TWI730812B - Fingerprint sensing chip module for a smart card and packaging method of the same - Google Patents

Abstract

The present invention relates to a fingerprint sensing chip module. It has a fingerprint chip attached to the flexible substrate with its back side. The sensing array on the active surface of the fingerprint sensing chip is away from the flexible substrate. The sensing array electrically connects to the flexible substrate. The encapsulant covers the fingerprint sensing chip. The present invention is directly arranged on the flexible substrate by the fingerprint sensing chip, and constitutes an independent package to reduce manufacturing time and cost. The distance between the sensing array of the fingerprint sensing chip and the top surface of the encapsulant can be effectively shortened to improve the sensitivity of the fingerprint sensing chip module.

Description

Fingerprint sensing chip module for smart card and packaging method thereof

The present invention relates to a fingerprint sensor chip module, in particular to a packaging method of a fingerprint sensor chip module for smart cards.

Many cards are used in people’s daily life. Traditional cards are only used as information recording interfaces, such as the user’s name, expiration date, etc. However, with the advancement of technology, cards are no longer traditional paper cards. The chip is used to provide functions such as calculation, access control, and data storage, and constitutes a smart card of the prior art. Compared with traditional cards, smart cards can carry more information and reduce the probability of being forged, thereby increasing the utilization and penetration rate of smart cards. However, with the popularization of smart cards, the phenomenon of stealing and fraudulent use of smart cards by other people has gradually appeared. At the same time, people will inevitably lose their smart cards inadvertently, leading to the possibility of smart cards being stolen by those who find them. Therefore, the verification function of the smart card itself is also important. In the prior art, a fingerprint sensor chip module has been integrated on a smart card, so as to provide users with identity verification when using the smart card.

Please refer to FIG. 14, a fingerprint sensor chip module 91 disposed on a smart card 90 in the prior art. The fingerprint sensor chip module 91 has a fingerprint sensor chip 911, and the fingerprint sensor chip must be first in the manufacturing process. 911 is placed on the hard substrate 92, and then the first package and singulation are performed (singulation) to form a single fingerprint sensor chip module 91 with a package, and then set it on a flexible printed circuit (FPC, Flexible Printed Circuit) 93 (FPC) of a tape-and-reel package, and then perform wire bonding and a second package, and then Set on the smart card.

However, in the fingerprint sensor chip module 91 provided on the smart card in the prior art, it needs to go through two encapsulation processes, which makes the manufacturing process more complicated, and the thickness of the encapsulant body is relatively thick. Furthermore, the distance H between the active surface (with a sensor array) of the fingerprint sensor chip 911 and the user-accessible surface H, in addition to the thickness of the encapsulant body of the fingerprint sensor chip module 911, also includes the thickness of the soft board 93. Generally, In the prior art, the distance H is 160 μm, so the sensing distance is relatively large, resulting in poor sensing sensitivity.

In view of this, the present invention improves the structure and packaging method of the fingerprint sensor chip module installed in the smart card in the prior art, in order to solve the problem of complex manufacturing process and thickness.

In order to achieve the above-mentioned purpose of the invention, the technical means adopted by the present invention is to provide a packaging method for a fingerprint sensor chip module for a smart card, which includes the following steps: a. providing a soft substrate; b. setting a plurality of fingerprints Sensor chips on the soft substrate, wherein the fingerprint sensor chips are arranged at intervals, the back of the fingerprint sensor chip faces the soft substrate, and the active surface of the fingerprint sensor chip is away from the soft substrate; c. The active surface of the fingerprint sensor chip includes a sensor array, and an electrical connection is formed between the sensor array and the soft substrate; d. A plurality of molding compounds are formed to respectively cover the fingerprint sensor chip, and Each encapsulant body is independent and not connected, and each encapsulant body covers the active surface and the side surface of the corresponding fingerprint sensor chip.

Furthermore, the present invention provides a fingerprint sensor chip module, which includes: a soft substrate; a fingerprint sensor chip, which has an active surface, a back surface and side edges, the active surface includes There is a sensor array, the back of the fingerprint sensor chip is set toward the soft substrate, and the sensor array of the fingerprint sensor chip is electrically connected to the soft substrate; a sealant covering the active surface and side of the fingerprint sensor chip On the other hand, the active surface of the fingerprint sensor chip faces the top surface of the molding compound.

The advantage of the present invention is that by directly disposing the fingerprint sensor chip on the soft substrate and performing independent packaging, it is simplified into a single packaging process, thereby shortening the process time and process cost, and effectively shortening the sensor array of the fingerprint sensor chip The distance from the surface of the fingerprint sensor chip module can shorten the sensing distance, and the fingerprint sensor chip module can increase the sensitivity under the premise of configuring the same sensor array.

1: Fingerprint sensor chip module

10, 10A, 10B: soft substrate

100, 100A: flexible substrate belt

11: First side

12: second side

13: Pin

20, 20A: fingerprint sensor chip

21, 21A: active side

22, 22A: back

23: colloid

24, 24A, 24C: sensor array

241: Wire

25A: Silicon perforation

251A: Conductive material

30: Sealing body

40: coating

50B, 50C: electronic components

51B: Wire

52C: Insulator

60, 60A: plastic injection mold

61, 61A: Mould cavity

62, 62A: Glue injection hole

70: Cutting unit

90: Smart Card

91: Fingerprint sensor chip module

911: fingerprint sensor chip

92: substrate

93: soft board

Fig. 1 is a side view partial component cross-sectional view of the first embodiment of the fingerprint sensor chip module of the present invention; Fig. 2 is a side view partial component cross-sectional view of the second embodiment of the fingerprint sensor chip module of the present invention Figure; Figure 3 is a cross-sectional side view of the third embodiment of the fingerprint sensor chip module of the present invention; Figure 4 is a side view of the fourth embodiment of the fingerprint sensor chip module of the present invention Component cross-sectional view; Figures 5 to 9 are schematic diagrams of the process steps of the packaging method of the fingerprint sensor chip module for smart cards of the present invention; Figures 10 to 13 are the fingerprint sensor chip for smart cards of the present invention A schematic diagram of the process steps of another embodiment of the module packaging method; FIG. 14 is a side cross-sectional view of a fingerprint sensor chip module in the prior art.

The following figures and embodiments of the present invention are used to further explain the technical means adopted by the present invention to achieve the intended purpose of the invention. The figures are simplified for illustrative purposes only and describe the relationship between the elements and components of the present invention. To illustrate the structure or method of the present invention, therefore, the elements shown in the figure are not presented in actual numbers, actual shapes, actual sizes, and actual ratios. The sizes or size ratios have been enlarged or simplified to provide a better description. , The actual number, actual shape or actual size ratio has been selectively designed and configured, and the detailed component layout may be more complicated.

Please refer to FIG. 1, the fingerprint sensor chip module 1 of the present invention is mainly applied to a smart card, and it includes a flexible substrate 10, a fingerprint sensor chip 20, a sealant 30 and a coating layer 40.

The aforementioned flexible substrate 10 has a first side surface 11 and a second side surface 12, the first side surface 11 is provided with a preset circuit (not shown in the figure), and the second side surface 12 can be provided with a plurality of pins 13, so The preset circuit is connected to an external circuit (for example, the internal circuit "inlay" of the smart card) through the pin 13. In one embodiment, the flexible substrate 10 is a flexible printed circuit (FPC, Flexible Printed Circuit), but it is not limited thereto.

The aforementioned fingerprint sensor chip 20 is disposed on the first side surface 11 of the flexible substrate 10, and the fingerprint sensor chip 20 is electrically connected to the pin 13 through a predetermined circuit in the flexible substrate 10. The fingerprint sensor chip 20 has an active surface 21 and a back surface 22. The fingerprint sensor chip 20 is disposed on the first side surface 11 of the flexible substrate 10 with the back surface 22. In one embodiment, the fingerprint sensor The back surface 22 of the chip 20 is disposed on the first side surface 11 of the flexible substrate 10 through a glue 23. The fingerprint sensor chip 20 is provided with a sensing array 24 on the active surface 21. In one embodiment, the sensing array 24 is composed of criss-crossing sensing electrodes. The capacitance change produced is detected by the sensor array 24 because the amount of capacitance change produced by the peak and valley of the fingerprint is different. The amount of capacitance change at each position is used to hook the fingerprint image of the touched finger. The sensing array 24 is electrically connected to the flexible substrate 10. In one embodiment (as shown in FIG. 1), the sensing array 24 is electrically connected to the flexible substrate 10 by at least one wire 241, and the sensing array 24 can pass through at least one wire on each of the left and right sides (not shown) An electrical connection is formed with the flexible substrate 10. In one embodiment (as shown in FIG. 2), the fingerprint sensor chip 20A has a silicon through hole 25A (TSV), the silicon through hole 25A penetrates the active surface 21A and the back surface 22A, and the inner wall surface of the silicon through hole 25A A conductive material 251A is provided, and the sensing array 24A is electrically connected to the flexible substrate 10A through the conductive material 251A.

The aforementioned encapsulant 30 covers the fingerprint sensor chip 20 and is arranged on the first side surface 11 of the flexible substrate 10. The aforementioned coating layer 40 is disposed on the surface of the encapsulant body 30 to provide a desired color or pattern on the surface of the encapsulant body 30 or to form a hard surface to protect the encapsulant body 30. In one embodiment, the distance h from the surface of the sensing array 24 to the surface of the molding compound 30 is 40 to 120 μm, and the distance h may be 60 μm. The thickness of the coating layer 40 depends on the desired color, pattern or protective effect. In one embodiment, the thickness of the coating layer 40 is 20 μm.

Furthermore, please refer to FIG. 3, the fingerprint sensor chip module 1B may include an electronic component 50B, and the electronic component 50B is electrically connected to the flexible substrate 10B through a wire 51B. In one embodiment (as shown in FIG. 3), the electronic component 50B is disposed on the first side surface 11B of the flexible substrate 10B, and is relatively located beside the fingerprint sensor chip 20B; in another embodiment ( As shown in FIG. 4), the electronic component 50C is disposed on the flexible substrate 10B, and the electronic component 50C is covered with an insulator 52C (such as DAF "Chip Adhesive Film"), and the fingerprint sensor chip 20C is stacked on the insulator On 52C, the fingerprint sensor chip 20C has a sensor array 24C. The electronic components 50B and 50C can be electronic components required to be used in conjunction with fingerprint sensor chips 20B and 20C, such as charge pumps. In this way, the electronic components 50B, 50C and the fingerprint sensor chips 20B, 20C are integrated into a single package structure to improve the functions provided by the single package structure.

Therefore, in the present invention, by directly disposing the fingerprint sensor chip 20 on the soft substrate 10, the distance between the sensor array 24 of the fingerprint sensor chip 20 and the top surface of the molding compound 23 is effectively shortened. The fingerprint sensor chip module 1 is positioned on the surface of the coating layer 40, so shortening the distance between the sensor array 24 of the fingerprint sensor chip 20 and the top surface of the encapsulant 23 means reducing the finger and the sensor The distance between the arrays 24 can effectively increase the sensitivity of the fingerprint sensor chip module 1 under the premise of configuring the same sensor array, thereby providing more accurate fingerprint sensing results.

The packaging method of the fingerprint sensor chip module used in the smart card of the present invention includes the following steps: Provide a flexible substrate tape 100 (as shown in FIG. 5): Since the smart card structure is limited by the thickness of the substrate, the substrate of the fingerprint sensor chip must be a flexible substrate, so the flexible substrate tape 100 can be configured as a tape-and-reel Flexible printed circuit board (FPC, Flexible Printed Circuit).

A plurality of fingerprint sensor chips 20 are arranged on the flexible substrate belt 100 (as shown in FIG. 6): the fingerprint sensor chips 20 are arranged with their back surfaces 22 facing the flexible substrate belt 100, and each fingerprint A sensing array 24 is provided on the active surface 21 of the sensing chip 20. In one embodiment, the back surface 22 of the fingerprint sensor chip 20 is first provided with a glue 23, and then the fingerprint sensor chip 20 is arranged on the flexible substrate belt 100 through the glue 23.

An electrical connection is formed between the fingerprint sensor chip 20 and the flexible substrate strip 100 (as shown in FIG. 7): in this embodiment, a wire 241 is formed in the fingerprint sensor by wire bonding. Between the sensing array 24 of the test chip 20 and the flexible substrate strip 100 to form an electrical connection Pick up. Each fingerprint sensor chip 20 can be electrically connected to the flexible substrate belt 100 by one side wire 241 (as shown in FIG. 7) or two sides (not shown).

A plurality of encapsulant bodies 23 are formed to cover each fingerprint sensor chip 20 (as shown in FIGS. 8 and 9): a encapsulant body 23 is formed outside each fingerprint sensor chip 20 to independently cover each of the fingerprint sensor chips. The molding compounds 23 are independent and not connected to each other, and each molding compound 23 covers the active surface and the side surface of the corresponding fingerprint sensor chip 20. In one embodiment, a plastic injection mold 60 is first covered on the flexible substrate belt 100. The plastic injection mold 60 has a plurality of cavities 61 that are not connected to each other, and each of the cavities 61 respectively covers one of the cavities 61. The fingerprint sensor chip 20 and the wires 241 connected thereto, each of the mold cavities 61 is provided with a glue injection hole 62. In one embodiment, the glue injection hole 62 is located on the top surface of the cavity 61. In one embodiment, an exhaust hole (not shown in the figure) may be provided on the side of each cavity 61 to discharge excess gas in the cavity 61 when the glue is injected. After the glue injection holes 62 are used to inject glue into each of the film holes 61, the glue injection mold 60 is removed to complete the step of setting the glue sealing body 23.

Steps of cutting, coating and setting pins: Please refer to Figures 1 and 9, after the encapsulant 23 is placed on the fingerprint sensor chip 20, a cutting unit 70 can be used to correspond to each fingerprint sensor chip 20. Separate fingerprint sensor chip modules 1 are cut out, and the cutting unit 70 can be a cutting knife, a laser, a punch, or the like. Furthermore, the coating layer 40 may be coated on the surface of each molding compound 23. Before coating the coating layer 40, the top surface of the molding compound 23 may be ground to reduce the thickness of the molding compound 23. At the same time, the flatness of the top surface of the sealing compound 23 can be trimmed. The bottom side of the flexible substrate 10 can be provided with pins 13 to form an electrical connection with an external circuit. The aforementioned steps of coating, grinding, and setting pins can all be performed before or after the cutting step.

In another embodiment, please refer to FIG. 10 to FIG. 13 in conjunction with FIG. 2. Each of the fingerprint sensor chips 20A has silicon through holes 25A. Therefore, in the step of forming electrical connections, each of the silicon through holes 25A The wall of the hole is provided with a conductive material 251A, so that the sensing array 24A can form an electrical connection with the flexible substrate belt 100A through the conductive material 251A. Subsequently, a plastic injection mold 60A with a plurality of independent mold cavities 61A is used to cover each fingerprint sensor chip 20A, and the plastic injection hole 62A is used to complete the injection to form a sealing plastic body 23A, and then the subsequent cutting, coating, grinding, and polishing are performed. After the steps of setting the pins, the packaging of the fingerprint sensor chip module is completed.

In another embodiment, if the electronic components 50B and 50C as shown in FIG. 3 or FIG. 4 are to be installed, they can be installed on the flexible substrate strip before or after the step of installing the fingerprint sensor chip, and then form the electronic components. In the connecting step, the electrical connection between the electronic components 50B, 50C and the flexible substrate tape is formed together, and in the step of forming the molding compound, each electronic component 50B, 50C and the corresponding fingerprint sensor chip are covered in the same molding compound. .

Therefore, in the present invention, the fingerprint sensor chip module can be packaged in a single packaging process through the foregoing steps, thereby simplifying the manufacturing process and shortening the packaging time. In addition, in the single packaging process of the present invention, the thickness of the packaging material between the finger and the fingerprint sensor chip 20 can be reduced, and the fingerprint sensor chip 20 and the pin 13 are located on the opposite side of the flexible substrate belt 100. The side surface further achieves the purpose of shortening the distance between the sensor array 24 of the fingerprint sensor chip 20 and the finger, thereby effectively improving the sensitivity.

The above are only the embodiments of the present invention and do not limit the present invention in any form. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field, Without departing from the scope of the technical solution of the present invention, when the technical content disclosed above can be used to make slight changes or modification into equivalent embodiments with equivalent changes, but any content that does not depart from the technical solution of the present invention is based on the technical essence of the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

1: Fingerprint sensor chip module

10: Soft substrate

11: First side

12: second side

13: Pin

20: Fingerprint sensor chip

21: Active side

22: back

23: colloid

24: sensor array

241: Wire

30: Sealing body

40: coating

Claims (11)

A packaging method for a fingerprint sensor chip module for a smart card, which includes the following steps: a. providing a flexible substrate belt; b. arranging a plurality of fingerprint sensor chips on the flexible substrate belt, wherein the The fingerprint sensor chips are arranged at intervals, and the back of the fingerprint sensor chip faces the flexible substrate belt, and the active surface of the fingerprint sensor chip is away from the flexible substrate belt; c. wherein the fingerprint sensor chip The active surface includes a sensing array, which forms an electrical connection between the sensing array and the flexible substrate strip; and d. forming a plurality of encapsulating bodies to cover the fingerprint sensor chips, and each encapsulating body is individually Independent and not connected, each encapsulant covers the active surface and side surface of the corresponding fingerprint sensor chip. The packaging method for a fingerprint sensor chip module for a smart card according to claim 1, wherein the aforementioned step d includes the following steps: d1. Covering an injection mold on the fingerprint sensor chip, the injection mold It includes a plurality of mold cavities, each of the mold cavities correspondingly covering the active surface and side surface of one of the fingerprint sensing chips; d2. injecting glue on each of the mold cavities; and d3. removing the glue injection mold. The packaging method for a fingerprint sensor chip module for a smart card according to claim 2, wherein in the aforementioned step d2, the glue is injected from one of the injection holes on the top surface of each cavity. The packaging method for a fingerprint sensor chip module for a smart card as described in claim 1, wherein after the aforementioned step d, the method further includes the following steps: e. Grind the top surface of the encapsulant body, wherein the top surface of the encapsulant body is the outer surface of the fingerprint sensor chip facing the active surface. The packaging method for a fingerprint sensor chip module for a smart card according to claim 1, wherein after the aforementioned step d, the method further includes the following steps: f. Disposing a coating layer on a top surface of the molding compound. The packaging method for a fingerprint sensor chip module for a smart card according to claim 4, which further comprises the following steps after the aforementioned step e: f. placing a coating layer on the top of the encapsulating body after grinding surface. The packaging method for a fingerprint sensor chip module for a smart card according to claim 5, wherein after the aforementioned step d, the method further includes the following steps: g. After the encapsulant is covered on the fingerprint sensor chip, The flexible substrate strip provided with the plurality of fingerprint sensing chips is cut, so that each of the fingerprint sensing chips is cut into a separate fingerprint sensing chip module. The packaging method for a fingerprint sensor chip module for a smart card according to claim 6, wherein after the aforementioned step f, it further comprises the following steps: g. After the encapsulant is covered on the fingerprint sensor chip, The flexible substrate strip provided with the plurality of fingerprint sensing chips is cut, so that each of the fingerprint sensing chips is cut into a separate fingerprint sensing chip module. The packaging method for a fingerprint sensor chip module for a smart card according to claim 1, wherein in the aforementioned step c, a wire is arranged in a wire-bonding manner to electrically connect the sensor array of the fingerprint sensor chip and the Soft substrate belt. The packaging method for a fingerprint sensor chip module for a smart card as described in claim 1, wherein each of the fingerprint sensor chips has a silicon through hole, and in the step c, the silicon of each fingerprint sensor chip A conductive material is arranged in the through hole to electrically connect the sensor array of the fingerprint sensor chip and the flexible substrate band. The packaging method for a fingerprint sensor chip module for a smart card according to claim 1, wherein in step b, a plurality of electronic components are further arranged, and each electronic component is arranged on the corresponding fingerprint sensor The side of the chip or the fingerprint sensor chip is stacked on the electronic component. In the aforementioned step d, each encapsulant is made to cover the fingerprint sensor chip and the electronic component.

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