Utility model content
The problem that the utility model solves is to provide a kind of fingerprint recognition chip-packaging structure, and described encapsulating structure can reduce the requirement of induction chip sensitivity, applies more extensive.
For addressing the above problem, the utility model provides a kind of fingerprint recognition chip-packaging structure, comprising: substrate; Be coupled in the induction chip of substrate surface, described induction chip has first surface and the second surface relative with first surface, and the first surface of described induction chip has induction zone, and the second surface of described induction chip is positioned at substrate surface; At least be positioned at the upper cap rock on the surface, induction zone of induction chip, the material of described upper cap rock is polymer; Be positioned at the plastic packaging layer on substrate and induction chip surface, described plastic packaging layer exposes described upper cap rock.
Optionally, the thickness of described upper cap rock is 20 microns～100 microns.
Optionally, in described upper cap rock, have photosensitive particle, the size of described photosensitive particle is less than 6 microns.
Optionally, the first surface of described induction chip also comprises: the external zones that surrounds described induction zone.
Optionally, described induction chip also comprises: be positioned at described external zones and have edge groove, the sidewall of described induction chip exposes described groove; Be positioned at the chip circuit of induction chip external zones, described chip circuit is positioned at the surface, external zones of induction chip and sidewall and the lower surface of groove, and the segment chip circuit that is positioned at bottom portion of groove has the first link.
Optionally, described edge groove is to surround the continuous groove of induction zone; Or described edge groove is to surround the some discrete groove of induction zone.
Optionally, described substrate has first surface, and described induction chip is coupled in the first surface of substrate, and the first surface of described substrate has the second link.
Optionally, also comprise: conductor wire, described conductor wire two ends are connected with the second link with the first link respectively.
Optionally, also comprise: be positioned at the conductive layer of induction chip sidewall surfaces, substrate first surface and edge groove, described conductive layer two ends are connected with the first link and the second link respectively.
Optionally, also comprise: the first tack coat between induction chip and substrate.
Optionally, described induction chip also comprises: run through the conductive plunger of described induction chip, the second surface of described induction chip exposes described conductive plunger, and one end of described conductive plunger is connected with the first link; The solder layer that is positioned at the conductive plunger top that induction chip second surface exposes, described solder layer is welded in the second link surface.
Optionally, also comprise: be positioned at the guard ring of substrate surface, described guard ring surrounds described induction chip, upper cap rock and plastic packaging layer.
Optionally, described guard ring is by described substrate ground connection.
Optionally, also comprise: surround the shell of described plastic packaging layer, induction chip and guard ring, described shell exposes described upper cap rock.
Optionally, also comprise: surround the shell of described plastic packaging layer and induction chip, described shell exposes described upper cap rock.
Optionally, one end of described substrate has connecting portion, and described connecting portion is used for making induction chip to be electrically connected with external circuit.
Compared with prior art, the technical solution of the utility model has the following advantages:
In encapsulating structure of the present utility model, the second surface of described induction chip is coupled in substrate surface, and the first surface of described induction chip has induction zone, and described induction zone is used for extracting user fingerprints; The surface, induction zone of described induction chip has upper cap rock; described upper cap rock is for the protection of the induction zone of induction chip; user's finger is placed in described upper cap rock surface, can make induction zone extract user fingerprints, and induction chip can be converted to described user fingerprints signal of telecommunication output.Because the material of described upper cap rock is polymer, and polymeric material has good ductility and pliability, and covering power is good, therefore, the described thinner thickness that can make cap rock, and hardness is higher, thus make described upper cap rock there is enough large hardness with protection induction chip; Simultaneously, described upper cap rock surface reduces to the distance of induction chip, makes induction chip be easy to detect user fingerprints, correspondingly, described encapsulating structure can reduce the requirement to induction chip sensitivity, makes the application of encapsulating structure of fingerprint recognition chip more extensive.And the material of described upper cap rock is polymer, make the cost of described upper cap rock low, reduce the manufacturing cost of encapsulating structure.
Further, the thickness of described upper cap rock is 20 microns～100 microns; The Mohs' hardness of described upper cap rock is more than or equal to 8H; The dielectric constant of described upper cap rock is more than or equal to 7.Wherein, the thinner thickness of described upper cap rock, and hardness is larger, and described upper cap rock has the induction zone of enough large hardness with protection induction chip; make described induction chip the user fingerprints that is placed in cap rock surface more easily be detected simultaneously, reduced the requirement to induction chip sensitivity.The dielectric constant of described upper cap rock is larger, makes the electric isolation performance of described upper cap rock better, makes described upper cap rock better to the protective capability of induction chip induction zone.
Further, described substrate surface also has the guard ring that surrounds described induction chip, upper cap rock and plastic packaging layer.Described guard ring is for carrying out electrostatic defending to described induction chip; avoid the user fingerprints data accuracy that induction zone detects to decline; or can eliminate the signal noise of induction chip output, make the signal of data that induction chip detects and output more accurate.
Embodiment
As stated in the Background Art, in existing fingerprint recognition device, the sensitivity of fingerprint recognition chip is had relatively high expectations, the manufacture of fingerprint recognition device and application are restricted.
Find through research; please continue to refer to Fig. 1; fingerprint recognition chip 101 surface coverage have glass substrate 102; described glass substrate 102 is for the protection of fingerprint recognition chip 101; and user's finger 103 directly contacts with described glass substrate 102; therefore,, in order to ensure that described glass substrate 102 has enough protective capabilities, the thickness of described glass substrate 102 is thicker.But, because the thickness of described glass substrate 102 is thicker, therefore require fingerprint recognition chip 101 to there is higher sensitivity, to guarantee accurately to extract user fingerprints.But highly sensitive fingerprint recognition chip manufacturing difficulty is large, manufacturing cost is higher, then causes the application of fingerprint recognition chip and popularization to be restricted.
Concrete, continue taking capacitance type fingerprint recognition means as example, when user's finger puts 103 during in glass substrate 102 surface, user points 103, and fingerprint recognition chip 101 in capacitor plate between can form electric capacity; Wherein, described user points 103 and the capacitor plate the two poles of the earth that are electric capacity, and described glass substrate 102 is the dielectric between electric capacity the two poles of the earth.But, because the thickness of described glass substrate 102 is thicker, make user point 103 and capacity substrate between capacitance larger, and that user points difference in height between 103 ridge and paddy is less, therefore, capacitance between described ridge and capacitor plate, minimum with respect to the difference between the capacitance between described paddy and capacitor plate, in order the difference of described capacitance accurately to be detected, requires described fingerprint recognition chip 101 to have higher sensitivity.
In order to address the above problem, the utility model proposes a kind of encapsulating structure of fingerprint recognition chip.Wherein, in described encapsulating structure, the induction zone surface coverage of induction chip has upper cap rock, and described upper cap rock has substituted traditional glass substrate, can be directly and user's finger contacts, and for the protection of induction chip.Because the material of described upper cap rock is polymer, and polymeric material has good ductility and pliability, can make thinner thickness and the hardness of described upper cap rock higher, in on described, cap rock is enough to protect induction chip, described upper cap rock surface reduces to the distance of induction chip, thereby makes induction chip be easy to detect user fingerprints; Correspondingly, described encapsulating structure has reduced the requirement to induction chip sensitivity, makes the application of encapsulating structure of fingerprint recognition chip more extensive.
For above-mentioned purpose of the present utility model, feature and advantage can more be become apparent, below in conjunction with accompanying drawing, specific embodiment of the utility model is described in detail.
Fig. 2 to Fig. 6 is the schematic diagram of the encapsulating structure of the fingerprint recognition chip of the utility model embodiment.
Please refer to Fig. 2, the encapsulating structure of described fingerprint recognition chip comprises:
Substrate 200;
Be coupled in the induction chip 201 on substrate 200 surfaces, described induction chip 201 has first surface 210 and the second surface 220 relative with first surface 210, the first surface 210 of described induction chip 201 has induction zone 211, and the second surface 220 of described induction chip 201 is positioned at substrate 200 surfaces;
The upper cap rock 202 that is at least positioned at 211 surfaces, induction zone of induction chip 201, the material of described upper cap rock 202 is polymer;
The plastic packaging layer 203 that is positioned at substrate 200 and induction chip 201 surfaces, described plastic packaging layer 203 exposes described upper cap rock 202.
To the encapsulating structure of above-mentioned fingerprint recognition chip be elaborated below.
Described substrate 200 is for fixing described induction chip 201, and described induction chip 201 is electrically connected with other device or circuit.Described substrate 200 is rigid substrate or flexible base plate, and device or terminal that described induction chip 201 can be set are as required adjusted; In the present embodiment, described substrate 200 is rigid substrate, and described rigid substrate is PCB substrate, glass substrate, metal substrate, semiconductor substrate or polymeric substrates.
Described substrate 200 has first surface 230, and described induction chip 201 is coupled in the first surface 230 of substrate 200.The first surface 230 of described substrate 200 has wiring layer (not shown), and described wiring layer is connected with the second link 205 that is positioned at substrate 200 first surfaces 230, described the second link 205 is for being connected with the chip circuit on induction chip 201 surfaces.
In the present embodiment, one end of described substrate 200 has connecting portion 204, the material of described connecting portion 204 comprises electric conducting material, connecting portion 204 is electrically connected with described wiring layer, thereby described chip circuit can be electrically connected with external circuit or device by wiring layer and the connecting portion 204 of substrate 200 first surfaces 230, thereby realize the transmission of the signal of telecommunication.
The induction zone 211 that is positioned at induction chip 201 first surfaces 210 for detection of with the finger print information that receives user, in described induction zone 211, can have capacitance structure or have induction structure, described capacitance structure or induction structure can be used in the user fingerprints information of obtaining.
In the present embodiment, in described induction zone 211, there is at least one capacitor plate, in the time that user's finger is placed in upper cap rock 202 surface, described capacitor plate, upper cap rock 202 and user point formation capacitance structure, and described induction zone 211 can obtain the capacitance difference between user's finger surface ridge and paddy and capacitor plate, and output after described capacitance difference is processed by chip circuit, obtain user fingerprints data with this.
The first surface 210 of described induction chip 201 also comprises the external zones 212 that surrounds described induction zone 211, the external zones 212 of described induction chip 201 first surfaces 210 has chip circuit (not indicating), described chip circuit is electrically connected with capacitance structure or induction structure in induction zone 211, for the signal of telecommunication of capacitance structure or induction structure output is processed.
Described induction chip 201 also comprises: be positioned at described external zones 212 and have edge groove 206, the sidewall of described induction chip 201 exposes described groove 206; The chip circuit that is positioned at induction chip 201 external zoness 212 is also positioned at sidewall and the lower surface of described groove 206, and the segment chip circuit that is positioned at groove 206 bottoms is connected to the first link 207.
Described edge groove 206, is used to form the output of chip circuit, i.e. described the first link 207, by the first link 207 is electrically connected with second link 205 on substrate 200 surfaces, can be realized the coupling of induction chip 201 and substrate 200.
In one embodiment, described edge groove 206 is for surrounding the continuous groove of induction zone 211, and described continuous edge groove 206 lower surface have one or several the first links 207; In another embodiment, the some discrete groove that described edge groove 206 is encirclement induction zone 211, and in each edge groove 206, there are one or several the first links 207.The quantity of described the first link 207 and distribution need design according to the physical circuit wiring of chip circuit.
In the present embodiment, the sidewall of described edge groove 206 is with respect to the surface tilt of induction chip 201, and the angle between sidewall and the bottom of described edge groove 206 in obtuse angle, edge groove 206 sidewall surfaces of described inclination are easy to form chip circuit, with the wiring between these induction zone 211 to first links 207.
Described upper cap rock 202 covers the induction zone 211 of induction chip 201, and described upper cap rock 202 can also external zones 212 around, induction zone, cover part 211.The material of described upper cap rock 202 is polymeric material; and polymeric material has good pliability, ductility and covering power; therefore can make the thinner thickness of described upper cap rock 202; can ensure that described upper cap rock 202 has higher hardness simultaneously; thereby strengthen the sensing capability of induction chip 201 to user's finger print, can ensure the protective capability of cap rock 202 to induction zone 211 simultaneously.
The thickness of described upper cap rock 202 is 20 microns～100 microns, the thinner thickness of described upper cap rock 202, in the time that user's finger is placed in described upper cap rock 202 surface, described finger reduces to the distance of induction zone 211, therefore, induction zone 211 more easily detects the fingerprint that user points, thereby has reduced the highly sensitive requirement of induction chip 201.
In the present embodiment, in described induction zone 211, there is capacitor plate, due to upper cap rock 202 thinner thicknesses, make user point distance between capacitor plate shorter, the capacitance between user's finger and capacitor plate is less, accordingly, capacitance between ridge and the capacity substrate of user's finger surface, differ greatly with respect to the capacitance between paddy and capacity substrate, make described induction zone 211 be easy to the finger print information that detects that user points.
The Mohs' hardness of described upper cap rock 202 is more than or equal to 8H; the hardness of described upper cap rock 202 is higher; therefore; even the thinner thickness of described upper cap rock 202; described upper cap rock 202 is also enough to protect the induction zone 211 of induction chip 201; when damage when mobile, can not caused to induction chip 201 in user finger cap rock 202 surfaces on described.And, because the hardness of described upper cap rock 202 is higher, therefore described upper cap rock 202 is difficult to occur deformation, even user's finger presses and described upper cap rock 202 surfaces, the thickness of described upper cap rock 202 is also difficult to change, thereby has ensured the testing result accuracy of induction zone 211.
The dielectric constant of described upper cap rock 202 is more than or equal to 7, and the electric isolating power of described upper cap rock 202 is stronger, and described upper cap rock 202 is stronger to the protective capability of induction zone 211.
In the present embodiment, due to the thinner thickness of upper cap rock 202, and capacitance between user finger and capacitor plate and the thickness of upper cap rock 202 are inversely proportional to, be directly proportional to the dielectric constant of upper cap rock 202, therefore, when the thinner thickness of upper cap rock 202, and dielectric constant is when larger, can make user point in the scope that the capacitance between capacitor plate can detect in induction zone 211, avoid capacitance excessive or too small and the detection of induction zone 211 was lost efficacy.
And, when the thickness of upper cap rock 202 is in the scope of 20 microns～100 microns, and dielectric constant is in the scope that is more than or equal to 7 time, along with the thickness of upper cap rock 202 increases, the dielectric constant of upper cap rock 202 is corresponding increase also, can be in a stable and detectable scope in induction zone 211 to make user point capacitance between capacitor plate.
The material of described upper cap rock 202 is epoxy resin, polyimide resin, benzocyclobutane olefine resin, polybenzoxazoles resin, polybutylene terephthalate, Merlon, PETG, polyethylene, polypropylene, polyolefin, polyurethane, polyolefin, polyether sulfone, polyamide, polyurethane, ethylene-vinyl acetate copolymer, polyvinyl alcohol or other suitable polymeric materials.
In the present embodiment, described polymeric material is light-sensitive material, has photosensitive particle in described polymeric material, and described photosensitive particle can make polymeric material can be exposed development, and realizes graphical.The size of described photosensitive particle is less than 6 microns, and the size that makes the upper cap rock 202 that described polymeric material forms afterwards in exposure accurately and be easy to control.
In the present embodiment, fingerprint recognition chip-packaging structure also comprises: conductor wire 208, described conductor wire 208 two ends are connected with the second link 205 with the first link 207 respectively, thereby chip circuit is electrically connected with the wiring layer on substrate 200 surfaces, and described wiring layer is electrically connected with connecting portion 204, thereby make the chip circuit on induction chip 201 surfaces and induction zone 211 carry out the transmission of the signal of telecommunication with external circuit or device.The material of described conductor wire 208 is metal, and described metal is copper, tungsten, aluminium, gold or silver-colored.
In the present embodiment, between the first link 207 and the second link 205, connect by conductor wire 208, therefore the encapsulating structure of described fingerprint recognition chip also comprises: the first tack coat 301 between induction chip 201 and substrate 200, and for induction chip 201 being fixed on to the first surface 230 of substrate 200.
In the present embodiment, the encapsulating structure of described fingerprint recognition chip also comprises: be positioned at the guard ring 209 on substrate 200 surfaces, described guard ring 209 surrounds described induction chip 201, upper cap rock 202 and plastic packaging layer 203.The material of described guard ring 209 is metal, and described guard ring 209 is by described substrate 200 ground connection, and described guard ring 209 is fixed on the first surface 230 of substrate 200.
In the present embodiment, described guard ring 209 is positioned at around induction chip 201, upper cap rock 202 and plastic packaging layer 203, is covered in part plastic packaging layer 203 top, and exposes cap rock 202 surfaces.In another embodiment, guard ring is only positioned at induction chip 201 and plastic packaging layer 203 around, and exposes the surface of plastic packaging layer 203 and upper cap rock 202.
The material of described guard ring 209 is metal, and described metal is copper, tungsten, aluminium, silver or golden.Described guard ring 209 is for carrying out electrostatic defending to described induction chip; because described guard ring 209 is metal; described guard ring 209 can conduct electricity; when user finger produces static when cap rock 202 in contact; first electrostatic charge can reach substrate 200 from described guard ring 209; thereby avoid cap rock 202 to be punctured by excessive electrostatic potential; protect induction chip 201 with this; improve the accuracy of fingerprint detection; eliminate the signal noise of induction chip output, make the signal of induction chip output more accurate.
In one embodiment, please refer to Fig. 3, the encapsulating structure of fingerprint recognition chip also comprises: the conductive layer 303 that is positioned at induction chip 201 sidewall surfaces, substrate 200 first surfaces 210 and edge groove 206, described conductive layer 303 two ends are connected with the first link 207 and the second link 205 respectively, to realize being electrically connected between induction zone 211 and chip circuit and substrate 200 surface wiring layers.The encapsulating structure of described fingerprint recognition chip also comprises: the first tack coat 301 between induction chip 201 and substrate 200.
In another embodiment, please refer to Fig. 4, in described induction chip 201, also have the conductive plunger 304 that runs through described induction chip 201, the second surface 220 of described induction chip 201 exposes described conductive plunger 304, and one end of described conductive plunger 304 is connected with the first link 207; The solder layer 305 that is positioned at conductive plunger 304 tops that induction chip 201 second surfaces 220 expose, described solder layer 305 is welded in the second link 205 surfaces, make to realize induction zone 211 and chip circuit, and substrate 200 surface wiring layers between be electrically connected.Because described induction chip 201 is welded in substrate 200 first surfaces 230 by solder layer 305, make described induction chip 201 fixing with respect to substrate 200.
In the present embodiment; please refer to Fig. 5; the encapsulating structure of described fingerprint recognition chip also comprises: the shell 400 that surrounds described plastic packaging layer 203, induction chip 201 and guard ring 209; described shell 400 exposes described upper cap rock 202; user is pointed and can touch described upper cap rock 202 surfaces, to carry out fingerprint detection.The solid colour of the color of described upper cap rock 202 and described shell 400, for example, in the time that shell 400 colors are black, the color of described upper cap rock 202 is black, in the time that shell 400 colors are white, described upper cap rock 202 colors are white, and the encapsulating structure overall appearance of fingerprint recognition chip is coordinated.
In another embodiment; please refer to Fig. 6; the encapsulating structure of described fingerprint recognition chip does not comprise above-mentioned guard ring 209; the encapsulating structure of described fingerprint recognition chip comprises: the shell that surrounds described plastic packaging layer 203 and induction chip 201; described shell 400 exposes described upper cap rock 202, the solid colour of the color of described upper cap rock 202 and described shell 400.
In the present embodiment, the second surface of described induction chip is coupled in substrate surface, and the first surface of described induction chip has induction zone, and described induction zone is used for extracting user fingerprints; The surface, induction zone of described induction chip has upper cap rock; described upper cap rock is for the protection of the induction zone of induction chip; user's finger is placed in described upper cap rock surface, can make induction zone extract user fingerprints, and induction chip can be converted to described user fingerprints signal of telecommunication output.Because the material of described upper cap rock is polymer, and polymeric material has good ductility and pliability, and covering power is good, therefore, the described thinner thickness that can make cap rock, and hardness is higher, thus make described upper cap rock there is enough large hardness with protection induction chip; Simultaneously, described upper cap rock surface reduces to the distance of induction chip, makes induction chip be easy to detect user fingerprints, correspondingly, described encapsulating structure can reduce the requirement to induction chip sensitivity, makes the application of encapsulating structure of fingerprint recognition chip more extensive.And the material of described upper cap rock is polymer, make the cost of described upper cap rock low, reduce the manufacturing cost of encapsulating structure.
Accordingly, the utility model embodiment also provides a kind of method for packing that forms above-mentioned fingerprint recognition chip-packaging structure, as shown in Fig. 7 to Figure 12.
Please refer to Fig. 7, substrate 200 is provided.
Described substrate 200 is rigid substrate or flexible base plate, and device or terminal that described induction chip 201 can be set are as required adjusted; In the present embodiment, described substrate 200 is rigid substrate, and described rigid substrate is PCB substrate, glass substrate, metal substrate, semiconductor substrate or polymeric substrates.
Described substrate 200 has first surface 230, and described first surface 230 is for the follow-up induction chip that is coupled.Form wiring layer and the second link 205 at the first surface 230 of described substrate 200, described wiring layer is connected with described the second link 205.
In the present embodiment, form connecting portion 204 in one end of substrate 200, the material of described connecting portion 204 comprises electric conducting material, and described wiring layer is connected to described connecting portion 204, thereby wiring layer and the second link can be electrically connected with external circuit or device.
Please refer to Fig. 8, at the fixing induction chip 201 of first surface 230 of described substrate 200, described induction chip 201 has first surface 210 and the second surface 220 relative with first surface 210, the first surface 210 of described induction chip 201 has induction zone 211, and the second surface 220 of described induction chip 201 is positioned at substrate 200 surfaces.
Induction zone 211 for detection of with receive user's finger print information, in described induction zone 211, can there is capacitance structure or there is induction structure, described capacitance structure or induction structure can be used in the user fingerprints information of obtaining.
In the present embodiment, in described induction zone 211, be formed with at least one capacitor plate, in the time that user's finger is placed in upper cap rock 202 surface, described capacitor plate, upper cap rock 202 and user point formation capacitance structure, and described induction zone 211 can obtain the capacitance difference between user's finger surface ridge and paddy and capacitor plate, and output after described capacitance difference is processed by chip circuit, obtain user fingerprints data with this.
Described induction chip 201 also comprises: the external zones 212 that surrounds described induction zone 211.In the external zones 212 of described induction chip 201, be formed with edge groove 206, the sidewall of described induction chip 201 exposes described groove 206; Form the first link 207 in described groove 206 bottoms; First surface 210 at induction chip 201 forms chip circuit, and described chip circuit extends in described groove 206, and is connected the output that described the first link 207 is chip circuit with the first link 207.
In one embodiment, described edge groove 206, for surrounding the continuous groove of induction zone 211, forms one or several the first links 207 in described continuous edge groove 206 lower surface.In another embodiment, the some discrete groove that described edge groove 206 is encirclement induction zone 211, and in each edge groove 206, be formed with one or several the first links 207.
In the present embodiment, the sidewall of described edge groove 206 is with respect to the surface tilt of induction chip 201, and angle between sidewall and the bottom of described edge groove 206 in obtuse angle.In the time of described edge groove 206 interior formation chip circuit, the chip circuit material being easy to being formed at described sloped sidewall surface carries out photoetching and etching technics, forms the wiring of chip circuit with this.
In the present embodiment, described induction chip is fixed on the first surface 230 of substrate 200 by the first tack coat 301, follow-up during by conductor wire or conductive layer the first link 207 be connected with the second articulamentum 205.
In another embodiment, please refer to Fig. 4, run through the conductive plunger 304 of described induction chip 201 in the interior formation of induction chip 201, the second surface 220 of described induction chip 201 exposes described conductive plunger 304, and one end of described conductive plunger 304 is connected with the first link 207; The solder layer 305 at conductive plunger 304 tops that expose at induction chip 201 second surfaces 220; Described solder layer 305 is welded in to the second link 205 surfaces, makes to interfix between described induction chip 201 and substrate 200.
Please refer to Fig. 9, epiphragma 202a on substrate 200 surfaces and induction chip 201 surface-coateds, the material of described upper epiphragma 202a is polymeric material.
The follow-up cap rock that is used to form of described upper epiphragma 202a.Described polymeric material has good pliability, ductility and covering power, and good fluidity, therefore can form the upper epiphragma 202a of thinner thicknesses on surface, induction zone 211 by coating process, thereby make the follow-up upper depth of cover that is formed at 211 surfaces, induction zone thinner.And the thinner thickness of described upper cap rock can strengthen the sensing capability of induction chip 201 to user's finger print, the corresponding requirement having reduced induction chip 201 detection sensitivities.
Described coating process comprises spin coating proceeding, spraying coating process or evaporation process, the material of the upper epiphragma 202a forming has for fluid, therefore can make to be formed at the upper epiphragma 202a thinner thickness on induction chip 201 surfaces, and the upper epiphragma 202a thickness on substrate 200 surfaces is thicker.The upper epiphragma 202a thickness that is formed at induction chip 201 surfaces is 20 microns～100 microns.
The material of described upper epiphragma 202a is epoxy resin, polyimide resin, benzocyclobutane olefine resin, polybenzoxazoles resin, polybutylene terephthalate, Merlon, PETG, polyethylene, polypropylene, polyolefin, polyurethane, polyolefin, polyether sulfone, polyamide, polyurethane, ethylene-vinyl acetate copolymer, polyvinyl alcohol or other suitable polymeric materials.
In the present embodiment, described polymeric material is light-sensitive material, has photosensitive particle in described polymeric material, described photosensitive particle can make polymeric material can be exposed development, therefore, follow-uply directly described upper epiphragma 202a is exposed, can form cap rock.The size of described photosensitive particle is less than 6 microns, makes the follow-up size with the upper cap rock 202 of formation after exposing accurately and is easy to control.
Please refer to Figure 10, remove substrate 200 surfaces and induction chip 201 surface induction districts 211 upper epiphragma 202a (as shown in Figure 9) in addition, form cap rock 202 on 211 surfaces, induction zone.
In the present embodiment, because the polymeric material of described upper epiphragma 202a is light-sensitive material, therefore, can remove the upper epiphragma 202a beyond induction zone 211, cap rock 202 in formation by exposure imaging technique.And, after carrying out exposure imaging, formed upper cap rock 202 is carried out to solid adhesive process, make the material cured of cap rock 202.The upper cap rock 202 forming, can also external zones 212 around, induction zone, cover part 211 except being covered in 211 surfaces, induction zone.
In another embodiment, the formation technique of described upper cap rock 202 comprises: form mask layer on upper epiphragma 202a surface, described mask layer has defined the correspondence position and the figure that need to form upper cap rock 202; Taking described mask layer as mask, upper epiphragma 202a described in etching, until expose substrate 200 and induction chip 201 surfaces, cap rock 202 in formation.
The thickness of upper cap rock 202 is 20 microns～100 microns, makes described induction zone 211 be easy to the finger print information that detects that user points.
Described upper epiphragma 202a is through after solid adhesive process, and Mohs' hardness is more than or equal to 8H, and the hardness of described upper cap rock 202 is higher, when damage when mobile, can not caused to induction chip 201 in user's finger cap rock 202 surfaces on described.And, because the hardness of described upper cap rock 202 is higher, therefore described upper cap rock 202 is difficult to occur deformation, even user's finger presses and described upper cap rock 202 surfaces, the thickness of described upper cap rock 202 is also difficult to change, thereby has ensured the testing result accuracy of induction zone 211.
The dielectric constant of described upper cap rock 202 is more than or equal to 7, and the electric isolating power of described upper cap rock 202 is stronger, and described upper cap rock 202 is stronger to the protective capability of induction zone 211.And in the present embodiment, when the thinner thickness of upper cap rock 202, and dielectric constant is when larger, can make user point in the scope that the capacitance between capacitor plate can detect in induction zone 211, avoid detecting and lost efficacy.
Please refer to Figure 11, on forming, after cap rock 202, described substrate 200 is coupled with induction chip 201.
In the present embodiment, because induction chip 201 is fixed on substrate 200 surfaces by the first tack coat 301, therefore can be by conductor wire or conductive layer time, substrate 200 be coupled with induction chip 201.
In the present embodiment, comprise in the method for the surperficial inductive coupling chip 201 of described substrate 200: conductor wire 208 is provided; Described conductor wire 208 two ends are connected with the second link 205 with the first link 207 respectively by welding procedure.The material of described conductor wire 208 is metal, and described metal is copper, tungsten, aluminium, gold or silver-colored.
In one embodiment, please refer to Fig. 3, method at the surperficial inductive coupling chip 201 of described substrate 200 comprises: the conductive layer 303 in induction chip 201 sidewall surfaces, substrate 200 first surfaces 230 and edge groove 206, described conductive layer 303 two ends are connected with the first link 207 and the second link 205 respectively.The formation technique of described conductive layer 303 comprises: form conducting film with depositing operation, electroplating technology or chemical plating process; Described in etched portions, conducting film is to form conductive layer 303.The material of described conductive layer 303 is metal, and described metal is one or more in copper, tungsten, aluminium, silver, gold, titanium, tantalum, nickel, titanium nitride, tantalum nitride.
Please refer to Figure 12, form plastic packaging layer 203 at substrate 200 and induction chip 201 surfaces, described plastic packaging layer 203 exposes described upper cap rock 202.
The material of described plastic packaging layer 203 is epoxy resin, polyethylene, polypropylene, polyolefin, polyamide, polyurethane, and described plastic packaging layer 203 can also adopt other suitable capsulation material.The formation technique of described plastic packaging layer 203 is Shooting Technique (injection molding), turns and mould technique (transfer molding) or silk-screen printing technique.The described envelope bed of material 400 can also adopt other suitable technique to form.
In the present embodiment, please continue to refer to Fig. 2, after forming encapsulated layer 203, form guard ring 209 on substrate 200 surfaces, described guard ring 209 surrounds described induction chip 201, upper cap rock 202 and plastic packaging layer 203.The material of described guard ring 209 is metal, and described guard ring 209 is by described substrate 200 ground connection.The material of described guard ring 209 is metal, and described metal is copper, tungsten, aluminium, silver or golden.
Described guard ring 209 is for carrying out electrostatic defending to described induction chip; avoid cap rock 202 to be punctured by excessive electrostatic potential, protect induction chip 201 with this, improve the accuracy of fingerprint detection; eliminate the signal noise of induction chip output, make the signal of induction chip output more accurate.
In the present embodiment; the first surface of described induction chip has the induction zone for extracting user fingerprints; surface, induction zone at described induction chip forms cap rock; make the induction zone of described upper cap rock for the protection of induction chip; described upper cap rock surface is used for placing user's finger, to carry out fingerprint detection.Because the material of described upper cap rock is polymer; and polymeric material has good ductility and pliability; and covering power is good; therefore, can make the thin thickness of formed upper cap rock, and hardness is high; therefore; the upper cap rock forming has enough large hardness with protection induction chip, and described upper cap rock surface reduces to the distance of induction chip, makes induction zone more easily obtain user fingerprints data.Therefore, the encapsulating structure forming reduces the requirement of induction chip sensitivity, and the scope of application of described method for packing is more extensive.And the material of described upper cap rock is polymer, the cost that forms described upper cap rock is low, and then has reduced the cost of manufacturing described encapsulating structure.
Although the utility model discloses as above, the utility model is not defined in this.Any those skilled in the art, not departing from spirit and scope of the present utility model, all can make various changes or modifications, and therefore protection range of the present utility model should be as the criterion with claim limited range.