CN111163254A

CN111163254A - Image sensing module

Info

Publication number: CN111163254A
Application number: CN202010119558.7A
Authority: CN
Inventors: 范成至; 周正三
Original assignee: Egis Technology Inc
Current assignee: Egis Technology Inc
Priority date: 2019-09-23
Filing date: 2020-02-26
Publication date: 2020-05-15
Also published as: TW202113949A; CN111163255A; CN211089753U; TW202113665A; TWM596898U; TWM596975U; TW202114184A; WO2021056960A1; WO2021056950A1; TWI715439B; CN211087275U; CN110911434A; CN211184079U; TWM596974U; TWM597018U; CN211555889U; TW202114190A; WO2021056961A1; CN111261650A

Abstract

The invention provides an image sensing module, which comprises an image sensor chip, a micro lens array, a wall structure and an optical filter. The micro lens array is configured on the image sensor chip, the fence structure is formed on the image sensor chip, and the optical filter is configured on the fence structure.

Description

Image sensing module

Technical Field

The present invention relates to a sensing module, and more particularly, to an image sensing module.

Background

With the progress of the photoelectric technology, the image sensing module has been developed rapidly to replace the traditional photosensitive film. In order to solve the problem of overexposure easily caused in outdoor sunlight scenes, an infrared light cut-off filter is usually added to the image sensing module to block infrared light. When the image sensing module is configured below the screen of the electronic device to serve as an in-screen optical fingerprint sensing module, it is also important to add an infrared cut-off filter.

As the thickness of the portable electronic device is thinner, the thickness of the image sensing module is also thinner. One method is to reduce the thickness of the glass substrate of the infrared cut-off filter, but the reduction of the glass substrate is likely to cause the glass substrate to be brittle and broken, and further reduce the yield of the back-end module.

On the other hand, the conventional infrared cut filter is finally attached after the module is completed, so that the distance between the infrared cut filter and the image sensor chip is not easy to control and is large by considering the wire bonding arc height and the tolerance of each process material, and further the thickness of the image sensing module is difficult to reduce.

Disclosure of Invention

The invention is directed to an image sensing module, which can have a thinner thickness and a higher process yield.

An embodiment of the invention provides an image sensing module, which includes an image sensor chip, a microlens array, a wall structure, and an optical filter. The micro lens array is configured on the image sensor chip, the fence structure is formed on the image sensor chip, and the optical filter is configured on the fence structure.

In the image sensing module according to the embodiment of the invention, since the enclosing wall structure on the image sensor chip is used for supporting the optical filter, the distance between the optical filter and the image sensor chip can be well controlled and can be smaller, so that the image sensing module according to the embodiment of the invention has a better sensing effect, and the overall thickness can be reduced. In addition, in the image sensing module according to the embodiment of the invention, since the filter uses the plastic substrate, the thickness of the filter is thin and the filter is not brittle or easily broken, so that the thickness of the image sensing module according to the embodiment of the invention is reduced.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

Fig. 1 is a schematic cross-sectional view of an image sensor module according to an embodiment of the invention;

fig. 2 is a schematic cross-sectional view of an image sensor module according to another embodiment of the invention.

Description of the reference numerals

100: an image sensing module;

110: a base plate;

120: an image sensor chip;

122: a conductive pad;

130: a microlens array;

140: a wall structure;

150: an optical filter;

152: a glass substrate;

154: a filter layer;

160: a flexible printed circuit board;

170: attaching a film to the chip;

180: a bonding wire;

t1: and (4) thickness.

Detailed Description

Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

Fig. 1 is a schematic cross-sectional view of an image sensor module according to an embodiment of the invention. Referring to fig. 1, the image sensing module 100 of the present embodiment includes an image sensor chip 120, a microlens array 130, a wall structure 140, and a filter 150. The microlens array 130 is disposed on the image sensor chip 120, the wall structure 140 is formed on the image sensor chip 120, and the filter 150 is disposed on the wall structure. In one embodiment, the image sensor chip 120 is, for example, a complementary metal oxide semiconductor image sensor chip (cmos image sensor chip), a charge coupled device chip (charged coupled device chip), or other suitable image sensor chip. The microlens array 130 may have a plurality of microlenses arranged in an array and disposed on the image sensor chip 120.

The fence structure 140 may be directly formed on the image sensor chip 120. In the present embodiment, the fence structure 140 can be formed by a semiconductor process, i.e., the fence structure 140 is formed on the image sensor chip 120 by a semiconductor process. For example, the wall structure 140 may be formed by photolithography and made of a photoresist material, or the wall structure 140 may be formed on the surface of the image sensor chip 120 by a screen printing process. The filter 150 may be directly attached to the wall structure 140 after the wall structure 140 is formed.

In the image sensor module 100 of the present embodiment, the barrier structure 140 on the image sensor chip 120 is used to support the filter 150, so that the distance between the filter 150 and the image sensor chip 120 can be well controlled and is thin. In other words, the distance between the image sensor chip 120 and the object to be measured is reduced, and the sensing effect is better. It can also be understood that the overall thickness of the image sensor module 100 of the present embodiment is also reduced due to the reduced distance between the filter 150 and the image sensor chip 120.

In the present embodiment, the image sensor chip 120 has at least one conductive pad 122, and the microlens array 130 and the conductive pad 122 are respectively located inside and outside the wall structure 140. In addition, in the present embodiment, the image sensor module 100 further includes a bottom plate 110, a flexible printed circuit 160 and at least one bonding wire 180. The image sensor chip 120 and the flexible printed circuit board 160 are disposed on the base plate 110. In the present embodiment, the flexible printed circuit board 160 is disposed around the image sensor chip 120. In one embodiment, the image sensor chip 120 may be attached to the base plate 110 by a die attach film (die attach film) 170. In addition, in the present embodiment, the bonding wire 180 is electrically connected to the conductive pad 122 and the flexible printed circuit board 160 and located outside the wall structure 140.

In the embodiment, before the image sensor chip 120 is assembled on the bottom plate 110 and electrically connected to the flexible printed circuit board 160 through the bonding wire 180, the optical filter 150 is already attached to the wall structure 140, so that the distance between the optical filter 150 and the image sensor chip 120 does not need to consider the arc height of the bonding wire 180, and the purpose of small distance and precise control can be achieved. In addition, since the microlens array 130 is protected by the filter 150 thereon, the microlens array 130 can be prevented from being damaged in the subsequent module assembly and wire bonding processes, and the process yield can be further improved.

In one embodiment, the optical filter 150 includes a glass substrate 152 and a filter layer 154, wherein the filter layer 154 is disposed on the glass substrate 152. In the present embodiment, the filter layer 154 is a multi-layer film made by using the principle of thin film interference, for example, and can filter infrared light. That is, the filter layer 154 is, for example, an infrared light cut filter layer, and the filter 150 is, for example, an infrared light cut filter. In the embodiment, the filter layer 154 is disposed on the upper surface of the glass substrate 152, however, in other embodiments, the filter layer 154 may be disposed on the lower surface of the glass substrate 152, or the filter layer 154 may be disposed on both the upper surface and the lower surface of the glass substrate 152, as shown in fig. 2. In the present embodiment, the thickness T1 of the glass substrate 152 may be slightly greater than about 100 microns. However, in other embodiments, the glass substrate 152 may be replaced by a plastic substrate, and the thickness of the plastic substrate may fall within a range of 50 micrometers to 150 micrometers, and preferably falls within a range of 60 micrometers to 100 micrometers. That is, since the plastic substrate is thinner, the plastic substrate is used as a part of the filter to further reduce the thickness of the image sensor module 100, and the problem that the glass substrate is fragile and easy to break can be solved. In addition, the filter layer 154 may be disposed on the upper surface of the plastic substrate, however, in other embodiments, the filter layer 154 may be disposed on the lower surface of the plastic substrate, or both the upper surface and the lower surface of the plastic substrate may be disposed with the filter layer 154.

In the image sensing module in which the optical filter is disposed on the flexible printed circuit board by the spacer, the distance between the optical filter and the image sensor chip should take into account the total tolerance of the thickness tolerance of the microlens array, the thickness tolerance of the image sensor chip, the thickness tolerance of the chip attachment film, the thickness tolerance of the flexible printed circuit board, the thickness tolerance of the spacer, and other tolerances. In contrast, the distance between the filter 150 and the image sensor chip 120 in fig. 1 only needs to take into account the thickness tolerance of the microlens array 130 and the thickness tolerance of the fence structure 140, so the distance between the filter 150 and the image sensor chip 120 in fig. 1 can be designed to be smaller.

In summary, in the image sensing module according to the embodiment of the invention, since the surrounding wall structure on the image sensor chip is used to support the optical filter, the distance between the optical filter and the image sensor chip can be well controlled and is small, so that the image sensing module according to the embodiment of the invention has a good sensing effect, and the overall thickness can be reduced. In addition, in the image sensing module according to the embodiment of the invention, since the filter uses the plastic substrate, the thickness of the filter is thin and the filter is not brittle or easily broken, so that the thickness of the image sensing module according to the embodiment of the invention is reduced.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An image sensing module, comprising:

an image sensor chip;

a microlens array disposed on the image sensor chip;

a fence structure formed on the image sensor chip; and

the optical filter is configured on the wall structure.

2. The image sensor module of claim 1, further comprising bonding wires electrically connecting the image sensor chip and the flexible printed circuit board and located outside the wall structure.

3. The image sensor module as claimed in claim 2, wherein the image sensor chip has conductive pads, the bonding wires electrically connect the conductive pads and the flexible printed circuit board, and the micro-lens array and the conductive pads are respectively located inside and outside the wall structure.

4. The image sensing module of claim 2, further comprising:

a chassis, wherein the image sensor chip is disposed on the chassis, and the flexible printed circuit board is disposed on the chassis.

5. The image sensing module of claim 1, wherein the filter comprises:

a glass substrate; and

and the filter layer is configured on the glass substrate.

6. The image sensing module of claim 1, wherein the filter comprises:

a glass substrate; and

and the two filter layers are respectively arranged on the upper surface and the lower surface of the glass substrate.

7. The image sensing module of claim 1, wherein the filter comprises:

a plastic substrate; and

and the filter layer is configured on the plastic substrate.

8. The image sensing module of claim 7, wherein the thickness of the plastic substrate is in a range of 50 to 150 microns.

9. The image sensing module of claim 1, wherein the filter comprises:

a plastic substrate; and

and the two filter layers are respectively arranged on the upper surface and the lower surface of the plastic substrate.