Image sensor packaging structure and packaging method

Abstract

The present application discloses an image sensor packaging structure and a packaging method, wherein the inner side surface of a side panel in the packaging structure has an inclined slope or a curved side panel surface extending downward toward a terminal pad, thereby reserving space for dispensing glue from one side of the inner side surface of the side panel; the distance between the side panel and the terminal pad can be controlled, and the space for dispensing glue from one side of the side panel can be controlled, thereby reserving sufficient space for dispensing glue; the packaging structure is particularly suitable for image sensor structures in which leads are relatively dense and it is not convenient to eject atomized filling glue from both sides below the leads.

Description

Technical Field

[0001] The present application relates to the field of semiconductor chip packaging technology, and in particular to an image sensor packaging structure and packaging method. Background Art

[0002] Image sensors are the core devices of digital imaging equipment, which can convert optical image signals into electronic signals for processing. In order to protect the chip of the image sensor, make it work stably and maintain good sensing sensitivity for a long time, it is usually necessary to design a stable and reliable packaging structure. When packaging the image sensor, on the one hand, the photosensitive area of ​​the sensing chip must be protected; on the other hand, the electrical connection lines between the sensor and the external circuit must be protected to prevent external factors from affecting the normal acquisition and processing of the sensing signal.

[0003] The applicant disclosed an image sensor packaging structure and packaging method in a patent application with publication number CN110021619A, in which filling glue is directly injected vertically above the lead, providing a relatively stable and reliable packaging structure. The possible minor defects are: after the filling glue is injected vertically above the lead, the filling glue is diverted after contacting the lead, and the filling glue cannot completely wrap around the lead at the part of the lead facing away from the injection direction, which may cause the lead to break in a bumpy environment.

[0004] In order to solve the problem of possible lead breakage, the applicant disclosed an image sensor packaging method in a patent application with publication number CN116936594A, which solves the problem of easy lead breakage by "using a nozzle to eject atomized filling glue from both sides of the lead at high frequency onto the lead, spraying the lead surface until the outside of the lead is completely covered with the filling glue; then, when the filling glue on the lead surface has not yet solidified, fill the filling glue into the filling chamber with liquid until the liquid level of the filling glue is higher than the highest height of all the leads". However, when the sensing chip needs to be electrically connected to the substrate through leads on all sides, the leads are densely distributed, especially the leads at the corners, which increases the difficulty of the nozzle ejecting atomized filling glue from both sides below the leads.

[0005] The image sensor obtained by the image sensor packaging method disclosed in the patent application with publication number CN116936594A can meet the AEC-Q series certification promoted by the North American automotive industry; in order to make the performance of the image sensor even better, the applicant continues to study on solving the problem of lead firmness of automotive-grade image sensors, hoping to obtain better options. Summary of the invention

[0006] In view of this, the present application provides an image sensor packaging method on one hand, wherein the inner side surface of the side plate has a side plate inclined surface extending downward toward one side of the terminal pad direction, and a space is reserved for glue dispensed from one side of the inner side surface of the side plate, so that the filling glue can first flow from one side of the inner side surface of the side plate into the first bottom surface of the substrate outside the sensing chip, and the liquid level of the filling glue rises from the bottom to the top, which can fully cover the lead wire, thereby solving the problem that the lead wire is easy to break;

[0007] The specific technical solutions are as follows:

[0008] The image sensor packaging method comprises the following steps:

[0009] S1. Provide a substrate, wherein the substrate has a first bottom surface and a second bottom surface opposite to the first bottom surface; the substrate comprises a side plate surrounding the substrate, and the inner side surface of the side plate has a side plate inclined surface extending downward toward the terminal pad;

[0010] S2, mounting the sensing chip on the substrate, wherein the second surface of the sensing chip is mounted on the first bottom surface of the substrate; the first surface of the sensing chip has a sensing area, and the first surface of the sensing chip is opposite to the second surface;

[0011] S3, installing a transparent cover plate, wherein the transparent cover plate is fixed on the sensing chip through a supporting dam layer, and the transparent cover plate includes a light-transmitting area, and the light-transmitting area is located above the sensing area;

[0012] S4, electrically connecting the sensing chip to the substrate by electrically connecting the terminal pads of the substrate and the bonding pads of the sensing chip through a plurality of leads;

[0013] S5. Glue is dispensed to form a filling glue layer, which is done by dispensing glue from the inner side of the side panel. The filling glue first flows from the inner side of the side panel into the first bottom surface of the substrate outside the sensing chip. The liquid level of the filling glue rises from bottom to top. The filling glue layer fills the filling cavity formed by the first bottom surface outside the sensing chip, the outer side surface of the sensing chip, the first surface of the sensing chip outside the supporting dam layer, the outer side surface of the supporting dam layer, the outer side surface of the transparent cover plate, and the inner side surface of the side panel. The filling glue wraps the leads located in the filling cavity.

[0014] In some embodiments, in step S1, the side panel inclined surface includes a side inclined slope surface or a side panel curved surface.

[0015] In some embodiments, the side panel inclined slope includes a stepped side inclined slope.

[0016] In some embodiments, the height of the side plate is higher than the height of the transparent cover plate.

[0017] In some embodiments, an image sensor packaging method includes the following steps:

[0018] S1. Provide a substrate, wherein the substrate has a first bottom surface and a second bottom surface opposite to the first bottom surface; the substrate comprises a side plate surrounding the substrate, and the inner side surface of the side plate has a side plate inclined surface extending downward toward the terminal pad;

[0019] S2, mounting the sensing chip on the substrate, wherein the second surface of the sensing chip is mounted on the first bottom surface of the substrate; the first surface of the sensing chip has a sensing area, and the first surface of the sensing chip is opposite to the second surface;

[0020] S3, installing a transparent cover plate, wherein the transparent cover plate comprises a light-transmitting area and a supporting portion; the light-transmitting area and the supporting portion are integrally formed, the supporting portion of the transparent cover plate is fixed on the sensing chip, and the light-transmitting area is located above the sensing area;

[0021] S4, electrically connecting the sensing chip to the substrate by electrically connecting the terminal pads of the substrate and the bonding pads of the sensing chip through a plurality of leads;

[0022] S5. Forming a filling glue layer by dispensing glue from the inner side surface of the side panel. The filling glue first flows from the inner side surface of the side panel into the first bottom surface of the substrate outside the sensing chip. The liquid level of the filling glue rises from bottom to top. The filling glue layer fills the filling cavity formed by the first bottom surface outside the sensing chip, the outer side surface of the sensing chip, the first surface of the sensing chip outside the transparent cover plate, the outer side surface of the transparent cover plate, and the inner side surface of the side panel. The filling glue wraps the leads located in the filling cavity.

[0023] In addition to using a support dam layer independent of the transparent cover plate to support the transparent cover plate, such as a support dam layer formed by dispensing; a transparent cover plate in which a support portion and a light-transmitting area are integrally formed can also be used, and the transparent cover plate is directly fixed above the outer area of ​​the sensing area of ​​the sensing chip through the support portion.

[0024] In some embodiments, the transparent cover is fixed above the outer area of ​​the sensing region of the sensing chip through the filling glue layer.

[0025] In some embodiments, the bottom of the supporting portion of the transparent cover is fixed above the outer area of ​​the sensing region of the sensing chip through an adhesive layer.

[0026] In some embodiments, the height of the side panel is higher than that of the transparent cover panel. Considering that the filling glue has a certain degree of adhesion, when the glue is dispensed from one side of the inner side of the side panel, the filling glue layer will form a slope slightly inclined downward from the side panel to one side of the transparent cover panel. In addition, the side panel is higher than the transparent cover panel, and to a certain extent, it protects the transparent cover panel.

[0027] The present application also provides an image sensor packaging structure obtained according to the image sensor packaging method described in the present application.

[0028] The existing technology adopts: using two nozzles to high-frequency eject atomized filling glue onto the lead from both sides below the lead, spraying the surface of the lead until the outside of the lead is completely covered with the filling glue, and then filling the liquid filling glue toward the filling chamber when the filling glue on the surface of the lead has not yet solidified; however, when the sensing chip needs to be electrically connected to the substrate through leads on all sides, the leads are densely distributed, especially the leads at the corners, which increases the difficulty of the nozzle ejecting the atomized filling glue from both sides below the lead.

[0029] Beneficial effects of this application:

[0030] 1) The present application provides a method of dispensing glue from one side of the side plate of the substrate. The inner side surface of the side plate has a side plate inclined slope or a side plate curved surface extending downward toward the terminal pad, so as to reserve space for dispensing glue from one side of the inner side surface of the side plate; the distance between the side plate and the terminal pad can be controlled, and the space for dispensing glue from one side of the side plate can be controlled, so that sufficient space for dispensing glue can be reserved;

[0031] 2) The present application abandons the method of injecting filling glue directly from vertically above the lead in the prior art; the present application adopts: avoiding the lead, dispensing glue from one side of the inner side of the side plate, and the liquid level of the filling glue rises from bottom to top to fully cover the lead.

[0032] 3) It is particularly suitable for image sensor structures where the leads are densely packed and it is not convenient to eject the atomized filling glue from both sides below the leads. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The image sensor packaging method disclosed in the patent application with publication number CN110021619A;

[0034] Figure 2 The image sensor packaging method disclosed in the patent application with publication number CN116936594A;

[0035] Figure 3 It is a schematic diagram of an image sensor with densely distributed leads;

[0036] Figure 4 This is the first image sensor packaging structure of the present application;

[0037] Figure 5 This is the second image sensor packaging structure of the present application;

[0038] Figure 6 This is the third image sensor packaging structure of the present application;

[0039] Figure 7 This is a fourth image sensor packaging structure of the present application;

[0040] Figure 8 This is another embodiment of the fourth image sensor packaging structure of the present application;

[0041] In the figure:

[0042] 10: substrate, 11, first bottom surface, 12, second bottom surface, 13, side panel, 14, inner side surface of the side panel, 140, inclined slope of the side panel, 141, curved surface of the side panel, 142, stepped inclined slope of the side panel, 15, terminal pad;

[0043] 20. sensing chip, 21. first surface, 22. second surface, 23. sensing area, 24. bonding pad, 25. outer side of the sensing chip;

[0044] 30. Transparent cover plate, 31. Light-transmitting area, 32. Supporting portion, 33 or 33a. Outer side surface of the transparent cover plate, 34. Receptacle;

[0045] 40. lead wire; 50. nozzle; 60. filling rubber layer; 70. support dam layer; 71. outer side surface of the support dam layer. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described in the present application are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0047] This application abandons the existing Figure 1 The method shown is to inject the filling glue from the vertical top of the lead.

[0048] This application also abandons the existing Figure 2 As shown, two nozzles 50 are used to inject atomized filling glue onto the lead at high frequency from both sides below the lead to spray the surface of the lead, so as to achieve the technology of completely wrapping the lead with the filling glue.

[0049] like Figure 3When the sensing chip needs to be electrically connected to the substrate through leads on all sides, the leads are densely distributed, especially the leads at the corners, which increases the difficulty of the nozzle to eject the atomized filling glue from both sides below the leads.

[0050] The present application optimizes the side panel arranged around the substrate, and the inner side surface of the side panel has an inclined slope or a curved side panel surface extending downward toward the terminal pad, reserving space for dispensing glue from one side of the inner side surface of the side panel, so that the filling glue can first flow from one side of the inner side surface of the side panel into the first bottom surface 11 of the substrate outside the sensing chip 20, and the liquid level of the filling glue rises from bottom to top, and can fully cover the lead 40.

[0051] Example 1

[0052] like Figure 4 , an image sensor packaging structure, comprising:

[0053] A substrate 10, the substrate having a first bottom surface 11 and a second bottom surface 12 opposite to the first bottom surface;

[0054] A sensing chip 20, the sensing chip having a first surface 21 and a second surface 22 opposite to the first surface, the sensing chip is disposed on the first bottom surface 11, and the first surface of the sensing chip has a sensing area 23;

[0055] A transparent cover plate 30, wherein the transparent cover plate comprises a light-transmitting area 31, and the light-transmitting area 31 is located above the sensing area 23; the transparent cover plate 30 is fixed on the sensing chip through a supporting dam layer 70; the supporting dam layer 70 is independent of the transparent cover plate 30, and the supporting dam layer 70 can be formed by dispensing glue;

[0056] A plurality of leads 40 electrically connecting the terminal pads 15 of the substrate 10 and the bonding pads 24 of the sensing chip 20;

[0057] The base plate 10 includes a side plate 13 surrounding the base plate;

[0058] A filling glue layer 60 formed by dispensing glue, wherein the filling glue layer 60 fills a filling cavity formed by the first bottom surface 11 outside the sensing chip 20, the outer side surface 25 of the sensing chip, the first surface 21 of the sensing chip outside the support dam layer, the outer side surface 71 of the support dam layer, the outer side surface 33a of the transparent cover plate, and the inner side surface 14 of the side plate, and the filling glue wraps the lead 40 located in the filling cavity;

[0059] The inner side surface 14 of the side plate has an inclined slope or a curved side surface extending downward toward one side of the terminal pad 15 , so as to reserve space for dispensing glue from one side of the inner side surface 14 of the side plate.

[0060] Figure 4 The inner side surface 14 of the side plate is shown as a side plate inclined slope 140, and the side plate inclined slope 140 can be understood as: Figure 4 In the longitudinal section shown, the inner side surface 14 of the side plate is a straight slope. The inclined slope of the side plate facilitates the dispensed filling glue to smoothly move down to the first bottom surface 11 outside the sensing chip 20.

[0061] like Figure 5 As shown, the side plate inclined slope also includes a stepped side plate inclined slope 142, which is inclined downward at different inclination angles.

[0062] like Figure 6 As shown, the inner side surface of the side panel is a side panel curved surface 141, presenting at least one curved arc;

[0063] The inner side surface 14 of the side panel may also be in a shape, such as an S-shape.

[0064] Example 2

[0065] Figure 7 On the basis of Example 1, the transparent cover plate 30 includes a light-transmitting area 31 and a supporting portion 32; the light-transmitting area 31 and the supporting portion 32 are integrally formed; the supporting portion 32 and the light-transmitting area 31 form a cavity 34, and the sensing area 23 is located in the cavity 34; the supporting portion 32 is placed above the outer area of ​​the sensing area of ​​the sensing chip;

[0066] In Example 1, the support dam layer 70 is independent of the transparent cover plate 30, and the support dam layer 70 can be formed by dispensing. The transparent cover plate 30 in Example 1 is fixed by the support dam layer 70. Example 2 adopts a transparent cover plate 30 provided with a support portion 32, and the transparent cover plate 30 is directly fixed above the outer area of ​​the sensing area of ​​the sensing chip through the support portion 32.

[0067] The filling glue layer 60 fills the filling cavity formed by the first bottom surface 11 outside the sensing chip, the outer side surface 25 of the sensing chip, the first surface 21 of the sensing chip outside the transparent cover plate, the outer side surface 33 of the transparent cover plate, and the inner side surface 14 of the side plate.

[0068] The transparent cover plate 30 is fixed above the outer area of ​​the sensing area of ​​the sensing chip through the filling glue layer 60; or, the bottom of the supporting portion 32 of the transparent cover plate is fixed above the outer area of ​​the sensing area of ​​the sensing chip through an adhesive layer; when the bottom of the supporting portion 32 of the transparent cover plate is fixed through the adhesive layer, the filling glue layer 60 still plays a fixing role on the transparent cover plate.

[0069] Figure 7The light-transmitting area 31 and the supporting portion 32 are integrally formed; the supporting portion 32 and the light-transmitting area 31 form a cavity 34, and the sensing area 23 is located in the cavity 34; the supporting portion 32 is placed above the outer area of ​​the sensing area of ​​the sensing chip.

[0070] like Figures 4 to 7 , the height of the side panel 13 is higher than the height of the transparent cover panel 30; considering that the filling glue has a certain viscosity, the filling glue layer 60 will form a slope slightly inclined downward from the side panel to the transparent cover panel when the glue is dispensed from the inner side surface 14 of the side panel; in addition, the side panel is higher than the transparent cover panel, which, to a certain extent, protects the transparent cover panel.

[0071] Combined with reference Figure 7 and Figure 8 , Figure 8 The distance between the side plate and the terminal pad is greater than Figure 7 The distance between the middle side plate and the terminal pad, the distance between the side plate and the terminal pad can be controlled, the space for glue dispensing from one side of the side plate can be controlled, and sufficient space for glue dispensing can be reserved.

[0072] Example 3

[0073] Figure 4 , an image sensor packaging method, comprising the following steps:

[0074] S1. Provide a substrate 10, wherein the substrate has a first bottom surface 11 and a second bottom surface 12 opposite to the first bottom surface; the substrate includes a side plate 13 surrounding the substrate, and the inner side surface 14 of the side plate has a side plate inclined slope 140 or a side plate curved surface 141 extending downward toward the terminal pad;

[0075] S2, mounting the sensing chip 20 on the substrate 10, that is, mounting the second surface 22 of the sensing chip on the first bottom surface 11 of the substrate; the first surface of the sensing chip has a sensing area 23, and the first surface 21 of the sensing chip is opposite to the second surface 22;

[0076] S3, installing a transparent cover plate 30, wherein the transparent cover plate 30 is fixed on the sensing chip 20 through a supporting dam layer 70, and the transparent cover plate 30 includes a light-transmitting area 31, and the light-transmitting area 31 is located above the sensing area 23;

[0077] S4, electrically connecting the sensing chip 20 to the substrate 10 by electrically connecting the terminal pads 15 of the substrate and the bonding pads 24 of the sensing chip through a plurality of leads 40;

[0078] S5. Glue dispensing forms a filling glue layer 60, which is done by dispensing glue from the inner side surface 14 of the side panel. The filling glue first flows from the inner side surface 14 of the side panel into the first bottom surface 11 of the substrate outside the sensing chip. The liquid level of the filling glue rises from bottom to top. The filling glue layer fills the filling cavity formed by the first bottom surface 11 outside the sensing chip, the outer side surface 25 of the sensing chip, the first surface 21 of the sensing chip outside the supporting dam layer, the outer side surface 71 of the supporting dam layer, the outer side surface 33a of the transparent cover plate, and the inner side surface 14 of the side panel. The filling glue wraps the lead 40 located in the filling cavity.

[0079] Example 4

[0080] Figure 7 , an image sensor packaging method, comprising the following steps:

[0081] S1. Provide a substrate 10, wherein the substrate has a first bottom surface 11 and a second bottom surface 12 opposite to the first bottom surface; the substrate 10 includes a side plate 13 surrounding the substrate, and the inner side surface 14 of the side plate has a side plate inclined slope or a side plate curved surface extending downward toward the terminal pad;

[0082] S2, mounting the sensing chip 20 on the substrate 10, that is, mounting the second surface 22 of the sensing chip 20 on the first bottom surface 11 of the substrate; the first surface 21 of the sensing chip has a sensing area 23, and the first surface 21 of the sensing chip is opposite to the second surface 22;

[0083] S3, installing a transparent cover plate 30, wherein the transparent cover plate 30 includes a light-transmitting area 31 and a supporting portion 32; the light-transmitting area 31 and the supporting portion 32 are integrally formed, the supporting portion 32 of the transparent cover plate is fixed on the sensing chip, and the light-transmitting area 31 is located above the sensing area 23;

[0084] S4, electrically connecting the sensing chip 20 to the substrate 10 by electrically connecting the terminal pads 15 of the substrate and the bonding pads 24 of the sensing chip through a plurality of leads 40;

[0085] S5. Glue is dispensed to form a filling glue layer 60, which is done by dispensing glue from the inner side surface of the side panel. The filling glue first flows from the inner side surface 14 of the side panel into the first bottom surface 11 of the substrate outside the sensing chip. The liquid level of the filling glue rises from bottom to top. The filling glue layer fills the filling cavity formed by the first bottom surface 11 outside the sensing chip, the outer side surface 25 of the sensing chip, the first surface 21 of the sensing chip outside the transparent cover plate, the outer side surface 33 of the transparent cover plate, and the inner side surface 14 of the side panel. The filling glue wraps the lead 40 located in the filling cavity.

Claims

1. An image sensor packaging method, characterized in that: The following steps are involved: S1. Provide a substrate, wherein the substrate has a first bottom surface and a second bottom surface opposite to the first bottom surface; the substrate comprises a side plate surrounding the substrate, and the inner side surface of the side plate has a side plate inclined surface extending downward toward the terminal pad; S2, mounting the sensing chip on the substrate, wherein the second surface of the sensing chip is mounted on the first bottom surface of the substrate; the first surface of the sensing chip has a sensing area, and the first surface of the sensing chip is opposite to the second surface; S3, installing a transparent cover plate, wherein the transparent cover plate is fixed on the sensing chip through a supporting dam layer, and the transparent cover plate includes a light-transmitting area, and the light-transmitting area is located above the sensing area; S4, electrically connecting the sensing chip to the substrate by electrically connecting the terminal pads of the substrate and the bonding pads of the sensing chip through a plurality of leads; S5. Glue is dispensed to form a filling glue layer, which is done by dispensing glue from the inner side of the side panel. The filling glue first flows from the inner side of the side panel into the first bottom surface of the substrate outside the sensing chip. The liquid level of the filling glue rises from bottom to top. The filling glue layer fills the filling cavity formed by the first bottom surface outside the sensing chip, the outer side surface of the sensing chip, the first surface of the sensing chip outside the supporting dam layer, the outer side surface of the supporting dam layer, the outer side surface of the transparent cover plate, and the inner side surface of the side panel. The filling glue wraps the leads located in the filling cavity.

2. The image sensor packaging method according to claim 1, characterized in that: In step S1, the side panel inclined surface includes a side panel inclined slope surface or a side panel curved surface.

3. The image sensor packaging method according to claim 2, characterized in that: The side plate inclined slope surface comprises a stepped side plate inclined slope surface.

4. The image sensor packaging method according to claim 1, characterized in that: The height of the side plate is higher than that of the transparent cover plate.

5. An image sensor packaging method, characterized in that: The following steps are involved: S1. Provide a substrate, wherein the substrate has a first bottom surface and a second bottom surface opposite to the first bottom surface; the substrate comprises a side plate surrounding the substrate, and the inner side surface of the side plate has a side plate inclined surface extending downward toward the terminal pad; S2, mounting the sensing chip on the substrate, wherein the second surface of the sensing chip is mounted on the first bottom surface of the substrate; the first surface of the sensing chip has a sensing area, and the first surface of the sensing chip is opposite to the second surface; S3, installing a transparent cover plate, wherein the transparent cover plate comprises a light-transmitting area and a supporting portion; the light-transmitting area and the supporting portion are integrally formed, the supporting portion of the transparent cover plate is fixed on the sensing chip, and the light-transmitting area is located above the sensing area; S4, electrically connecting the sensing chip to the substrate by electrically connecting the terminal pads of the substrate and the bonding pads of the sensing chip through a plurality of leads; S5. Forming a filling glue layer by dispensing glue from the inner side surface of the side panel. The filling glue first flows from the inner side surface of the side panel into the first bottom surface of the substrate outside the sensing chip. The liquid level of the filling glue rises from bottom to top. The filling glue layer fills the filling cavity formed by the first bottom surface outside the sensing chip, the outer side surface of the sensing chip, the first surface of the sensing chip outside the transparent cover plate, the outer side surface of the transparent cover plate, and the inner side surface of the side panel. The filling glue wraps the leads located in the filling cavity.

6. The image sensor packaging method according to claim 5, characterized in that: The transparent cover is fixed above the outer area of ​​the sensing area of ​​the sensing chip through the filling glue layer.

7. The image sensor packaging method according to claim 5, characterized in that: The bottom of the supporting portion of the transparent cover is fixed above the outer area of ​​the sensing region of the sensing chip through an adhesive layer.

8. An image sensor packaging structure obtained according to the image sensor packaging method according to any one of claims 1 to 7.

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