CN211957644U - Chip module and electronic equipment - Google Patents

Abstract

The application discloses chip module and electronic equipment, the chip module includes: the optical sensing chip is provided with a first surface and a second surface which are opposite, and a bonding pad and a sensing area are formed in the first surface; the plurality of optical through holes are positioned in the optical sensing chip, penetrate through the partial thickness of the optical sensing chip from the second surface, correspond to the sensing area of the optical sensing chip and are used for sensing optical signals to the sensing area; the light-transmitting layer is filled in the light through hole, and the optical structure is positioned above the light-transmitting layer; and the conductive structure is positioned on the same side of the second surface of the optical sensing chip and is electrically connected to the bonding pad. The thickness of the chip module is low.

Description

Chip module and electronic equipment

Technical Field

The application relates to the technical field of sensing, in particular to a chip module and electronic equipment.

Background

Recently, the development trend of electronic products such as mobile phones is approaching to the full-screen and light-weight direction, the reduction of the total thickness of the biological detection and identification module under the full-screen carrying screen becomes an urgent need, and the conventional cob (chip on board) scheme is generally adopted in the industry at present, but the conventional cob (chip on board) scheme has a larger overall thickness because an optical lens needs to be matched with a holder for use in a terminal, and no method is available for the existing technical requirements.

With the continuous development and progress of the technology, the micro-lens directly replaces the traditional camera lens, directly reduces the thickness of the lens in the module from millimeter level to micrometer level, and further reduces the thickness of the module. However, the structure of the microlens needs to depend on optical elements such as glass, and a single optical microlens portion needs to be attached to a chip in a single-particle manner, which has a strict requirement on alignment precision in this step, so that the productivity and yield are relatively low. And the micro lens is supported on the optical element, so that the thickness of the chip module is larger.

How to further reduce the thickness of the chip module is a problem to be solved.

SUMMERY OF THE UTILITY MODEL

In view of this, the present application provides a chip module and an electronic device to reduce the thickness of the chip module.

The technical scheme of the utility model a chip module is provided, include: the optical sensing chip is provided with a first surface and a second surface which are opposite, and a bonding pad and a sensing area are formed in the first surface; the plurality of optical through holes are positioned in the optical sensing chip, penetrate through the partial thickness of the optical sensing chip from the second surface, correspond to the sensing area of the optical sensing chip and are used for sensing optical signals to the sensing area; the light-transmitting layer is filled in the light through hole, and the optical structure is positioned above the light-transmitting layer; and the conductive structure is positioned on the same side of the second surface of the optical sensing chip and is electrically connected to the bonding pad.

Optionally, the method further includes: a substrate; the circuit board is fixed on the surface of the substrate and provided with an opening, and part of the surface of the substrate is exposed out of the opening; the first surface of the optical sensing chip faces the substrate and is fixed on the surface of the substrate at the bottom of the opening; and the conductive structure and the circuit board are electrically connected through a bonding wire.

Optionally, the conductive structure includes an electrical connection layer connected to the pad.

Optionally, the conductive structure includes: the groove is positioned in the second surface of the optical sensing chip, and the bottom of the groove is exposed out of the bonding pad on the first surface of the optical sensing chip; an electrical connection layer covering at least the trench bottom and/or a portion of the sidewalls, the electrical connection layer being electrically connected to the pad.

Optionally, the conductive structure includes: the bottom of the conductive through hole is exposed out of a bonding pad of the optical sensing chip; and the electric connection layer covers the inner wall of the conductive through hole.

Optionally, an insulating layer is formed between the electrical connection layer and the semiconductor substrate of the optical sensing chip.

Optionally, the sensing area includes a plurality of discrete sub-sensing areas, and the optical through holes correspond to the sub-sensing areas one to one.

Optionally, the optical sensor further includes a protection structure located on the second surface of the optical sensor chip and surrounding the optical structure, and a top of the protection structure is higher than a top of the optical structure.

Optionally, the light-transmitting layer further covers the second surface of the optical sensing chip.

The technical scheme of the utility model an electronic equipment is still provided, include as above-mentioned arbitrary chip module.

The utility model discloses a chip module is formed with the light through-hole in the opposite side surface relative with the sensing area of optical sensing chip the light through-hole intussuseption is filled with the euphotic layer and is formed the optical structure who is located the euphotic layer top, and optical structure directly forms on the chip surface, need not to utilize the glass substrate as the carrier, can reduce the thickness of chip module. And a conductive structure is formed on the side where the optical through hole is formed and connected to a bonding pad of the optical sensing chip, and the signal connecting end is led out to the side where the optical structure is formed through the conductive structure, so that the subsequent electric connection with the circuit board through a lead bonding mode is facilitated.

Furthermore, the optical sensing chip is fixed on the surface of the substrate in an inverted mode, the circuit board is fixed on the surface of the substrate, and the optical sensing chip is located in the opening of the circuit board, so that the circuit board does not occupy the whole thickness of the chip module, and the thickness of the chip module can be effectively reduced. The conductive structure and the circuit board are electrically connected through a lead bonding process, and compared with a flip-chip bonding process, no solder occupies the thickness of the chip module, so that the thickness of the chip module can be further reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 to 8 are schematic structural diagrams illustrating a forming process of a chip module according to an embodiment of the present invention;

fig. 9 to 12 are schematic structural diagrams illustrating a forming process of a chip module according to an embodiment of the present invention;

fig. 13 to 16 are schematic structural diagrams illustrating a forming process of a chip module according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present application are clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. The following embodiments and their technical features may be combined with each other without conflict.

Please refer to fig. 1 to 8, which are schematic structural views illustrating a forming process of a chip module according to an embodiment of the present invention.

Referring to fig. 1, an optical sensor chip 100 is provided, where the optical sensor chip 100 has a first surface 110 and a second surface 120 opposite to the first surface 110, and a bonding pad 111 and a sensing region 112 are formed in the first surface 110.

The first surface 110 may be understood as a front surface of the optical sensor chip 100, and the second surface 120 is an opposite back surface of the optical sensor chip 100.

The bonding pads 111 are formed on the periphery of the sensing region 112, and are connected to the interconnect structure in the optical sensing chip 100 as connection points for signal output. Specifically, as an embodiment, the optical sensing chip 100 includes a semiconductor substrate and a dielectric layer formed on a top surface of the semiconductor substrate, where the top surface of the dielectric layer is a first surface 110, the bottom surface of the semiconductor substrate is a second surface 120, a light sensing unit is formed in the top surface of the semiconductor substrate, and the light sensing unit may be a photosensitive sensing unit such as a CMOS sensing unit or a CCD sensing unit. An interconnection structure connected to the light sensing unit is formed in the dielectric layer, and the bonding pad 111 is located above the interconnection structure and connected with the interconnection structure. The sensing region 112 is illustrated in FIG. 1 as a rough location only and does not represent the actual sensing region 112 location and size.

Although fig. 1 shows only a single chip structure, in an actual forming process, the optical sensor chip 100 may be a part of an entire wafer, or may be a single bare chip obtained after the wafer is diced.

Referring to fig. 2, the second surface 120 of the optical sensor chip 100 is thinned to a target thickness.

In order to avoid damage to the first surface 110 of the optical sensor chip 100 and provide physical support for the optical sensor chip 100, the first surface 110 of the optical sensor chip 100 is fixed to a surface of a temporary carrier 200 before thinning.

The temporary carrier 200 may be glass, a plastic substrate, a steel plate, etc., and can provide a strong physical support and protect the first surface 110 of the optical sensor chip 100. In this embodiment, the optical sensor chips 100 are a part of a wafer, the temporary carrier 200 may be a carrier with a size equivalent to that of the wafer, the entire wafer is fixed on the surface of the temporary carrier 200, and the second surfaces 120 of all the optical sensor chips 100 in the wafer may be thinned at the same time. In the embodiment of the present invention, the optical sensor chip 100 may be fixed on the surface of the temporary carrier 200 through an adhesive layer or a bonding process.

The second surface 120 of the optical sensor chip 100 may be thinned by at least one of etching and chemical mechanical polishing, so that the thinned optical sensor chip 100a has a target thickness, and difficulty of a subsequent etching or deposition process is reduced. The target thickness can be 40 μm to 60 μm at the lowest, and even 30 μm, and can be adjusted according to specific requirements. In other embodiments, the thinning step may be omitted when the thickness of the optical sensor chip 100 is small.

Referring to fig. 3, the second surface 120 of the optical sensor chip 100a is etched, and a plurality of optical through holes 301 corresponding to the sensing region 112 are formed in the thinned optical sensor chip 100a for transmitting optical signals to the sensing region 112.

In fig. 3, two optical through holes 301 are taken as an example. And etching the second surface 120 of the optical sensing chip 100a to the inside of the semiconductor substrate of the optical sensing chip by a dry etching process to form an optical through hole 301 penetrating through a part of the thickness of the optical sensing chip 100 a. The optical via 301 corresponds to the sensing region 112, so that an optical signal entering the semiconductor substrate irradiated to the bottom of the optical via 301 from the optical via 301 can be received by the sensing region 112, and an optical sensing signal, i.e., an electrical signal generated by a photoelectric conversion effect, is generated. If the thickness of the semiconductor substrate at the bottom of the optical through hole 301 is too small, the sensing unit in the optical sensing region 112 may be damaged, resulting in a decrease in the photoelectric conversion capability of the sensing region; if the thickness of the semiconductor substrate at the bottom of the optical via 301 is too large, the optical signal loss will be too large, so that the photoelectric conversion efficiency is low. In some embodiments, the semiconductor substrate at the bottom of the optical via 301 has a thickness in the range of 10 μm to 50 μm. Those skilled in the art can adjust the depth of the optical via 301 according to actual requirements to adjust the thickness of the semiconductor substrate at the bottom of the optical via 301, which is not limited by the embodiments of the present invention.

The spacing between adjacent optical vias 301 cannot be too small to avoid crosstalk between optical signals between adjacent optical vias 301. Preferably, the range of the distance between adjacent optical vias 301 may be greater than twice the thickness of the semiconductor substrate at the bottom of the optical via 301, so that the semiconductor substrate material between adjacent optical vias 301 can achieve a better optical isolation effect, and the optical signal entering the optical via 301 can only be received by the local optical sensing region at the bottom of the optical via 301. The plurality of optical vias 301 constitute an optical via array.

In some embodiments, the sensing region 112 is a whole sensing region, and includes a plurality of sensing units arranged in an array, and only a portion of the sensing region located at the bottom of the optical through hole 301 can receive optical signals, so as to generate optical sensing signals for forming an optical sensing image.

In some embodiments, the sensing region 112 may include a plurality of sub-sensing regions, which are in one-to-one correspondence with the optical through holes 301, and the sub-sensing regions are located in the projection region of the corresponding optical through hole on the first surface, and each sub-sensing region includes one or more sensing units. The adjacent sub-sensing regions can be isolated by an isolation structure, such as a shallow trench isolation structure, so that the problems of crosstalk and the like between optical sensing signals (electrical signals) generated by the sub-sensing regions are avoided.

Referring to fig. 4, the optical through hole 301 (see fig. 3) is filled with a transparent layer 401.

The material of the light-transmitting layer 401 may be a material having a self-filling effect, and may be capable of self-filling in the light through hole 301, and a flat surface covering the second surface 120 is formed at a position slightly higher than the second surface 120, and the light-transmitting layer 401 may be formed in the light through hole 301 and on the second surface 120 of the chip by at least one or more of vacuum spin coating, multiple spin coating, and printing.

In this embodiment, after the light-transmitting layer 401 forms a flat plane through a self-leveling effect, the surface of the light-transmitting layer 401 is further processed through processes of mechanical or chemical mechanical polishing, etching, and the like, so that the surface is more flat, diffuse reflection of incident light by the light-transmitting layer 401 is reduced, and optical performance is improved; further, the height of the light-transmitting layer 401 may be adjusted, and a portion higher than the second surface 120 may be removed, so that the light-transmitting layer 401 is only located in the light-passing hole 401.

Those skilled in the art may adjust the thickness of light-transmitting layer 401 according to specific requirements, so that the surface of light-transmitting layer 401 is flush with second surface 120, or covers second surface 120.

Referring to fig. 5, the second surface 120 of the optical sensor chip 100a is etched to form a trench.

In this embodiment, the semiconductor substrate of the optical sensor chip 100a is etched from the second surface 120 to form a trench. The groove is located at the edge of the optical sensor chip 100a, and corresponds to the position of the bonding pad 111. Specifically, the trenches include a first trench 501 and a second trench 502 located above the first trench 501 and communicated with the first trench 501, a width of the second trench 502 is greater than a width of the first trench 501, the pad 111 is exposed at the bottom of the first trench 501, and a conductive structure is formed in the trench subsequently.

Referring to fig. 6, an electrical connection layer 602 is formed in the trench to connect the pads 111.

The electrical connection layer 602 is connected to the bonding pad 111, and is used for leading out the bonding pad 111 to the second surface 120 side of the optical sensing chip 100 a.

In this embodiment, forming an insulating layer 601 between the electrical connection layer 602 and the semiconductor substrate of the optical sensor chip is further included. The method for forming the insulating layer 601 and the electrical connection layer 602 includes: forming an insulating material layer covering the back surface of the optical sensing chip, patterning the insulating material layer, and forming an insulating layer 601 covering the side wall of the first groove 501 and the step surface at the joint of the first groove 501 and the second groove 502, wherein the insulating layer 601 exposes the surface of the bonding pad 111; forming an electrical connection material layer covering the back surface of the optical sensing chip 100a, and patterning the electrical connection material layer to form an electrical connection layer connected to the bonding pad 111. In this embodiment, the electrical connection layer 602 covers the surface of the pad 111 on the inner wall of the first trench 501 and the surface of the insulating layer 601.

The electrical connection layer 602 includes a redistribution layer (RDL), the adopted material may be copper, gold, silver, or aluminum, and the pattern of the electrical connection lines in the electrical connection layer 602 may be reasonably designed according to the distribution position of the pads 111 and the signal connection requirement.

Referring to fig. 7, an optical structure is formed on the top of the light-transmitting layer 401.

In this embodiment, the optical structure is a microlens 702, the microlens 702 is formed on each optical through hole filled with the light-transmitting layer 401, and the microlenses 702 and the optical through holes are in one-to-one correspondence to form a microlens array. The size of the micro-lens 702 may be slightly larger than the size of the light through hole. In other embodiments, microlenses with larger dimensions may also be formed such that there are multiple light passing holes under each microlens.

In other embodiments, the optical structure may further include functional layers such as a filter layer, an anti-reflection layer, and the like. In some embodiments, a filtering layer may be coated on the surface of the formed microlens 702 to filter the light of the unwanted wavelength band. In other embodiments, a filter material may be doped in the material of the microlens 702, so that the microlens 702 itself has a filtering function; in other embodiments, a filter material may be doped in the light-transmitting layer 401, so that the light-transmitting layer 401 has a light filtering effect, or the microlens 702 may be formed after a filter layer is formed on the surface of the light-transmitting layer 401. In other embodiments, an anti-reflection layer may also be formed on the surface of the microlens 702 and/or the interface between the light-transmissive layer 401 and the microlens 702 to improve the optical performance of the formed optical sensor chip.

The material of the micro lens 702 may be an organic polymer material such as photoresist and resin, and is formed by printing or etching. Since etching and high temperature processes are used in the process of forming the conductive structure, it is necessary to form the optical structure after the electrical connection layer 602 is formed.

In this embodiment, a light shielding layer 701 is further formed on the surface of the semiconductor substrate between adjacent optical through holes to prevent a part of the optical signal in the wavelength band with higher transmittance, such as infrared light, from penetrating through the semiconductor substrate and entering into the sensing region outside the bottom of the optical through hole. In other embodiments, the thickness of the semiconductor substrate can be adjusted, so that the semiconductor substrate itself can block the optical signal without forming an additional light shielding layer.

The above processes can be performed at the wafer level, which can reduce the alignment difficulty of each step, especially reduce the alignment difficulty of forming optical structures, especially microlens. The method can control the alignment precision of the micro lens within 2 μm, thereby improving the yield and the productivity. And an optical structure is directly formed on the surface of the optical sensing chip, glass is not required to be used as an optical structure carrier, the thickness of the finally formed optical sensor can be reduced, and the step of mounting is reduced.

After the above steps are completed, the wafer may be peeled off the temporary carrier 200 and diced, so as to obtain a single optical sensor chip 800 (see fig. 8).

Referring to fig. 8, a substrate 810 is provided, a circuit board 820 is fixed on a surface of the substrate 810, the circuit board 820 has an opening 821, and the opening 821 exposes a portion of the surface of the substrate 810; the first surface 110 of the processed optical sensor chip 800 is fixed on the surface of the substrate 810 at the bottom of the opening 821, and an electrical connection is formed between the conductive structure of the optical sensor chip 800 and the circuit board 820 by a wire bonding method.

The substrate 810 is a plate material with a certain mechanical strength, such as a reinforced steel plate, a glass substrate, a ceramic substrate, etc., and is used for providing a mechanical support for the optical sensor chip 800. The substrate 810 may also be a rigid circuit board, such as a BT substrate, an FR-4 substrate, etc., which provides mechanical support and functions as a signal transmission. The circuit board 820 is a Flexible Printed Circuit Board (FPCB), has a low thickness, and can improve the flexibility of connecting the chip module with an external device due to the flexible characteristic.

The circuit board 820 has an opening 821 for accommodating the optical sensing chip 800, so that the circuit board 820 does not occupy the thickness of the whole chip module, thereby reducing the thickness of the whole chip module.

The circuit board 820 and the optical sensing chip 800 are fixed on the surface of the substrate 810 through an adhesive layer 811. The electrical connection layer 602 of the optical sensor chip 800 is connected to the bonding pad 822 on the surface of the circuit board 820 by a bonding wire, so that an electrical connection is formed between the optical sensor chip 800 and the circuit board 820.

Please refer to fig. 9 to 12, which are schematic structural views illustrating a chip module forming process according to another embodiment of the present invention.

Referring to fig. 9, on the basis of the structure shown in fig. 4, the second surface 120 of the optical sensing chip 100a is etched to form a conductive via 901, and the bottom of the conductive via 901 is exposed out of the pad 111.

Referring to fig. 10, an insulating layer 1001 covering the sidewall of the conductive via 901 is formed; forming an electrical connection layer 1002 covering the surface of the pad 111 at the bottom of the conductive through hole 901 and the surface of the insulating layer 1001; then, an optical structure 1003 is formed on top of the light-transmitting layer 401.

The insulating layer 1001 also covers the surface of the semiconductor substrate between the light-transmitting layers 401 in adjacent light-passing holes of the optical sensor chip, as a light-shielding layer. In other embodiments, the insulating layer 1001 may cover only the sidewall of the conductive via 901.

The electrical connection layer 1002 further includes electrical connection pins on the second surface 120 as bonding pins for connection to a circuit board.

Referring to fig. 11a and 11b, a protection structure 1101 surrounding the optical structure 1003 is formed, and the top of the protection structure 1101 is higher than the top of the optical structure 1003. Fig. 11b is a schematic top view of the optical structure 1003 and the protection structure 1101.

The protection structure 1101 is used for protecting the optical structure 1003, and can play a role of protection and support around the optical structure 1003.

Referring to fig. 11b, in this embodiment, the protection structure 1101 surrounds the optical structure 1003 to form a circular space. In other embodiments, the edge of the protection structure 1101 facing the optical structure 1003 may further enclose a triangle, a square, a trapezoid, or a polygon, and may be adjusted according to the optical path requirement to improve the optical imaging characteristic of the optical structure 1003. In order to avoid contact with the optical structure 1003 or too close a distance to the optical structure 1003 affecting the imaging of the optical structure 1003, the lateral distance between the protective structure 1101 and the optical structure 1003 needs to be larger than 1 μm.

Two or more optical structures 1003 may be formed in the space surrounded by the protection structure 1101.

The distance between the top of the protection structure 1101 and the top of the optical structure 1003 may be 1 μm to 2mm for sufficient support and protection, and may be adjusted by one skilled in the art according to the actual situation.

The material of the protection structure 1101 is a polymer material such as photoresist or resin, or may be a metal or other mechanical material, which is easy to form and has little influence on light propagation. The material of the protection structure 1101 has a large young's modulus, has a certain hardness, and is not easily deformed, thereby playing a role in strong support.

In this embodiment, the material of the protection structure 1101 is a photoresist layer. After a photoresist layer is formed on the surface of the optical sensing chip by a spin coating process, the photoresist layer is patterned to form the protection structure 1101.

In other embodiments, the protection structure 1101 may also be made of a metal or a dielectric layer, and the patterned protection structure 1101 may be formed through deposition and etching processes.

In other embodiments, the protection structure 1101 may be formed by a screen printing process.

The temporary carrier 200 is removed, and a processed optical sensor chip 1200 is obtained (see fig. 12).

Referring to fig. 12, a substrate 1210 is provided, a circuit board 1220 is fixed on a surface of the substrate 1210, the circuit board 1220 has an opening 1221, and a portion of the surface of the substrate 1210 is exposed by the opening 1221; the first surface of the processed optical sensor chip 1200 is fixed on the surface of the substrate 1210 at the bottom of the opening 1221, and an electrical connection is formed between the conductive structure of the optical sensor chip 1200 and the circuit board 1220 by a wire bonding method.

The optical sensing chip 1200 is located in the opening 1221, so that the thickness of the whole chip module can be reduced.

The bonding wires 1223 connect the pads 1222 of the circuit board 1220 and the electrical connection layer 1002 of the conductive structure of the optical sensing chip 1200, so as to realize electrical connection between the optical sensing chip 1200 and the circuit board 1220.

The circuit board 1220, the optical sensor chip 1200 and the substrate 1210 are fixed by an adhesive layer 1211.

Please refer to fig. 13 to fig. 16, which are schematic structural views illustrating a chip module forming process according to another embodiment of the present invention.

Referring to fig. 13, on the basis of the structure of fig. 4, the second surface 120 of the optical sensing chip 100a is etched to form a trench 1301, and the bottom of the trench 1301 exposes the bonding pad 111 of the optical sensing chip. The groove 1301 is located at the edge of the optical sensing chip, and only has a single-side inclined sidewall, and the other side is communicated with the outside of the chip.

Referring to fig. 14, an insulating layer 1401 covering the sidewall of the trench 1301 and an electrical connection layer 1402 covering the insulating layer 1401 in the trench 1301 and the surface of the pad 111 at the bottom are formed; after the electrical connection layer 1402 is formed, an optical structure 1403 covering the light-transmitting layer 401 is formed.

The insulating layer 1401 also covers the semiconductor substrate between adjacent light-transmitting layers as a light-shielding layer.

Referring to fig. 15, a protective structure 1501 is formed around the optical structure 1403. The protection structure 1501 also covers the electrical connection layer 1402 for protecting the electrical connection layer 1402. The second surface 120 of the optical sensor chip exposes a portion of the electrical connection layer 1402, which serves as a pin for subsequent connection with a circuit board.

Referring to fig. 16, the optical sensor chip 1600 with the temporary carrier 200 removed is fixed on a surface of a substrate 1610, a circuit board 1620 having an opening 1621 is disposed on the surface of the substrate 1610, the optical sensor chip 1600 is disposed in the opening 1621, and the electrical connection between the electrical connection layer 1402 and the circuit board 1620 is realized by wire bonding, so as to form a chip module. Specifically, the bonding wires 1623 connect the electrical connection layer of the optical sensor chip 1600 to the pads 1622 of the circuit board 1620.

According to the forming method of the chip module, the optical through hole is formed in the surface of the other side, opposite to the sensing area, of the optical sensing chip, the light transmitting layer is filled in the optical through hole, the optical structure located above the light transmitting layer is formed, the optical structure can be directly formed on the surface of the chip, the glass substrate does not need to be used as a carrier, and the thickness of the chip module can be reduced. And the conductive structure is formed on the side of the optical through hole and connected to the bonding pad of the optical sensing chip, and the signal connecting end is led out to the side of the optical structure through the conductive structure, so that the subsequent electric connection with the circuit board is formed in a lead bonding mode.

Furthermore, the optical sensing chip is fixed on the surface of the substrate in an inverted mode, the circuit board is fixed on the surface of the substrate, and the optical sensing chip is located in the opening of the circuit board, so that the circuit board does not occupy the whole thickness of the chip module, and the thickness of the chip module can be effectively reduced. And electrically connecting the conductive structure and the circuit board through a lead bonding process, wherein compared with a flip-chip bonding process, no solder occupies the thickness of the chip module, so that the thickness of the chip module can be further reduced.

The embodiment of the utility model provides a chip module is still provided.

Please refer to fig. 8, which is a schematic structural diagram of a chip module according to the present invention.

In this embodiment, the chip module includes: an optical sensing chip 800, wherein the optical sensing chip 800 has a first surface 110 and a second surface which are opposite to each other, and a bonding pad 111 and a sensing region 112 are formed in the first surface 110; a plurality of optical through holes located in the optical sensor chip 800, the optical through holes penetrating through a part of the thickness of the optical sensor chip from the second surface, corresponding to the sensing region 112 of the optical sensor chip, and configured to guide optical signals to the sensing region; a light-transmitting layer 401 filled in the light through hole and an optical structure located above the light-transmitting layer 401; and the conductive structure is positioned on the same side of the second surface of the optical sensing chip and is connected to the bonding pad 111.

In some embodiments, the sensing region 112 is a whole sensing region, and includes a plurality of sensing units arranged in an array, and only a portion of the sensing region located at the bottom of the optical through hole 301 can receive optical signals, so as to generate optical sensing signals for forming an optical sensing image.

In some embodiments, the sensing region 112 may include a plurality of sub-sensing regions, which are in one-to-one correspondence with the optical through holes 301, and the sub-sensing regions are located in the projection region of the corresponding optical through hole on the first surface, and each sub-sensing region includes one or more sensing units. The adjacent sub-sensing regions can be isolated by an isolation structure, such as a shallow trench isolation structure, so that the problems of crosstalk and the like between optical sensing signals (electrical signals) generated by the sub-sensing regions are avoided.

The conductive structure includes: a trench in the second surface of the optical sensor chip 800. The groove is located at the edge of the optical sensor chip 100a, and corresponds to the position of the bonding pad 111. Specifically, the trenches include a first trench 501 and a second trench 502 located above the first trench 501 and communicating with the first trench 501, a width of the second trench 502 is greater than a width of the first trench 501, and the bottom of the first trench 501 is exposed out of the pad 111. The conductive structure further includes: an electrical connection layer 602 covering the bottom and sidewalls of the second trench, the electrical connection layer 602 being electrically connected to the pad 111. An insulating layer 601 is further formed between the electric connection layer 5601 and the semiconductor substrate.

The chip module further comprises: a substrate 810; a circuit board 820 fixed on the surface of the substrate 810, the circuit board 820 having an opening 821, the opening 821 exposing a part of the surface of the substrate 810; the first surface 110 of the optical sensor chip 800 faces the substrate 810 and is fixed on the surface of the substrate 810 at the bottom of the opening 821; the electrical connection layer 602 of the conductive structure is electrically connected to the pad 822 of the circuit board 820 through a bonding wire 823.

In this embodiment, the optical structure is a microlens 702, the microlens 702 is formed on each optical through hole filled with the light-transmitting layer 401, and the microlenses 702 and the optical through holes are in one-to-one correspondence to form a microlens array. In other embodiments, the optical structure may further include functional layers such as a filter layer, an anti-reflection layer, and the like.

In this embodiment, a light shielding layer 701 is further formed on the surface of the semiconductor substrate between adjacent optical through holes to prevent a part of optical signals in a wavelength band with high transmittance, such as infrared light, from penetrating through the semiconductor substrate and entering into a sensing region outside the bottom of the optical through hole. In other embodiments, the thickness of the semiconductor substrate can be adjusted, so that the semiconductor substrate itself can block the optical signal without forming an additional light shielding layer.

Please refer to fig. 12, which is a schematic structural diagram of a chip module according to another embodiment of the present invention.

In this embodiment, the chip module includes an optical sensor chip 1200, and the conductive structure of the optical sensor chip includes: a conductive via penetrating the optical sensor chip 1200 from the back side of the optical sensor chip 1200 to the surface of the pad 111, an insulating layer 1001 covering the sidewall of the conductive via, and an electrical connection layer 1002 covering the insulating layer 1001 in the conductive via and the surface of the pad 111.

An optical structure 1003 is formed on the light-transmitting layer 401 in the light through hole in the optical sensing chip 1200. The insulating layer 1001 also covers the surface of the semiconductor substrate between the light-transmitting layers 401 in adjacent light-passing holes of the optical sensor chip, as a light-shielding layer.

The electrical connection layer 1002 further includes electrical connection pins on the second surface 120 as bonding pins for connection to a circuit board.

The optical sensing chip 1200 further includes a protection structure 1101 disposed around the optical structure 1003, and a top of the protection structure 1101 is higher than a top of the optical structure 1003. The protection structure 1101 is used for protecting the optical structure 1003, and can play a role of protection and support around the optical structure 1003.

The chip module further comprises a substrate 1210, wherein a circuit board 1220 is fixed on the surface of the substrate 1210, and the circuit board 1220; the optical sensor chip 1200 is provided with an opening 1221, the opening 1221 exposes a part of the surface of the substrate 1210, the first surface 110 of the optical sensor chip 1200 is fixed on the surface of the substrate 1210 at the bottom of the opening 1221, and the pads 1222 of the circuit board 1220 and the conductive structures of the optical sensor chip 1200 are electrically connected through bonding wires 1223.

The circuit board 1220, the optical sensor chip 1200 and the substrate 1210 are fixed by an adhesive layer 1211.

Please refer to fig. 16, which is a schematic structural diagram of a chip module according to another embodiment of the present invention.

In this embodiment, the chip module includes an optical sensor chip 1600, and the conductive structure of the optical sensor chip 1600 includes: and a groove 1301 penetrating the optical sensing chip 1200 from the back surface of the optical sensing chip 1200 to the surface of the bonding pad 111. The groove 1301 is positioned at the edge of the optical sensing chip, only has a single-side inclined side wall, and the other side of the groove is communicated with the outside of the chip; an insulating layer 1401 covering the side wall of the trench 1301, and an electrical connection layer 1402 covering the insulating layer 1401 in the trench 1301 and the surface of the pad 111 at the bottom. The insulating layer 1401 also covers the semiconductor substrate between adjacent light-transmitting layers as a light-shielding layer.

The optical sensor chip 1600 further includes an optical structure 1403 covering the light-transmissive layer 401 and a protective structure 1501 disposed around the optical structure 1403. The protection structure 1501 also covers the electrical connection layer 1402 for protecting the electrical connection layer 1402. The second surface 120 of the optical sensor chip exposes a portion of the electrical connection layer 1402, which serves as a pin for subsequent connection with a circuit board.

The chip module further includes a substrate 1610, a circuit board 1620 is fixed on the surface of the substrate 1610, the circuit board 1620 has an opening 1621, the opening 1621 exposes a portion of the surface of the substrate 1610, the first surface 110 of the optical sensor chip 1600 is fixed on the surface of the substrate 1610 at the bottom of the opening 1621, and an electrical connection is formed between a pad 1622 of the circuit board 1620 and the electrical connection layer 1402 of the optical sensor chip 1600 through a bonding wire 1623. The circuit board 1620, the optical sensor chip 1600 and the substrate 1610 are fixed by an adhesive layer 1611.

Other embodiments of the present invention further provide an electronic device including the above chip module.

The chip module can be used as a fingerprint identification device under a screen of electronic equipment, the optical structure of the optical sensing chip of the chip module faces the lower part of a fingerprint detection position of the electronic equipment, and reflected light on the surface of a fingerprint penetrates through the optical sensing structure to enter the light through hole and is received by a sensing area at the bottom of the light through hole to form a corresponding sensing image. Although a plurality of partial images corresponding to the positions of the light through holes are formed, the fingerprint pattern characteristics in the partial images can be obtained, and therefore fingerprint identification is achieved.

In other embodiments, the chip module may also be used as other optical sensing devices, for example, as a sensing device for face recognition, and the feature information of multiple positions of the face is extracted by acquiring multiple local images of the face, so as to realize face recognition.

Because the thickness of chip module is lower, be favorable to reducing electronic equipment's thickness, reduce the device overall arrangement degree of difficulty in the electronic equipment.

The above-mentioned embodiments are only examples of the present application, and not intended to limit the scope of the present application, and all equivalent structures or equivalent flow transformations made by the contents of the specification and the drawings, such as the combination of technical features between the embodiments and the direct or indirect application to other related technical fields, are also included in the scope of the present application.

Claims (10)

1. A chip module, comprising:

the optical sensing chip is provided with a first surface and a second surface which are opposite, and a bonding pad and a sensing area are formed in the first surface;

the plurality of optical through holes are positioned in the optical sensing chip, penetrate through the partial thickness of the optical sensing chip from the second surface, correspond to the sensing area of the optical sensing chip and are used for sensing optical signals to the sensing area;

the light-transmitting layer is filled in the light through hole, and the optical structure is positioned above the light-transmitting layer;

and the conductive structure is positioned on the same side of the second surface of the optical sensing chip and is electrically connected to the bonding pad.

2. The chip module according to claim 1, further comprising: a substrate; the circuit board is fixed on the surface of the substrate and provided with an opening, and part of the surface of the substrate is exposed out of the opening; the first surface of the optical sensing chip faces the substrate and is fixed on the surface of the substrate at the bottom of the opening; and the conductive structure and the circuit board are electrically connected through a bonding wire.

3. The chip module according to claim 1, wherein the conductive structure comprises an electrical connection layer connected to the bonding pad.

4. The chip module according to claim 3, wherein the conductive structure comprises: the groove is positioned in the second surface of the optical sensing chip, and the bottom of the groove is exposed out of the bonding pad on the first surface of the optical sensing chip; the electrical connection layer covers at least the bottom and/or part of the side wall of the groove.

5. The chip module according to claim 3, wherein the conductive structure comprises: the bottom of the conductive through hole is exposed out of a bonding pad of the optical sensing chip; the electric connection layer covers the inner wall of the conductive through hole.

6. The chip module according to claim 3, wherein an insulating layer is formed between the electrical connection layer and the semiconductor substrate of the optical sensor chip.

7. The chip module according to claim 1, wherein the sensing area comprises a plurality of discrete sub-sensing areas, and the optical vias are in one-to-one correspondence with the sub-sensing areas.

8. The chip module according to claim 1, further comprising: and the protective structure is positioned on the second surface of the optical sensing chip and surrounds the optical structure, and the top of the protective structure is higher than that of the optical structure.

9. The chip module according to claim 1, wherein the light-transmitting layer further covers the second surface of the optical sensor chip.

10. An electronic device comprising a chip module according to any one of claims 1 to 9.

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