TWI250465B - Fingerprint sensor package with electrostatic discharge on chip - Google Patents

Abstract

A fingerprint sensor package with electrostatic discharge on chip mainly includes a substrate, a fingerprint sensor chip, an ESD (electrostatic discharge) bar, and a package body. The fingerprint sensor chip is attached to the substrate. The ESD bar protrudes from the active surface of the fingerprint sensor chip. The package body is formed on the substrate and surrounds the fingerprint sensor chip. The package body is higher than the active surface of the fingerprint sensor chip and partially covers a portion of the active surface so as to connect the ESD bar. Moreover the package body has an opening exposing at least the sensor region of the fingerprint sensor chip on the active surface. The ESD bar is also partially exposed out of the package body along the fringes of the opening to achieve electrostatic discharge on chip.

Description

1250465

V. INSTRUCTIONS (1) [Resistance in the technical field of the invention] § Encapsulation, electrostatic discharge on the seed wafer, her 4" clothing structure, the daily pattern recognizer, and the prior art] The structure of the structure can be miniaturized, so the note type electric pattern is prepared by the conventional touch-sensing package structure system and the slide-type fingerprint is arranged on the pattern identifier and fingerprint identification. The pattern recognition device is made up of a half-conductance sensor attached to various types of brain or PDA handheld computer such as the sensing mode and optical sensing, etc., in a long strip-shaped semiconductor crystal sensing element The fingerprint electrical connection is in the package structure of the appropriate pressure corrector, and the electronic product is used to slide over the sensing area when used, and the package structure can have a comparative structure that has been visible in Europe due to the current fingerprint identifier. , body wafer or glass substrate to reach, j electronic products, such as mobile phones, etc., to identify the user's finger is mainly divided into pressure touch sensing, electrical on the traditional touch-slip fingerprint reader sheet (矽 substrate) Integral After passage identification chip is attached Is provided on a substrate encapsulant mold, to form a tactile fingerprint reader system may be configured to package a finger contacts the fingerprint contact sliding-type identification means, so that the sliding contact type small size. The related art refers to the patent EP 1 3390 09. Referring to FIGS. 1, 2 and 3, a conventional fingerprint identifier package structure 100 mainly includes a substrate 110, a fingerprint identifier wafer 120, a plurality of bonding wires 130, and a stamper formed by a stamper. The fingerprint identifier wafer 120 is a semiconductor wafer fabricated with a fingerprint sensing device, and the fingerprint identifier wafer 120 has an active surface 1 21, a back surface 22, and an active surface 1 2 1 Two corresponding longer sides between the back side 1 22

Page 8 1250465 V. Description of invention (2)

12^ and the corresponding shorter side 124, the active surface 121 includes a sensing ^ 125 'a plurality of sensing devices with pressure sensing or capacitive sensing are provided on the active surface 1 2 1 The upper surface 111 of the substrate 11 is formed with a plurality of connecting fingers 113. Referring to FIG. 2, one of the lower surfaces of the substrate 110 is formed with a plurality of electrical connections to the corresponding connecting fingers. a connection port 114 of the fingerprint identifier, the back surface 122 of the fingerprint identifier wafer 12 is adhered to the upper surface 111 of the substrate by an adhesive tape 5 such as a tape or epoxy glue. The bonding wires 130 are connected to the plurality of pads 126 of the fingerprint reader chip 12 to the connecting fingers 113 of the substrate 11 , and the sealing body 140 covers the bonding wires 13 固定 and fix the fingerprint The identifier wafer 12 is formed on the upper surface 111 of the substrate 11 and surrounds the longer side 123 and the shorter side 124 of the fingerprint identifier wafer 120. The encapsulant 140 has an opening 141 to expose The sensing area 125 of the fingerprint identifier wafer 12 is in the direction of the finger sliding The encapsulant 14 has several known constitutive forms, one of which is a colloidal formation of a conventional fingerprint identifier package structure, which is that the encapsulant 14 〇 corresponds to the fingerprint identifier wafer 120 The side edge 42 of the long side 123 is slightly higher than the active surface 1 21 of the fingerprint identifier wafer 120 (not shown) to cover the active surface of the fingerprint identifier wafer 120. The outer periphery and the sharp edge, but the formation of the sealant is easy to produce a shadow effect, and the correct identification effect cannot be obtained. Another common type is that, referring to Figures 2 and 3, the encapsulant 140 corresponds to the side of the encapsulant 142 of the longer side 123 of the fingerprint reader wafer 12 (i.e., for the sliding side of the fingerprint). The active surface 121 of the fingerprint identifier chip '120 is used to slide the finger of the operator and prevent shadows.

1250465 V. Description of invention (3) Occurs to obtain the correct identification effect. However, the sharp edge 127 of the active surface 121 of the fingerprint reader wafer 120 is also lacking proper protection (as shown in FIG. 3). The wafer protection layer on the active surface 121 during the repeated sliding operation ( The passivation layer (not shown) is easily stripped from the fingerprint reader wafer 120 (pe e 1 - 〇 ff ) and the static electricity is concentrated on the sharp corner of the active surface 121 of the fingerprint reader wafer 120 as the finger slides. The edge 'causes the sensing element to be damaged; in addition, it is known that the sealing body 丨4 〇 is formed by molding, and the higher sealing body 14 容易 is easily formed with a mold flash to contaminate the fingerprint. The sensing region 125 of the identifier wafer 12 is the case. SUMMARY OF THE INVENTION The main object of the present invention is to provide a fingerprint identifier package structure for electrostatic discharge on a wafer, which mainly includes a substrate and a fingerprint identifier (ESD bar, electrostatic discharge bar). And a gel, the fingerprint identifier chip is set. The electrostatic discharge bar is protruded on the moving surface of the fingerprint identifier chip, and the rubber system is formed on the substrate and surrounds the fingerprint reader f, and the sealing system is higher than The active surface of the fingerprint identifier wafer is partially covered to a portion of the active surface, for example, the active surface is in a region with a pad and the encapsulant is connected to the electrostatic discharge strip, and the electrostatic discharge strip portion is exposed The edge of the sealant opening is used to achieve electrostatic discharge on the wafer and there is no problem of waste rubber contamination of the sealant and peeling of the protective layer. The second object of the present invention is to provide a package for electrostatic discharge on a wafer, and a package structure comprising an electrostatic discharge bar.

1250465

5. The fingerprint identifier wafer of the invention (4) and a sealant 2 surrounding the longer side of the fingerprint and the corresponding shorter side; the two correspond to the longer sides and have a higher than Electrostatic discharge; strip ': package f to prevent the waste glue of the sealant from contaminating to the fingerprint identifier crystal J = According to the present invention, an on-wafer electrostatic discharge structure mainly comprises a buckle identifier encapsulating the substrate to the crepe recognizer The wafer, an ESD bar and a gel, the fingerprint identifies the upper surface of the electrostatic discharge substrate and is electrically connected to the substrate: ", the moving surface and a corresponding, the back, the active : a package/product, the electrostatic discharge strip is protruded from the fingerprint identifier wafer: =, the encapsulation system is formed on the upper surface of the substrate and surrounds the fingerprint reader wafer, and the encapsulation system is partially covered to The active surface includes a pad portion connected to the electrostatic discharge strip. Further, the body is open to expose at least the sensing region of the fingerprint reader chip, and the electrostatic discharge strip portion is exposed at the edge of the opening. [Embodiment] The present invention will be described by way of the following examples. According to an embodiment of the present invention, FIG. 4 is a top plan view of a fingerprint identifier package structure 200, which is a cross section of the fingerprint identifier package structure 200 along line 5-5 of FIG. FIG. 6 is a schematic cross-sectional view of the package structure 20 0 along the line 6-6 of FIG. 4 . Referring to FIGS. 4 and 5 , the fingerprint identifier package structure 2 includes a substrate. 21〇, a fingerprint identifier wafer 220, an electrostatic discharge strip 230 (ESD ^ar) Ι^βΠΗΙ page 11 1250465 5. Invention description (5) and a colloid 250. Referring to FIG. 5, the substrate 210 can be a double-sided electrically conductive hard circuit board, such as a multilayer printed circuit board or a multilayer ceramic circuit board, having an upper surface 211 and a lower surface 212, in this embodiment. The substrate 210 is an LGA (Land Grid Array) package substrate. The upper surface 21 1 is formed with a plurality of connection fingers 2 1 3 , and the lower surface 21 2 is formed with a plurality of connections. Pads 2 1 4, the connecting fingers 21 3 are electrically connected to the connecting pads 2丨4 (not shown) corresponding to the internal lines of the substrate 210. Referring to Figures 4, 5 and 6, the fingerprint identifier wafer 22 is disposed on the upper surface 211 of the substrate 210. The fingerprint identifier wafer 2 1 has an active surface 221 and a corresponding surface. The back surface 222 and the plurality of longer side surfaces 223 and the corresponding shorter side surfaces 224 between the active surface 221 and the back surface 222, refer to FIG. 7 , the active surface 221 includes a sensing region 225 . a plurality of fingerprint sensing elements (not shown) are disposed, and a plurality of pads 2 26 are formed on the outer side of the sensing area 2 2 5 of the active surface 21, in this embodiment, The pads 226 are adjacent to the shorter side 224 and include at least one ground pad. The back surface 222 of the fingerprint identifier wafer 22 is attached to the upper surface 211 of the substrate 2 by a die bond 215, and is connected by a plurality of bonding wires 240 or other conventional electrical connecting components such as TAB wires. The pads 226 of the fingerprint reader chip 220 and the connection pads 213 of the substrate 21 are electrically connected to the fingerprint identifier wafer 22 and the substrate 2 . Referring to FIG. 8, before the encapsulation operation, the active surface 221 of the fingerprint identifier 曰曰 220 defines a revealing area boundary 227, bounded & =

Page 12 1250465 V. Description of the Invention (6) The exposed area of the active surface 221 of the reticle disc 220 and the area covered by the encapsulant 250, the exposed area within the exposed area boundary 227 includes at least the sensing area 2 2 5, the coverage area outside the boundary of the exposed area 2 2 7 includes the pads 226 such that the encapsulant 250 partially covers a predetermined portion of the active surface 221 'that is, covering the solder pads 2 2 6 reveals the sensing area 2 2 5 . The electrostatic discharge strip 230 is preliminarily disposed on the active surface 221 of the fingerprint identifier wafer 220. In the embodiment, the electrostatic discharge strip 230 is a gold bar (Au bar) protruding from Preferably, the height of the active surface 221 is between 15 and 25 /zm, and the electrostatic discharge strip 23() is disposed around the active surface 221 along the display path 227. To highlight the closed loop of the active surface 2 21 to circle the sensing region 2 2 5 ; or, in various embodiments, the electrostatic discharge strip 230 may also be a straight strip or other discontinuous geometry The pattern is disposed on the two longer corresponding sides of the fingerprint reader chip 22 for the finger to slide. Referring to FIG. 8 again, in the embodiment, the fingerprint identifier chip 220 is further fabricated with a plurality of metal bumps 231 such as gold, and the metal bumps 231 are transmitted through one of the active surfaces 221 . The grounding pad 226 is electrically coupled to the ground pad of the substrate 21 to discharge static electricity around the sensing region 225. The electrostatic discharge bar 23 and the fingerprint identifier chip 220 are plural, such as gold. The metal bump 231 is formed in the electroplating process of a wafer, and the electrostatic discharge strip 23 and the metal bump 231 are simultaneously disposed on the active surface of the fingerprint identifier wafer 22 * Synchronously formed in the 1 & mask process, so the electrostatic discharge strip 230, 'does not increase the cost of the fingerprint identifier wafer 220, and preferably, in the same wafer process, an electrostatic discharge strip 23〇 Cross

iMi Page 13 1250465 V. INSTRUCTIONS (7) The dicing line of the wafer is formed between two adjacent fingerprint reader wafers 2 2 ' 'The electrostatic discharge strip 2 3 〇 will be extended to after the wafer is diced The upper side of the longer side 2 2 3 of the fingerprint reader wafer 220 is used for the purpose of simple fabrication. Referring to the drawings 4 and 5, the encapsulant 250 is formed on the upper surface 211 of the substrate 210 and surrounds the fingerprint identifier wafer 2 2 〇, and the encapsulant 250 can be formed by stamping. The encapsulant 25 is covered to the four longer sides 2 2 3 and the shorter side 2 2 4 , and the encapsulant 250 is higher than the active surface 221 of the fingerprint reader wafer 220 to partially cover A portion of the pads 226 is included in the active surface 221 and an opening 251 is formed in the active surface 221. Referring to FIG. 5 , the encapsulant 25 is coated on the shorter sides 224 and has a height 253 higher than the short side of the active surface 221 , which is higher than the height difference of the active surface 221 . Between 5 〇 and 1 〇〇, to cover the solder pads 214 and the bonding wires 24 〇; referring to FIG. 6 , the encapsulant 2 50 is coated on the longer sides 223 and has three The height 252 of the electrostatic discharge strip 230 is higher than the height 252 of the electrostatic discharge strip 230 to avoid contamination of the sensing strip 225 by the stamper 200, but the long side height 252 of the sealant 250 should still be Slightly above the active surface 221 to prevent the protective layer on the active surface 221 of the fingerprint reader wafer 22 from peeling off after a plurality of slidings of the hand/finger. In addition, the encapsulant 25Q is connected to the electrostatic discharge strip '230, and the opening 251 of the encapsulant 250 corresponds to the exposed area boundary 227 to expose at least the sensing area of the fingerprint identifier wafer 22 In any case, the opening 251 is formed by attaching a release film to the sensing region 225 of the fingerprint reader wafer 220 during compression molding.

1250465 V. Inventive Note (8), to prevent the stamper mold from crushing the sensing area 225 and facilitating demolding, and removing the release film after the stamper to form the opening 250 of the sealant 25 And the electrostatic discharge strip 230 is partially exposed at the edge of the opening 251. In the process of forming the encapsulant 250 by the stamper, the electrostatic discharge strip 230 can be connected to the metal bumps 231, and the electrostatic discharge strip 230 can be grounded through the active surface 221. 226 is electrically coupled to the ground pad of the base plate 210. 1

Therefore, in the above-mentioned fingerprint identifier package structure 2, the electrostatic discharge strip 230 protruded from the active surface 221 of the fingerprint identifier wafer 220, and the encapsulant 250 partially covers the active surface 221 One of them ^ preview. The clamping position (up to the exposed area boundary 227) is connected to the electrostatic discharge strip 2 3 0 ' such that the electrostatic discharge strip 2 3 〇 portion is exposed on the side of the opening 2 5 1

The edge reaches the electrostatic discharge effect on the active surface 221 of the fingerprint identifier wafer 220. During each finger touch to identify the fingerprint, any improper I set on the fingerprint identifier wafer 220 generates static electricity. The electrostatic discharge strip 230 can be smoothly derived. In addition, a protective layer on the active surface 221 of the fingerprint reader chip 2 2 is covered by the encapsulant 25 on the side of the edge of the active surface 221, which is not easy to be covered. Stripped $ icon. Furthermore, the electrostatic discharge strip 203 is protruded from the active surface 221 of the fingerprint identifier wafer 220, so that the sealant 25 〇 is coated on the edge of the active surface 21, but the stamper is pressed. Under the blockage of the electrostatic discharge strip 230, it is still not easy to overflow the sensing area 225 of the fingerprint identifier wafer 22A. The scope of protection of the present invention is defined by the scope of the appended patent application.

Page 15 1250465

Page 16 1250465 Brief description of the drawing [Simplified description of the drawing Figure 1] The second figure of the conventional fingerprint identifier package structure. The conventional fingerprint identifier sealing structure is intentional; Figure 3 · Conventional fingerprint identification Illustrated in accordance with the present invention; FIG. 5 is a schematic cross-sectional view of a line according to the present invention; FIG. 6 is a schematic cross-sectional view of a line according to the present invention; According to the invention, the main identifier of the main identifier of the fingerprint identifier wafer after the electrostatic discharge strip is fabricated is as follows: 10 0 fingerprint Identifier package structure 110 substrate 111 upper surface 113 connection finger 114 connection pad 120 fingerprint identifier wafer 121 ^ movable surface 122 back surface 123 long side surface 124 short side top surface schematic view, the first Figure 2-2 line section shows the first 3-3 is a cross-sectional view showing a fingerprint identifier package structure showing the fingerprint identifier package structure along the fourth figure 5-5 5H fingerprint identifier package structure along the fourth figure 6-6 of the fingerprint identifier package Constructed fingerprint identification surface It is intended; fingerprint surface and the package structure of FIG. 11 2 lower surface 11 5 adhesive glue 1 2 5 sensing area page 17 1250465 simple illustration 126 fresh 塾 127 sharp edge 140 encapsulant 141 opening 200 fingerprint identifier package construction 210 substrate 211 upper surface 213 connection finger 214 Connection pad 220 fingerprint identifier wafer 221 active surface 222 back 1 3 0 wire 142 side 212 lower surface 2 1 5 adhesive 223 longer side 2 2 6 fresh 塾 230 electrostatic discharge strip 250 sealant 2 5 3 short side Height 224 shorter side 227 exposed area boundary 2 31 metal bump 251 opening 225 sensing area 240 bond line 252 long side height

Page 18

Claims (1)

1250465 VI. Patent Application Range [Shenzhen Patent Range] 1. A fingerprint identifier package structure for electrostatic discharge on a wafer, comprising: a substrate having an upper surface; and a fingerprint identifier wafer mounted on the substrate The upper surface is electrically connected to the substrate, the fingerprint identifier chip has an active surface and a corresponding back surface, the active surface includes a sensing area; an electrostatic discharge strip (ESD bar), the system is protruding Provided on the active surface of the fingerprint identifier chip; and A gel is formed on the upper surface of the substrate and surrounds the fingerprint identifier wafer, the encapsulation system partially covering the active surface and connected to the electrostatic discharge strip. 2. The fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 1, wherein the sealant system has an opening to expose at least the sensing region, and the electrostatic discharge strip portion is exposed The edge of the opening. 3. The fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 1, wherein the electrostatic discharge strip is a gold bar (Au bar). 4. The fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 1, wherein the height of the electrostatic discharge strip is between 15 and 25 // m 〇 5, as in claim 1 A fingerprint identifier package structure for electrostatic discharge on a wafer, wherein the electrostatic discharge strip is disposed on at least two corresponding sides of the active surface. The invention relates to a fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 1, wherein the electrostatic discharge strip is disposed around the active surface. 7. The fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 6, wherein the electrostatic discharge strip is a closed loop. 8. The fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 6, wherein the electrostatic discharge strip is discontinuous. 9. The fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 1, further comprising a plurality of metal bumps disposed on an active surface of the fingerprint identifier chip. The fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 9, wherein the electrostatic discharge strip is in contact with the metal bumps. 11. The fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 9, wherein the metal bumps are electrically coupled to the ground pad of the substrate through a pad on the active surface. The fingerprint identifier package structure for electrostatic discharge on a wafer according to claim 1, wherein the fingerprint identifier chip has a plurality of sides between the active surface and the back surface, Covered with a sealant. 1 . The fingerprint identifier package structure of the electrostatic discharge on a wafer according to claim 1 wherein the fingerprint identifier wafer has two corresponding longer sides and two between the active surface and the back surface. Corresponding to the shorter side, the encapsulation system is coated on the longer sides and has a height not higher than the long side of the electrostatic discharge strip. Page 20, 1250465 6. Patent Application U. The invention relates to an electrostatic discharge on a wafer as described in claim 13 of the patent application, wherein the encapsulation system is coated on the shorter sides. A height higher than the short side of the active surface, the difference between the two degrees higher than the active surface is between 50 and 100 //m. The method of electrostatic discharge according to claim 1 or claim 4, further comprising a plurality of bonding wires for electrically connecting the identifier wafer to the substrate And is sealed and coated in the sealant body. A wafer assembly for identifying 16 patterns, comprising: a surface > a buckle identifier wafer having an active surface and a corresponding back surface; the active surface layer comprising a sensing region and a plurality of pads; and An electrostatic discharge strip (ESD bar), which is provided on the active surface of the fingerprint identifier 曰 片 ^ ^ ^ ^ ^ ^ ^ ^ 如 如 , , , , , , , , , , , , It is a gold bar (Au bar). 1 Second like:! The chip set & of the fingerprint identifier of claim 16 wherein the height of the electrostatic discharge strip is between 15 and 25. The chip set & of the fingerprint identifier of claim 16, wherein the electrostatic discharge strip is a closed loop. 20. The fingerprint identification writing component of claim 19, wherein the electrostatic discharge strip surrounds the sensing area. ... around the active surface of the sea, 21, as described in claim 16 of the scope of the patent application, wherein the soldering systems comprise at least one grounding welding two; static electricity: Μ Page 21 1250465 VI. Patent Application Range Electrical strips are electrically coupled to the ground pad. 2. The wafer assembly of the fingerprint reader of claim 16 or claim 2, further comprising a plurality of metal bumps disposed on the active surface of the fingerprint identifier chip. 23. The chip set of the fingerprint identifier according to claim 22, wherein the metal bumps are electrically connected to the ground pad. Joint 'long τ Page 22