FINGERPRINT RECOGNITION CHIP PACKAGING STRUCTURE AND PACKAGING METHOD

• US 20170162620A1
• Filed: 06/30/2015
• Published: 06/08/2017
• Est. Priority Date: 07/01/2014
• Status: Active Grant

• Current Assignee: China Wafer Level CSP Co., Ltd.
• Original Assignee: China Wafer Level CSP Co., Ltd.
• Inventors: WANG, Zhiqi, YU, Qiong, WANG, Wei
• Granted Patent: US 10,096,643 B2
• Time in Patent Office: Days
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G06V 40/1329 Protecting the fingerprint sensor against damage caused by the finger
• CPC Class Codes: G06V 40/1359 Extracting features related to ridge properties; Determining the fingerprint type, e.g. whorl or loop
• CPC Class Codes: G06V 40/1365 Matching; Classification
• CPC Class Codes: G06V 40/1376 Matching features related to ridge properties or fingerprint texture
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/32227 the layer connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/43848 Thermal treatments, e.g. annealing, controlled cooling
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45139 Silver (Ag) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/45184 Tungsten (W) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 2224/92247 : the second connecting process involving a wire connector
• CPC Class Codes: H01L 23/293 : Organic, e.g. plastic
• CPC Class Codes: H01L 23/3121 : a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/60 : Protection against electrostatic charges or discharges, e.g. Faraday shields
• CPC Class Codes: H01L 24/00 : Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/92 : Specific sequence of method steps
• CPC Class Codes: H01L 27/14618 : Containers
• CPC Class Codes: H01L 27/14636 : Interconnect structures
• CPC Class Codes: H01L 27/14678 : Contact-type imagers
• CPC Class Codes: H01L 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape

Abstract

A packaging structure and a packaging method for a fingerprint identification chip are provided. The packaging structure includes a substrate, a sensing chip, a wire and a plastic encapsulation layer. The substrate is provided with a first solder pad layer. The sensing chip has a first surface and a second surface opposite to the first surface, the first surface comprises a sensing area and a peripheral area surrounding the sensing area, and the surface of the sensing chip in the peripheral area is provided with a second solder pad layer. Two ends of the wire are electrically connected to the first solder pad layer and the second solder pad layer respectively. The plastic encapsulation layer is made of a polymer, the plastic encapsulation layer surrounds the wire and the sensing chip.

Claims

1. A packaging structure for a fingerprint identification chip, comprising:

a substrate, wherein the substrate has a substrate surface, and the substrate surface is provided with a first solder pad layer;

a sensing chip arranged on the substrate surface, wherein the sensing chip has a first surface and a second surface arranged opposite to the first surface, the second surface of the sensing chip is arranged on the substrate surface, the first surface of the sensing chip comprises a sensing area and a peripheral area surrounding the sensing area, and the surface of the sensing chip in the peripheral area is provided with a second solder pad layer;

a wire, wherein two ends of the wire are electrically connected to the first solder pad layer and the second solder pad layer respectively, a point of the wire farthest away from the substrate surface is a vertex, and a distance from the vertex to the first surface of the sensing chip is a first distance; and

a plastic encapsulation layer arranged on the substrate surface and the first surface of the sensing chip, wherein the plastic encapsulation layer is made of a polymer, the plastic encapsulation layer surrounds the wire and the sensing chip, a surface of the plastic encapsulation layer on the sensing area is flat, a distance from the surface of the plastic encapsulation layer to the first surface of the sensing chip is a second distance, and the second distance is greater than the first distance.

2. The packaging structure for a fingerprint identification chip according to claim 1, wherein the first distance ranges from 50 micron to 80 micron, and the second distance ranges from 100 micron to 150 micron.

3. The packaging structure for a fingerprint identification chip according to claim 1, wherein a Mohs hardness of the plastic encapsulation layer is greater than or equal to 8H.

4. The packaging structure for a fingerprint identification chip according to claim 1, wherein a dielectric constant of the plastic encapsulation layer ranges from 7 to 9.

5. The packaging structure for a fingerprint identification chip according to claim 1, wherein the plastic encapsulation layer is made of an epoxy resin, a polyimide resin, a benzocyclobutene resin, polybenzoxazole resin, polybutylene terephthalate, a polycarbonate, polyethylene glycol terephthalate, polyethylene, polypropylene, a polyolefin, polyurethane, a polyolefin, a polyethersulfone, a polyamide, a polyurethane, an ethylene vinyl acetate copolymer or a polyvinyl alcohol.

6. The packaging structure for a fingerprint identification chip according to claim 1, further comprising a protecting ring arranged on the substrate surface, wherein the protecting ring surrounds the sensing chip, the wire and the plastic encapsulation layer.

7. The packaging structure for a fingerprint identification chip according to claim 6, wherein the protecting ring is further arranged on the surface of the plastic encapsulation layer, and the plastic encapsulation layer on a surface of the sensing area of the sensing chip is at least exposed from the protecting ring.

8. The packaging structure for a fingerprint identification chip according to claim 7, further comprising a groove arranged in the plastic encapsulation layer around the sensing area, wherein the groove is exposed from a side wall of the plastic encapsulation layer, and part of the protecting ring arranged on the surface of the plastic encapsulation layer is arranged in the groove.

9. The packaging structure for a fingerprint identification chip according to claim 6, wherein a bottom of the protecting ring is fixed on the substrate surface, and the protecting ring is connected to a ground via the substrate.

10. The packaging structure for a fingerprint identification chip according to claim 6, wherein the protecting ring is made of metal.

11. The packaging structure for a fingerprint identification chip according to claim 6, further comprising a housing surrounding the plastic encapsulation layer, the wire, the sensing chip and the protecting ring, wherein the plastic encapsulation layer on a surface of the sensing area is at least exposed from the housing, and a color of the plastic encapsulation layer is the same as a color of the housing.

12. The packaging structure for a fingerprint identification chip according to claim 1, further comprising an adhesive layer arranged between the sensing chip and the substrate, wherein the adhesive layer is configured to fix the sensing chip on the substrate surface.

13. The packaging structure for a fingerprint identification chip according to claim 1, further comprising a glass plate arranged on the surface of the plastic encapsulation layer, wherein the glass plate at least covers the sensing area of the sensing chip.

14. The packaging structure for a fingerprint identification chip according to claim 1, further comprising a housing surrounding the plastic encapsulation layer, the wire and the sensing chip, wherein the plastic encapsulation layer on a surface of the sensing area is exposed from the housing, and a color of the plastic encapsulation layer is the same as a color of the housing.

15. The packaging structure for a fingerprint identification chip according to claim 1, further comprising a connecting part arranged at an end of the substrate, wherein the connecting part is configured to electrically connect the sensing chip with an outside circuit.

16. The packaging structure for a fingerprint identification chip according to claim 1, wherein the substrate is a hard substrate or a soft substrate.

17. A packaging method for forming a packaging structure for a fingerprint identification chip, wherein the packaging structure comprises a substrate, a sensing chip, a wire and a plastic encapsulation layer, and the packaging method comprises:

providing the substrate, wherein the substrate has a substrate surface, and the substrate surface is provided with a first solder pad layer;

fixing the sensing chip on the substrate surface, wherein the sensing chip has a first surface and a second surface arranged opposite to the first surface, the second surface of the sensing chip is arranged on the substrate surface, the first surface of the sensing chip comprises a sensing area and a peripheral area surrounding the sensing area, and the surface of the sensing chip in the peripheral area is provided with a second solder pad layer, the number of the first solder pad layers is the same as the number of the second solder pad layers, a position of the first solder pad layer has a one-to-one correspondence with a position of the second solder pad layer;

forming the wire, wherein two ends of the wire are electrically connected to the first solder pad layer and the second solder pad layer respectively, a point of the wire farthest away from the substrate surface is a vertex, and a distance from the vertex to the first surface of the sensing chip is a first distance; and

forming the plastic encapsulation layer on the substrate surface and the first surface of the sensing chip, wherein the plastic encapsulation layer is made of a polymer, the plastic encapsulation layer surrounds the wire and the sensing chip, a surface of the plastic encapsulation layer on the sensing area is flat, a distance from the surface of the plastic encapsulation layer to the first surface of the sensing chip is a second distance, and the second distance is greater than the first distance.

18. The packaging method for a fingerprint identification chip according to claim 17, wherein a craftwork for forming the plastic encapsulation layer is an injection molding craftwork, a transfer molding craftwork or a silkscreen craftwork.

19. The packaging method for a fingerprint identification chip according to claim 17, wherein after the plastic encapsulation layer is formed, a groove is formed in the plastic encapsulation layer around the sensing area, the groove is exposed from a side wall of the plastic encapsulation layer, a protecting ring is formed on the substrate surface around the plastic encapsulation layer, the wire and the sensing chip, part of the protecting ring is arranged on a surface of the plastic encapsulation layer, the plastic encapsulation layer on a surface of the sensing area of the sensing chip is at least exposed from the protecting ring, and the part of the protecting ring arranged on the surface of the plastic encapsulation layer is arranged in the groove.