Chip packaging structure and packaging method

Abstract

The present invention discloses a chip packaging structure and packaging method, the packaging structure includes a first circuit board, a substrate, a first chip, a first metal ball, a second circuit board, a second chip and a second metal ball, the first circuit board includes a first surface and a second surface arranged opposite to each other, and a through hole penetrating the first surface and the second surface; the substrate is located on the first surface and covers the through hole; the first chip is located on the side of the substrate facing the through hole, and the first chip extends toward the through hole; the first metal ball connects the substrate and the first surface; the second circuit board is located on the second surface and covers the through hole; the second chip is located on the side of the second circuit board facing the through hole, and the second chip extends toward the through hole; the second metal ball connects the second circuit board and the second surface. The first metal ball and the second metal ball of the present invention can not only effectively adjust the distance between the first chip and the second chip, but also realize signal transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, and in particular to a chip packaging structure and a packaging method. Background Art

[0002] With the continuous development of science and technology, more and more electronic devices are widely used in people's daily life and work, bringing great convenience to people's daily life and work, and becoming an indispensable and important tool for people today.

[0003] The main component of electronic devices to realize preset functions is the chip. With the continuous advancement of integrated circuit technology, the integration of chips is getting higher and higher, the functions of chips are getting more and more powerful, and the size of chips is getting smaller and smaller. Therefore, the chip needs to be packaged to form a packaging structure to facilitate the electrical connection between the chip and the external circuit board.

[0004] In the prior art, Figure 1 The package structure 100 includes a first chip 11 and a second chip 12 . The distance between the first chip 11 and the second chip 12 needs to be precisely controlled to achieve precise interaction between the first chip 11 and the second chip 12 .

[0005] For example, the first chip 11 is a transmitter, and a laser transmitter is taken as an example here, which has optical characteristics such as high brightness, good directionality, good monochromaticity and good coherence. In particular, due to the good directionality of the laser, the laser becomes the preferred light source for barcode scanning.

[0006] During the barcode scanning process, in addition to the laser chip, a scanning device is also required to realize the scanning of the light emitted by the laser chip. The second chip 12 is a diffraction optical element that plays a scanning role.

[0007] In the prior art, the first chip 11 is fixed on the frame 13, the second chip 12 is fixed on the substrate 14, and the end of the frame 13 is fixed to the substrate 14 by glue 15. At this time, the distance B between the first chip 11 and the second chip 12 is mainly adjusted by controlling the thickness of the glue 15. This adjustment method requires special equipment and materials, has high cost and long processing time, and has low yield. Summary of the invention

[0008] The object of the present invention is to provide a chip packaging structure and packaging method which can improve optical accuracy, assembly efficiency and reduce costs.

[0009] To achieve one of the above-mentioned purposes of the invention, an embodiment of the present invention provides a chip packaging structure, including:

[0010] A first circuit board comprises a first surface and a second surface arranged opposite to each other, and a through hole penetrating the first surface and the second surface;

[0011] a substrate, located on the first surface and covering the through hole;

[0012] A first chip is located on a side of the substrate facing the through hole, and the first chip extends toward the through hole;

[0013] a first metal ball connecting the substrate and the first surface;

[0014] a second circuit board, located on the second surface and covering the through hole;

[0015] A second chip is located on a side of the second circuit board facing the through hole, and the second chip extends toward the through hole;

[0016] The second metal ball connects the second circuit board and the second surface.

[0017] As a further improvement of an embodiment of the present invention, both the first metal ball and the second metal ball are gold balls.

[0018] As a further improvement of an embodiment of the present invention, the first chip includes a transmitter, and the second chip includes a diffractive optical element.

[0019] As a further improvement of an embodiment of the present invention, the packaging structure further includes a first packaging adhesive connecting the side edge of the substrate and the first surface, and a second packaging adhesive connecting the side edge of the second circuit board and the second surface.

[0020] As a further improvement of an embodiment of the present invention, the substrate is a transparent substrate.

[0021] As a further improvement of one embodiment of the present invention, a metal circuit layer is provided on the side of the substrate facing the through hole, the first circuit board includes a first interconnection circuit, the second circuit board includes a second interconnection circuit and a third interconnection circuit, the first chip is electrically connected to the metal circuit layer through a first bonding wire, the metal circuit layer is electrically connected to the first interconnection circuit through the first metal ball, the first interconnection circuit is electrically connected to the second interconnection circuit through the second metal ball, and the second chip is electrically connected to the third interconnection circuit through a second bonding wire.

[0022] As a further improvement of one embodiment of the present invention, a second connecting terminal and a third connecting terminal are provided on a side of the second circuit board away from the through hole, the second connecting terminal conducts the second interconnection line, the third connecting terminal conducts the third interconnection line, and the second circuit board is electrically connected to an external circuit board through the second connecting terminal and the third connecting terminal.

[0023] As a further improvement of an embodiment of the present invention, both the first circuit board and the second circuit board are printed circuit boards.

[0024] To achieve one of the above-mentioned purposes of the invention, an embodiment of the present invention provides a chip packaging method, comprising the steps of:

[0025] Fixing the first chip to the substrate and forming a first metal ball on the substrate to form a first part;

[0026] Fixing the second chip to the second circuit board, and forming a second metal ball on the second circuit board to form a second part;

[0027] Forming a through hole on the first circuit board that penetrates the first surface and the second surface that are oppositely disposed on the first circuit board;

[0028] Bonding the first portion to the first surface of the first circuit board by a flip-chip process, wherein the first chip extends toward the through hole;

[0029] The second portion is bonded to the second surface of the first circuit board through a flip-chip process, and the second chip extends toward the through hole.

[0030] As a further improvement of an embodiment of the present invention, the step of "bonding the second portion to the second surface of the first circuit board by a flip-chip process, wherein the second chip extends toward the through hole" further includes:

[0031] Acquire a first distance between a second surface of the first circuit board away from the first part and a first action surface of the first chip away from the substrate, and acquire a desired height of the second metal ball according to a target distance between the second action surface of the second chip and the first action surface of the first chip and the first distance;

[0032] During the flip-chip process, the welding force is controlled so that the molding height of the second metal ball is the desired height.

[0033] As a further improvement of an embodiment of the present invention, the step of "fixing the first chip to the substrate and forming a first metal ball on the substrate to form the first part" specifically includes:

[0034] forming a metal circuit layer on the substrate;

[0035] Fixing the first chip to a side of the substrate provided with the metal circuit layer by a die bonding process;

[0036] Electrically connecting the first chip and the metal circuit layer through a wire bonding process;

[0037] A first metal ball electrically connected to the metal circuit layer is formed to form a first part.

[0038] As a further improvement of an embodiment of the present invention, the step of "fixing the second chip to the second circuit board and forming a second metal ball on the second circuit board to form the second part" specifically includes:

[0039] Fixing the second chip to the second circuit board by a die bonding process;

[0040] electrically connecting the second chip and a third interconnection line in the second circuit board by a wire bonding process;

[0041] A second metal ball electrically connected to a second interconnection line in the second circuit board is formed to form a second part.

[0042] As a further improvement of an embodiment of the present invention, the step of "bonding the first part to the first surface of the first circuit board by a flip-chip process, and the first chip extends toward the through hole; bonding the second part to the second surface of the first circuit board by a flip-chip process, and the second chip extends toward the through hole" specifically includes:

[0043] The first metal ball is electrically connected to the first interconnection line in the first circuit board through a flip-chip process;

[0044] The second metal ball is electrically connected to the first interconnection circuit and the second interconnection circuit in the second circuit board through a flip-chip process.

[0045] As a further improvement of an embodiment of the present invention, the method further comprises the steps of:

[0046] A second connection terminal for conducting with the second interconnection line and a third connection terminal for conducting with the third interconnection line are formed on a side of the second circuit board away from the through hole.

[0047] Compared with the prior art, the beneficial effects of the present invention are: the height of the first metal ball and the second metal ball in one embodiment of the present invention can be effectively controlled by the welding force, that is, the height of the first metal ball and the second metal ball can be effectively controlled by adjusting the welding force, thereby effectively controlling the distance between the first chip and the second chip, greatly improving the optical accuracy between the first chip and the second chip, and greatly improving the assembly efficiency and reducing costs; in addition, the signal transmission between the substrate, the first circuit board and the second circuit board can be directly realized through the first metal ball and the second metal ball. In other words, the first metal ball and the second metal ball can not only effectively adjust the distance between the first chip and the second chip, but also realize signal transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the packaging structure in the prior art;

[0049] Figure 2 is a schematic diagram of a packaging structure of an embodiment of the present invention;

[0050] Figure 3 is a step diagram of a packaging method according to an embodiment of the present invention;

[0051] Figures 4 to 13 It is a schematic diagram of various steps of a packaging method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] The present invention will be described in detail below in conjunction with the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional changes made by a person skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0053] In various drawings of the present invention, for the convenience of illustration, some sizes of structures or parts are exaggerated relative to other structures or parts, and thus, only the basic structure of the subject matter of the present invention is illustrated.

[0054] Combination Figure 2 , is a schematic diagram of a chip packaging structure 200 according to an embodiment of the present invention.

[0055] The package structure 200 includes a first circuit board 20 , a substrate 30 , a first chip 31 , a first metal ball 32 , a second circuit board 40 , a second chip 41 and a second metal ball 42 .

[0056] The first circuit board 20 includes a first surface 21 and a second surface 22 opposite to each other, and a through hole 23 penetrating the first surface 21 and the second surface 22 .

[0057] The substrate 30 is located on the first surface 21 and covers the through hole 23 .

[0058] The first chip 31 is located on a side of the substrate 30 facing the through hole 23 , and the first chip 31 extends toward the through hole 23 .

[0059] The first metal ball 32 connects the substrate 30 and the first surface 21 .

[0060] The second circuit board 40 is located on the second surface 22 and covers the through hole 23 .

[0061] The second chip 41 is located on a side of the second circuit board 40 facing the through hole 23 , and the second chip 41 extends toward the through hole 23 .

[0062] The second metal ball 42 connects the second circuit board 40 and the second surface 22 .

[0063] Here, the substrate 30 is connected to the first circuit board 20 via the first metal ball 32, and the second circuit board 40 is connected to the first circuit board 20 via the second metal ball 42. The heights of the first metal ball 32 and the second metal ball 42 can be effectively controlled by the welding force. That is, the heights of the first metal ball 32 and the second metal ball 42 can be effectively controlled by adjusting the welding force, thereby effectively controlling the distance between the first chip 31 and the second chip 41, greatly improving the optical accuracy between the first chip 31 and the second chip 41, and greatly improving the assembly efficiency and reducing the cost.

[0064] In addition, the substrate 30 and the first circuit board 20, and the first circuit board 20 and the second circuit board 40 are respectively connected through the first metal ball 32 and the second metal ball 42 with conductive properties. Signal transmission between the substrate 30, the first circuit board 20 and the second circuit board 40 can be directly achieved through the first metal ball 32 and the second metal ball 42. In other words, the first metal ball 32 and the second metal ball 42 can not only effectively adjust the distance between the first chip 31 and the second chip 41, but also realize signal transmission.

[0065] It should be noted that the first chip 31 and the second chip 41 are aligned in the vertical direction X so that light can be transmitted between the first chip 31 and the second chip 41. The vertical direction X is defined as the stacking direction of the substrate 30, the first circuit board 20 and the second circuit board 40.

[0066] In addition, “the first metal ball 32 is connected to the substrate 30” means that the first metal ball 32 is located on one side of the substrate 30, and the first metal ball 32 and the substrate 30 can be directly connected or indirectly connected. In other words, a component described in this embodiment is connected, fixed to or located on another component, which means that the two components are directly connected or indirectly connected.

[0067] In this embodiment, the first chip 31 includes a transmitter 31, and the second chip 41 includes a diffractive optical element 41 (DOE). The first chip 31 and the second chip 41 cooperate with each other to achieve barcode scanning, but the present invention is not limited thereto.

[0068] When the diffractive optical element 41 receives the downward scanning light sent by the transmitter 31, the diffractive optical element 41 divides the scanning light into multiple scanning light beams to achieve a scanning effect. At this time, it is necessary to effectively control the distance between the emitting surface of the transmitter 31 and the receiving surface of the diffractive optical element 41 so that the diffractive optical element 41 can completely receive the scanning light, that is, it is necessary to control the target distance H between the first active surface 311 of the first chip 31 and the second active surface 411 of the second chip 41. In this embodiment, the target distance H can be effectively controlled by the first metal ball 32 and the second metal ball 42.

[0069] In this embodiment, the substrate 30 is a transparent substrate, which allows the multiple scanning light beams emitted by the diffractive optical element 41 to be transmitted to the outside of the packaging structure 100 .

[0070] The first metal ball 32 and the second metal ball 42 are both gold balls, which can effectively improve signal transmission performance.

[0071] The first circuit board 20 and the second circuit board 40 are both printed circuit boards to ensure the overall strength of the packaging structure 100 and the accuracy of the target distance H adjustment process.

[0072] In this embodiment, the first circuit board 20 includes a first interconnection circuit 201, which is a circuit of the first circuit board 20 itself, and the first interconnection circuit 201 extends to the first surface 21 and the second surface 22 of the first circuit board 20 respectively; the second circuit board 40 includes a second interconnection circuit 401 and a third interconnection circuit 402, which is a circuit of the second circuit board 40 itself, and the second interconnection circuit 401 and the third interconnection circuit 402 extend to the upper surface 43 and the lower surface 44 of the second circuit board 40 respectively.

[0073] A second connection terminal 4011 and a third connection terminal 4021 are provided on one side of the second circuit board 40 away from the through hole 23 (i.e., the lower surface 44 of the second circuit board 40). The second connection terminal 4011 conducts the second interconnection line 401, and the third connection terminal 4021 conducts the third interconnection line 402. The second circuit board 40 is electrically connected to an external circuit board through the second connection terminal 4011 and the third connection terminal 4021. The external circuit board is, for example, a system control board.

[0074] A metal circuit layer 33 is disposed on a side of the substrate 30 facing the through hole 23 , and the first chip 31 is electrically connected to the metal circuit layer 33 via a first bonding wire 34 .

[0075] Here, the metal circuit layer 33 includes a protective layer 301, a redistribution layer 302 and a solder resist layer 303 which are sequentially connected to the substrate 30. The thermal expansion coefficient of the protective layer 301 may be between that of the substrate 30 and the redistribution layer 302, but is not limited thereto. The setting of the protective layer 301 may prevent the redistribution layer 301 and the substrate 30 from separating from each other under stress.

[0076] One end of the first metal ball 32 is electrically connected to the solder resist layer 303 , and the first chip 31 is electrically connected to the redistribution layer 302 through the first bonding wire 34 .

[0077] The metal circuit layer 33 is electrically connected to the first interconnection line 201 through the first metal ball 32, and the first interconnection line 201 is electrically connected to the second interconnection line 401 through the second metal ball 42. In this way, the first chip 31 can be electrically connected to the external circuit board through the first bonding wire 34, the metal circuit layer 33, the first metal ball 32, the first interconnection line 201, the second interconnection line 401 and the second connection terminal 4011 in sequence, so that the first chip 31 can be controlled through the external circuit board, for example, the power on and off operations of the first chip 31 can be controlled.

[0078] The second chip 41 is electrically connected to the third interconnection line 402 through the second bonding wire 45. In this way, the second chip 41 can be electrically connected to the external circuit board through the second bonding wire 45, the third interconnection line 402 and the third connection terminal 4021 in sequence, so that the second chip 41 can be controlled through the external circuit board, for example, the scanning direction and scanning range of the second chip 41 can be controlled.

[0079] It can be seen that in this embodiment, the first metal ball 32 and the second metal ball 42 can achieve conduction between the substrate 30, the first circuit board 20 and the second circuit board 40, so that the first chip 31 and the second chip 41 can be electrically connected to the external circuit board, and the chip control can be achieved through a simple structure.

[0080] In this embodiment, the packaging structure 100 also includes a first packaging glue 35 connecting the side edge 304 of the substrate 30 and the first surface 21 of the first circuit board 20, and a second packaging glue 46 connecting the side edge 403 of the second circuit board 40 and the second surface 22. The setting of the first packaging glue 35 can improve the stability of the fit between the substrate 30 and the first circuit board 20. Similarly, the setting of the second packaging glue 46 can improve the stability of the fit between the second circuit board 40 and the first circuit board 20.

[0081] An embodiment of the present invention further provides a chip packaging method, combining the above description of the packaging structure 100 and Figures 3 to 13 , the chip packaging method includes the steps of:

[0082] S1: Combination Figures 4 to 7, fixing the first chip 31 to the substrate 30, and forming a first metal ball 32 on the substrate 30 to form a first part P1;

[0083] Step S1 specifically includes:

[0084] Forming a metal circuit layer 33 on the substrate 30;

[0085] Here, the metal circuit layer 33 includes a protection layer 301 , a redistribution layer 302 , and a solder resist layer 303 which are sequentially connected to the substrate 30 .

[0086] The first chip 31 is fixed to the side of the substrate 30 provided with the metal circuit layer 33 by a die bonding process;

[0087] The first chip 31 and the metal circuit layer 33 are electrically connected by a wire bonding process;

[0088] Here, the first chip 31 is electrically connected to the redistribution layer 302 through the first bonding wires 34 .

[0089] A first metal ball 32 electrically connected to the metal wiring layer 33 is formed to form a first portion P1 .

[0090] Here, one end of the first metal ball 32 is electrically connected to the solder resist layer 303 . The first part P1 at this time includes the substrate 30 , the first chip 31 , the first metal ball 32 , the metal circuit layer 33 and the first bonding wire 34 .

[0091] S3: Combination Figure 8 and Fig. 9 , fixing the second chip 41 to the second circuit board 40, and forming a second metal ball 42 on the second circuit board 40 to form a second part P2;

[0092] Step S3 specifically includes:

[0093] The second chip 41 is fixed to the second circuit board 40 by a die bonding process;

[0094] Here, the second chip 41 is fixed to the upper surface 43 of the second circuit board 40 .

[0095] The second chip 41 and the third interconnection line 402 in the second circuit board 40 are electrically connected by a wire bonding process;

[0096] Here, the second chip 41 is electrically connected to the third interconnection line 402 through the second bonding wire 45 .

[0097] A second metal ball 42 electrically connected to the second interconnection line 401 in the second circuit board 40 is formed to form the second portion P2.

[0098] Here, one end of the second metal ball 42 is electrically connected to the second interconnection line 401 . At this time, the second part P2 includes the second circuit board 40 , the second chip 41 , the second metal ball 42 and the second bonding wire 45 .

[0099] S5: Combination Fig.10 , forming a through hole 23 on the first circuit board 20 that penetrates the first surface 21 and the second surface 22 that are oppositely disposed on the first circuit board 20;

[0100] S7: Combined Fig.11 , the first part P1 is bonded to the first surface 21 of the first circuit board 20 by a flip-chip process, and the first chip 31 extends toward the through hole 23;

[0101] S9: Combined Fig.12 The second portion P2 is bonded to the second surface 22 of the first circuit board 20 by a flip-chip process, and the second chip 41 extends toward the through hole 23 .

[0102] Specifically, steps S7 and S9 are: the first metal ball 32 is electrically connected to the first interconnection line 201 in the first circuit board 20 through the flip-chip process. Similarly, the second metal ball 42 is electrically connected to the first interconnection line 201 in the first circuit board 20 and the second interconnection line 401 in the second circuit board 40 through the flip-chip process. In this way, the interconnection between the first part P1 and the first circuit board 20 and the interconnection between the second part P2 and the first circuit board 20 are realized.

[0103] Here, it should be noted that, in order to improve the stability of the cooperation between the substrate 30 and the first circuit board 20, and to improve the stability of the cooperation between the first circuit board 20 and the second circuit board 40, steps S7 and S9 further include:

[0104] A first packaging adhesive 35 is formed to connect the side edge 304 of the substrate 30 and the first surface 21 of the first circuit board 20 , and a second packaging adhesive 46 is formed to connect the side edge 403 of the second circuit board 40 and the second surface 22 .

[0105] The specific operation flow of steps S7 and S9 is as follows:

[0106] Obtain a first distance H1 between the second surface 22 of the first circuit board 20 away from the first portion P1 and the first action surface 311 of the first chip 31 away from the substrate 30, and obtain a desired height H' of the second metal ball 42 according to a target distance H between the second action surface 411 of the second chip 41 and the first action surface 311 of the first chip 31 and the first distance H1;

[0107] During the flip-chip process, the welding force is controlled so that the molding height of the second metal ball 42 is the desired height H′.

[0108] Here, it is assumed that the distance between the first active surface 311 of the first chip 31 and the surface of the substrate 30 close to the through hole 23 is H2, the distance between the first metal ball 32 and the surface of the substrate 30 close to the through hole 23 is H3, and the thickness of the first circuit board 20 is H4. Then, the first distance H1=H4+H3-H2. The distances H1 and H2 can be effectively controlled by controlling the process, material, welding strength, etc., and then the thickness H4 can be obtained by selecting a first circuit board 20 of a certain specification. In this way, the first distance H1 can be obtained. In actual operation, the distances H1 and H2 can be made constants through certain processes, materials, welding strength, etc. At this time, the first distance H1 can be directly obtained by selecting a first circuit board 20 with a known thickness of H4.

[0109] Then, according to different packaging structures 100, the target distance H between the second active surface 411 of the second chip 41 and the first active surface 311 of the first chip 31 is different. At this time, the target distance H of the corresponding packaging structure 100 can be obtained in advance, and the expected height H' of the second metal ball 42 can be obtained according to the target distance H and the first distance H1.

[0110] Here, assuming that the distance between the second active surface 411 of the second chip 41 and the upper surface 43 of the second circuit board 40 is H5, then the expected height H' of the second metal ball 42 is H+H5-H1. In actual operation, the distance H5 can be made a constant through certain processes, materials, etc. At this time, the expected height H' of the second metal ball 42 can be directly obtained based on the first distance H1 obtained above.

[0111] After obtaining the desired height H' of the second metal ball 42, the welding force can be controlled during the flip-chip process in step S9 so that the molding height of the second metal ball 42 is the desired height H'. At this time, it is ensured that the distance between the second active surface 411 of the second chip 41 and the first active surface 311 of the first chip 31 is the desired target distance H.

[0112] In addition, the process of this embodiment also includes the steps of:

[0113] S11: Combination Fig.13 A second connection terminal 4011 conducting to the second interconnection line 401 and a third connection terminal 4021 conducting to the third interconnection line 402 are formed on a side of the second circuit board 40 away from the through hole 23 .

[0114] It can be seen that the substrate 30 is connected to the first circuit board 20 via the first metal ball 32, and the second circuit board 40 is connected to the first circuit board 20 via the second metal ball 42. By adjusting the welding force, the desired height H' of the second metal ball 42 can be effectively controlled, thereby effectively controlling the target distance H between the first chip 31 and the second chip 41, greatly improving the optical accuracy between the first chip 31 and the second chip 41, and greatly improving the assembly efficiency and reducing costs.

[0115] In addition, the first chip 31 can be electrically connected to the external circuit board through the first bonding wire 34, the metal circuit layer 33, the first metal ball 32, the first interconnection line 201, the second interconnection line 401 and the second connection terminal 4011 in sequence, so that the first chip 31 can be controlled through the external circuit board, for example, controlling the power-on and power-off operations of the first chip 31, etc. The second chip 41 is electrically connected to the third interconnection line 402 through the second bonding wire 45. In this way, the second chip 41 can be electrically connected to the external circuit board through the second bonding wire 45, the third interconnection line 402 and the third connection terminal 4021 in sequence, so that the second chip 41 can be controlled through the external circuit board, for example, controlling the scanning direction and scanning range of the second chip 41. In this embodiment, the substrate 30, the first circuit board 20 and the second circuit board 40 can be connected through the first metal ball 32 and the second metal ball 42, so that the first chip 31 and the second chip 41 can be electrically connected to the external circuit board, and the chip control can be achieved through a simple structure.

[0116] For other descriptions of the process method of this embodiment, reference may be made to the description of the aforementioned packaging structure 100 , which will not be repeated here.

[0117] It should be emphasized that the above step numbers S1, S3, S5, S7, S9, and S11 do not actually limit the order of the steps. For example, the second part P2 forming step S3 may be located before the first part P1 forming step S1. In addition, the second part P2 may be combined with the first circuit board 20 first, and then the height of the first metal ball 32 may be controlled by adjusting the welding force to control the target distance H between the first chip 31 and the second chip 41.

[0118] It should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0119] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A chip packaging structure, characterized in that: include: A first circuit board comprises a first surface and a second surface arranged opposite to each other, and a through hole penetrating the first surface and the second surface; a substrate, located on the first surface and covering the through hole; A first chip is located on a side of the substrate facing the through hole, and the first chip extends toward the through hole; A first metal ball connecting a side surface of the substrate facing the first circuit board and the first surface; a second circuit board, located on the second surface and covering the through hole; A second chip is located on a side of the second circuit board facing the through hole, and the second chip extends toward the through hole; a second metal ball connecting a side surface of the second circuit board facing the first circuit board and the second surface; A metal circuit layer is provided on a side of the substrate facing the through hole, the first circuit board includes a first interconnection circuit, the second circuit board includes a second interconnection circuit and a third interconnection circuit, the first chip is electrically connected to the metal circuit layer through a first bonding wire, the metal circuit layer is electrically connected to the first interconnection circuit through the first metal ball, the first interconnection circuit is electrically connected to the second interconnection circuit through the second metal ball, and the second chip is electrically connected to the third interconnection circuit through a second bonding wire; a second connection terminal and a third connection terminal are provided on a side of the second circuit board away from the through hole, the second connection terminal conducts the second interconnection circuit, the third connection terminal conducts the third interconnection circuit, and the second circuit board is electrically connected to an external circuit board through the second connection terminal and the third connection terminal.

2. The packaging structure according to claim 1, characterized in that: The first metal ball and the second metal ball are both gold balls.

3. The packaging structure according to claim 1, characterized in that: The first chip includes a transmitter and the second chip includes a diffractive optical element.

4. The packaging structure according to claim 1, characterized in that: The packaging structure further includes a first packaging adhesive connecting the side edge of the substrate and the first surface, and a second packaging adhesive connecting the side edge of the second circuit board and the second surface.

5. The packaging structure according to claim 1, characterized in that: The substrate is a transparent substrate.

6. The packaging structure according to claim 1, characterized in that: The first circuit board and the second circuit board are both printed circuit boards.

7. A chip packaging method, characterized in that: Includes steps: Fixing the first chip to the substrate and forming a first metal ball on the substrate to form a first part; Fixing the second chip to the second circuit board, and forming a second metal ball on the second circuit board to form a second part; Forming a through hole on the first circuit board that penetrates the first surface and the second surface that are oppositely disposed on the first circuit board; Bonding the first portion to the first surface of the first circuit board by a flip-chip process, wherein the first chip extends toward the through hole; bonding the second portion to the second surface of the first circuit board by a flip-chip process, wherein the second chip extends toward the through hole; The step of "fixing the first chip to the substrate and forming a first metal ball on the substrate to form the first part" specifically includes: forming a metal circuit layer on the substrate; Fixing the first chip to a side of the substrate provided with the metal circuit layer by a die bonding process; Electrically connecting the first chip and the metal circuit layer through a wire bonding process; Forming a first metal ball electrically connected to the metal circuit layer to form a first part; The step of "fixing the second chip to the second circuit board and forming a second metal ball on the second circuit board to form the second part" specifically includes: Fixing the second chip to the second circuit board by a die bonding process; electrically connecting the second chip and a third interconnection line in the second circuit board by a wire bonding process; forming a second metal ball electrically connected to a second interconnection line in the second circuit board to form a second part; The step of "bonding the first part to the first surface of the first circuit board by a flip-chip process, with the first chip extending toward the through hole; bonding the second part to the second surface of the first circuit board by a flip-chip process, with the second chip extending toward the through hole" specifically includes: The first metal ball is electrically connected to the first interconnection line in the first circuit board through a flip-chip process; The second metal ball is electrically connected to the first interconnection circuit and the second interconnection circuit in the second circuit board through a flip-chip process; The method further comprises the steps of: A second connection terminal for conducting with the second interconnection line and a third connection terminal for conducting with the third interconnection line are formed on a side of the second circuit board away from the through hole.

8. The packaging method according to claim 7, characterized in that: The step of "bonding the second portion to the second surface of the first circuit board by a flip-chip process, wherein the second chip extends toward the through hole" further includes: Acquire a first distance between a second surface of the first circuit board away from the first part and a first action surface of the first chip away from the substrate, and acquire a desired height of the second metal ball according to a target distance between the second action surface of the second chip and the first action surface of the first chip and the first distance; During the flip-chip process, the welding force is controlled so that the molding height of the second metal ball is the desired height.

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