A kind of mobile terminal with fingerprint sensor package structure and preparation method thereof
Technical field
The present invention relates to field of semiconductor package, especially relate to encapsulation technology and the correlation technique of a kind of condenser type semiconductor fingerprint sensor, more particularly, more specifically it relates to a kind of mobile terminal with fingerprint sensor package structure and preparation method thereof.
Background technology
Recently as the rise of Fructus Mali pumilae iphone5S fingerprint identification device TouchID, sweep the agitation of one fingerprint recognition in smart mobile phone field.
But, the fingerprinting scheme of prior art needs to slot in the front of handset shell or the back side to install fingerprint recognition assembly, so that the collection of fingerprint recognition assembly is showed out, thus contacting with finger. The scheme especially front panel of casing fluting needs in touch screen perforate, this not only adds the processing step of touch screen, also affects overall structure and the outward appearance of terminal unit so that ID design becomes complicated.
Further, the capacitive fingerprint sensing device of prior art is limit because of design principle and framework, and its limit detection sensitivity also can only achieve 100um. Although, the detectivity of RF-type fingerprint sensor is higher than condenser type, but need radio-frequency electrode, and touch screen processing technique is difficult to produce on the surface of touch screen cover plate the radio-frequency electrode of conduction so that the support of RF-type fingerprint sensor is almost not attainable by existing touch screen.
Summary of the invention
In view of above-mentioned background, on the mobile terminal such as mobile phone, panel computer, it is an object of the invention to provide a kind of coverslip encapsulation technology (GlassCoverModule, it is called for short GCM), this technology can make cell phone manufacturer put into fingerprint sensor without fluting on Mobile telephone front panel or back cover, but fingerprint sensor is placed under touch panel, that is, the GCM technology of the present invention does not change the ID style of the original design of mobile phone, changes the use habit to Android mobile phone without user.
For achieving the above object, technical scheme is as follows:
A kind of mobile terminal with touch screen, including casing, LCDs and touch screen, described touch screen includes touching cover plate and touch sensible sensor film, also include fingerprint sensor module, by anisotropic conductive (ACF), described fingerprint sensor module is bonded under described touch cover plate.
Specifically, the material of described touch cover plate can be sapphire glass (Sapphire), and its hardness is 9H, dielectric constant: A to 13.2, C to 11.4; Can also is that strengthening glass, its hardness can reach 7H, and dielectric constant is 6.0~7.38, for instance, the healthy and free from worry gorilla glass (GorillaGlass) of the third generation.
Further, being arranged below with the silk-screen layer made a check mark of described touch cover plate, it is used for pointing out user fingerprints sensor module touching position below cover plate, it is simple to user presses finger.
In one embodiment, described fingerprint sensor module, including: the sensor pixel array on semiconductor fingerprint sensor die and surface, for the pin in sensor die front being guided into silicon through hole (TSV) structure at the back side, for carrying the substrate of sensor die, for being electrically connected copper post or the copper ball of sensor die back side pin and substrate pin, wrap the encapsulating material in region between copper post or copper ball and the substrate of the sensor die side of surface exposure, die back side.
Further, described substrate is the structure of the soft combination of steel, and the side of its rigidity is used for carrying sensor die, and the side of flexibility leads to FPC soft board, and its one end dress posts connector, and described connector is electrically connected for the mainboard with mobile terminal.
FPC soft board is generally divided into lamina, doubling plate, multi-layer sheet, dual platen etc.
The structure of FPC monolayer soft board: the flexible board of this structure is the flexible board of most simple structure. Usual base material+transparent adhesive tape+Copper Foil is a set of raw material bought, and protecting film+transparent adhesive tape is the raw material that another kind is bought. First, Copper Foil such as to perform etching at the circuit that PROCESS FOR TREATMENT obtains needing, and protecting film to carry out holing to expose corresponding pad. After cleaning again by rolling process in combination with getting up. Then protect at the pad portion electrogilding exposed or stannum etc. again. So, big plate is just carried out. The general little circuit board also striking out respective shapes. Also having and directly print solder mask without protecting film on Copper Foil, such cost can be lower, but the mechanical strength of circuit board can be deteriorated. Unless requirement of strength is not high but price needs as far as possible low occasion, it is preferred to the method for application pasting protective film. The structure of FPC bilayer soft board: when the circuit of circuit is too complicated, lamina cannot connect up or need Copper Foil to carry out grounded shield, it is necessary to select doubling plate even multi-layer sheet. Multi-layer sheet and the most typical difference of lamina are the increase in via structure to link each layer Copper Foil. First processing technique of general base material+transparent adhesive tape+Copper Foil makes via exactly. First holing on base material and Copper Foil, plate certain thickness copper after cleaning, via is just carried out. Processing technology and lamina afterwards are about the same. Additionally, there is pad on the two sides of dual platen, it is mainly used in the connection with other circuit boards. Although it is similar with lamina structure, but processing technology difference is very big. Its raw material is Copper Foil, protecting film+transparent adhesive tape. First to hole on protecting film by pad locations requirement, then Copper Foil is sticked, after eroding away pad and lead-in wire, stick another hole-drilled protecting film again.
In another kind of embodiment, described fingerprint sensor module, including: the sensor pixel array on semiconductor fingerprint sensor die and surface, for the pin in sensor die front being guided into silicon through hole (TSV) structure at the back side, for carrying the substrate of sensor die, the described die back side pin positions corresponding with die front side is provided with back side pin, the pin in front and the pin at the back side are carried out UNICOM by described silicon through hole, die back side is provided with the pad (LandGridArray) of grid array, by rerouting layer (RDL) technology, the pin of die back side is connected with the pad of grid array, the microscopic dimensions of described grid array pads is tens times of die back side pin, so that described pad is readily employed solder reflow techniques and tube core and the substrate of fingerprint sensor is made directly welding.Also include wrapping the sensor die side of surface exposure, the encapsulating material in region between tube core and substrate.
Further, described substrate is the structure of the soft combination of steel, and the side of its rigidity is used for carrying sensor die, and the side of flexibility leads to FPC soft board, and its one end dress posts connector, and described connector is electrically connected for the mainboard with mobile terminal.
It is highly preferred that adopt aforementioned die back side to arrange the structure of pad of grid array, it is possible to plant ball technique without semiconductor packages, simplify processing step, reduce encapsulation difficulty, improve yield, save packaging cost.
In another kind of embodiment, described fingerprint sensor module, including: the sensor pixel array on semiconductor fingerprint sensor die and surface, deep recess process (Trench) is adopted to form dell in the pin outer rim of described tube core, again through rerouting layer technology, the pin of described tube core is placed in dell, for carrying the substrate of sensor die, for being electrically connected the bonding lead of described tube core pin and substrate pin, by bonding lead (wirebond), the pin of the pin in described dell and substrate is electrically connected, wrap the sensor die side of surface exposure, the encapsulating material in region between bonding lead and substrate.
Further, described substrate is the structure of the soft combination of steel, and the side of its rigidity is used for carrying sensor die, and the side of flexibility leads to FPC soft board, and its one end dress posts connector, and described connector is electrically connected for the mainboard with mobile terminal.
In another kind of embodiment, fingerprint sensor module adopts injection moulding (Moulding) technique individual packages to become moulding, described sensor module includes: the sensor pixel array on semiconductor fingerprint sensor die and surface, for carrying the substrate of sensor die, for being electrically connected sensor die pin and the bonding lead of substrate pin, by bonding lead (wirebond), the pin of described tube core and the pin of substrate are electrically connected, wrap sensor die (the sensor pixel array comprising surface), the injected plastics material of bonding lead and substrate, optionally, described sensor moulding can be injection moulded into rectangle, strip, circle or other shapes applicatory. described substrate back is provided with the pad (LandGridArray) of grid array, for described sensor moulding and liner plate being electrically connected.
Further, described liner plate is the structure of the soft combination of steel, and the side of its rigidity is used for carrying sensor die, and the side of flexibility leads to FPC soft board, and its one end dress posts connector, and described connector is electrically connected for the mainboard with mobile terminal.
More preferably, aforementioned Shooting Technique (Moulding) is the most frequently used semiconductor packaging process, extremely cheap compared to expensive TSV technique and Trench+RDL technique, technology difficulty is substantially reduced, yield is significantly high, the encapsulation of fingerprint sensor module can be accomplished very cheap, be conducive to the scale of mass production of fingerprint sensor module.
Further object is that the making and assembly method that propose a kind of mobile terminal with fingerprint sensor module. Described mobile terminal can be but not limited to the portable electron devices such as mobile phone, panel computer, individual's PDA device. The method includes: a casing and the electronic circuit being included in, LCDs, touch screen, and described touch screen includes touch sensible sensor film, touches cover plate, also includes fingerprint sensor module.Described touch sensible sensor film has the perforate of a fingerprint sensor size of components size, by the fingerprint sensor module above-mentioned touch sensible sensor film of traverse, fingerprint sensor module is bonded under described touch cover plate finally by anisotropic conductive. Described fingerprint sensor module includes at least a flexible PCB (FPC) and the adapter being attached thereto, together with fingerprint sensor module is connected electrically to by described adapter with the electronic circuit of casing internal.
Accompanying drawing explanation
One exemplary embodiment is described in detail in conjunction with the drawings, and These characteristics and the advantage of the present invention will be apparent from, and in the accompanying drawings, adopt similar accompanying drawing labelling to represent similar element between each accompanying drawing. Described accompanying drawing is only exemplary rather than drawn to scale. In the accompanying drawings:
Fig. 1 is the top view according to a kind of embodiment of mobile terminal of the present invention
Fig. 2 is be sectional elevation view according to a kind of embodiment of mobile terminal of the present invention, it is shown that be placed in the fingerprint sensor module touched under cover plate
Fig. 3 be Fig. 2 along the cross-sectional side elevational view in direction shown in A--A ' dotted line, the structure of this each element of assembly is shown further
Fig. 4 is the Fig. 2 die back side top view adopting TSV technique according to the fingerprint sensor module of another kind embodiment of the present invention
Fig. 5 is the sectional elevation view of the mobile terminal according to another kind embodiment of the present invention, it is shown that be placed in the fingerprint sensor module touched under cover plate
Fig. 6 is the fingerprint sensor module of the employing Shooting Technique individual packages according to another kind embodiment of the present invention
Fig. 7 is the dorsal view of Fig. 6 fingerprint sensor module
Symbol description in figure
10/10'/10 ". fingerprint sensor injection molding group
20. casing
21. touch screen
22. LCDs
23. touch sensible sensor film
24. the perforate of touch sensible sensor film
30. finger
100. touch cover plate
200/200'/200 ". semiconductor fingerprint sensor die
201/201'/201 ". the sensor pixel array of fingerprint sensor die surfaces
202/202'/202 ". the pin of fingerprint sensor die front side
203. the pin of fingerprint sensor die back side
204. reroute layer cabling
205. the pad of grid array
206. silicon through hole
207. replacement pin
208. the dell of fingerprint sensor tube core
300/300'/300 ". substrate
301/301'/301 ". the pin of substrate
302'/302 ". bonding lead
303. anisotropic conductive
304/304'. encapsulating material
305. injected plastics material
306.FPC soft board
307. connector
308. copper post or copper ball
309. liner plate
Detailed description of the invention
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.
It should be noted that the present invention can embody in many different forms and be not intended to be limited to embodiments set forth here. These embodiments are provided so that the disclosure is by thorough and complete, and will fully pass on the scope of the present invention to those skilled in the art. Similar accompanying drawing labelling indicates similar element all the time.
First, the top view that Fig. 1, Fig. 1 are a kind of embodiment according to mobile terminal of the present invention is referred to. As it can be seen, the mobile terminal presently described includes casing 20, touch screen 21 and LCDs 22, this touch screen 21, except including touch sensible sensor film 23 and touching cover plate 100, also includes fingerprint sensor module 10/10'/10 ".
LCDs 22 covers under touch screen 21 and occupies overwhelming majority space to form viewing area, fingerprint sensor module 10/10'/10 " need to anisotropic conductive 303 be bonded in touch cover plate 100 bottom non-display area near entity Home key position, or with fingerprint sensor module 10/10'/10 " replace entity Home key function form virtual Home key.
Being arranged below by the silk-screen layer (not show) that makes a check mark of this touch cover plate 100, is used for pointing out user these fingerprint sensor module 10/10'/10 " the virtual Home key position at place, it is simple to user presses finger 30.
Referring to Fig. 2~3, Fig. 2 is be the sectional elevation view of a kind of embodiment according to mobile terminal of the present invention, it is shown that be placed in the fingerprint sensor module touched under cover plate, Fig. 3 be Fig. 2 along the cross-sectional side elevational view in direction shown in A--A ' dotted line, the structure of this each element of assembly is shown further. in an embodiment of the present invention, this fingerprint sensor module 10 includes: the sensor pixel array 201 on semiconductor fingerprint sensor die 200 and surface, the pin 202 in tube core 200 front is guided into the back side by silicon through hole 206, to form pin 203 corresponding with pin 202 position, tube core 200 front at tube core 200 back side, by planting, ball technique pin 203 overleaf plants upper copper post or copper ball 308, the pin 301 of die back side pin 203 and substrate 300 is electrically connected by the mode again through Reflow Soldering, finally with an adhesive process, encapsulating material 304 is wrapped the side (surface needs exposed so that can bond with touching cover plate 100) of sensor die 200, region between copper post or copper ball 308 and the substrate 300 of die back side.
Referring to Fig. 4, Fig. 4 is the Fig. 2 die back side top view adopting TSV technique according to the another kind of embodiment of fingerprint sensor module of the present invention. in an embodiment of the present invention, this fingerprint sensor module 10 includes: the sensor pixel array 201 on semiconductor fingerprint sensor die 200 and surface, the pin 202 in tube core 200 front is guided into the back side by silicon through hole 206, to form the pin 203 corresponding with pin 202 position, tube core 200 front at tube core 200 back side, tube core 200 back side is provided with the pad 205 of grid array, by rerouting layer cabling 204, the pin 203 at tube core 200 back side is connected with the pad 205 of grid array, the microscopic dimensions of this grid array pads 205 is tens times of die back side pin 203, so that this pad 205 is readily employed solder reflow techniques and tube core 200 and the substrate 300 of fingerprint sensor is made directly welding, finally with an adhesive process, encapsulating material 304 is wrapped the side (surface needs exposed so that can bond with touching cover plate 100) of sensor die 200, region between tube core 200 and substrate 300.
It should be noted that adopt camber that this TSV technique can avoid fingerprint sensor pin to be formed because of front routing and make the surface being bonded in fingerprint sensor tube core 200 that touch cover plate 100 can not be smooth. Efficiently solve the difficult problem that fingerprint sensor module assembles on the mobile terminal device.
It is highly preferred that adopt aforementioned tube core 200 back side to arrange the structure of pad 205 of grid array, it is possible to plant ball technique without semiconductor packages, simplify processing step, reduce encapsulation difficulty, improve yield, save packaging cost.
Refer to the sectional elevation view that Fig. 5, Fig. 5 are the another kind of embodiment according to mobile terminal of the present invention, it is shown that be placed in the fingerprint sensor module touched under cover plate. in an embodiment of the present invention, this fingerprint sensor module 10' includes: the sensor pixel array 201' on semiconductor fingerprint sensor die 200' and surface, deep recess process is adopted to form dell 203' in the outer rim of this tube core 200' front pin 202' and form replacement pin 207 in dell, by rerouting layer cabling (not show), this front pin 202' is connected with the replacement pin 207 in dell, again through bonding lead 302', the pin 301' resetting pin 207 and substrate 300' in this dell 203' is electrically connected, finally encapsulating material 304' is wrapped the replacement pin 207 in the dell 203' of sensor die 200' and dell and substrate 300' with dripping adhesive process.
More preferably, the technology adopting Trench+RDL can make pin 202' routing in dell of fingerprint sensor tube core 200', because bonding lead 302' carries out routing by replacement pin 207 in dell 203', its camber will not exceed the horizontal plane of tube core 200' so that touches cover plate 100 and can entirely be bonded in the surface of fingerprint sensor tube core 200'. Efficiently solving the difficult problem that fingerprint sensor module assembles on the mobile terminal device, and this technique is more relatively cheap than TSV technique, yield is higher.
It should be noted that above-mentioned encapsulating material 304/304' is integrated circuit packaging material known in the field, to protect sensor die 200/200' not by the damage of machinery, electricity and environment.
Further, aforesaid substrate 300/300' is the structure of the soft combination of steel, the side of its rigidity is used for carrying sensor die 200/200', and the side of flexibility leads to FPC soft board 306, its one end dress posts connector 307, and this connector 307 is for being electrically connected with the mainboard (not show) in mobile terminal casing 20.
Referring to Fig. 6~7, Fig. 6 is the fingerprint sensor module of the employing Shooting Technique individual packages according to another kind embodiment of the present invention; Fig. 7 is the dorsal view of Fig. 6 fingerprint sensor module. In an embodiment of the present invention, this fingerprint sensor module 10 " adopt injection moulding (Moulding) technique individual packages to become moulding; this sensor module 10 ", including semiconductor fingerprint sensor die 200 " and the sensor pixel array 201 on surface ", by bonding lead 302 " sensor die front pin 202 " and substrate 300 " pin 301 " be electrically connected, by injection molding manner, injected plastics material 305 is wrapped sensor die 200 " (the sensor pixel array 201 comprising surface "), bonding lead 302 " and substrate 300 ".
This substrate 300 " back side is provided with the pad 205 of grid array, for by this sensor module 10 " and liner plate 309 be electrically connected. This liner plate 309 is the structure of the soft combination of steel, the side of its rigidity is used for carrying sensor module 10 "; and the side of flexibility leads to FPC soft board 306; its one end dress posts connector 307, and this connector 307 is for being electrically connected with the mainboard (not show) in mobile terminal casing 20.
It should be noted that, this injected plastics material 305 is the injection moulding encapsulant that known traditional integrated circuit injection molding process adopts, epoxy resin as known in the art, its dielectric constant (3.1~4.2) is generally relatively low, it means that cover sensor die 200 " thickness of the injected plastics material 305 on (the sensor pixel array 201 comprising surface ") surface can not more than 100um. Optionally, this sensor module 10 " rectangle, strip, circle or other shapes applicatory can be injection moulded into.
More preferably, the pattern making equipment adopting standard in packaging technology carries out moulding (Molding), without using expensive nonstandard pattern making equipment, extremely cheap compared to expensive TSV technique and Trench+RDL technique, technology difficulty is substantially reduced, yield is significantly high, it is possible to the encapsulation of fingerprint sensor module is accomplished very cheap, is conducive to the scale of mass production of fingerprint sensor module.
It should be noted that, above-mentioned semiconductor fingerprint sensor die 200/200'/200 " usually there is the silicon-based semiconductor being formed at one or more layers; and this layer includes such as IC-components and interconnection line, through holes such as transistor, electric capacity, resistance, and this device is formed by photoetching or other semiconductor fabrication process. Specifically, tube core 200/200'/200 " there are image storage unit (not show) formed thereon, image reading circuit (not show) and sensor pixel array 201/201'/201 ".
It should be noted that the material of this touch cover plate 100 can be sapphire glass (Sapphire), its hardness is 9H, dielectric constant: A to 13.2, C to 11.4; Can also is that strengthening glass, its hardness can reach 7H, and dielectric constant is 6.0~7.38, for instance the healthy and free from worry gorilla glass (GorillaGlass) of the third generation. Because the dielectric constant of sapphire glass is higher, the thickness of this touch cover plate 100 can be higher, it is possible to is the 500um of standard; And the dielectric constant of strengthening glass is relatively low, it is necessary to suitably thinning to promote fingerprint sensor module 10/10'/10 " detectivity, be conducive to sensor module to gather image.
The material of above-mentioned touch cover plate 100 is as sensor module 10/10'/10 " the protection material on surface is ideal. Sensor module 10/10'/10 are installed " mobile equipment be placed in pocket or bag, and contact with key therein, pen or other hard objects, rub, sensor module 10/10'/10 " protection material hardness significantly high and avoid being damaged. It is highly preferred that the surface of this touch cover plate 100 is also coated with one layer of hydrophobic nano material, so can effectively prevent the fingerprint residues that capacitive fingerprint sensing device is formed in sampling process. Have the thickness of hundreds of micron owing to touching cover plate 100, finger electrostatic is difficult to sensor module 10/10'/10 touched under cover plate " cause electrostatic damage.
A kind of manufacture method of the mobile terminal of the present invention is as follows: first, prepare fingerprint sensor module 10/10'/10 "; its preparation method can select the one in aforementioned four kinds of embodiments, it is more preferred to, adopt the pattern making equipment of standard to carry out moulding the mode of (Molding). Then touch screen 21 is prepared, this touch screen 21 includes touching cover plate 100 and touch sensible sensor film 23, this touch sensible sensor film 23 is for finger sensing signal on the touchscreen, a hole 24 is opened near Home key position by the middle of non-display area bottom touch sensible sensor film 23, the size of this touch sensible sensor film perforate 24 should be slightly bigger than fingerprint sensor module 10/10'/10 " size so that sensor module 10/10'/10 " this perforate 24 can be passed. Last in fingerprint sensor module 10/10'/10 " surface coat very thin one layer anisotropic conductive 303, then by sensor module 10/10'/10 " be bonded under touch cover plate 100. When finger 30 presses virtual Home key position shown in broken box in the drawings time, fingerprint sensor module 10/10'/10 " just can gather the fingerprint image of finger 30. Certainly, it will be recognized by those skilled in the art, this mobile terminal can be the electronic equipment with all touch screen such as such as mobile phone, panel computer, individual's PDA device. Skilled persons will also appreciate that, this is the assemble method that a kind of possible manufacture method also has other similar.
What be more than somebody's turn to do is only the preferred embodiments of the present invention; this embodiment is also not used to limit the scope of patent protection of the present invention; therefore the equivalent structure change that the description of every utilization present invention and accompanying drawing content are made, in like manner should be included in protection scope of the present invention.