TW202201664A - 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 sensing chip module, in particular to a packaging method for a fingerprint sensing chip module for smart cards.

People's daily life is full of the use of many cards. The traditional card is only used as an interface for recording information, such as the card user's name, expiration date, etc. With the advancement of technology, the card is no longer a traditional paper card. A chip is used to provide functions such as computing, access control, and data storage, and constitute a smart card in the prior art. Compared with traditional cards, smart cards can carry more information and reduce the chance of being counterfeited, thereby increasing the usage and popularity of smart cards. However, with the popularization of the use of smart cards, the phenomenon of unscrupulous people stealing and using other people's smart cards has gradually appeared. At the same time, people will inevitably lose the smart cards inadvertently, resulting in the possibility of the smart cards being stolen by the finder. 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 a user for identity verification when using the smart card.

Please refer to FIG. 14 , the fingerprint sensing chip module 91 disposed on the smart card in the prior art has a fingerprint sensing chip 911 in the fingerprint sensing chip module 91 , and the fingerprint sensing chip 911 needs to be assembled first in the manufacturing process. It is disposed on the rigid substrate 92, and then performs the first encapsulation and singulation to form a single fingerprint sensor chip module 91 with encapsulation, and then is disposed on the flexible board 93 ( FPC, Flexible Printed Circuit), and then perform wire bonding and second packaging, and then set it on the smart card.

However, in the fingerprint sensing chip module 91 disposed on the smart card in the prior art, it needs to undergo two encapsulations, the manufacturing process is complicated, and the thickness of the encapsulant is also relatively thick. Furthermore, the distance H between the active surface of the fingerprint sensor chip 911 (with the sensor array) and the surface that can be contacted by the user not only includes the thickness of the encapsulant of the fingerprint sensor chip module 911 , but also includes the thickness of the soft board 93 . It is said that in the prior art, the distance H is 160 μm, so the sensing distance is large, resulting in poor sensing sensitivity.

In view of this, the present invention is aimed at improving the structure and packaging method of the fingerprint sensor chip module disposed in the smart card in the prior art, in order to solve the problems of complex manufacturing process and thickness.

In order to achieve the above purpose of the invention, the technical means adopted by the present invention is to provide a packaging method for a fingerprint sensing chip module for smart cards, which includes the following steps: a. providing a flexible substrate; b. setting a plurality of fingerprints The sensing chip is on the flexible substrate, wherein the fingerprint sensing chips are arranged at intervals, the backside of the fingerprint sensing chip faces the flexible substrate, and the active surface of the fingerprint sensing chip is away from the flexible substrate; c. A sensing array is included on the active surface of the fingerprint sensing chip, and an electrical connection is formed between the sensing array and the flexible substrate; d. A plurality of encapsulation bodies are formed to cover the fingerprint sensing chips respectively, and Each of the encapsulation bodies is independent and not connected, and each of the encapsulation bodies covers the active surface and the side surface of the corresponding fingerprint sensing chip.

Further, the present invention provides a fingerprint sensor chip module, which includes: a flexible substrate; a fingerprint sensor chip, which has an active surface, a back surface and a side, the active surface includes a sensor array, the fingerprint sensor The backside of the sensing chip faces the flexible substrate, and the sensing array of the fingerprint sensing chip forms an electrical connection with the flexible substrate; a colloid covers the active surface and the side of the fingerprint sensing chip, and the fingerprint sensing chip forms an electrical connection. The active surface faces the top surface of the sealing body.

The advantage of the present invention is that the fingerprint sensor chip is directly disposed on the flexible substrate and packaged independently, thereby simplifying a single packaging process, thereby shortening the process time and cost, and effectively shortening the sensing array of the fingerprint sensor chip. The distance from the surface of the fingerprint sensing chip module can shorten the sensing distance, and on the premise of configuring the same sensing array, the fingerprint sensing chip module can improve the sensitivity.

The technical means adopted by the present invention to achieve the predetermined purpose of the present invention are further described below in conjunction with the drawings and the embodiments of the present invention, wherein the drawings are simplified for the purpose of illustration only, and describe the relationship between the elements and components of the present invention. to illustrate the structure or method invention of the present invention, therefore, the elements shown in the figures are not presented in the actual number, actual shape, actual size and actual scale, and the size or size ratio has been exaggerated or simplified to provide a better description. , has been selectively designed and configured actual quantity, actual shape or actual size ratio, while the detailed component layout may be more complex.

Please refer to FIG. 1 , the fingerprint sensing chip module 1 of the present invention is mainly applied to a smart card, and includes a flexible substrate 10 , a fingerprint sensing 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 predetermined circuit (not shown in the figure), and a plurality of pins 13 may be provided on the second side surface 12 . The preset circuit is connected to an external circuit (eg, an internal circuit "inlay" of a smart card) through the pin 13 . In one embodiment, the flexible substrate 10 is a flexible printed circuit board (FPC, Flexible Printed Circuit), but not limited thereto.

The aforementioned fingerprint sensing chip 20 is disposed on the first side surface 11 of the flexible substrate 10 , and the fingerprint sensing chip 20 is electrically connected to the pins 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 . A sensing array 24 is disposed on the active surface 21 of the fingerprint sensing chip 20. In one embodiment, the sensing array 24 is composed of sensing electrodes that are crisscrossed. The generated capacitance changes, because the peaks and valleys of the fingerprint have different capacitance changes, so the sensing array 24 detects the capacitance changes at various positions to hook out the fingerprint image of the finger in contact. The sensing array 24 is electrically connected to the flexible substrate 10 . In an 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 the left and right sides (not shown in the figure) 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 TSV 25A (TSV), the TSV 25A runs through the active surface 21A and the back surface 22A, and the inner wall surface of the TSV 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 sensing chip 20 and is disposed 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 for setting desired colors or patterns on the surface of the encapsulant body 30 , or for forming 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 encapsulant 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 protection effect. In one embodiment, the thickness of the coating layer 40 is 20 μm.

Furthermore, as shown in FIG. 3 , the fingerprint sensing 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 sensing 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 (eg, DAF "die attach film"), and the fingerprint sensing chip 20C is stacked on the insulator 52C. The electronic components 50B, 50C may be electronic components that are required to be used in conjunction with the fingerprint sensing chips 20B, 20C, such as a charge pump, etc., thus the electronic components 50B, 50C and the fingerprint sensing chips 20B, 20C, etc. The 20C is integrated into a single package structure to enhance the functions that a single package structure can provide.

Therefore, the present invention effectively shortens the distance between the sensing array 24 of the fingerprint sensing chip 20 and the top surface of the encapsulant 23 by disposing the fingerprint sensing chip 20 directly on the flexible substrate 10. The position of the fingerprint sensing chip module 1 is the surface of the coating layer 40 , so shortening the distance between the sensing array 24 of the fingerprint sensing chip 20 and the top surface of the encapsulant 23 means reducing the distance between fingers and the sensing The distance between the arrays 24 can effectively improve the sensitivity of the fingerprint sensing chip module 1 on the premise of configuring the same sensing array, thereby providing more accurate fingerprint sensing results.

The packaging method for the fingerprint sensing chip module of the smart card of the present invention comprises the following steps:

Provide a flexible substrate tape body 100 (as shown in FIG. 5 ): Since the smart card structure is limited by the thickness of the substrate, the substrate of the fingerprint sensing chip must be a flexible board, so the flexible substrate tape body 100 can form a tape-and-reel type Flexible Printed Circuit Board (FPC, Flexible Printed Circuit).

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

An electrical connection is formed between the fingerprint sensing chip 20 and the flexible substrate tape 100 (as shown in FIG. 7 ): in this embodiment, wires 241 are formed on the fingerprint sensing device by wire bonding. An electrical connection is formed between the sensing array 24 of the wafer 20 and the flexible substrate tape body 100 . Each of the fingerprint sensing chips 20 can be electrically connected to the flexible substrate strip 100 by one side of the wire 241 (as shown in FIG. 7 ) or by two sides of the wire (not shown in the figure).

A plurality of sealing compounds 23 are formed to cover the fingerprint sensing chips 20 respectively (as shown in FIG. 8 and FIG. 9 ): a sealing compound 23 is formed to cover the fingerprint sensing chips 20 independently. The encapsulation bodies 23 are independent and not connected to each other, and each of the encapsulation bodies 23 covers the active surface and the side surface of the corresponding fingerprint sensing chip 20 . In one embodiment, a plastic injection mold 60 is firstly covered on the flexible substrate tape body 100 . The plastic injection mold 60 has a plurality of mold cavities 61 that are not communicated with each other, and each of the mold cavities 61 respectively covers one of the mold cavities 61 . For 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 mold cavity 61 . In one embodiment, a vent hole (not shown in the figure) may be provided on the side of each of the mold cavities 61 for discharging excess gas in the mold cavity 61 during plastic injection. After the glue injection holes 62 are used to inject glue into the film cavities 61 , the glue injection mold 60 is removed to complete the step of disposing the sealing body 23 .

Steps of cutting, coating and setting pins: please refer to FIG. 1 and FIG. 9 , after disposing the encapsulant 23 on the fingerprint sensing chip 20 , a cutting unit 70 can be used to correspond to each fingerprint sensing chip 20 . The respective independent fingerprint sensing 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 of the sealing compounds 23. Before the coating layer 40 is applied, the top surface of the sealing compounds 23 may be ground to reduce the thickness of the sealing compounds 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 electrical connection with external circuits. The aforementioned steps of coating, grinding, and setting pins can 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 a TSV 25A, so in the step of forming the electrical connection, each of the TSVs 25A has a TSV 25A. A conductive material 251A is disposed on the hole wall, so that the sensing array 24A is electrically connected to the flexible substrate strip 100A through the conductive material 251A. Subsequently, each fingerprint sensor chip 20A is covered with a plastic injection mold 60A having a plurality of independent mold cavities 61A, and plastic injection is completed from the plastic injection hole 62A to form a plastic sealing body 23A, and then the subsequent cutting, coating, grinding, After steps such as setting pins, the packaging of the fingerprint sensing chip module is completed.

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

Therefore, the present invention can package the fingerprint sensor chip module in a single packaging process through the aforementioned steps, so as to simplify the process and shorten 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 sensing chip 20 can also be reduced, and the fingerprint sensing chip 20 and the pins 13 are located on opposite sides of the flexible substrate tape 100 . side, thereby achieving the purpose of shortening the distance between the sensing array 24 of the fingerprint sensing chip 20 and the finger, thereby effectively improving the sensitivity.

The above description is only an embodiment of the present invention, and is not intended to limit the present invention in any form. Although the present invention has been disclosed as above by embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field, Within the scope of not departing from the technical solution of the present invention, when the technical content disclosed above can be used to make some changes or modifications to equivalent embodiments with equivalent changes, but any content that does not depart from the technical solution of the present invention, according to 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 solutions of the present invention.

1: Fingerprint sensor chip module 10, 10A, 10B: soft substrate 100, 100A: soft substrate belt 11: The first side 12: Second side 13: Pin 20, 20A: Fingerprint sensor chip 21, 21A: Active side 22, 22A: back 23: Colloid 24: Induction Array 241: Wire 25A: TSV 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 91: Fingerprint sensor chip module 911: Fingerprint Sensing Chip 92: Substrate 93: FPC

FIG. 1 is a side cross-sectional view of part of the components of the first embodiment of the fingerprint sensing chip module of the present invention; 2 is a side cross-sectional view of a part of components of a second embodiment of the fingerprint sensing chip module of the present invention; FIG. 3 is a side cross-sectional view of part of components of a third embodiment of the fingerprint sensing chip module of the present invention; 4 is a side cross-sectional view of a part of the components of the fourth embodiment of the fingerprint sensing chip module of the present invention; FIG. 5 to FIG. 9 are schematic flow charts of the packaging method of the fingerprint sensing chip module for smart card according to the present invention; 10 to 13 are schematic flowcharts of flow steps of another embodiment of a packaging method for a fingerprint sensing chip module for a smart card according to the present invention; 14 is a side cross-sectional view of a fingerprint sensing chip module of the prior art.

1: Fingerprint sensor chip module

10: Soft substrate

11: The first side

12: Second side

13: Pin

20: Fingerprint sensor chip

21: Active side

22: Back

23: Colloid

24: Induction Array

241: Wire

30: Sealing body

40: Coating

Claims (17)

A packaging method for a fingerprint sensing chip module for a smart card, comprising the following steps: a. Provide a flexible substrate belt; b. Arranging a plurality of fingerprint sensing chips on the flexible substrate belt, wherein the fingerprint sensing chips are arranged at intervals, and the back of the fingerprint sensing chips faces the flexible substrate belt, and the fingerprint sensing chips are arranged at intervals. The active surface of the measuring chip is far away from the flexible substrate belt; c. The active surface of the fingerprint sensing chip includes a sensing array, and an electrical connection is formed between the sensing array and the flexible substrate strip; and d. A plurality of encapsulation bodies are formed to cover the fingerprint sensing chips respectively, and the encapsulation bodies are independent and not connected, and the encapsulation bodies cover the active surface and the side surface of the corresponding fingerprint sensing chip. The packaging method for a fingerprint sensing chip module for a smart card according to claim 1, wherein the aforementioned step d comprises the following steps: d1. Covering a plastic injection mold on the fingerprint sensing chip, the plastic injection mold includes a plurality of mold cavities, and each of the mold cavities covers the active surface and the side surface of one of the fingerprint sensing chips correspondingly; d2. Injection of glue into each of the mold cavities; and d3. Remove the injection mold. The packaging method for a fingerprint sensing chip module for a smart card as claimed in claim 2, wherein in the aforementioned step d2, glue injection is performed through a glue injection hole on the top surface of each of the mold cavities. The packaging method for a fingerprint sensing chip module for a smart card according to claim 1, further comprising the following steps after the aforementioned step d: e. Grinding the top surface of the encapsulant, wherein the top surface of the encapsulant is the outer surface toward which the active surface of the fingerprint sensing chip faces. The packaging method for a fingerprint sensing chip module for a smart card according to claim 1, further comprising the following steps after the aforementioned step d: f. Arrange a coating layer on a top surface of the encapsulant. The packaging method for a fingerprint sensing chip module for a smart card according to claim 4, further comprising the following steps after the aforementioned step e: f. Arrange a coating layer on the top surface of the encapsulant after grinding. The packaging method for a fingerprint sensing chip module for a smart card according to claim 5, further comprising the following steps after the aforementioned step d: g. After the encapsulant is covered on the fingerprint sensing chip, cut the flexible substrate tape with the plurality of fingerprint sensing chips, so that each fingerprint sensing chip is cut out of the fingerprint sensing chip which is independent of each other. Test chip module. The packaging method for a fingerprint sensing chip module for a smart card according to claim 6, further comprising the following steps after the aforementioned step f: g. After the encapsulant is covered on the fingerprint sensing chip, cut the flexible substrate tape with the plurality of fingerprint sensing chips, so that each fingerprint sensing chip is cut out of the fingerprint sensing chip which is independent of each other. Test chip module. The packaging method for a fingerprint sensing chip module for a smart card as claimed in claim 1, wherein in the aforementioned step c, a wire is provided by wire bonding to electrically connect the sensing array of the fingerprint sensing chip and the sensor array. Flexible substrate belt. The packaging method for a fingerprint sensing chip module for a smart card as claimed in claim 1, wherein each of the fingerprint sensing chips has a TSV, and in the aforementioned step c, the silicon of each of the fingerprint sensing chips is A conductive material is arranged in the through hole to electrically connect the sensing array of the fingerprint sensing chip and the flexible substrate strip. 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 of the electronic components is arranged on the corresponding fingerprint sensor The side of the chip or the stack of the fingerprint sensing chips is disposed above the electronic component. In the aforementioned step d, each of the encapsulation bodies is made to cover the fingerprint sensing chip and the electronic component. A fingerprint sensing chip module, comprising: a flexible substrate having a first side surface and a second side surface, and the second side surface is provided with a plurality of pins; A fingerprint sensor chip, which has an active surface and a back surface, the active surface includes a sensor array, the back surface of the fingerprint sensor chip is disposed toward the first side of the flexible substrate, the sensor array of the fingerprint sensor chip and the The flexible substrate forms electrical connections; and A sealing body covers the active surface of the fingerprint sensing chip and its side edges, and the active surface of the fingerprint sensing chip faces a top surface of the sealing body. The fingerprint sensing chip module of claim 12, wherein the distance between the top surface of the encapsulant and the active surface of the fingerprint sensing chip is 40 μm to 120 μm. The fingerprint sensing chip module of claim 12, wherein the sensing array of the fingerprint sensing chip is electrically connected with the flexible substrate by a wire. The fingerprint sensing chip module of claim 12, wherein the fingerprint sensing chip has a TSV, and a conductive material is disposed therein to electrically connect the sensing array of the fingerprint sensing chip and the flexible substrate. The fingerprint sensing chip module of claim 12, wherein a coating layer is provided on the top surface of the encapsulant. The fingerprint sensing chip module according to claim 12, further comprising an electronic component disposed on the side of the fingerprint sensing chip or the fingerprint sensing chip is stacked above the electronic component, and the encapsulant covers The fingerprint sensing chip and the electronic component.

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