additionally provide a rubber ring or a ring cover, and has the function of electrostatic protection, and the touch panel maintains a smooth surface.

To achieve the foregoing objective, the touch panel of the present invention comprises: a circuit board comprising: a circuit board body including a plurality of sensing electrodes for performing a touch operation; and a fingerprint sensor mounted on the circuit board body a surface; and a static electricity protection electrode formed on the surface of the circuit board body, disposed around the fingerprint sensor, the static electricity protection electrode is electrically connected to the ground end of the circuit board; and a cover plate is attached to the surface a surface of the circuit board body, the cover plate forming a pair of openings corresponding to the fingerprint sensor, the opening is for receiving the fingerprint sensor, wherein the fingerprint sensor has a gap between the opening and the electrostatic The guard electrode corresponds to the gap, and the fingerprint sensor, the board body and the like can be protected from being destroyed by static electricity.

When the cover plate of the present invention is attached to the main body of the circuit board, the center of the opening is aligned with the center of the fingerprint sensor, and the center alignment manner ensures that the fingerprint sensor is surely accommodated inside the opening. Moreover, it has a small gap, so that no tampon is added inside the gap, so that the overall touch panel has a beautiful and flat surface.

The touch panel according to the present invention may be a capacitive touch panel including a circuit board 10, a fingerprint sensor 20 and a cover 30. The circuit board 10 There is a circuit board body 11 having a plurality of sensing electrodes 12 on its surface for performing a touch operation. A static electricity shielding electrode 13 is formed at a corner of the surface of the circuit board body 11. The static electricity protection electrode 13 is formed by a conductor (for example, metal). In the embodiment, the static electricity protection electrode 13 is a closed ring shape. In other embodiments, the configuration of the static electricity protection electrode 13 may also be other shapes. A plurality of connection pads 17 are provided in a region surrounded by the static electricity protection electrode 13. The fingerprint sensor 20 is an integrated circuit (IC) having a plurality of electrical contacts. The fingerprint sensor 20 is mounted on the surface of the circuit board body 11, and a plurality of electrical contacts are electrically connected to the plurality of electrical contacts. Connect the pad 17. The static electricity protection electrode 13 is disposed around the fingerprint sensor 20. The static electricity protection electrode 13 is electrically connected to a ground end of the circuit board body 11, and how the static electricity protection electrode 13 is electrically connected to the ground end is further described below.

In the embodiment shown in FIG. 1, the surface periphery of the circuit board body 11 has a first grounding ring 14, which is formed by a conductor (for example, metal) line, and the static shielding electrode 13 is formed on the circuit board. A conductor (e.g., metal) line 131 on the surface of the body 11 is electrically coupled to the first ground ring 14. Referring to FIG. 3 again, the circuit board body 11 also forms a second grounding ring 15 on the periphery of the bottom surface. The second grounding ring 15 is electrically connected to the first grounding ring 14, for example, on the circuit board body. A plurality of conductive through holes 18 are formed in the periphery of the plurality of conductive through holes 18, and two ends of each of the conductive through holes 18 are electrically connected to the first ground ring 14 and the second ground ring 15, respectively. The back surface of the circuit board body 11 has at least one ground pad 16 , and the ground terminal includes the ground pad 16 . In this embodiment, the ground pad 16 is electrically connected to the second ground ring 15 . The ground pad 16 can be electrically connected to the ground of an electronic device, for example, to the ground of a notebook computer. With the above configuration, the static electricity protection electrode 13 is electrically connected to the ground pad 16 via the conductor line 131, the first grounding ring 14, the conductive through hole 18, and the second grounding ring 15, thereby achieving a grounding effect.

However, the present invention is not limited to the foregoing structure, and the static electricity protection electrode 13 may be electrically connected to the ground pad 16 by other means. In one embodiment, the static electricity protection electrode 13 is electrically connected to the ground pad 16 through a wiring of the circuit board body 11, and the wiring may be a wire formed inside or on the surface of the circuit board body 11. In another embodiment, the static electricity protection electrode 13 is connected to the first grounding ring 14 , and the first grounding ring 14 is electrically connected to the grounding pad 16 through the conductive through hole 18 or a wire inside the circuit board body 11 .

Referring to FIG. 4, the cover 30 is attached to the surface of the circuit board body 11. The cover 30 forms a pair of openings 31 corresponding to the fingerprint sensor 20 for receiving the fingerprint sensing. After the cover 30 is attached, the fingerprint sensor 20 is received inside the opening 31, and an annular gap 40 is formed between the fingerprint sensor 20 and the periphery of the opening 31. The circuit board body The static electricity protection electrode 13 on the 11 corresponds to the gap 40, as shown in FIG.

According to an embodiment of the present invention, when the cover plate 30 is attached to the circuit board body 11, the center A of the opening 31 is aligned with the center B of the fingerprint sensor 20 (as shown in FIG. 6A). After the A and B are aligned, the cover 30 is adhered to the surface of the circuit board body 11 (as shown in FIG. 6B) to complete the assembly operation of the touch panel. Different from the prior art, the alignment between the board body and the edge of the cover plate is performed. The present invention ensures that the fingerprint sensor 20 must be accommodated inside the opening 31 by means of the center alignment. Therefore, the opening is The size of the lens 31 only needs to be slightly larger than the size of the fingerprint sensor 20, and the opening size is not intentionally increased. Thus, the width of the gap 40 can be reduced from 1 mm or more to 0.1 mm compared with the prior art. After the bonding is completed, the center A of the opening 31 corresponds to the center B of the fingerprint sensor 20, and the gaps 40 around the fingerprint sensor 20 are substantially equal in width.

The touch panel of the present invention has at least the following advantages over the existing touch panel:

1. The appearance is flat: the width of the gap 40 between the opening 31 on the cover 30 and the fingerprint sensor 20 is reduced, and the rubber ring or the ring cover is not required to be filled in the gap 40, so the fingerprint sensor 20 There is no obvious protrusion around the periphery, and the surface of the cover 30 is substantially flattened to improve the appearance of the touch panel.

Second, reduce costs and simplify the assembly process: because it is not necessary to fill the gap 40 into the rubber ring or insert the ring cover, the component cost can be reduced and the assembly process can be simplified.

Third, providing a comfortable operating surface: the present invention can reduce the width of the gap 40, and no protruding rubber ring or ring cover is disposed around the fingerprint sensor 20, and the boundary between the fingerprint sensor 20 and the cover 30 The substantially flat surface can be presented, and when the user operates the touch panel, whether the fingerprint sensor 20 or the cover 30 is touched, the touch sensor has a smooth operating touch.

4. Electrostatic (ESD) Protection: The electrostatic protection electrode 13 is disposed around the fingerprint sensor 20, and static electricity entering from the gap 40 is conducted to the ground pad 16 via the static electricity protection electrode 13. Therefore, the fingerprint sensor 20 and the sensing electrode 12 on the board body 11 can be protected.

In one embodiment, the side of the fingerprint sensor 20 exposes a metal layer (eg, copper) that belongs to a carrier that is used to carry the wafer within the fingerprint sensor 20, and The chip transmits a signal between the electrical contacts under the fingerprint sensor 20, and the metal layer is used to make a signal for transmitting signals. In this embodiment, a layer of insulating glue is applied to the exposed metal layer, that is, the side of the fingerprint sensor 20, to prevent static electricity from entering the metal layer and destroying the fingerprint sensor 20.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

10‧‧‧ boards
11‧‧‧Board body
12‧‧‧Induction electrodes
13‧‧‧Electrostatic protective electrode
131‧‧‧Conductor lines
14‧‧‧First grounding ring
15‧‧‧Second grounding ring
16‧‧‧ Grounding mat
17‧‧‧Connecting mat
18‧‧‧ Conductive through holes
20‧‧‧Finger sensor
30‧‧‧ Cover
31‧‧‧ openings
40‧‧‧ gap
90‧‧‧Touchpad
91‧‧‧Circuit board
92‧‧‧ cover
93‧‧‧Finger sensor
94‧‧‧ openings
95‧‧‧Rubber ring
96‧‧‧ ring cover

Figure 1 is a perspective exploded view of the present invention. Figure 2 is a front elevational view of the circuit board of the present invention. Figure 3 is a schematic illustration of the back side of the circuit board of the present invention. Figure 4 is a partial cross-sectional view of the present invention. Figure 5 is a partial enlarged view of the fingerprint sensor of the present invention. Figure 6A is a schematic view showing the alignment of the cover of the present invention and the body of the circuit board. 6B is a schematic view showing the appearance of the cover plate of the present invention after alignment with the circuit board body. FIG. 7 is a partial schematic view showing the appearance of the existing touch panel. Figure 8: Schematic diagram of an existing touch panel. Figure 9: Schematic diagram of an existing touch panel.

10‧‧‧ boards

11‧‧‧Board body

12‧‧‧Induction electrodes

13‧‧‧Electrostatic protective electrode

14‧‧‧First grounding ring

20‧‧‧Finger sensor

30‧‧‧ Cover

31‧‧‧ openings

Claims (15)

A circuit board of a touch panel, comprising a circuit board body, comprising a plurality of sensing electrodes for performing a touch operation; a fingerprint sensor mounted on a surface of the circuit board body; and an electrostatic protection electrode formed on the circuit The surface of the board body is disposed around the fingerprint sensor, and the static electricity protection electrode is electrically connected to a ground end of the circuit board body. The circuit board of the touch panel of claim 1, wherein the circuit board body has a bottom surface opposite to the surface, the ground end includes at least one ground pad disposed on the bottom surface, the static protection electrode is electrically connected to the ground pad. The circuit board of the touch panel of claim 2, wherein the circuit board body further has a first grounding ring surrounding the periphery of the surface and a second grounding ring surrounding the periphery of the bottom surface, the first grounding ring transmitting through the conductive The hole is electrically connected to the second grounding ring, and the first grounding ring and the second grounding ring are electrically connected to the grounding pad, and the static electricity shielding electrode is electrically connected to the first grounding ring. The circuit board of the touch panel of claim 2, wherein the circuit board body further has a first grounding ring surrounding the periphery of the surface, the first grounding ring is electrically connected to the grounding pad through the conductive through hole, the static electricity protection The electrode system is electrically connected to the first ground ring. The circuit board of the touch panel of claim 2, wherein the static electricity protection electrode is electrically connected to the ground pad through a wiring on the circuit board body. The circuit board of the touch panel of claim 3 or 4, wherein the static protection electrode and the first ground ring are electrically connected by a conductor line. The circuit board of the touch panel of claim 1, further comprising an insulating glue coated on a side of the fingerprint sensor. A touch panel includes: a circuit board comprising: a circuit board body including a plurality of sensing electrodes for performing a touch operation; a fingerprint sensor mounted on a surface of the circuit board body; and an electrostatic protection electrode Formed on a surface of the circuit board body, disposed around the fingerprint sensor, the static electricity protection electrode is electrically connected to a ground end of the circuit board body; and a cover plate is attached to the circuit board body a surface, the cover plate forms a pair of openings for the fingerprint sensor, the opening is for receiving the fingerprint sensor, wherein the fingerprint sensor has a gap between the opening and the electrostatic protection electrode pair Should be a gap. The touch panel of claim 8, wherein a center of the opening is aligned with a center of the fingerprint sensor. The touch panel of claim 8, wherein the circuit board body has a bottom surface opposite to the surface, the ground end comprising at least one ground pad disposed on the bottom surface, the static protection electrode being electrically connected to the ground pad. The touch panel of claim 10, wherein the circuit board body has a first grounding ring surrounding the periphery of the surface and a second grounding ring surrounding the periphery of the bottom surface, the first grounding ring being electrically connected through the conductive through hole The second grounding ring is electrically connected to the grounding pad and the second grounding ring is electrically connected to the first grounding ring. The touch panel of claim 10, wherein the circuit board body further has a first grounding ring surrounding the periphery of the surface, the first grounding ring being electrically connected to the grounding pad through the conductive through hole, the static shielding electrode system Electrically connected to the first ground ring. The touch panel of claim 10, wherein the static electricity protection electrode is electrically connected to the ground pad through a wiring on the circuit board body. The touch panel of claim 11 or 12, wherein the static protection electrode and the first ground ring are electrically connected by a conductor line. The touch panel of claim 8, further comprising an insulating glue coated on a side of the fingerprint sensor.