Photoelectric chip stacked package and preparation method thereof, and array preparation method
By vertically stacking the optical transmitter chip and the optical receiver chip and using bent metal sheets to achieve electrical connection and insulation, the problems of large package area and signal acquisition distortion in the existing technology are solved, and the miniaturization of the optoelectronic chip and the accuracy of signal acquisition are achieved.
Patent Information
- Application Number
- CN202511125076.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-12
- Publication Date
- 2025-10-03
AI Technical Summary
In existing PPG sensors, the light emitting chip and the light receiving chip are arranged in parallel, resulting in a large package area and an offset of the optical center axis, leading to signal acquisition distortion.
Bending metal sheets are used to vertically stack the light emitting chip and the light receiving chip, and the metal sheets are used to achieve electrical connection and insulation, ensuring that the light emitting chip and the light receiving chip are stacked in the vertical direction, reducing the occupied area in the horizontal direction, and enhancing information collection through light of different wavelengths.
The miniaturization of the optoelectronic chip is achieved, the horizontal area of the package is reduced, the problem of signal acquisition distortion caused by the offset of the optical center axis is solved, and the accuracy of signal acquisition is improved.
Smart Images
Figure CN120751804A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of chip packaging, and in particular to a photoelectric chip stacking package and a preparation method thereof, and an array preparation method. Background Art
[0002] With the continuous evolution of semiconductor technology, breakthroughs in chip integration and packaging processes are driving the development of electronic devices towards miniaturization and multifunctionality. Against this backdrop, photoelectric sensing technology, as a key link in information collection, is increasingly being applied in healthcare, consumer electronics, and other fields. Photoplethysmography (PPG) sensors, with their non-invasive detection capabilities, have become a core component for smart wearable devices (such as smartwatches and health monitoring bracelets) to monitor physiological parameters such as heart rate and blood oxygen saturation.
[0003] Existing PPG sensors generally adopt a planar, parallel layout, mounting the light emitting chip and light receiving chip in a two-dimensional, side-by-side arrangement on the substrate surface. This layout results in the package occupying a large horizontal area, making it difficult to meet the integration requirements of miniaturized ultra-thin wearable devices such as smartwatches. Furthermore, because the light emitting chip and the light receiving chip are located at different lateral positions, which are far apart from each other on the substrate, their optical center axes are significantly offset in the vertical direction. This results in an angular deviation in the light path received by the light receiving chip after the emitted light penetrates or reflects from the skin tissue. Non-vertically incident light causes uneven energy distribution on the photosensitive surface of the light receiving chip, leading to signal acquisition distortion. Summary of the Invention
[0004] Based on this, the purpose of the present invention is to overcome the defects or shortcomings of the prior art and provide an optoelectronic chip stack package and a preparation method thereof.
[0005] An optoelectronic chip stack package comprises a substrate, a light receiving chip, a first metal sheet, a second metal sheet, a first light emitting chip and a second light emitting chip stacked in sequence; The substrate is provided with circuit traces; The light receiving chip is mounted on the substrate and is electrically connected to the substrate through wire bonding; The first metal sheet and the second metal sheet each include a first end, a second end, and a bent portion connecting the first end and the second end; one side of the first end of the first metal sheet is mounted on the light receiving chip and is electrically insulated from a contact portion of the top surface of the light receiving chip, and the other side of the first end is mounted on the first light emitting chip and is electrically connected to a contact portion of the first light emitting chip; the second end of the first metal sheet is mounted on the substrate and is electrically connected to a trace of the substrate; One side of the first end of the second metal sheet is mounted on the light receiving chip and is electrically insulated from the contact portion of the top surface of the light receiving chip, and the other side of the first end is mounted on the second light emitting chip and is electrically connected to the contact portion of the second light emitting chip; the second end of the second metal sheet is mounted on the substrate and is electrically connected to the trace of the substrate; The light emitted by the first light emitting chip and the light emitted by the second light emitting chip have different wavelengths.
[0006] Compared with the existing technology, the optoelectronic chip stacking package proposed in the present invention uses a bent metal sheet to ensure the electrical connection relationship between the optical receiving chip, the first optical emitting chip and the second optical emitting chip and the substrate respectively, and the electrical insulation relationship between the first optical emitting chip and the second optical emitting chip and the optical receiving chip, thereby realizing the stacking of the first optical emitting chip and the second optical emitting chip in the vertical direction of the optical receiving chip, saving the horizontal arrangement area.
[0007] The light of different wavelengths emitted by the first light emitting chip and the second light emitting chip have different penetration capabilities, thereby enabling the light receiving chip to receive different information.
[0008] Furthermore, a plurality of first light emitting chips are mounted on the first end of the first metal sheet.
[0009] Furthermore, a plurality of second light emitting chips are mounted on the first end of the second metal sheet.
[0010] By arranging a plurality of first light emitting chips on the first metal sheet or arranging a plurality of second light emitting chips on the second metal sheet, the power of the light emitted thereby is enhanced.
[0011] Furthermore, the present invention further includes an Nth metal sheet and an Nth light emitting chip, where N is greater than or equal to 3; the Nth metal sheet includes a first end, a second end, and a bent portion connecting the first end and the second end; one side of the first end of the Nth metal sheet is mounted on the light receiving chip and is electrically insulated from the contact portion of the top surface of the light receiving chip, and the other side of the first end is mounted on the Nth light emitting chip and is electrically connected to the contact portion of the Nth light emitting chip; the second end of the Nth metal sheet is mounted on the substrate and is electrically connected to the traces of the substrate; The light emitted by the Nth light emitting chip, the first light emitting chip, and the second light emitting chip has a different wavelength.
[0012] By arranging the Nth light emitting chip to emit light of different wavelengths from the first light emitting chip and the second light emitting chip, the light emitted by the entire packaging structure can have different penetrating capabilities, further improving the information received by the light receiving chip.
[0013] Furthermore, the light receiving chip includes a sensing area and a non-sensing area; the first ends of the first metal sheet, the second metal sheet, and the Nth metal sheet that contact the surface of the light receiving chip only occupy the non-sensing area or the edge of the sensing area on the light receiving chip to prevent the metal sheet from blocking and affecting the sensing effect of the light receiving chip.
[0014] Furthermore, the wavelength of light emitted by the first light emitting chip, the second light emitting chip, and the Nth light emitting chip is within the range of 400 nm to 2000 nm.
[0015] Furthermore, the distance between the first metal sheet, the second metal sheet and the Nth metal sheet is 20um-200um.
[0016] Furthermore, the connection method between the first metal sheet, the second metal sheet, the Nth metal sheet and the light receiving chip is non-conductive bonding; the connection between the first metal sheet, the second metal sheet, the Nth metal sheet and the first light emitting chip, the second light emitting chip, the Nth emitting chip and the substrate is conductive bonding.
[0017] At the same time, the present invention also provides a method for preparing an optoelectronic chip stack package, comprising the following steps: S1: Mount the light receiving chip on the substrate and electrically connect it to the substrate; S2: Adhere one side of the first end of the first metal sheet to the non-sensing area or the edge of the sensing area of the light receiving chip by means of an electrical insulating adhesive, and attach the second end of the first metal sheet connected to the first end by bending to the substrate and electrically connect it to the wiring of the substrate; Adhere one side of the first end of the second metal sheet to the non-sensing area or the edge of the sensing area of the light receiving chip by means of an electrical insulating adhesive, and attach the second end of the second metal sheet connected to the first end by bending to the substrate and electrically connect it to the wiring of the substrate; S3: mounting the first light emitting chip and the second light emitting chip on the other side of the first end of the first metal sheet and the other side of the first end of the second metal sheet respectively, and electrically connecting the first metal sheet and the second metal sheet respectively; S4: electrically connecting the pins of the optical receiving chip, the first optical emitting chip, and the second optical emitting chip to the wiring of the substrate by wire bonding to obtain the main structure of the optoelectronic chip stack package; S5: placing the main structure of the optoelectronic chip stack package in a mold for injection molding to obtain a plastic-sealed optoelectronic chip stack package.
[0018] Compared with the prior art, the present invention provides a method for preparing a photoelectric chip stack package with simple steps. The resulting photoelectric chip stack package has the same beneficial effects as the above-mentioned photoelectric chip stack package, which will not be described in detail here.
[0019] In order to improve the packaging efficiency, the present invention also provides a method for preparing an array of stacked optoelectronic chips, comprising the following steps: S0': Prefabricate a metal frame, which is a metal part with a frame-shaped structure, having a plurality of hollow areas arranged in an array, the size of the hollow areas being the same as the size of the substrate, and the array arrangement of the hollow areas of the metal frame being the same as the arrangement of the plurality of substrates in the substrate panel; integrate the second ends of the first metal sheet, the second metal sheet, and the Nth metal sheet on the metal frame, so that the first end of each metal sheet is suspended in the hollow area of the metal frame, wherein the first end and the second end of each metal sheet are bent and connected, and the number and arrangement positions of the metal sheets match the requirements of the optical receiving chip, the first optical emitting chip, the second optical emitting chip, and the Nth optical emitting chip to be packaged; S1′: mounting a plurality of light receiving chips one by one on a plurality of substrates arranged in an array in a substrate panel, wherein each light receiving chip is electrically connected to its corresponding substrate; S2': placing a metal frame integrating multiple metal sheets on a substrate panel, so that each hollow area of the metal frame wraps the corresponding substrate; placing the first end of each metal sheet on the corresponding light receiving chip, and the second end of each metal sheet on the corresponding wiring of the substrate; bonding one side of the first end of each metal sheet to the non-sensing area or the edge of the sensing area of the corresponding light receiving chip with an electrically insulating adhesive; and bonding the second end of each metal sheet to the corresponding substrate and electrically connecting it to the wiring of the substrate; S3′: mounting a plurality of first light emitting chips, a second light emitting chip, and an Nth light emitting chip on the other side of the first end of their corresponding metal sheets and electrically connecting them to the corresponding metal sheets; S4′: electrically connecting the pins of the plurality of light receiving chips and the plurality of first light emitting chips, the second light emitting chip, and the Nth light emitting chip to the traces of their corresponding substrates by wire bonding to obtain the main structure of the optoelectronic chip stacking package of the array; S5′: placing the main structure of the optoelectronic chip stack package of the array in a mold for injection molding to obtain a plastic-sealed optoelectronic chip stack package of the array; S6': cutting the metal frame along the array gaps of the multiple arrays of plastic-sealed optoelectronic chip stack packages, separating the metal frame from the second ends of the multiple metal sheets, and separating the substrate from the substrate assembly to obtain multiple plastic-sealed optoelectronic chip stack packages.
[0020] The present invention provides an array preparation method for a photoelectric chip stacking package, which can stack and package a plurality of photoelectric chips at one time, thereby greatly improving production efficiency.
[0021] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 This is a schematic diagram of the optoelectronic chip stacking package of the present invention; Figure 2 This is a back view of the substrate of the optoelectronic chip stack package of the present invention; Figure 3 Schematic diagram of the steps of a method for preparing a stacked optoelectronic chip package of the present invention; Figure 4 A schematic diagram of the steps of a method for preparing an array of optoelectronic chip stacking packages according to the present invention; Figure 5 It is a schematic diagram of the main structure of the metal frame structure and the optoelectronic chip stacking package of the array according to the present invention. DETAILED DESCRIPTION
[0023] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention.
[0024] See also Figure 1 The optoelectronic chip stack package provided by the present invention includes a substrate 10, a light receiving chip 20, a first metal sheet 30, a second metal sheet 40, a first light emitting chip 50, and a second light emitting chip 60 stacked in sequence.
[0025] Specifically, see Figure 2 The substrate 10 is provided with circuit traces, and a plurality of pads connected to the traces are provided on the substrate 10. The light receiving chip 20, the first metal sheet 30, the second metal sheet 40, the first light emitting chip 50, and the second light emitting chip 60 can be electrically connected to the traces of the substrate through the pads.
[0026] The light receiving chip 20 includes pins, a sensing area, and a non-sensing area. The light receiving chip 20 is mounted on the substrate 10, specifically by dispensing or printing conductive adhesive or a conductive polymer adhesive. The pins of the light receiving chip 20 are connected to pads on the substrate 10 by wire bonding, thereby electrically connecting to the traces on the substrate 10 to ensure good mechanical and electrical performance.
[0027] The first metal sheet 30 includes a first end, a second end, and a bent portion connecting the first end and the second end. Specifically, one side of the first end of the first metal sheet 30 is mounted on the optical receiving chip 20 and is electrically insulated from the surface contact portion of the optical receiving chip 20. The other side of the first end is mounted on the first optical transmitting chip 50 and is electrically connected to the contact portion of the first optical transmitting chip 50, ensuring electrical isolation between the optical receiving chip 20 and the first optical transmitting chip 50. The first metal sheet 30 extends from the first end toward the outside of the optical receiving chip 20 and bends toward the substrate 10 to adhere to the substrate 10 as the second end. The second end of the first metal sheet 30 is mounted on the substrate 10 and is electrically connected to the wiring of the substrate 10.
[0028] The second metal sheet 40 includes a first end, a second end, and a bent portion connecting the first end and the second end. Specifically, one side of the first end of the second metal sheet 40 is mounted on the optical receiving chip 20 and is electrically insulated from the surface contact portion of the optical receiving chip 20. The other side of the first end is mounted on the second optical emitting chip 60 and is electrically connected to the contact portion of the second optical emitting chip 60, ensuring electrical isolation between the optical receiving chip 20 and the second optical emitting chip 60. The second metal sheet 40 extends from the first end toward the outside of the optical receiving chip 20 and bends toward the substrate 10 to adhere to the substrate 10 as the second end. The second end of the second metal sheet 40 is mounted on the substrate 10 and is electrically connected to the wiring of the substrate 10.
[0029] Furthermore, in order to prevent the first metal sheet 30 and the second metal sheet 40 from blocking and affecting the sensing effect of the light receiving chip 20, the first ends of the first metal sheet 30 and the second metal sheet 40 that are in contact with the surface of the light receiving chip 20 only occupy the non-sensing area or the edge of the sensing area on the light receiving chip 20.
[0030] The first and second light emitting chips 50 and 60 include pins. The first and second light emitting chips 50 and 60 are indirectly stacked and placed on the light receiving chip 20 via the first and second metal sheets 30 and 40, respectively. Specifically, the first light emitting chip 50 is mounted on the other side of the first end of the first metal sheet 30 and electrically connected to the surface contact portion of the first metal sheet 30, ensuring electrical communication between the first light emitting chip 50 and the substrate 10 via the first metal sheet 30. The second light emitting chip 60 is mounted on the other side of the first end of the second metal sheet 40 and electrically connected to the surface contact portion of the second metal sheet 40, ensuring electrical communication between the second light emitting chip 40 and the substrate 10 via the second metal sheet 40. The pins of the first and second light emitting chips 50 and 60 are connected to pads on the substrate 10 by wire bonding, thereby electrically connecting to the traces of the substrate 10, ensuring good mechanical and electrical performance. At this time, for the first light emitting chip 50 and the second light emitting chip 60 , the portions thereof connected to the substrate 10 through the bonding wires and the first metal sheet 30 and the second metal sheet 40 have different polarities.
[0031] Specifically, the electrical connection method includes using conductive glue or conductive polymer adhesive to perform conductive bonding in a dispensing or printing manner.
[0032] In the optoelectronic chip stacking package provided by the present invention, a first metal sheet 30 is bent between its first and second ends to connect the first light emitting chip 50 and the light receiving chip 20, which are located at different heights. A second metal sheet 40 is also bent between its first and second ends to connect the second light emitting chip 60, which is located at different heights, to the light receiving chip 20. While ensuring electrical connections between the light receiving chip 20, the first light emitting chip 40, and the first light emitting chip 50 and the substrate, and electrical insulation between the first light emitting chip 50 and the second light emitting chip 60 and the light receiving chip 20, the first light emitting chip 50 and the second light emitting chip 60 can be stacked vertically on the light receiving chip 20, saving horizontal layout area.
[0033] When the first light emitting chip 50 and the second light emitting chip 50 are stacked vertically on the light receiving chip 20, the horizontal distance between the first light emitting chip 50, the second light emitting chip 50, and the light receiving chip 20 is shortened. This not only saves space when the first light emitting chip 50, the second light emitting chip 60, and the light receiving chip 20 are arranged horizontally, but also solves the problem of signal acquisition distortion caused by a significant vertical offset between the optical center axes of the first light emitting chip 50, the second light emitting chip 60, and the light receiving chip 20. Specifically, the first light emitting chip 50 and the second light emitting chip 60 can be infrared wavelength laser chips, red wavelength laser chips, or other wavelength laser chips. Preferably, the wavelengths of light emitted by the first light emitting chip 50 and the second light emitting chip 60 are between 400 nm and 2000 nm, and the light emitted by the first light emitting chip 50 and the second light emitting chip 60 are different. By emitting different wavelengths, detection accuracy is improved.
[0034] In some embodiments, a plurality of first light emitting chips 50 are mounted on the first end of the first metal sheet 30. The plurality of first light emitting chips 50, located at different heights, are connected to the light receiving chip 20 by a bend between the first and second ends of the first metal sheet 30. A plurality of second light emitting chips 60 are mounted on the first end of the second metal sheet 40. The plurality of second light emitting chips 60, located at different heights, are connected to the light receiving chip 20 by a bend between the first and second ends of the second metal sheet 40. By arranging a plurality of first light emitting chips 50 on the first metal sheet 30 or a plurality of second light emitting chips 60 on the second metal sheet 40, the power of the light emitted thereby is enhanced.
[0035] In some other embodiments, an Nth metal sheet and an Nth light emitting chip (not shown) are further included, where N is greater than or equal to 3. The Nth metal sheet includes a first end, a second end, and a bent portion connecting the first end and the second end. One surface of the first end of the Nth metal sheet is mounted on the light receiving chip 20 and is electrically insulated from a portion contacting the top surface of the light receiving chip 20. The other surface of the first end is mounted on the Nth light emitting chip and is electrically connected to a contact portion of the Nth light emitting chip. The second end of the Nth metal sheet is mounted on the substrate 10 and is electrically connected to a trace on the substrate 10. The light emitted by the Nth light emitting chip, the first light emitting chip 50 , and the second light emitting chip 60 has different wavelengths.
[0036] One side of the first end of the first metal sheet 30, the second metal sheet 40 and the Nth metal sheet are all bonded and mounted on the light receiving chip 20 by electrical insulating adhesive, wherein the distance between the first metal sheet 30, the second metal sheet 40 and the Nth metal sheet is 20um-200um.
[0037] At the same time, the present invention also provides a method for preparing a stacked package of optoelectronic chips, see Figure 3 , which includes the following steps: S1 : Mounting the light receiving chip 20 on the substrate 10 and electrically connecting the light receiving chip 20 to the substrate 10 .
[0038] Specifically, the electrical connection method includes using conductive glue or conductive polymer adhesive to perform conductive bonding in a dispensing or printing manner.
[0039] S2: Adhere one side of the first end of the first metal sheet 30 to the non-sensing area or the edge of the sensing area on the optical receiving chip 20 through an electrically insulating adhesive, and attach the second end of the first metal sheet 30 connected to its first end by bending to the substrate 10 and electrically connected to the wiring of the substrate 10; Adhere one side of the first end of the second metal sheet 40 to the non-sensing area or the edge of the sensing area on the optical receiving chip 20 through an electrically insulating adhesive, and attach the second end of the second metal sheet 40 connected to its first end by bending to the substrate 10 and electrically connected to the wiring of the substrate 10.
[0040] Specifically, the electrical connection method includes dispensing or printing conductive adhesive or conductive polymer adhesive. The first and second metal sheets 30 and 40 are connected by bending between their respective first and second ends. That is, the metal sheets extend from their respective first ends toward the outside of the light receiving chip 20 and bend toward the substrate 10 to form their respective second ends.
[0041] S3: Mount the first light emitting chip 50 and the second light emitting chip 60 on the other side of the first end of the first metal sheet 30 and the other side of the first end of the second metal sheet 40 respectively and electrically connect them to the first metal sheet 30 and the second metal sheet 40 respectively.
[0042] Specifically, the electrical connection method includes using conductive glue or conductive polymer adhesive to perform conductive bonding in a dispensing or printing manner.
[0043] S4: electrically connecting the pins of the optical receiving chip 20 , the first optical emitting chip 50 , and the second optical emitting chip 60 to the wiring of the substrate 10 by wire bonding to obtain the main structure of the optoelectronic chip stacking package.
[0044] S5: placing the main structure of the optoelectronic chip stack package in a mold for injection molding to obtain a plastic-sealed optoelectronic chip stack package.
[0045] Preferably, the mold is further provided with a cavity protection structure for the optical path region. The cavity protection structure can cover the top of the sensing area of the optical receiver chip 20 and the tops of the first and second optical transmitter chips 50 and 60. During injection molding, the molding material only fills the non-optical path region of the mold and forms an encapsulation cavity therein, leaving the optical path region exposed. Injection molding protects the physical properties of the main structure of the optoelectronic chip stack package.
[0046] Preferably, the optical path area may be covered with a transparent film or filled with a transparent plastic compound to protect the optical receiving chip 20 and the first optical emitting chip 50 and the second optical emitting chip 60 without affecting their functions.
[0047] At the same time, in order to improve the packaging efficiency, the present invention also provides a method for preparing a stacked package of optoelectronic chips, please refer to Figure 4 and Figure 5 , which includes the following steps: S0': Prefabricate a metal frame 70, which is a metal part with a frame-shaped structure, having a plurality of hollow areas arranged in an array, the size of the hollow areas being the same as the size of the substrate 10, and the array arrangement of the hollow areas of the metal frame 70 being the same as the arrangement of the plurality of substrates 10 in the substrate panel; integrate the second ends of the plurality of first metal sheets 30 and the second metal sheets 40 on the metal frame 70, so that the first end of each metal sheet is suspended in the hollow area of the metal frame 70, wherein the first end and the second end of each metal sheet are bent and connected, and the number of metal sheets and the arrangement position of the metal sheets match the requirements of the optical receiving chip 20, the first optical emitting chip 50, and the second optical emitting chip 60 to be packaged.
[0048] S1': Arrange multiple substrates 10 in an array according to the number of hollow areas in the multiple array arrangements of the metal frame and the intervals between the hollow areas; and mount multiple light receiving chips 20 one by one on the multiple substrates 10 arranged in an array in the substrate assembly, and each light receiving chip 20 is electrically connected to its corresponding substrate 10.
[0049] Specifically, the electrical connection method includes using conductive glue or conductive polymer adhesive to perform conductive bonding in a dispensing or printing manner.
[0050] S2': Place a metal frame 70 integrating multiple bent metal sheets on the substrate assembly so that each hollow area of the metal frame 70 wraps the corresponding substrate 10; place the first end of each metal sheet on the corresponding light receiving chip 20, and the second end of each metal sheet on the corresponding wiring of the substrate 10; adhere one side of the first end of each metal sheet to the non-sensing area or the edge of the sensing area on the corresponding light receiving chip 20 through electrical insulating glue; and attach the second end of each metal sheet to the corresponding substrate 10 and electrically connect it to the wiring of the substrate 10.
[0051] S3 ′: mounting a plurality of first light emitting chips 50 and second light emitting chips 60 on the other side of the first end of the corresponding metal sheet and electrically connecting the metal sheet.
[0052] Specifically, the electrical connection method includes using conductive glue or conductive polymer adhesive to perform conductive bonding in a dispensing or printing manner.
[0053] S4′: electrically connecting the pins of the plurality of optical receiving chips 20 , the plurality of first optical emitting chips 50 , and the plurality of second optical emitting chips 60 to the corresponding traces of the substrate 10 by wire bonding to obtain the main structure of the optoelectronic chip stacking package of the array.
[0054] S5′: placing the main structure of the optoelectronic chip stack package of the array in a mold for injection molding to obtain a plastic-sealed optoelectronic chip stack package of the array.
[0055] S6': cutting the metal frame 70 along the array gaps of the multiple arrays of plastic-sealed optoelectronic chip stack packages, separating the metal frame 70 from the second ends of the multiple metal sheets, and separating the substrate 10 from the substrate assembly to obtain multiple plastic-sealed optoelectronic chip stack packages.
[0056] Preferably, the mold is further provided with a cavity protection structure for the optical path region. The cavity protection structure can cover the top of the sensing area of the optical receiver chip 20 and the tops of the first and second optical transmitter chips 50 and 60. During injection molding, the molding material only fills the non-optical path region of the mold and forms an encapsulation cavity therein, leaving the optical path region exposed. Injection molding protects the physical properties of the main structure of the optoelectronic chip stack package.
[0057] Preferably, the optical path area may be covered with a transparent film or filled with a transparent plastic compound to protect the light receiving chip 20 , the first light emitting chip 50 and the second light emitting chip 60 without affecting their functions.
[0058] Compared to existing planar, parallel-layout chip packaging structures, the optoelectronic chip stacking package and its preparation method of the present invention vertically stacks a first light-emitting chip and a second light-emitting chip on a light-receiving chip via a metal sheet. This insulates the first and second light-emitting chips from the light-receiving chip while electrically connecting them to the substrate. This allows the light-receiving chips, first light-emitting chip, and second light-emitting chip to be stacked vertically, saving significant horizontal area. This also addresses the issue of signal acquisition distortion caused by significant vertical offset of the optical center axes of the light-receiving, first light-emitting, and second light-emitting chips.
[0059] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, and the present invention is intended to encompass such modifications and variations.
Claims
1. An optoelectronic chip stack package, characterized in that: It includes a substrate, a light receiving chip, a first metal sheet, a second metal sheet, a first light emitting chip and a second light emitting chip stacked in sequence; The substrate is provided with circuit traces; The light receiving chip is mounted on the substrate and is electrically connected to the substrate through wire bonding; The first metal sheet and the second metal sheet each include a first end, a second end, and a bent portion connecting the first end and the second end; one side of the first end of the first metal sheet is mounted on the light receiving chip and is electrically insulated from a contact portion of the top surface of the light receiving chip, and the other side of the first end is mounted on the first light emitting chip and is electrically connected to a contact portion of the first light emitting chip; the second end of the first metal sheet is mounted on the substrate and is electrically connected to a trace of the substrate; One side of the first end of the second metal sheet is mounted on the light receiving chip and is electrically insulated from the contact portion of the top surface of the light receiving chip, and the other side of the first end is mounted on the second light emitting chip and is electrically connected to the contact portion of the second light emitting chip; the second end of the second metal sheet is mounted on the substrate and is electrically connected to the trace of the substrate; The light emitted by the first light emitting chip and the light emitted by the second light emitting chip have different wavelengths.
2. The optoelectronic chip stack package according to claim 1, wherein: A plurality of first light emitting chips are mounted on the first end of the first metal sheet.
3. The optoelectronic chip stack package according to claim 1, wherein: A plurality of second light emitting chips are mounted on the first end of the second metal sheet.
4. The optoelectronic chip stack package according to any one of claims 1 to 3, wherein: The device further includes an Nth metal sheet and an Nth light emitting chip, where N is greater than or equal to 3; the Nth metal sheet includes a first end, a second end, and a bent portion connecting the first end and the second end; one surface of the first end of the Nth metal sheet is mounted on the light receiving chip and is electrically insulated from a contact portion of the top surface of the light receiving chip, and the other surface of the first end is mounted on the Nth light emitting chip and is electrically connected to a contact portion of the Nth light emitting chip; The second end of the Nth metal sheet is mounted on the substrate and electrically connected to the wiring of the substrate; The light emitted by the Nth light emitting chip has a different wavelength from that of the first light emitting chip and the second light emitting chip.
5. The optoelectronic chip stack package according to claim 4, wherein: The light receiving chip includes a sensing area and a non-sensing area; the first ends of the first metal sheet, the second metal sheet, and the Nth metal sheet that contact the surface of the light receiving chip only occupy the non-sensing area or the edge of the sensing area on the light receiving chip.
6. The optoelectronic chip stack package according to claim 5, wherein: The wavelength of light emitted by the first light emitting chip, the second light emitting chip, and the Nth light emitting chip is within the range of 400 nm to 2000 nm.
7. The optoelectronic chip stack package according to claim 6, wherein: The distance between the first metal sheet, the second metal sheet and the Nth metal sheet is 20um-200um.
8. The optoelectronic chip stack package according to claim 7, wherein: The connection method between the first metal sheet, the second metal sheet, the Nth metal sheet and the light receiving chip is non-conductive bonding; the connection between the first metal sheet, the second metal sheet, the Nth metal sheet and the first light emitting chip, the second light emitting chip, the Nth emitting chip and the substrate is conductive bonding.
9. A method for preparing a stacked optoelectronic chip package, characterized in that: The following steps are involved: S1: Mount the light receiving chip on the substrate and electrically connect it to the substrate; S2: Adhere one side of the first end of the first metal sheet to the non-sensing area or the edge of the sensing area of the light receiving chip by means of an electrical insulating adhesive, and attach the second end of the first metal sheet connected to the first end by bending to the substrate and electrically connect it to the wiring of the substrate; Adhere one side of the first end of the second metal sheet to the non-sensing area or the edge of the sensing area of the light receiving chip by means of an electrical insulating adhesive, and attach the second end of the second metal sheet connected to the first end by bending to the substrate and electrically connect it to the wiring of the substrate; S3: mounting the first light emitting chip and the second light emitting chip on the other side of the first end of the first metal sheet and the other side of the first end of the second metal sheet respectively, and electrically connecting the first metal sheet and the second metal sheet respectively; S4: electrically connecting the pins of the optical receiving chip, the first optical emitting chip, and the second optical emitting chip to the wiring of the substrate by wire bonding to obtain the main structure of the optoelectronic chip stack package; S5: placing the main structure of the optoelectronic chip stack package in a mold for injection molding to obtain a plastic-sealed optoelectronic chip stack package.
10. A method for preparing an array of stacked optoelectronic chips, characterized in that: The following steps are involved: S0': Prefabricate a metal frame, which is a metal part with a frame-shaped structure, having a plurality of hollow areas arranged in an array, the size of the hollow areas being the same as the size of the substrate, and the array arrangement of the hollow areas of the metal frame being the same as the arrangement of the plurality of substrates in the substrate panel; integrate the second ends of the plurality of first metal sheets and the second metal sheets on the metal frame, so that the first end of each metal sheet is suspended in the hollow area of the metal frame, wherein the first end and the second end of each metal sheet are bent and connected, and the number and arrangement positions of the metal sheets match the requirements of the optical receiving chip, the first optical emitting chip, and the second optical emitting chip to be packaged; S1′: mounting a plurality of light receiving chips one by one on a plurality of substrates arranged in an array in a substrate panel, wherein each light receiving chip is electrically connected to its corresponding substrate; S2': placing a metal frame integrating multiple metal sheets on a substrate panel, so that each hollow area of the metal frame wraps the corresponding substrate; placing the first end of each metal sheet on the corresponding light receiving chip, and the second end of each metal sheet on the corresponding wiring of the substrate; bonding one side of the first end of each metal sheet to the non-sensing area or the edge of the sensing area of the corresponding light receiving chip with an electrically insulating adhesive; and bonding the second end of each metal sheet to the corresponding substrate and electrically connecting it to the wiring of the substrate; S3′: mounting a plurality of first light emitting chips and a second light emitting chip on the other side of the first end of the corresponding metal sheet and electrically connecting the chips to the corresponding metal sheet; S4′: electrically connecting the pins of the plurality of light receiving chips and the plurality of first light emitting chips and the second light emitting chips to the traces of their corresponding substrates by wire bonding to obtain the main structure of the optoelectronic chip stacking package of the array; S5′: placing the main structure of the optoelectronic chip stack package of the array in a mold for injection molding to obtain a plastic-sealed optoelectronic chip stack package of the array; S6': cutting the metal frame along the array gaps of the multiple arrays of plastic-sealed optoelectronic chip stack packages, separating the metal frame from the second ends of the multiple metal sheets, and separating the substrate from the substrate assembly to obtain multiple plastic-sealed optoelectronic chip stack packages.