TWI526942B - Fingerprint sensor device - Google Patents

Description

Fingerprint sensing device

The invention relates to a sensing device, and in particular to a fingerprint sensing device applied to fingerprint identification technology.

The fingerprint identification technology uses a fingerprint sensing device to sense a user's fingerprint to identify an individual's identity. The fingerprint sensing device can be classified according to the applied technical category, such as an optical fingerprint sensing device, an ultrasonic fingerprint sensing device, a pressure fingerprint sensing device or a capacitive fingerprint sensing device. Among them, the capacitive fingerprint sensing device has the advantage of small size, and is suitable for application on a personal electronic device, such as a smart phone or a tablet computer.

In the case of a capacitive fingerprint sensing device, there are two main types of capacitive fingerprint sensing devices. The first is a sense of fingerprint on the printed circuit board (PCB) of the sensing layer and the control chip. The second device is a fingerprint sensing device in which the sensing layer and the control circuit are integrated into a fingerprint sensing chip. The first type of fingerprint sensing device described above uses a printed circuit board process to form a sensing layer. The sensing layer is electrically connected to the control chip by a printed circuit board trace. However, limited by the printed circuit board process, the resolution of the first type of fingerprint sensing device described above cannot be effectively improved. In another aspect, the second fingerprint sensing device described above forms a sensing layer within the wafer. Through the wafer process, the sensing electrode spacing in the sensing layer can be reduced, thereby improving the fingerprint sense The resolution of the measurement. However, the second type of fingerprint sensing device described above is relatively expensive to manufacture.

An object of the present invention is to provide a fingerprint sensing device, which is characterized in that it has the advantages of high fingerprint recognition resolution, low manufacturing cost, and large fingerprint sensing area.

In accordance with the above objects of the present invention, a fingerprint sensing device is proposed. The fingerprint sensing device includes a substrate, a sensing layer, a control wafer, and a protective layer. The sensing layer is disposed on the substrate and has a first side and a second side opposite to each other, wherein the first side is connected to the substrate. The control wafer is disposed on the second side of the sensing layer. The protective layer is disposed on the second side of the sensing layer and between the sensing layer and the control wafer.

According to an embodiment of the invention, the fingerprint sensing device further comprises a plurality of metal traces. The metal traces are disposed on the second side of the sensing layer, and the metal traces are used to electrically connect the control chip to the sensing layer.

According to still another embodiment of the present invention, the substrate is a glass substrate.

According to still another embodiment of the present invention, the sensing layer is a glass type sensing layer or a film type sensing layer.

According to the above object of the present invention, a fingerprint sensing device is further proposed. The fingerprint sensing device includes a substrate, a sensing layer, a control wafer, and a protective layer. The substrate has a first side and a second side opposite to each other. The sensing layer is disposed on the first side of the substrate. The control wafer is disposed on the second side of the substrate. The protective layer is disposed on the second side of the substrate and is located on the substrate and the control Between wafers.

According to an embodiment of the invention, the fingerprint sensing device further comprises a plurality of metal traces. The metal traces straddle the substrate in the thickness direction of the substrate, and the metal traces are used to electrically connect the control wafer to the sensing layer.

According to still another embodiment of the present invention, the substrate is a glass substrate.

According to still another embodiment of the present invention, the first side surface of the substrate has a contact surface and a non-contact surface. Wherein, the contact surface is directly in contact with the finger, and the control chip is disposed on the non-contact surface.

According to still another embodiment of the present invention, the fingerprint sensing device further includes a shielding layer. The shielding layer is disposed on the control wafer and covers the control wafer.

According to still another embodiment of the present invention, the sensing layer is a glass sensing layer or a thin film sensing layer.

100,200‧‧‧Fingerprint sensing device

110, 210‧‧‧ substrate

120, 220‧‧‧ Sensing layer

120A, 210A‧‧‧ first side

120B, 210B‧‧‧ second side

130, 230‧‧‧Control wafer

140, 240‧‧‧Metal routing

150, 250‧‧ ‧ protective layer

212‧‧‧Contact surface

214‧‧‧ Non-contact surface

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; 1 is a side view of a fingerprint sensing device of FIG. 1A; and FIG. 2 is a side view of a fingerprint sensing device according to still another embodiment of the present invention.

Embodiments of the invention are discussed in detail below. However, understandable Yes, the embodiments provide many applicable inventive concepts that can be implemented in a wide variety of specific content. The specific embodiments discussed are illustrative only and are not intended to limit the scope of the invention.

Please refer to FIG. 1A, which is a top view of a fingerprint sensing device 100 according to an embodiment of the invention. The fingerprint sensing device 100 is used to obtain fingerprint information of a user, and can be applied to an electronic device or a system such as a notebook computer, a tablet computer, a smart phone, a digital camera, an access control system, or a vehicle anti-theft system, but is not limited thereto. this.

In FIG. 1A, the fingerprint sensing device 100 includes a substrate 110, a sensing layer 120, a control wafer 130, and a metal trace 140. The substrate 110 is used for direct contact with the user's fingers. In the present invention, the substrate 110 may be a glass substrate, a resin substrate or the like. The sensing layer 120 is disposed on the substrate 110 and has a first side surface 120A and a second side surface 120B opposite to each other, wherein the first side surface 120A is coupled to the substrate 110. The sensing layer 120 is used to sense the fingerprint pattern of the user's finger, and the sensing layer 120 performs a corresponding sensing method according to its structure type. For example, if the sensing layer 120 is a capacitive sensing layer, the sensing layer 120 may have a plurality of electrode structures arranged in a matrix, and the electrode structures are respectively associated with the ridges and grooves of the fingers. The (valley) acts to accumulate different amounts of charge, and the different amounts of charge generate a sensing signal, and then the sensing signal is processed by the back-end processing circuit to obtain fingerprint image information. The sensing layer 120 as a capacitive sensing layer may be a glass type sensing layer or a film type sensing layer, the related embodiments of which are well known to those of ordinary skill in the art, and thus Unexplained. Further, in the present invention, the sensing layer 120 may also be, for example A pressure sensing layer or a thermal sensing layer or the like.

The control chip 130 is disposed on the second side 120B of the sensing layer 120 and electrically connected to the sensing layer 120 through the metal traces 140 disposed on the second side 120B of the sensing layer 120. The control chip 130 can have a plurality of pins for connecting the metal traces 140 to receive the sensing signals of the sensing layer 120, and the control circuit inside the control wafer 130 can process the sensing signals to obtain Fingerprint image information.

In addition, please refer to FIG. 1B simultaneously, and a protective layer 150 is further disposed on the second side surface 120B of the sensing layer 120. As shown in FIG. 2 , the protective layer 150 is disposed between the sensing layer 120 and the control wafer 130 to prevent the control wafer 130 from directly contacting the sensing layer 120 to cause damage of the control wafer 130 . The protective layer 150 may include, for example, a non-conductive polymer (NCP) or other adhesive material having a viscosity. In some embodiments, the protective layer 150 may include an anisotropic conductive film (ACF) for electrically connecting the pads of the control wafer 130 to the metal traces 140, and controlling the body and sense of the wafer 130. The measurement layer 120 is electrically insulated.

It should be noted that in FIG. 1A, the control wafer 130 is disposed at the center of the fingerprint sensing device 100. In practical applications, the control wafer 130 may not be limited to being located at the center of the fingerprint sensing device 100. For example, the control wafer 130 may be disposed at a side or a corner of the fingerprint sensing device 100 according to the layout of the electrodes and the metal traces 140 in the sensing layer 120.

The fingerprint sensing device of the invention is characterized in that it has the advantages of high fingerprint recognition resolution, low manufacturing cost and large fingerprint sensing area. change In other words, the fingerprint sensing device of the present invention is a sensing layer and control compared to a conventional chip on film (COF) or chip on board (COB) fingerprint sensing device. The wafers are overlapped in the thickness direction of the substrate, and the planar space on the substrate can be more effectively utilized, and the sensing layer is disposed on the glass substrate by an appropriate process, thereby improving the resolution of the fingerprint sensing. On the other hand, the fingerprint sensing device of the present invention can reduce manufacturing costs and increase fingerprint sensing area compared to conventional fingerprint sensing wafers.

Please refer to FIG. 2, which is a side view of a fingerprint sensing device 200 according to still another embodiment of the present invention. In FIG. 2, the fingerprint sensing device 200 includes a substrate 210, a sensing layer 220, a control wafer 230, a metal trace 240, and a protective layer 250. The substrate 210 may be a glass substrate, a resin substrate, or the like. The substrate 210 has a first side surface 210A and a second side surface 210B opposite to each other. The sensing layer 220 is disposed on the first side surface 210A of the substrate 210. The sensing layer 220 is used to sense the finger fingerprint of the user. And corresponding sensing methods are performed according to their structure types. The sensing layer 220 may have the same structure type as the sensing layer 120. For the description of the sensing layer 220, please refer to the description of the sensing layer 120 in the previous paragraph, and details are not described herein again.

The control wafer 230 is disposed on the second side surface 210B of the substrate 210 and electrically connected to the sensing layer 220 through the metal traces 240 that straddle the substrate 210 in the thickness direction of the substrate 210. In this embodiment, the second side surface 210B of the substrate 210 can be divided into a contact surface 212 and a non-contact surface 214, wherein the contact surface 212 is directly in contact with the user's finger, and the non-contact surface 214 is provided for the control wafer 230 to be disposed on the control wafer 230. On it. Non-contact surface 214 is preferably located The side of the fingerprint sensing device 200, such that the second side 210B of the substrate 210 has a larger contact surface 212 for direct contact by the user's fingers. The control chip 230 can have a plurality of pins for connecting the metal traces 240 to receive the sensing signals of the sensing layer 220, and the control circuit inside the control wafer 230 can process the sensing signals to obtain fingerprint images. News.

The protective layer 250 is disposed between the substrate 210 and the control wafer 230 to prevent the control wafer 230 from directly contacting the substrate 210 and causing damage to the control wafer 230. The protective layer 250 may comprise, for example, a non-conductive glue or other viscous insulating material or the like. In some embodiments, the protective layer 250 may include an anisotropic conductive paste to electrically connect the pads of the control wafer 230 to the metal traces 240 and electrically insulate the body of the control wafer 230 from the substrate 210.

In addition, in some embodiments, a shielding layer (not shown) may be disposed on the control wafer 230 of the fingerprint sensing device 200 and/or at the side of the control wafer 230 to cover the control wafer 230. The user's finger is prevented from directly contacting the control wafer 230.

In summary, the fingerprint sensing device of the present invention overlaps the sensing layer and the control wafer in the thickness direction of the substrate, and the sensing layer is disposed on the glass substrate or the sensing layer by a suitable process. The fingerprint sensing device according to the embodiment of the invention can simultaneously have the advantages of high fingerprint identification resolution, low manufacturing cost, and large fingerprint sensing area.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and those skilled in the art may, without departing from the spirit of the invention. And the scope of the invention is defined by the scope of the appended claims.

100‧‧‧Fingerprint sensing device

110‧‧‧Substrate

120‧‧‧Sensor layer

120A‧‧‧ first side

120B‧‧‧ second side

130‧‧‧Control chip

140‧‧‧Metal routing

150‧‧‧protection layer

Claims (9)

A fingerprint sensing device includes: a substrate; a sensing layer disposed on the substrate, the sensing layer having a first side and a second side opposite to each other, wherein the first side of the sensing layer Connected to the substrate; a control chip disposed on the second side of the sensing layer; and a protective layer disposed on the second side of the sensing layer and located in the sensing layer and the control chip between. The fingerprint sensing device of claim 1, further comprising a plurality of metal traces disposed on the second side of the sensing layer, and the metal traces are used to enable the control The wafer is electrically connected to the sensing layer. The fingerprint sensing device of claim 1, wherein the substrate is a glass substrate. The fingerprint sensing device of claim 1, wherein the sensing layer is a glass type sensing layer or a film type sensing layer. A fingerprint sensing device includes: a substrate having a first side and a second side opposite to each other; a sensing layer disposed on the first side of the substrate; and a control wafer disposed on the substrate a second protective layer disposed on the second side of the substrate and located at the base Between the board and the control chip; and a plurality of metal traces, the metal traces straddle the substrate in a thickness direction of the substrate, and the metal traces are used to electrically connect the control chip to the Sensing layer. The fingerprint sensing device of claim 5, wherein the substrate is a glass substrate. The fingerprint sensing device of claim 5, wherein the first side of the substrate has a contact surface and a non-contact surface, the contact surface is in direct contact with a finger, and the control chip is disposed on the non-contact surface on. The fingerprint sensing device of claim 7, further comprising a shielding layer disposed on the control wafer, and the shielding layer covers the control wafer. The fingerprint sensing device of claim 5, wherein the sensing layer is a glass type sensing layer or a film type sensing layer.