U.S. patent application number 16/210989 was filed with the patent office on 2020-07-23 for optical fingerprint recognition chip package and packaging method.
This patent application is currently assigned to China Wafer Level CSP Co., Ltd.. The applicant listed for this patent is China Wafer Level CSP Co., Ltd.. Invention is credited to Hanqing Hu, Zhiqi Wang, Guoliang Xie.
Application Number | 20200234028 16/210989 |
Document ID | / |
Family ID | 66814486 |
Filed Date | 2020-07-23 |
United States Patent
Application |
20200234028 |
Kind Code |
A9 |
Wang; Zhiqi ; et
al. |
July 23, 2020 |
OPTICAL FINGERPRINT RECOGNITION CHIP PACKAGE AND PACKAGING
METHOD
Abstract
An optical fingerprint recognition chip package and a packaging
method are provided. In the optical fingerprint recognition chip
package, a cover plate is arranged on a front surface of an optical
fingerprint recognition chip, the cover plate includes a substrate
and a light shielding layer. The light shielding layer is arranged
on a surface of the substrate facing away from the optical
fingerprint recognition chip. The substrate is provided with
multiple first through holes for exposing photosensitive pixels of
the optical fingerprint recognition chip. The light shielding layer
is provided with multiple second through holes in one-to-one
correspondence with the first through holes. During fingerprint
recognition, light reflected by a finger is split through the first
through holes and the second through holes, such that crosstalk
among different photosensitive pixels is reduced, and the accuracy
of fingerprint recognition is improved.
Inventors: |
Wang; Zhiqi; (Suzhou,
CN) ; Xie; Guoliang; (Suzhou, CN) ; Hu;
Hanqing; (Suzhou, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
China Wafer Level CSP Co., Ltd. |
Suzhou |
|
CN |
|
|
Assignee: |
China Wafer Level CSP Co.,
Ltd.
Suzhou
CN
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20190188447 A1 |
June 20, 2019 |
|
|
Family ID: |
66814486 |
Appl. No.: |
16/210989 |
Filed: |
December 5, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06K 9/00053 20130101;
H01L 27/14618 20130101; H01L 27/14687 20130101; H01L 27/14678
20130101; G06K 9/00046 20130101; H01L 27/14625 20130101; H01L
27/1463 20130101; H01L 27/14623 20130101 |
International
Class: |
G06K 9/00 20060101
G06K009/00; H01L 27/146 20060101 H01L027/146 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2017 |
CN |
201711364625.6 |
Dec 18, 2017 |
CN |
201721773041.X |
Claims
1. An optical fingerprint recognition chip package, comprising: an
optical fingerprint recognition chip having a front surface and a
back surface opposite to each other, wherein the front surface
comprises a fingerprint recognition region and a peripheral region
surrounding the fingerprint recognition region, the fingerprint
recognition region is provided with a plurality of photosensitive
pixels, and the peripheral region is provided with a contact pad
electrically connected to the photosensitive pixels; and a cover
plate arranged opposite to the front surface of the optical
fingerprint recognition chip and comprising a substrate and a light
shielding layer, wherein the light shielding layer is located on a
side of the substrate facing away from the optical fingerprint
recognition chip, the substrate is provided with a plurality of
first through holes for exposing the photosensitive pixels, and the
light shielding layer is provided with a plurality of second
through holes in one-to-one correspondence with the plurality of
first through holes.
2. The optical fingerprint recognition chip package according to
claim 1, wherein the cover plate is spaced from the optical
fingerprint recognition chip by a preset interval, to adjust an
image distance for pinhole imaging through the cover plate.
3. The optical fingerprint recognition chip package according to
claim 1, wherein a glass filter is arranged between the cover plate
and the optical fingerprint recognition chip, to remove light
outside a detection light wave band.
4. The optical fingerprint recognition chip package according to
claim 1, wherein a glass filter is arranged on a surface of the
cover plate facing away from the optical fingerprint recognition
chip, to remove light outside a detection light wave band.
5. The optical fingerprint recognition chip package according to
claim 1, wherein a spacer with a preset thickness is arranged
between a periphery of the cover plate and a periphery of the
optical fingerprint recognition chip.
6. The optical fingerprint recognition chip package according to
claim 1, wherein the substrate is provided with a first opening at
a position corresponding to the contact pad, to expose the contact
pad, the light shielding layer is provided with a second opening at
a position corresponding to the first opening, to expose the first
opening, and the contact pad is configured to be electrically
connected to a metal wire through the first opening and the second
opening, so as to be electrically connected to a pad of a backplane
through the metal wire.
7. The optical fingerprint recognition chip package according to
claim 6, wherein the first opening comprises a first groove and a
second groove located in the first groove, and the contact pad is
exposed by the first groove and the second groove.
8. The optical fingerprint recognition chip package according to
claim 1, wherein the optical fingerprint recognition chip is
provided with a through silicon via at a position on the back
surface corresponding to the contact pad, and the contact pad is
exposed by the through silicon via, a sidewall of the through
silicon via and the back surface of the optical fingerprint
recognition chip are covered with an insulating layer, a surface of
the insulating layer is covered with a rewiring layer, and the
rewiring layer is electrically connected to the contact pad through
the through silicon via and extends outside the through silicon
via, and the rewiring layer is covered with a solder mask, the
solder mask is provided with an opening in a region corresponding
to the back surface of the optical fingerprint recognition chip,
and the opening is configured to accommodate a solder bump for
electrical connection to a pad of a backplane.
9. The optical fingerprint recognition chip package according to
claim 1, wherein the substrate is a silicon substrate, and the
light shielding layer is made of dry film photoresist or wet film
photoresist.
10. The optical fingerprint recognition chip package according to
claim 1, wherein a depth-to-width ratio of the first through hole
is less than or equal to than 6:1, and a depth-to-width ratio of
the second through hole is less than or equal to 6:1.
11. The optical fingerprint recognition chip package according to
claim 1, wherein a thickness of the substrate is less than or equal
to 200 .mu.m, and a thickness of the light shielding layer is less
than or equal to 200 .mu.m.
12. The optical fingerprint recognition chip package according to
claim 1, wherein the photosensitive pixels are arranged in an
array, and the first through holes are in one-to-one correspondence
with the pixels.
13. A packaging method for fabricating the optical fingerprint
recognition chip package according to claim 1, comprising:
preparing a wafer, wherein the wafer comprises a plurality of
optical fingerprint recognition chips, each of the optical
fingerprint recognition chips has a front surface and a back
surface opposite to each other, the front surface comprises a
fingerprint recognition region and a peripheral region surrounding
the fingerprint recognition region, the fingerprint recognition
region is provided with a plurality of photosensitive pixels, and
the peripheral region is provided with a contact pad electrically
connected to the photosensitive pixels; securing a substrate on the
wafer; forming a light shielding layer on a surface of the
substrate facing away from the optical fingerprint recognition
chip; patterning the light shielding layer to form a plurality of
second through holes extending through the light shielding layer
patterning the substrate by using the patterned light shielding
layer as a mask layer, to form a plurality of first through holes
extending through the substrate, wherein the photosensitive pixels
are exposed by the plurality of first through holes, and the
plurality of first through holes are in one-to-one correspondence
with the plurality of second through holes; and cutting the wafer,
the substrate and the light shielding layer by a cutting process to
form a plurality of single packages, wherein the wafer is cut to
obtain a plurality of optical fingerprint recognition chips, each
of the substrate and the light shielding layer is cut to obtain a
plurality of parts in one-to-one correspondence with the plurality
of optical fingerprint recognition chips.
14. The packaging method according to claim 13, wherein the
securing the substrate on the wafer comprises: attaching the
substrate with the wafer, wherein a preset region of the front
surface of each of the optical fingerprint recognition chips is
secured to a preset region of the substrate, and the substrate is
spaced from the optical fingerprint recognition chip by a preset
interval, to adjust an image distance for pinhole imaging through a
cover plate comprising the substrate and the light shielding
layer.
15. The packaging method according to claim 14, wherein after
forming the plurality of first through holes, the method further
comprises: attaching glass filters on a surface of the light
shielding layer facing away from the substrate, the glass filters
being in one-to-one correspondence with the optical fingerprint
recognition chips.
16. The packaging method according to claim 15, wherein a spacer is
arranged between the substrate and each of the optical fingerprint
recognition chips at a periphery of the optical fingerprint
recognition chip, a thickness of the spacer is equal to the preset
interval, and the spacer is configured to secure the substrate to
the optical fingerprint recognition chip.
17. The packaging method according to claim 13, wherein the
securing the substrate on the wafer comprises: attaching glass
filters on front surfaces of the optical fingerprint recognition
chips, respectively, and securing the substrate on surfaces of the
glass filters, wherein the substrate covers the glass filters, and
the substrate is spaced from the optical fingerprint recognition
chips by a preset interval due to a thickness of the glass filters,
to adjust an image distance for pinhole imaging through a cover
plate comprising the substrate and the light shielding layer.
18. The packaging method according to claim 13, wherein the light
shielding layer is made of dry film photoresist or wet film
photoresist, the plurality of second through holes in one-to-one
correspondence with the plurality of photosensitive pixels are
formed on the light shielding layer by an exposure and development
process, and the substrate is a silicon substrate, and the
plurality of first through holes are formed on the substrate by a
silicon etching process using the light shielding layer as a mask
layer.
19. The packaging method according to claim 18, wherein a second
opening is formed at a position on the light shielding layer
corresponding to the contact pad by an exposure and development
process while the plurality of second through holes are formed, and
a first opening is formed at a position on the substrate
corresponding to the contact pad by an etching process on the basis
of the second opening, to expose the contact pad, and the contact
pad is configured to be electrically connected to a metal wire
through the first opening and the second opening, so as to be
electrically connected to a pad of a backplane through the metal
wire.
20. The packaging method according to claim 13. wherein before the
cutting the wafer, the substrate and the light shielding layer, the
packaging method further comprises: forming a through silicon via
on a surface of each of the optical fingerprint recognition chips
facing away from the substrate, wherein the contact pad is exposed
by the through silicon via, forming an insulating layer covering a
sidewall of the through silicon via and the back surface of the
optical fingerprint recognition chip, forming a rewiring layer
covering the insulating layer, wherein the rewiring layer is
electrically connected to the contact pad through the through
silicon via and extends outside the through silicon via, and
forming a solder mask covering the rewiring layer, wherein the
solder mask is provided with an opening in a region corresponding
to the back surface of each of the optical fingerprint recognition
chips, the opening is configured to accommodate a solder bump for
electrical connection to a pad of a backplane.
Description
[0001] This application claims priorities to Chinese Patent
Application No. 201711364625.6, titled "OPTICAL FINGERPRINT
RECOGNITION CHIP PACKAGE AND PACKAGING METHOD", filed on Dec. 18,
2017 with the Chinese Patent Office, and Chinese Patent Application
N. 201721773041.X, titled "OPTICAL FINGERPRINT RECOGNITION CHIP
PACKAGE", filed on Dec. 18, 2017 with the Chinese Patent Office,
which are incorporated herein by reference in their entireties.
FIELD
[0002] The present disclosure relates to the technical field of
chip packaging, and in particular to an optical fingerprint
recognition chip package and a packaging method for fabricating the
optical fingerprint recognition chip package.
BACKGROUND
[0003] With the continuous development of science and technology,
more and more electronic devices are widely used in and bring great
convenience to people's daily life and work, and these electronic
devices become indispensable important tools to people currently.
With the continuous increase in the functions of electronic
devices, electronic devices store more and more important
information. The identification authentication technology for
electronic devices becomes a major direction in development of
electronic devices currently.
[0004] The fingerprint recognition technology is characterized by
high safety, high reliability and simple operation because of
uniqueness and invariability of human fingerprints. Therefore, the
fingerprint recognition technology has become a mainstream
technology for identification authentication in various electronic
devices.
[0005] At present, the optical fingerprint recognition chip is
commonly used in conventional electronic devices. The optical
fingerprint recognition chip collects fingerprint information of a
user through a great number of photosensitive pixels in the
fingerprint recognition region, and each of the photosensitive
pixels functions as a detection point. Specifically, during
fingerprint recognition, light is irradiated to a fingerprint
surface of the user and is reflected by the fingerprint surface to
the photosensitive pixels. The photosensitive pixels convert light
signals of the fingerprint into electrical signals, such that
fingerprint information may be acquired based on the electrical
signals converted by all the pixels.
[0006] In a case where a conventional optical fingerprint
recognition chip is packaged, a transparent cover plate is directly
arranged on the photosensitive surface. However, since the
transparent cover plate is completely light-transmitting, crosstalk
may be caused among different photosensitive pixels, such that the
accuracy of fingerprint recognition can be affected.
SUMMARY
[0007] In order to solve the above problems, an optical fingerprint
recognition chip package and a packaging method for fabricating the
optical fingerprint recognition chip package are provided according
to the technical solution of the present disclosure, to eliminate
the crosstalk among different photosensitive pixels, such that
accuracy of fingerprint recognition can be improved.
[0008] The following technical solutions are provided according to
the present disclosure.
[0009] An optical fingerprint recognition chip package is provided,
which includes an optical fingerprint recognition chip, and a cover
plate.
[0010] The optical fingerprint recognition chip has a front surface
and a back surface opposite to each other. The front surface
includes a fingerprint recognition region and a peripheral region
surrounding the fingerprint recognition region, the fingerprint
recognition region is provided with multiple photosensitive pixels,
and the peripheral region is provided with a contact pad
electrically connected to the photosensitive pixels.
[0011] The cover plate is arranged opposite to the front surface of
the optical fingerprint recognition chip and includes a substrate
and a light shielding layer.
[0012] The light shielding layer is located on a side of the
substrate facing away from the optical fingerprint recognition
chip, the substrate is provided with multiple first through holes
for exposing the photosensitive pixels, and the light shielding
layer is provided with multiple second through holes in one-to-one
correspondence with the multiple first through holes.
[0013] In an embodiment, in the above optical fingerprint
recognition chip package, the cover plate is spaced from the
optical fingerprint recognition chip by a preset interval, to
adjust an image distance for pinhole imaging through the cover
plate.
[0014] In an embodiment, in the above optical fingerprint
recognition chip package, a glass filter is arranged between the
cover plate and the optical fingerprint recognition chip, to remove
light outside a detection light wave band.
[0015] In an embodiment, in the above optical fingerprint
recognition chip package, a glass filter is arranged on a surface
of the cover plate facing away from the optical fingerprint
recognition chip, to remove light outside a detection light wave
band.
[0016] In an embodiment, in the above optical fingerprint
recognition chip package, a spacer with a preset thickness is
arranged between a periphery of the cover plate and a periphery of
the optical fingerprint recognition chip.
[0017] In an embodiment, in the above optical fingerprint
recognition chip package, the substrate is provided with a first
opening at a position corresponding to the contact pad, to expose
the contact pad, the light shielding layer is provided with a
second opening at a position corresponding to the first opening, to
expose the first opening, and the contact pad is configured to be
electrically connected to a metal wire through the first opening
and the second opening, so as to be electrically connected to a pad
of a backplane through the metal wire.
[0018] In an embodiment, in the above optical fingerprint
recognition chip package, the first opening includes a first groove
and a second groove located in the first groove, and the contact
pad is exposed by the first groove and the second groove.
[0019] In an embodiment, in the above optical fingerprint
recognition chip package, the optical fingerprint recognition chip
is provided with a through silicon via at a position on the back
surface corresponding to the contact pad, and the contact pad is
exposed by the through silicon via, a sidewall of the through
silicon via and the back surface of the optical fingerprint
recognition chip are covered with an insulating layer, a surface of
the insulating layer is covered with a rewiring layer, and the
rewiring layer is electrically connected to the contact pad through
the through silicon via and extends outside the through silicon
via, and the rewiring layer is covered with a solder mask, the
solder mask is provided with an opening in a region corresponding
to the back surface of the optical fingerprint recognition chip,
and the opening is configured to accommodate a solder bump for
electrical connection to a pad of a backplane.
[0020] In an embodiment, in the above optical fingerprint
recognition chip package, the substrate is a silicon substrate.
[0021] In an embodiment, in the above optical fingerprint
recognition chip package, the light shielding layer is made of dry
film photoresist or wet film photoresist.
[0022] In an embodiment, in the above optical fingerprint
recognition chip package, a depth-to-width ratio of the first
through hole is less than or equal to than 6:1.
[0023] In an embodiment, in the above optical fingerprint
recognition chip package, depth-to-width ratio of the second
through hole is less than or equal to 6:1.
[0024] In an embodiment, in the above optical fingerprint
recognition chip package, a thickness of the substrate is less than
or equal to 200 .mu.m.
[0025] In an embodiment, in the above optical fingerprint
recognition chip package, a thickness of the light shielding layer
is less than or equal to 200 .mu.m.
[0026] In an embodiment, in the above optical fingerprint
recognition chip package, the substrate is attached to the optical
fingerprint recognition chip by a die attach film (DAF).
[0027] In an embodiment, in the above optical fingerprint
recognition chip package, the photosensitive pixels are arranged in
an array, and the first through holes are in one-to-one
correspondence with the pixels.
[0028] A packaging method for fabricating the optical fingerprint
recognition chip package is further provided according to the
present disclosure. The packaging method includes:
[0029] preparing a wafer, where the wafer includes multiple optical
fingerprint recognition chips, each of the optical fingerprint
recognition chips has a front surface and a back surface opposite
to each other, the front surface includes a fingerprint recognition
region and a peripheral region surrounding the fingerprint
recognition region, the fingerprint recognition region is provided
with multiple photosensitive pixels, and the peripheral region is
provided with a contact pad electrically connected to the
photosensitive pixels;
[0030] securing a substrate on the wafer;
[0031] forming a light shielding layer on a surface of the
substrate facing away from the optical fingerprint recognition
chip;
[0032] patterning the light shielding layer multiple second through
holes extending through the light shielding layer;
[0033] patterning the substrate by using the patterned light
shielding layer as a mask layer, to form multiple first through
holes extending through the substrate, where the photosensitive
pixels are exposed by the multiple first through holes, and the
multiple first through holes are in one-to-one correspondence with
the multiple second through holes; and
[0034] cutting the wafer, the substrate and the light shielding
layer by a cutting process to form multiple single packages, where
the wafer is cut to obtain multiple optical fingerprint recognition
chips, each of the substrate and the light shielding layer is cut
to obtain multiple parts in one-to-one correspondence with the
multiple optical fingerprint recognition chips.
[0035] In an embodiment, in the above packaging method, the
securing the substrate on the wafer includes: attaching the
substrate with the wafer, where a preset region of the front
surface of each of the optical fingerprint recognition chips is
secured to a preset region of the substrate, and the substrate is
spaced from the optical fingerprint recognition chip by a preset
interval, to adjust an image distance for pinhole imaging through a
cover plate including the substrate and the light shielding
layer.
[0036] In an embodiment, in the above packaging method, after
forming the multiple first through holes, the method further
includes: attaching glass filters on a surface of the light
shielding layer facing away from the substrate, the glass filters
being in one-to-one correspondence with the optical fingerprint
recognition chips.
[0037] In an embodiment, in the above packaging method, a spacer is
arranged between the substrate and each of the optical fingerprint
recognition chips at a periphery of the optical fingerprint
recognition chip, and a thickness of the spacer is equal to the
preset interval.
[0038] In an embodiment, in the above packaging method, the spacer
is configured to secure the substrate to the optical fingerprint
recognition chip.
[0039] In an embodiment, in the above packaging method, the
securing the substrate on the wafer includes: attaching glass
filters on front surfaces of the optical fingerprint recognition
chips, respectively, and securing the substrate on surfaces of the
glass filters, where the substrate covers the glass filters, and
the substrate is spaced from the optical fingerprint recognition
chips by a preset interval due to a thickness of the glass filters,
to adjust an image distance for pinhole imaging through a cover
plate including the substrate and the light shielding layer
[0040] In an embodiment, in the above packaging method, the light
shielding layer is made of dry film photoresist or wet film
photoresist, the multiple second through holes in one-to-one
correspondence with the multiple photosensitive pixels are formed
on the light shielding layer by an exposure and development
process, and the substrate is a silicon substrate, and the multiple
first through holes are formed on the substrate by a silicon
etching process using the light shielding layer as a mask
layer.
[0041] In an embodiment, in the above packaging method, a second
opening is formed at a position on the light shielding layer
corresponding to the contact pad by an exposure and development
process while the multiple second through holes are formed, and a
first opening is formed at a position on the substrate
corresponding to the contact pad by an etching process on the basis
of the second opening, to expose the contact pad, and the contact
pad is configured to be electrically connected to a metal wire
through the first opening and the second opening, so as to be
electrically connected to a pad of a backplane through the metal
wire.
[0042] In an embodiment, in the above packaging method, before the
cutting the wafer, the substrate and the light shielding layer, the
packaging method further includes:
[0043] forming a through silicon via on a surface of each of the
optical fingerprint recognition chips facing away from the
substrate, where the contact pad is exposed by the through silicon
via,
[0044] forming an insulating layer covering a sidewall of the
through silicon via and the back surface of the optical fingerprint
recognition chip,
[0045] forming a rewiring layer covering the insulating layer,
where the rewiring layer is electrically connected to the contact
pad through the through silicon via and extends outside the through
silicon via, and
[0046] forming a solder mask covering the rewiring layer, where the
solder mask is provided with an opening in a region corresponding
to the back surface of each of the optical fingerprint recognition
chips, the opening is configured to accommodate a solder bump for
electrical connection to a pad of a backplane.
[0047] It can be known from the above description that, in the
optical fingerprint recognition chip package and the packaging
method for fabricating the optical fingerprint recognition chip
package according to the technical solution of the present
disclosure, the cover plate is arranged on the front surface of the
optical fingerprint recognition chip, and the cover plate includes
the substrate and the light shielding layer. The light shielding
layer is arranged on a surface of the substrate facing away from
the optical fingerprint recognition chip. The substrate is provided
with multiple first through holes for exposing photosensitive
pixels of the optical fingerprint recognition chip. The light
shielding layer is provided with multiple second through holes in
one-to-one correspondence with the multiple first through holes.
During fingerprint recognition, light reflected by a finger may be
split by the first through holes and the second through holes which
are in one-to-one correspondence with the first through holes, such
that the crosstalk among different photosensitive pixels is
reduced, and the accuracy of the fingerprint recognition is
improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] The drawings to be used in the description of the
embodiments or the conventional technology will be described
briefly as follows, so that the technical solutions according to
the embodiments of the present disclosure or according to the
conventional technology will become clearer. It is apparent that
the drawings in the following description only illustrate some
embodiments of the present disclosure. For those skilled in the
art, other drawings may be obtained according to these drawings
without any creative work.
[0049] FIG. 1a is a schematic structural diagram of an optical
fingerprint recognition chip package according to an embodiment of
the present disclosure;
[0050] FIG. 1b is a schematic structural diagram of an optical
fingerprint recognition chip package according to another
embodiment of the present disclosure;
[0051] FIG. 2a is a schematic structural diagram of an optical
fingerprint recognition chip package according to another
embodiment of the present disclosure;
[0052] FIG. 2b is a schematic structural diagram of an optical
fingerprint recognition chip package according to another
embodiment of the present disclosure;
[0053] FIG. 3a schematic structural diagram of an optical
fingerprint recognition chip package according to another
embodiment of the present disclosure;
[0054] FIG. 3b schematic structural diagram of an optical
fingerprint recognition chip package according to another
embodiment of the present disclosure;
[0055] FIG. 4a schematic structural diagram of an optical
fingerprint recognition chip package according to another
embodiment of the present disclosure;
[0056] FIG. 4b schematic structural diagram of an optical
fingerprint recognition chip package according to another
embodiment of the present disclosure;
[0057] FIG. 5a to FIG. 10 are schematic diagrams showing a
procedure of a packaging method according to an embodiment of the
present disclosure; and
[0058] FIG. 11 to FIG. 14 are schematic diagrams showing a
procedure of a packaging method according to another embodiment of
the present disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
[0059] The technical solution according to the embodiments of the
present disclosure will be described clearly and completely as
follows in conjunction with the drawings. It is apparent that the
described embodiments are only a few rather than all of the
embodiments according to the present disclosure. Any other
embodiments obtained by those skilled in the art based on the
embodiments in the present disclosure without any creative work
fall in the scope of the present disclosure.
[0060] To make the above object, features and advantages of the
present disclosure more apparent and easier to be understood, the
disclosure is illustrated in detail in conjunction with the
drawings and specific embodiments hereinafter.
[0061] Referring to FIG. 1a, FIG. 1a is a schematic structural
diagram of an optical fingerprint recognition chip package
according to an embodiment of the present disclosure. The optical
fingerprint recognition chip package includes an optical
fingerprint recognition chip 11 and a cover plate. The optical
fingerprint recognition chip 11 has a front surface 111 and a back
surface 112 opposite to each other. The front surface 111 includes
a fingerprint recognition region and a peripheral region
surrounding the fingerprint recognition region. The fingerprint
recognition region is provided with multiple photosensitive pixels
113. The peripheral region is provided with a contact pad 114
electrically connected to the photosensitive pixels 113. The cover
plate is arranged opposite to the front surface 111 of the optical
fingerprint recognition chip 11. The cover plate includes a
substrate 12 and a light shielding layer 13. The light shielding
layer 13 is arranged on a side of the substrate 12 facing away from
the optical fingerprint recognition chip 11. The substrate 12 is
provided with multiple first through holes T1 for exposing the
photosensitive pixels 113. The light shielding layer 13 is provided
with multiple second through holes T2 in one-to-one correspondence
with the multiple first through holes T1.
[0062] In an embodiment, the optical fingerprint recognition chip
11 is further provided with a transparent film layer. The
transparent film layer covers the front surface of the optical
fingerprint recognition chip 11 for planarizing the front surface
of the optical fingerprint recognition chip 11, so as to protect
the photosensitive pixels 113 and facilitate securing of the
optical fingerprint recognition chip 11 with other structures. The
transparent film layer has a preset refractive index and may also
function as an antireflection layer to increase light
transmittance. The transparent film layer covers the photosensitive
pixels 113. The contact pad 114 is exposed through the transparent
film layer.
[0063] In the optical fingerprint recognition chip package
according to the embodiment of the present disclosure, an aperture
of the first through hole T1 is the same as that of the second
through hole T12, or is smaller than that of the second through
hole T2. A center of the first through hole T1 is aligned with a
center of the second through hole T2.
[0064] The cover plate is provided with the first through holes T1
and the second through holes T2 in one-to-one correspondence the
first through holes T1. The aperture of the first through holes T1
and the aperture of the second through holes T2 have the same order
of magnitude as the size of the light sensing pixels 113. That is,
the apertures of the first through hole T1 and the second through
hole T2 are small, such that a pinhole imaging function may he
realized through the cover plate with the first through holes T1
and the second through holes T2. Light reflected by a finger may be
adjusted by the cover plate through the pinhole imaging function,
such that the crosstalk among different photosensitive pixels 113
is reduced and the accuracy of fingerprint recognition is improved.
As shown in FIG. 1a, the cover plate is spaced from the optical
fingerprint recognition chip 11 by a preset interval, to adjust an
image distance for pinhole imaging through the cover plate. The
image distance is adjusted by adjusting the interval, such that a
fingerprint image acquired through the photosensitive pixels 13 has
a good quality. An appropriate interval may be set based on
specific experiments or tests, so as to set an appropriate image
distance. The interval is not specifically limited in the
embodiment of the present disclosure.
[0065] The optical fingerprint recognition chip package further
includes a glass filter L. The glass filter L is configured to
remove light outside the detection light wave band, so as to reduce
disturbance from the light and improve the accuracy of fingerprint
recognition.
[0066] In the embodiment shown in FIG. 1a, the glass filter L is
arranged on a surface of the cover plate facing away from the
optical fingerprint recognition chip 11. The glass filter L covers
only the photosensitive pixels 113. The contact pads 114 are
exposed through the glass filter L. In this case, a spacer J with a
preset thickness is arranged between a periphery of the cover plate
and a periphery of the optical fingerprint recognition chip 11. The
thickness of the spacer J is equal to the interval, and matches
with the image distance for pinhole imaging through the cover
plate. In this embodiment, the image distance for pinhole imaging
through the cover plate is adjusted by setting the thickness of the
spacer J, thereby facilitating adjustment of light. In this
embodiment, the spacer J is configured to secure the substrate 12
to the optical fingerprint recognition chip 11.
[0067] Another embodiment is as shown in FIG. 1b. FIG. 1b is a
schematic structural diagram of an optical fingerprint recognition
chip package according to another embodiment of the present
disclosure. In this embodiment, the glass filter L is arranged
between the cover plate and the optical fingerprint recognition
chip 11. In this case, the thickness of the glass filter L is equal
to the interval, and matches with the image distance for pinhole
imaging through the cover plate. In this embodiment, the image
distance for pinhole imaging through the cover plate is adjusted by
setting the thickness of the glass filter L, thereby facilitating
adjustment of light.
[0068] In the embodiments shown in FIG. 1a and FIG. 1b, the
substrate 12 is provided with a first opening K1 at a position
corresponding to the contact pad 114 to expose the contact pad 114.
The light shielding layer 13 is provided with a second opening K2
at a position corresponding to the first opening K1 to expose the
first opening K1. The contact pad 114 is configured to be
electrically connected to a metal wire through the first opening K1
and the second opening K2, so as to be electrically connected to a
pad of a backplane through the metal wire. In a case where the
contact pad 114 is electrically connected to the backplane, the
metal wire, the first openings K1 and the second openings K2 may be
covered with a mold material layer.
[0069] In the embodiments shown in FIG. 1a and FIG. 1b, the first
opening K1 includes a first groove Ka and a second groove Kb
located in the first groove Ka. The contact pad 114 is exposed by
the first groove Ka and the second groove Kb. A depth of the second
groove Kb is less than the thickness of the substrate 12.
[0070] In an embodiment, the backplane is a PCB panel, a ceramic
substrate or a glass substrate. The substrate 12 is a silicon
substrate. The light shielding layer 13 is made of dry film
photoresist or wet film photoresist, and the second through holes
T2 may be formed by a photolithography process on the light
shielding layer 13. The light shielding layer 13 may also function
as a mask layer for the substrate 12 to form the first through
holes T1.
[0071] In the optical fingerprint recognition chip package
according to the embodiment of the present disclosure, a
depth-to-width ratio of the first through hole T1 is less than or
equal to 6:1. A depth-to-width ratio of the second through hole T2
is less than or equal to 6:1. A thickness of the substrate 12 is
less than or equal to 200 .mu.m. A thickness of the light shielding
layer 13 is less than or equal to 200 .mu.m. In this way, the
pinhole imaging function may be realized by the cover plate with a
small thickness.
[0072] In an embodiment, the substrate 12 is secured to the optical
fingerprint recognition chip 11 by a die attach film (DAF). In this
case, the glass filter is located on the surface of the light
shielding layer 13 facing away from the optical fingerprint
recognition chip 11. In a case where the glass filter is located
between the substrate 12 and the optical fingerprint recognition
chip 11, the glass filter may be secured to the optical fingerprint
recognition chip 11 by the DAF film, and the substrate 12 is
attached to a surface of the glass filter facing away from the
optical fingerprint recognition chip 11.
[0073] The photosensitive pixels 113 are arranged in an array. In
order to avoid the crosstalk among different photosensitive pixels
113 to a maximum degree, the first through holes T1 may be arranged
in one-to-one correspondence with the photosensitive pixels
113.
[0074] In the embodiments shown in FIG. 1a and FIG. 1b, the contact
pad 114 of the optical fingerprint recognition chip 11 is
electrically connected to the pad of the backplane by a wire
process. In other embodiments, the contact pad 114 of the optical
fingerprint recognition chip 11 may be electrically connected to
the pad of the backplane by the TSV (through silicon via) process.
Since the through silicon via extends through the back surface of
the optical fingerprint recognition chip 11, it is not required to
form an opening on the cover plate for exposing the contact pad
114. Therefore, the glass filter L and the cover plate may be
configured to have the same size, and cover the entire front
surface of the optical fingerprint recognition chip 11. In this
case, the optical fingerprint recognition chip package may be as
shown in FIG. 2a to FIG. 4b.
[0075] Referring to FIG. 2a, FIG. 2a is a schematic structural
diagram of an optical fingerprint recognition chip package
according to another embodiment of the present disclosure. In this
embodiment, the optical fingerprint recognition chip 11 is provided
with a through silicon via GT on the back surface at a position
corresponding to the contact pad 114. The contact pad 114 is
exposed by the through silicon via GT. A sidewall of the through
silicon via GT and the back surface of the optical fingerprint
recognition chip are covered with an insulating layer 21. A surface
of the insulating layer 21 is covered with a rewiring layer 22. The
rewiring layer 22 is electrically connected to the contact pad 114
through the through silicon via GT and extends outside the through
silicon via GT. The rewiring layer 21 is covered with a solder mask
23, and the solder mask 23 is provided with an opening in a region
corresponding to the back surface 112 of the optical fingerprint
recognition chip 11 for accommodating a solder bump 24, such that
the contact pad 114 is electrically connected to a pad of a
backplane through the solder bump 24. The solder bump 24 is
electrically connected to the rewiring layer 22 at the opening. The
solder bump 24 may be a solder ball and is connected to the contact
pad by welding. In this embodiment, an adhesive layer is further
arranged between the optical fingerprint recognition chip 11 and
the backplane to secure the optical fingerprint recognition chip 11
to the backplane.
[0076] In the embodiment shown in FIG. 2a, the optical fingerprint
recognition chip 11 is electrically connected to the backplane by a
through silicon via (TSV) process. In this embodiment, the through
silicon via GT is a stepped through hole having two steps. The
stepped through hole includes a groove GT1 located on the back
surface 112 of the optical fingerprint recognition chip 11 and a
through hole GT2 located in the groove GT1. A depth of the groove
GT1 is less than the thickness of the optical fingerprint
recognition chip 11. The through hole GT2 extends through the
optical fingerprint recognition chip 11, to expose the contact pad
114. The groove GT1 corresponding to multiple through holes GT2 on
the same side of the optical fingerprint recognition chip 11 may be
formed into an integral structure.
[0077] In the embodiment shown in FIG. 2a, the glass filter L is
located on a surface of the cover plate facing away from the
optical fingerprint recognition chip 11. In this case, a spacer J
is arranged between the cover plate and the optical fingerprint
recognition chip 11. The image distance for pinhole imaging through
the cover plate is adjusted by setting the thickness of the spacer
J. In this embodiment, a stepped through silicon via having two
steps is used.
[0078] In a case where the contact pad 114 of the optical
fingerprint recognition chip 11 is electrically connected to the
pad of the backplane through the stepped through silicon via having
two steps, the optical fingerprint recognition chip package may
also be as shown in FIG. 2b. FIG. 2b is a schematic structural
diagram of an optical fingerprint recognition chip package
according to another embodiment of the present disclosure. FIG. 2b
is different from FIG. 2a in that the glass filter L is arranged
between the cover plate and the optical fingerprint recognition
chip 11, and the image distance for pinhole imaging through the
cover plate is adjusted by setting the thickness of the glass
filter L.
[0079] In a case where the optical fingerprint recognition chip 11
is electrically connected to the backplane by the TSV process, the
through silicon via GT may also be a straight hole as shown in FIG.
3a. FIG. 3a is a schematic structural diagram of an optical
fingerprint recognition chip pkkage according to another embodiment
of the present disclosure. A width of the straight hole in a first
direction remains constant. The first direction is perpendicular to
the optical fingerprint recognition chip 11, and is from the front
surface 111 of the optical fingerprint recognition chip 11 toward
the back surface 112 of the optical fingerprint recognition chip
11. In this embodiment, the glass filter is located on the surface
of the cover plate facing away from the optical fingerprint
recognition chip 11. In this case, a spacer J is arranged between
the cover plate and the optical fingerprint recognition chip
11.
[0080] In a case where the through silicon via GT is a straight
hole, as shown in FIG. 3b, which is a schematic structural diagram
of an optical fingerprint recognition chip package according to
another embodiment of the present disclosure, the glass filter may
also be arranged between the cover plate and the optical
fingerprint recognition chip 11.
[0081] In a case where the optical fingerprint recognition chip 11
is electrically connected to the backplane by the TSV process, the
through silicon via GT may also be a trapezoid hole as shown in
FIG. 4a. FIG. 4a is a schematic structural diagram of an optical
fingerprint recognition chip package according to another
embodiment of the present disclosure. A width of the trapezoid hole
increases gradually in a first direction. The first direction is
perpendicular to the optical fingerprint recognition chip 11, and
is from the front surface 111 of the optical fingerprint
recognition chip 11 toward the back surface 112 of the optical
fingerprint recognition chip 11. In this embodiment, the glass
filter is located on the surface of the cover plate facing away
from the optical fingerprint recognition chip 11. In this case, a
spacer J is arranged between the cover plate and the optical
fingerprint recognition chip 11.
[0082] In a case where the through silicon via GT is a trapezoid
hole, as shown in FIG. 4b, which is a schematic structural diagram
of an optical fingerprint recognition chip package according to
another embodiment of the present disclosure, the glass filter may
also be arranged between the cover plate and the optical
fingerprint recognition chip 11.
[0083] In the optical fingerprint recognition chip package
according to the embodiment of the present disclosure, the contact
pad 114 may be exposed by an opening arranged on a front surface of
the cover plate to facilitate the electrical connection to an
external circuit, as shown in FIG. 1a and FIG. 1b. Alternatively,
an interconnection structure may be arranged on the back surface of
the optical fingerprint recognition chip 11, for electrical
connection to an external circuit. The interconnection structure
includes an interconnection layer. The interconnection layer
includes the insulating layer 21, the rewiring layer 22 and the
solder mask 23.
[0084] It can be seen from the above description that in the
optical fingerprint recognition chip package according to the
embodiment of the present disclosure, the substrate 12 provided
with the first through holes T1 is arranged on the front surface
111 of the optical fingerprint recognition chip 11, and the light
shielding layer 13 is arranged on a surface of the substrate 12
facing away from the optical fingerprint recognition chip 11. The
light shielding layer 13 is provided with second through holes T2
in one-to-one correspondence with the first through holes T1. With
the first through holes T1 and the second through holes T2, the
light reflected at a specific angle may travel through the cover
plate, and enters the fingerprint recognition region, such that the
light path is controlled and the crosstalk is avoided. The first
through holes T1 may be in one-to-one correspondence with the
photosensitive pixels 113, or one first through hole T1 may
correspond to multiple photosensitive pixels 113.
[0085] During fingerprint recognition, the light reflected by the
finger may be split by the first through holes T1 and the second
through holes T2 in one-to-one correspondence the first through
holes T1 so as to reduce the crosstalk among different
photosensitive pixels, and improve the accuracy of fingerprint
recognition.
[0086] Based on the above embodiments of the optical fingerprint
recognition chip package, a packaging method is further provided
according to another embodiment of the present disclosure. The
packaging method is used for packaging an optical fingerprint
recognition chip to form the optical fingerprint recognition chip
package described in the above embodiments. The packaging method is
shown in FIG. 5a to FIG. 10, which show a procedure of a packaging
method according to an embodiment of the present disclosure. The
packaging method includes the following steps S11 to S16.
[0087] In step S11, as shown in FIG. 5a and FIG. 5b, a wafer 10 is
prepared.
[0088] FIG. 5a is a top view of the wafer 10 corresponding to the
front surface of the optical fingerprint recognition chip, and FIG.
5b is a cross-sectional view of the wafer shown in FIG. 5a taken
along A-A'. The wafer 10 includes multiple optical fingerprint
recognition chips 11. Each of the optical fingerprint recognition
chips 11 has a front surface 111 and a back surface 112 opposite to
each other. The front surface 111 includes a fingerprint
recognition region and a peripheral region surrounding the
fingerprint recognition region. The fingerprint recognition region
is provided with multiple photosensitive pixels 113. The peripheral
region is provided with a contact pad 114 electrically connected to
the photosensitive pixels 113. A cutting trench 20 is provided
between adjacent optical fingerprint recognition chips 11.
[0089] In step S12, as shown in FIG. 6, a substrate 12 is secured
to the wafer 10.
[0090] In this step, the substrate 12 is secured to the wafer 10 in
the following manner. The substrate 12 is attached with the wafer
10. A preset region of the front surface of each of the optical
fingerprint recognition chips 11 is secured to a preset region of
the substrate 12, such that in each of the packages obtained by the
cutting process, the optical fingerprint recognition chip 11 is
secured to a cover plate obtained by cutting the substrate 12
corresponding to the optical fingerprint recognition chip 11. The
substrate 12 is spaced from the optical fingerprint recognition
chip 11 by a preset interval to adjust the image distance for
pinhole imaging through the cover plate. The cover plate includes
the substrate and a light shielding layer described below.
[0091] In this embodiment, the substrate 12 is directly secured to
the front surface of each of the optical fingerprint recognition
chips 11 by a spacer J at the periphery of the front surface of the
optical fingerprint recognition chips 11. The spacer is arranged
between the optical fingerprint recognition chip 11 and the
substrate 12 at the periphery of the optical fingerprint
recognition chips 11. A thickness of the spacer matches with the
image distance for pinhole imaging through the cover plate. In this
embodiment, as shown in FIG. 6, the cover plate is directly secured
to the front surface of each of the optical fingerprint recognition
chips 11 at the periphery of the front surface.
[0092] In an embodiment, the substrate 12 is a silicon substrate.
In a subsequent step, first through holes T1 are formed on the
substrate 12 by a silicon etching process using the light shielding
layer 13 as a mask layer.
[0093] In step S13, as shown in FIG. 7, a light shielding layer 13
is formed on a surface of the substrate 12 facing away from the
optical fingerprint recognition chip 11.
[0094] In an embodiment, the light shielding layer 13 is made of
dry film photoresist or wet film photoresist, to facilitate
formation of the second through holes T2 on the light shielding
layer 13 which are in one-to-one correspondence with the
photosensitive pixels 113 by an exposure and development process in
a subsequent step.
[0095] In step S14, as shown in FIG. 8, the light shielding layer
13 is patterned to form multiple second through holes T2 extending
through the light shielding layer 13.
[0096] In step S15, as shown in FIG. 9, the substrate 12 is
patterned by using the patterned light shielding layer 13 as a mask
layer, to form the first through holes T1 extending through the
substrate 12.
[0097] The first through holes T1 are configured to expose the
photosensitive pixels 113, and the first through holes T1 are in
one-to-one correspondence with the second through holes T2.
[0098] In step S16, as shown in FIG. 10, the wafer 10, the
substrate 12 and the light shielding layer 13 are cut by a cutting
process to form multiple single packages.
[0099] The wafer 10 is cut to obtain multiple optical fingerprint
recognition chips 11. Each of the substrate 12 and the light
shielding layer 13 is cut to obtain multiple parts in one-to-one
correspondence with the optical fingerprint recognition chips
11.
[0100] After the first through holes T1 are formed, the packaging
method further includes: attaching glass filters L on a surface of
the light shielding layer 13 facing away from the substrate 12. The
formed package is as shown in FIG. 1a. The glass filters L are in
one-to-one correspondence with the optical fingerprint recognition
chips. In this case, the glass filters L may be attached to regions
respectively corresponding to the optical fingerprint recognition
chips 11 before the cutting process is performed, or the glass
filter L may be attached to a region corresponding to the optical
fingerprint recognition chip 11 after the cutting process is
performed.
[0101] In the packaging method shown in FIGS. 5a to 10, a spacer J
is arranged between the substrate 12 and the optical fingerprint
recognition chip 11 at the periphery of the optical fingerprint
recognition chip 11, and the thickness of the spacer J is equal to
the interval. The spacer J is configured to secure the substrate 12
to the optical fingerprint recognition chip 11.
[0102] In the packaging method according to the embodiment of the
present disclosure, the light shielding layer 13 is made of dry
film photoresist dry film or wet film photoresist, and the second
through holes T2 in one-to-one correspondence with the
photosensitive pixels 113 are formed on the light shielding layer
13 by an exposure and development process. The substrate 12 is a
silicon substrate. The first through holes T1 are formed on the
substrate 12 by a silicon etching process using the light shielding
layer 13 as a mask layer.
[0103] In the packaging method shown in FIGS. 5a to 10, a second
opening K2 is formed at a position on the light shielding layer 13
corresponding to the contact pad 114 by an exposure and development
process while the second through holes T2 are formed. On the basis
of the second opening K2, a first opening K1 is formed at a
position on the substrate corresponding to the contact pad 114 by
an etching process, to expose the contact pad 114. The contact pad
114 is configured to be electrically connected to a metal wire
through the first opening K1 and the second opening K2, so as to be
electrically connected to a pad of a backplane through the metal
wire. The first opening includes a first groove Ka and a second
groove Kb located in the first groove Ka. The first opening K1 may
be formed while the first through hole T1 is formed.
[0104] In other embodiments, the glass filters L may be
respectively attached to the optical fingerprint recognition chips
11 before the substrate 12 is secured on the wafer 10. In this
case, the securing the substrate 12 on the wafer 10 includes:
attaching glass filters L on front surfaces 111 of the optical
fingerprint recognition chips 11 respectively, and securing the
substrate 12 on surfaces of the glass filters L. The substrate 12
covers all of the glass filters L. The substrate 12 is spaced from
the optical fingerprint recognition chip 11 by a preset interval
due to the thickness of the glass filter L, to adjust the image
distance for pinhole imaging through the cover plate. Similarly,
the cover plate includes the substrate 12 and the light shielding
layer 13, and the formed package is as shown in FIG. 1b.
[0105] In the packaging method according to the embodiment of the
present disclosure, the substrate 12 provided with the first
through holes T1 and the light shielding layer 13 provided with the
second through holes T2 are arranged on the front surface 111 of
the optical fingerprint recognition chip, such that the crosstalk
among different photosensitive pixels 113 can be effectively
avoided, and the accuracy of fingerprint recognition is improved.
In this case, the light shielding layer 13 may also be used as a
mask layer for the substrate 12, such that the process flow is
simplified and the manufacturing cost is reduced.
[0106] The packaging method further includes: arranging a backplane
on a side of the optical fingerprint recognition chip facing away
from the substrate. The backplane includes a metal circuit layer
and a pad electrically connected to the metal circuit layer. The
contact pad 114 is electrically connected to the pad of the
backplane, so as to be electrically connected to an external
circuit through the backplane. The optical fingerprint recognition
chip may be electrically connected to the backplane through a
wire.
[0107] In other embodiments, an interconnection structure may be
formed on the back surface of the package by a TSV process, thereby
facilitating electrical connection to the backplane, thus realizing
electrical connection to an external circuit through the backplane.
The formed package is as shown in FIG. 2a to FIG. 4b.
[0108] The packages as shown in FIGS. 2a to 4a are fabricated by a
packaging method shown in FIGS. 11 to 14. After the first through
holes T1 and the second through holes T2 are formed, the method
further includes the following steps S21 to S24.
[0109] In step S21, as shown in FIG. 11, before the cutting process
is performed, a through silicon via GT is formed on a surface of
each of the optical fingerprint recognition chips 11 facing away
from the substrate 12. The contact pad 114 is exposed by the
through silicon via GT.
[0110] In this step, the wafer 10 is inverted, such that the cover
plate faces downward, thereby facilitating the formation of the
through silicon via GT. In FIG. 11, a stepped through hole
including two steps is shown as an example. The stepped through
hole includes a groove GT1 located on the back surface 112 of the
optical fingerprint recognition chip 11 and a through hole GT2
located in the groove GT1.
[0111] In step S22, as shown in FIG. 12, an insulating layer 21
covering a sidewall of the through silicon via GT and the back
surface of the optical fingerprint recognition chip 11 is
formed.
[0112] In step S23, as shown in FIG. 13, a rewiring layer 22
covering the insulating layer 21 is formed. The rewiring layer 22
is electrically connected to the contact pad 114 through the
through silicon via GT and extends outside the through silicon via
GT.
[0113] In step S24, as shown in FIG. 14, a solder mask 23 covering
the rewiring layer 22 is formed. The solder mask 23 is provided
with an opening in a region opposite to the back surface of each of
the optical fingerprint recognition chips 11 to accommodate a
solder bump 24. The solder bump 24 is configured to be electrically
connected to a pad of a backplane.
[0114] After the back surface interconnection structure is formed
on the back surface of the wafer, first, the back surface
interconnection structure of the wafer is precut to partition the
interconnect layer (including the insulating layer, the rewiring
layer and the solder mask). The pre-cutting process may be
performed by laser along a cutting trench. After the pre-cutting
process is performed, the backplane and the wafer are cut by a
cutter. Since the interconnect layer is made of a material which is
relatively brittle and has low ductility and toughness, the back
surface interconnection structure is pre-cut by laser, to reduce
damage to the interconnection layer, thereby avoiding cracking or
faults of the interconnection layer, thus ensuring the reliability
of the chip. The wafer, the substrate and the light shielding layer
are respectively made of materials with the same or similar
hardness and may be cut using the same cutter along a mark
pre-formed by laser, while ensuring the flatness of the cutting end
face and avoiding damage to the end face.
[0115] After the cutting process is performed, the glass filter L
is attached, and the formed package is as shown in FIG. 2a. The
differences between the packages shown in FIG. 2b to FIG. 4b are
that the through silicon vias GT have different shapes and the
glass filter is located at different positions. For the formation
process, reference may be made to the above description and is not
repeated here.
[0116] The optical fingerprint recognition chip package described
in the above embodiments can be fabricated with the packaging
method according to the embodiments of the present disclosure with
simple processes at a low manufacturing cost. With the formed
optical fingerprint recognition chip package, the crosstalk between
different photosensitive pixels can be avoided, and the accuracy of
fingerprint recognition is improved.
[0117] The above embodiments are described in a progressive manner.
Each of the embodiments is mainly focused on describing its
differences from other embodiments, and references may be made
among these embodiments with respect to the same or similar parts.
For the packaging method disclosed in the embodiment, since the
packaging method corresponds to the optical fingerprint recognition
chip package disclosed in the embodiments, the packaging method is
described simply. For the relevant part, reference may be made to
the corresponding part of the optical fingerprint recognition chip
package.
[0118] The above illustration of the disclosed embodiments enables
those skilled in the art to implement or practice the present
disclosure. Various modifications to the embodiments are apparent
to the person skilled in the art, and the general principle herein
can be implemented in other embodiments without departing from the
spirit or scope of the present disclosure. Therefore, the present
disclosure is not limited to the embodiments described herein, but
should be in accordance with the broadest scope consistent with the
principle and novel features disclosed herein.
* * * * *