TWI550525B - Wiring pattern forming method, fingerprint sensing circuit board and manufacturing method thereof - Google Patents

Description

Wire pattern forming method, fingerprint sensing circuit board and manufacturing method thereof

The present invention relates to a wire pattern forming method, a fingerprint sensing circuit board, and a method of fabricating the same, and in particular, the present invention relates to a method for easily forming a wire pattern, and a fingerprint sensing circuit board produced by the method .

Circuit boards are an integral part of a variety of electronic devices. Regardless of the type of circuit board, wires are disposed thereon to electrically connect various electronic components disposed on the circuit board. As the functional requirements of electronic devices become more complex, electronic components and circuits on the board are becoming more and more dense.

In general, the circuit board is first wired, that is, a wire for electrically connecting each electronic component or an external circuit is disposed on the substrate. The wire is usually laid through the steps of: coating a metal layer on the substrate, coating the photoresist layer on the metal layer, exposing and developing the photoresist layer, and performing a metal layer having the developed photoresist layer pattern thereon; The steps of etching to form a wire pattern, and removing residual photoresist (release). As described above, in addition to the cumbersome steps of the conventional circuit board, the production cost is increased, and various chemical liquids (for example, photoresist, developer, etching liquid, etc.) used have different degrees of pollution to the environment. .

On the other hand, in recent years, due to the development of communication and the Internet, the way of information exchange between people has changed from face-to-face to network communication, and the type of business transactions has continued to change, credit cards, financial cards, and Electronic wallets and the like are becoming increasingly popular. Although computer and network-based electronic information transmission is quite convenient, relatively third parties can easily obtain important personal information, such as personal accounts and passwords. Therefore, how to prevent the theft of important information is a part of the information society that cannot be neglected. In particular, it has become an indispensable mobile device in modern people's lives, such as smart phones, tablets, notebook computers, etc., and it is more dependent on the improvement of data protection functions to prevent data leakage.

At present, whether it is a fixed electronic device or a mobile communication device, the biometric method can be used to encrypt the device itself, in other words, using the physical characteristics of the individual to identify whether the user is operating the device owner or the allowed device. By. The known biometric methods include fingerprint identification, voiceprint recognition, iris recognition and retina recognition. Among them, based on the comprehensive consideration of safety comfort and recognition efficiency, fingerprint recognition has become the mainstream of biometric identification.

The fingerprint identification method described above can be achieved through a fingerprint sensing circuit and a chip. In the prior art, one form of the fingerprint sensing circuit board is provided with mutually perpendicular groups of wires at corresponding positions on opposite surfaces of the substrate, and two mutually perpendicular groups of wires form a grid-like sensing circuit. The group of wires on both sides of the fingerprint sensing circuit board is also formed on the substrate by the lithography etching method as described in the prior art. Therefore, the formation of the sensing circuit also needs to be coated, exposed, developed, etched, etc., which also causes the aforementioned cumbersome process and environmental pollution.

Based on the above problems, it is necessary to develop a method for easily forming a wiring pattern on a substrate to reduce the production cost of the circuit board (including the fingerprint sensing circuit board) and the environmental pollution caused.

One aspect of the present invention is to provide a wire pattern forming method. According to an embodiment of the present invention, a wire pattern forming method includes the steps of: applying a liquid glue layer over a predetermined position of a wire pattern of a substrate; The conductive particles are on the liquid glue layer; finally, the liquid glue layer is subjected to a curing process, so that the liquid glue layer is changed from a liquid state to a semi-solid state, and then further converted into a solid state, thereby forming a wire at a predetermined position of the wire pattern of the substrate. pattern.

Another aspect of the present invention is to provide a fingerprint sensing circuit board. According to another embodiment of the present invention, a fingerprint sensing circuit board includes a substrate, a first colloidal conductor pattern, and a second colloidal conductor pattern. The substrate has opposite first and second surfaces, and the first surface and the second surface respectively have a first line setting area and a second line setting area corresponding to each other. The first colloidal conductor pattern is disposed in the first line setting area along the first direction, and the second colloidal conductor pattern is disposed in the second line setting area along the second direction perpendicular to the first direction, and the first colloid The conductive pattern and the second colloidal conductor pattern comprise a plurality of conductive particles.

Another aspect of the present invention is to provide a method for fabricating a fingerprint sensing circuit board. According to another embodiment of the present invention, a method for fabricating a fingerprint sensing circuit board includes the following steps: providing an opposite first surface and a second a substrate on the surface, the first surface and the second surface respectively have corresponding first line setting areas and second line setting areas; Applying a liquid glue layer in a first direction to form a first gel line layer on the first line setting area; and applying a liquid glue layer in a second direction perpendicular to the first direction on the second line setting area Forming a second colloidal circuit layer; arranging a plurality of conductive particles on the first colloidal wiring layer and the second colloidal wiring layer; finally, performing a curing process on the first colloidal wiring layer and the second colloidal wiring layer of the liquid adhesive layer to make the liquid The glue layer is transformed from a liquid state to a semi-solid state, and further converted into a solid state to form a first colloidal wire pattern and a second colloidal wire pattern.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

20‧‧‧Substrate

200‧‧‧Wire pattern predetermined position

22‧‧‧Wire pattern

22a‧‧‧ glue layer

24‧‧‧ conductive particles

M1‧‧‧Mold

3‧‧‧Fingerprint sensing circuit board

30‧‧‧Substrate

300‧‧‧ first surface

302‧‧‧ second surface

3000‧‧‧First line setting area

3020‧‧‧Second line setting area

32‧‧‧First colloidal wire pattern

34‧‧‧Second colloidal wire pattern

36‧‧‧Insulating protective layer

38‧‧‧Electronic components

5‧‧‧ conductive particles

40‧‧‧Substrate

400‧‧‧ first surface

402‧‧‧ second surface

4000‧‧‧First line setting area

4020‧‧‧Second line setting area

42a‧‧‧First gel line layer

44a‧‧‧Second gel line layer

42‧‧‧First colloidal wire pattern

44‧‧‧Second colloidal wire pattern

46‧‧‧Electrical particles

48‧‧‧Insulating protective layer

M2‧‧‧Mold

FIG. 1A to FIG. 1E are schematic flow charts showing a method of forming a wire pattern according to various embodiments of the present invention.

2A is a side elevational view of a fingerprint sensing circuit board in accordance with an embodiment of the present invention.

2B is a top view of the fingerprint sensing circuit board of FIG. 2A.

FIG. 3A to FIG. 3H are schematic flowcharts showing a method of fabricating a fingerprint sensing circuit board according to various embodiments of the present invention.

Referring to FIG. 1A to FIG. 1C, FIG. 1A to FIG. 1C are schematic flowcharts showing a method for forming a wire pattern according to an embodiment of the present invention. According to a specific embodiment, the wire pattern forming method comprises the steps of: coating a liquid glue layer 22a on a predetermined position 200 of the wire pattern of the substrate 20, as shown in FIG. 1A; and arranging a plurality of conductive particles 24 in a liquid glue layer. 22a, as shown in FIG. 1B; and, the liquid layer 22a is subjected to a curing process, The liquid glue layer 22a is converted from a liquid state to a semi-solid state and further converted into a solid state to form a wire pattern 22 above the predetermined position 200 of the wire pattern, as shown in FIG.

In FIG. 1A, the liquid glue layer 22a can be formed on the predetermined position 200 of the wire pattern by a printing method such as screen printing or ink jet printing. In FIG. 1B, the conductive particles 24 may be sprayed on the liquid glue layer 22a. In practice, the conductive particles 24 sprayed on the liquid layer 22a slowly penetrate into the liquid layer 22a. In practice, the material of the conductive particles 24 may be selected from graphite, carbon black, carbon nanotubes, carbon spheres or carbon fibers, or gold (Au), silver (Ag), platinum (Pt), nickel (Ni), Aluminum (Al), titanium (Ti), iron (Fe), copper (Cu), molybdenum (Mo), tin (Sn), tantalum (Ta), magnesium (Mg), tungsten (W) or an alloy of the above metals, It can also be selected from any combination of the various materials listed above.

The liquid glue layer 22a contains a plurality of conductive particles 24 inside and has a function of conducting electricity. After the solidification process in FIG. 1C is converted into a solid state, a solid wire pattern 22 is formed. In order to enable the wires of the formed wire pattern 22 to have more uniform conductivity, it can be further processed in the curing step of the wire pattern forming method of the above specific embodiment. Please refer to FIG. 1D and FIG. 1E. FIG. 1D to FIG. 1E are schematic flow diagrams showing a method for forming a wire pattern according to another embodiment of the present invention. In the present embodiment, the wire pattern forming method still includes the steps of applying the liquid glue layer 22a to the substrate 20 and the plurality of conductive particles 24 to the liquid glue layer 22a as shown in FIG. 1A and FIG. Then, in the liquid phase of the liquid layer 22a shown in FIG. 1C, the liquid layer 22a is converted from a liquid state to a semi-solid state.

Next, as shown in FIG. 1D, pressure is applied to the semi-solid glue layer 22a such that the conductive particles 24 are deeply and evenly distributed in the semi-solid glue layer 22a; and, in FIG. In the middle, the pressed semi-solid adhesive layer 22a is further subjected to a curing process to be converted into a solid adhesive layer, that is, a wire pattern 22 is formed. In FIG. 1D, the step of applying pressure to the semi-solid glue layer 22a can be applied to the substrate 20 through the mold M1 to apply pressure to the semi-solid glue layer 22a. The plurality of conductive particles 24 sprayed on the surface of the liquid adhesive layer 22a in FIG. 1B are further pressed into the semi-solid adhesive layer 22a after being pressed, and uniformly distributed in the semi-solid adhesive layer. Within 22a. Moreover, the conductive particles 24 are pressed to form a tightly connected conductive structure in the adhesive layer 22a, which is more advantageous for electrical conduction. It should be noted that FIG. 1C, FIG. 1D, and FIG. 1E are not limited to the stepwise step, that is, the curing process does not need to be stopped in the middle and the curing is continued after the pressure is completed, but The curing process is continuously performed until the adhesive layer 22a is turned into a solid state, and the curing process and pressure are simultaneously performed when the adhesive layer 22a is turned into a semi-solid state.

In summary, the wire pattern forming method of the present invention can form various circuit structures on various substrates easily by using a colloid commonly used in a semiconductor process or an IC package, and with conductive particles distributed in the colloid. Therefore, the complicated micro-lithography etching process steps such as coating, exposure, development, etching, etc. are omitted, and the chemical liquid used in the above process can be prevented from polluting the environment.

Please refer to FIG. 2A and FIG. 2B. FIG. 2A is a side view of the fingerprint sensing circuit board 3 according to an embodiment of the present invention, and FIG. 2B is a fingerprint sensing circuit board of FIG. Top view of 3. As shown in FIG. 2A and FIG. 2B, the fingerprint sensing circuit board 3 includes a substrate 30, a first colloidal conductor pattern 32, and a second colloidal conductor pattern 34. The substrate 30 has an opposite first surface 300 and a second surface 302 respectively, and has a first line setting area 3000 and a second line setting area 3020 corresponding to each other. The substrate 30 can be a high dielectric material in practice. The material, for example, a ceramic substrate, or may be a flexible substrate.

The first colloidal conductor pattern 32 may be a plurality of wires disposed within the first line setting region 3000 along the first direction. The second colloidal conductor pattern 34 may be a plurality of wires disposed in the second line setting region 3020 along the second direction, wherein the first direction and the second direction are perpendicular to each other. The plurality of conductive particles 5 are included in each of the first colloidal conductor patterns 32 and the second colloidal conductor patterns 34. Therefore, the first colloidal conductor patterns 32 and the second colloidal conductor patterns 34 are formed on the opposite surfaces of the substrate 30 to form a net. The grid-shaped fingerprint sensing circuit allows the user to sense the fingerprint directly or indirectly with a finger contact.

In FIG. 2A, the fingerprint sensing circuit board 3 further includes an insulating protective layer 36 overlying at least partially over the first colloidal conductor pattern 32 and the second colloidal conductor pattern 34 to provide a fingerprint sensing line protection effect. In addition, the fingerprint sensing circuit board 3 may also include other electronic components 38 such as a wafer, a package, a passive component, and the like. For example, when the electronic component 38 is a wafer, the wafer can be electrically connected to the first colloidal conductor pattern 32 and the second colloidal conductor pattern 34 to receive the sensing signal of the fingerprint sensing line and calculate the sensing result accordingly. .

The fingerprint sensing circuit board can be further connected to another printed circuit board or a flexible circuit board to form a fingerprint identification system to utilize the identification result to achieve specific functions, such as access control, login to various electronic devices or systems, and the like. Moreover, according to another embodiment, the sensing circuit board can be directly integrated into another circuit board without the use of an additional substrate. For example, the first colloidal conductor pattern 32 and the second colloidal conductor pattern 34, the wafer, and the external circuit are simultaneously disposed on the flexible circuit board. In other words, the flexible circuit board herein is the substrate 30 in the foregoing specific embodiment. In practice, the first colloidal conductor pattern 32 and the second glue The body conductor patterns 34 may be respectively disposed on two corresponding regions of the same surface of the flexible circuit board along the mutually perpendicular first direction and the second direction, and then the flexible circuit board is folded such that the two corresponding regions are stacked back to back, thereby forming The aforementioned grid-like fingerprint sensing circuit.

In the previous specific embodiments, the first colloidal conductor pattern 32 and the second colloidal conductor pattern 34 respectively include a plurality of conductive particles 5 and form a plurality of wires on the two opposite surfaces 300, 302 of the substrate 30. The material of the conductive particles 5 may be selected from graphite, carbon black, carbon nanotubes, carbon spheres or carbon fibers, or gold (Au), silver (Ag), platinum (Pt), nickel (Ni), aluminum (Al). , titanium (Ti), iron (Fe), copper (Cu), molybdenum (Mo), tin (Sn), tantalum (Ta), magnesium (Mg), tungsten (W) or alloys of the above metals, may also be selected from Any combination of the above materials.

Please refer to FIG. 3A to FIG. 3E. FIG. 3A to FIG. 3E are schematic flowcharts showing a method for fabricating a fingerprint sensing circuit board according to an embodiment of the present invention. The fingerprint sensing circuit board 3 of FIG. 2A and FIG. 2B can be fabricated by the manufacturing method of FIG. 3A to FIG. Hereinafter, a method of manufacturing the fingerprint sensing circuit board of the specific embodiment will be described.

The method for fabricating the fingerprint sensing circuit board of the present embodiment includes the following steps: as shown in FIG. 3A, a substrate 40 is provided, wherein the substrate 40 has a first surface 400 and a second surface 402 opposite thereto, and the first surface 400 has a first line setting area 4000, the second surface 402 has a second line setting area 4020 corresponding to the first line setting area 4000; as shown in FIG. 3B, on the first line setting area 4000, the liquid is applied in the first direction a first colloidal wiring layer 42a is formed on the second bonding region 4020, and a liquid adhesive layer is applied in the second direction to form a second colloidal wiring layer 44a, and a second The direction is perpendicular to the first direction; as shown in FIG. 3D, a plurality of conductive particles 46 are disposed on the first colloid line layer 42a and the second colloid line layer 44a; and, as shown in FIG. 3E, the liquid is Adhesive layer The first colloidal wiring layer 42a and the second colloidal wiring layer 44a are subjected to a curing process to convert the liquid adhesive layer containing the conductive particles 46 from a liquid state to a semi-solid state, and further converted into a solid state to form a first colloidal conductor pattern 42 and a first The second colloidal conductor pattern 44, the first colloidal conductor pattern 42 and the second colloidal conductor pattern 44 can be referred to the first colloidal conductor pattern 32 and the second colloidal conductor pattern 34 of FIGS. 2A and 2B. In the method of the embodiment, the first colloidal conductor pattern 42 and the second colloidal conductor pattern 44 formed in the first line setting area 4000 and the second line setting area 4020 may correspond to a grid-shaped fingerprint sensing line, The user can directly or indirectly touch the finger to sense the fingerprint.

Similarly, in FIG. 3B and FIG. 3C, the liquid glue layer can be formed on the first line setting area 4000 and the second line setting area 4020 by printing methods such as screen printing or ink jet printing. In FIG. 3D, conductive particles 46 may be disposed on the first colloid line layer 42a and the second colloid line layer 44a by spraying. The material of the conductive particles 46 may be selected from graphite, carbon black, carbon nanotubes, carbon spheres or carbon fibers, or gold (Au), silver (Ag), platinum (Pt), nickel (Ni), aluminum (Al). ), titanium (Ti), iron (Fe), copper (Cu), molybdenum (Mo), tin (Sn), tantalum (Ta), magnesium (Mg), tungsten (W) or alloys of the above metals, also available Any combination of the various materials listed above.

Referring to FIG. 3F and FIG. 3G, FIG. 3F and FIG. 3G are schematic flowcharts showing a method for fabricating a fingerprint sensing circuit board according to another embodiment of the present invention. In this embodiment, the method for fabricating the fingerprint sensing circuit board further includes the steps of applying a liquid glue layer on the substrate and arranging the plurality of conductive particles 46 to the liquid glue layer as shown in FIG. 3A to FIG. 3D. Next, in the curing process of the liquid colloid shown in FIG. 3E, the liquid colloids of the first colloidal wiring layer 42a and the second colloidal wiring layer 44a are converted from a liquid state to a semi-solid state.

Next, as shown in FIG. 3F, a pressure is applied to the semi-solid glue layer by the mold M2. The force causes the first colloidal wiring layer 42a and the second colloidal wiring layer 44a to be planarized, and the conductive particles 46 are deeply and uniformly distributed in the two; and, as shown in FIG. 3G, the first after being pressed The semi-solid adhesive layer of the colloidal wiring layer 42a and the second colloidal wiring layer 44a is further subjected to a curing process to be converted into a solid adhesive layer to form a first colloidal conductor pattern 42 and a second colloidal conductor pattern 44. The fingerprint sensing circuit of the fingerprint sensing circuit board produced by the method of the embodiment has uniform conductivity.

Please refer to FIG. 3H. FIG. 3H is a schematic flow chart of a method for fabricating a fingerprint sensing circuit board according to another embodiment of the present invention. In this embodiment, the method for fabricating the fingerprint sensing circuit board still includes the flow steps of FIG. 3A to FIG. 3E, and when the steps are performed, the first colloidal conductor pattern 42 and the second colloidal conductor pattern 44 are obtained. After the fingerprint sensing circuit, the method further includes the step of forming an insulating protective layer 48 on the substrate 40, and at least partially covering the first colloidal conductor pattern 42 and the second colloidal conductor pattern 44, respectively. The insulating protective layer 48 formed in this step can be referred to the insulating protective layer 36 of FIG. 2A, which can be used to provide a fingerprint sensing line protection effect.

In summary, the wire pattern forming method of the present invention can easily form a circuit structure on a substrate, and can avoid the cumbersome manufacturing process when the wire pattern is conventionally fabricated by a photolithography process, and can also avoid the use in the foregoing process. Chemical liquids can cause pollution damage to the environment. In addition, the wire pattern forming method of the present invention can be used to form a sensing circuit on a fingerprint sensing circuit board, which uses a colloid containing conductive particles as a wire pattern, which is simple in steps and reduces the use of chemical liquids harmful to the environment. It can effectively reduce the production cost of the fingerprint sensing circuit board.

With the detailed description of the above preferred embodiments, it is hoped that the description will be more clearly described. The scope and spirit of the present invention is not limited by the preferred embodiments disclosed herein. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed.

3‧‧‧Fingerprint sensing circuit board

30‧‧‧Substrate

32‧‧‧First colloidal wire pattern

34‧‧‧Second colloidal wire pattern

36‧‧‧Insulating protective layer

38‧‧‧Electronic components

300‧‧‧ first surface

302‧‧‧ second surface

3000‧‧‧First line setting area

3020‧‧‧Second line setting area

5‧‧‧ conductive particles

Claims (12)

A wire pattern forming method comprising the steps of: coating a liquid glue layer on a predetermined position of a wire pattern of a substrate; arranging a plurality of conductive particles on the liquid glue layer; and curing the liquid glue layer The process is such that the liquid glue layer is converted from a liquid state to a semi-solid state and further converted into a solid state, so that the glue layer transformed into a solid state directly forms a wire pattern at a predetermined position of the wire pattern. The method for forming a wire pattern according to claim 1, further comprising the step of: applying pressure to the semi-solid glue layer to deepen the conductive particles when the liquid glue layer is changed from a liquid state to a semi-solid state; Evenly distributed in the semi-solid glue layer. The method of forming a wire pattern according to claim 1, wherein the method of arranging the conductive particles on the liquid glue layer comprises spraying. The method for forming a wire pattern according to claim 1, wherein the material of the conductive particles is selected from the group consisting of graphite, carbon black, carbon nanotubes, carbon spheres and carbon fibers, or gold. (Au), silver (Ag), platinum (Pt), nickel (Ni), aluminum (Al), titanium (Ti), iron (Fe), copper (Cu), molybdenum (Mo), tin (Sn), tantalum A group consisting of (Ta), magnesium (Mg), tungsten (W), and alloys thereof. A fingerprint sensing circuit board comprising: a substrate having a first surface and a second surface, the first surface having a first line setting area, the second surface having a corresponding first line setting a second line setting area; a first colloidal conductor pattern disposed in the first line setting area along a first direction, the first colloidal conductor pattern comprising a plurality of conductive particles; and a second colloidal conductor The pattern is disposed in the second line setting area along a second direction, the second direction is perpendicular to the first direction, and the second colloidal conductor pattern comprises a plurality of conductive particles. The fingerprint sensing circuit board of claim 5, further comprising an insulating protective layer covering at least partially the first colloidal conductor pattern and the second colloidal conductor pattern. The fingerprint sensing circuit board of claim 5, wherein the material of the conductive particles is selected from the group consisting of graphite, carbon black, carbon nanotubes, carbon spheres and carbon fibers, or Gold (Au), silver (Ag), platinum (Pt), nickel (Ni), aluminum (Al), titanium (Ti), iron (Fe), copper (Cu), molybdenum (Mo), tin (Sn), A group consisting of tantalum (Ta), magnesium (Mg), tungsten (W), and alloys thereof. A method for fabricating a fingerprint sensing circuit board, comprising the steps of: providing a substrate having a first surface and a second surface, the first surface having a first line setting area, the second surface Having a second line setting area corresponding to one of the first line setting areas; applying a liquid glue layer along a first direction on the first line setting area to form a first glue circuit layer; and setting the second line circuit layer Applying a liquid adhesive layer along a second direction to form a second colloidal wiring layer, wherein the second direction is perpendicular to the first direction; and arranging a plurality of conductive particles on the first colloidal wiring layer and the second And a curing process of the first colloidal circuit layer and the second colloidal circuit layer of the liquid adhesive layer, the liquid adhesive layer is changed from a liquid state to a semi-solid state and further converted into a solid state to be respectively converted into a solid state The first colloidal wiring layer and the second colloidal wiring layer of the adhesive layer directly form a first colloidal conductor pattern and a second colloidal conductor pattern. The method for fabricating a fingerprint sensing circuit board according to claim 8 , further comprising the steps of: applying pressure to the semi-solid glue layer to change the first gel line when the liquid glue layer is converted into a semi-solid state; The layer and the second colloidal wiring layer are planarized, and the conductive particles are deeply and uniformly distributed in the first colloidal wiring layer and the second colloidal wiring layer. The method for manufacturing a fingerprint sensing circuit board according to claim 8 further includes the following steps: An insulating protective layer is formed to at least partially cover the first colloidal conductor pattern and the second colloidal conductor pattern. The method for fabricating a fingerprint sensing circuit board according to claim 8, wherein the method of disposing the conductive particles on the first colloidal wiring layer and the second colloidal wiring layer comprises spraying. The method for fabricating a fingerprint sensing circuit board according to claim 8, wherein the material of the conductive particles is selected from the group consisting of graphite, carbon black, carbon nanotubes, carbon spheres and carbon fibers. Or by gold (Au), silver (Ag), platinum (Pt), nickel (Ni), aluminum (Al), titanium (Ti), iron (Fe), copper (Cu), molybdenum (Mo), tin ( A group consisting of Sn), tantalum (Ta), magnesium (Mg), tungsten (W), and alloys thereof.