CN112635505A - Packaging structure and packaging method - Google Patents

Abstract

The invention discloses a packaging structure, comprising: the chip unit is provided with a front surface and a back surface which are opposite, and the front surface of the chip unit is provided with a sensing area; the light-transmitting cover plate covers the front surface of the chip unit; and the plastic packaging layer is used for shading the side wall of the light-transmitting cover plate in the direction vertical to the sensing area and exposing the area opposite to the sensing area. The invention also discloses a packaging method. The present case is through in the process of moulding plastics, shelters from the lateral wall of printing opacity apron through the plastic envelope layer, avoids incident light reflection, interference induction area, influences the formation of image effect.

Description

Packaging structure and packaging method

Technical Field

The invention belongs to the technical field of semiconductors, and particularly relates to a packaging structure and a packaging method.

Background

The light sensing chip is an electronic device capable of sensing external light and converting the external light into an electrical signal. The photosensitive chip is usually manufactured by a semiconductor manufacturing process. After the photosensitive chip is manufactured, a series of packaging processes are performed on the photosensitive chip to form a packaged structure, so that the packaged structure is used in electronic equipment such as a digital camera and a digital video camera.

The package structure of the photosensitive chip in the prior art includes a transparent cover plate, which is used for protecting an optical area of the photosensitive chip and transmitting light.

However, in the specific use process of the existing photosensitive chip, the transparent cover plate has a vertical side wall, the side wall has the problem of incident light reflection, and reflected light at different angles can be reflected to an optical area to interfere effective direct light to enter the optical area, thereby affecting the imaging effect.

Disclosure of Invention

An embodiment of the present invention provides a package structure and a method for solving the technical problems of the prior art that the side wall of a light-transmitting cover plate reflects incident light and interferes the effective direct light entering an optical area, thereby affecting the imaging effect, including:

in one embodiment, a package structure includes:

the chip unit is provided with a front surface and a back surface which are opposite, and the front surface of the chip unit is provided with a sensing area;

the light-transmitting cover plate covers the front surface of the chip unit;

and the plastic packaging layer is used for shading the side wall of the light-transmitting cover plate in the direction vertical to the sensing area and exposing the area opposite to the sensing area.

Preferably, in the above package structure, the sidewall of the light-transmitting cover plate is an inclined surface,

the plastic packaging layer is combined on the inclined plane.

Preferably, in the above package structure, a step portion is formed at the peripheral edge of the light-transmitting cover plate,

the plastic packaging layer is filled on the step part.

Preferably, in the above package structure, the molding layer does not protrude out of the surface of the light-transmitting cover plate away from the chip unit.

Preferably, in the above package structure, the light-transmitting cover plate is supported on the surface of the chip unit through a support structure,

the sensing region is located in a cavity defined by the support structure.

Preferably, in the above package structure, the package structure further includes a circuit board, the back surface of the chip unit is attached and fixed to the circuit board,

the welding pads of the chip unit are electrically connected with the circuit board through metal leads,

the plastic packaging layer is arranged on the surface of the circuit board for fixing the chip unit and surrounds the chip unit and the metal lead.

Preferably, in the above package structure, the light-transmitting cover plate is a dry film, inorganic glass or organic glass.

In another embodiment, the present application further provides a packaging method of a package structure, including:

providing the chip unit;

covering the front surface of the chip unit with a light-transmitting cover plate;

and plastically packaging the chip unit and the light-transmitting cover plate, wherein the formed plastic packaging layer is used for shading the side wall of the light-transmitting cover plate in the direction vertical to the sensing area and exposing the area opposite to the sensing area.

In another embodiment, the present application further provides a packaging method of a package structure, including:

providing a wafer, wherein the wafer is provided with a plurality of chip units;

providing a light-transmitting cover plate, and covering the front surface of the chip unit with the light-transmitting cover plate;

cutting the wafer and the light-transmitting cover plate through a cutting process to form a plurality of single-grain packaging structures;

and carrying out plastic package on the single-grain packaging structure, wherein the formed plastic package layer is used for shading the side wall of the light-transmitting cover plate in the direction vertical to the sensing area and exposing the area opposite to the sensing area.

Preferably, in the packaging method of the above-mentioned packaging structure, the method further includes:

bonding a plurality of single-grain packaging structures on a circuit board, and then carrying out plastic packaging on the single-grain packaging structures;

and after plastic packaging, cutting the circuit board to form a plurality of single-grain packaging bodies.

Compared with the prior art, the present case is through in the process of moulding plastics, shelters from the lateral wall of printing opacity apron through the plastic envelope layer, avoids incident light reflection, interference response region, influences the formation of image effect.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a sectional view of a package structure in embodiment 1 of the present application;

fig. 2 is a sectional view of a package structure in embodiment 2 of the present application;

fig. 3 to 8 are schematic views of intermediate structures formed by the package structure in embodiment 1 of the present application.

Detailed Description

The present invention will be more fully understood from the following detailed description, which should be read in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed embodiment.

Referring to fig. 1, in an embodiment of the present application, apackage structure 10 is provided, which includes achip unit 11, a light-transmissive cover plate 12, acircuit board 13, and amolding compound layer 16.

As shown in fig. 4, thechip unit 11 has afront surface 111 and aback surface 112 opposite to each other, the front surface has asensing region 113, and thefront surface 111 of thechip unit 11 is provided with apad 114 outside thesensing region 113.

Thechip unit 11 is a photosensitive chip, and may be a fingerprint sensor chip, an image sensor chip, or the like.

The light-transmittingcover plate 12 covers thefront surface 111 of thechip unit 11 for protecting the front surface of thechip unit 11 to be packaged. Since it is necessary that the light reaches thesensing region 113 through thetransparent cover 12, thetransparent cover 12 has high light transmittance and is made of a transparent material. The two surfaces of the light-transmittingcover plate 12 are flat and smooth, and do not scatter or diffuse incident light.

Specifically, the material of thetransparent cover plate 12 may be a dry film, inorganic glass, organic glass, or other transparent material with a specific strength, and the transmittance needs to be more than 92%.

In an embodiment, the light-transmissive cover 12 is supported on the front surface of thechip unit 11 through the supportingstructure 14, acavity 114 is defined between the supportingstructure 14, the light-transmissive cover 12 and thechip unit 11, and thesensing region 113 is formed in thecavity 114.

In another embodiment, thetransparent cover 12 can also be bonded and fixed to the chip unit without a gap by an optical adhesive layer (not shown) having high light transmittance. In this embodiment, a package structure without a cavity is adopted, and the plastic package mold can directly act on the transparent cover plate.

Thecircuit board 13 is used for connecting an external circuit, the back surface of thechip unit 11 is adhered to one surface of thecircuit board 13, and the other surface of thecircuit board 13 is provided withsolder balls 131 electrically connected with the external circuit. Thepads 114 of thechip unit 11 are electrically connected to thecircuit board 13 throughmetal wires 15.

In another embodiment, the pad may be connected to the outside by a through silicon via, and specifically, thechip unit 11 further includes: and a through hole (not shown) extending from theback surface 112 to thefront surface 111 of thechip unit 11, wherein the through hole exposes thepad 114, thepad 114 is electrically connected to thesolder ball 131 through a metal wiring layer (not shown), and thechip unit 11 is electrically connected to other external circuits through thesolder ball 131.

Themolding layer 16 is formed by injection molding, and shields the sidewall of thetransparent cover plate 12 in a direction perpendicular to thesensing region 113, and exposes a region opposite to thesensing region 113.

In the present embodiment, theplastic sealing layer 16 shields the side wall of thetransparent cover plate 12, so that the incidence of external light on the side wall of thetransparent cover plate 12 can be reduced as much as possible. Meanwhile, themolding layer 16 also surrounds thesolder pads 114 and the metal leads 15.

Themolding layer 16 may serve to reflect light incident on theside wall 121 of the light-transmissive cover plate 12 as long as it can cover theside wall 121 of the light-transmissive cover plate 12.

Themolding layer 16 may be made of epoxy molding compound. In particular, in order to increase the light reflection and absorption of themolding layer 16, themolding layer 16 is optionally a black molding layer.

In order to improve the packaging effect, themolding layer 16 does not protrude out of the surface of the light-transmitting cover plate away from the chip unit, and in a preferred embodiment, the surface of the molding layer and the light incident surface of the light-transmitting cover plate are located on the same plane.

In order to achieve the above purpose, satisfy the light shielding effect, and not increase the injection molding cost, as shown in fig. 1, in the first embodiment, thesidewall 121 of the light-transmittingcover plate 12 is an inclined surface, and the inclined surface gradually approaches thesensing region 113 along the vertical direction away from the photosensitive chip.

In the first embodiment, the specific position of the projection edge of themolding layer 16 on thechip unit 11 is not limited, and when the projection edge of themolding layer 16 on thechip unit 11 is closer to thesensing region 113 toward the edge of thesensing region 113, the more thesidewall 121 of the light-transmittingcover 12 is inclined, the less the light incident on thesidewall 121 of the light-transmittingcover 12, therefore, the closer the projection edge of themolding layer 16 on thechip unit 11 is to the edge of thesensing region 113, the better in the embodiment.

Referring to fig. 2, in the second embodiment, astep portion 122 is formed at the peripheral edge of the light-transmittingcover plate 12, thestep portion 122 is filled with themolding layer 16, and themolding layer 16 can shield the top surface of thestep portion 122.

In the second embodiment, the specific position of the projection edge of themolding layer 16 on thechip unit 11 is not limited, and when the projection edge of themolding layer 16 on thechip unit 11 is closer to thesensing region 113 toward the edge of thesensing region 113, the longer the length of thestep portion 122 in the horizontal direction is, the less light is incident on theside wall 121 of the light-transmittingcover plate 12.

Note that the thickness of thestep portion 122 in the direction perpendicular to thephotosensitive region 113 should be as small as possible.

Correspondingly, the embodiment of the invention provides a packaging method for forming the packaging structure shown in fig. 1. Fig. 3 to 7 are schematic views of intermediate structures formed in a packaging process of a packaging method according to an embodiment of the invention.

Step s 1: referring to fig. 3 and 4, a wafer to be packaged is provided, in which fig. 3 is a schematic top view of the wafer to be packaged, and fig. 4 is a cross-sectional view taken along a-a in fig. 3 (for example, a single chip unit).

The wafer to be packaged has afront side 111 and aback side 112 opposite to thefront side 111. Thewafer 100 includes a plurality ofchip units 11 arranged in an array. Theadjacent chip units 11 havedicing channels 110 therebetween to facilitate a dicing process in a subsequent dicing process.

Thefront surface 111 includes asensing region 113 and a non-sensing region surrounding the sensing region, and thebonding pads 114 are disposed in the non-sensing region.

It should be noted that the cuttingchannel 110 between twoadjacent chip units 11 is only a margin area reserved between twochip units 11 for cutting, and there is no actual boundary line between the cuttingchannel 110 and thechip units 11 on both sides.

Step s 2: as shown in fig. 5, a light-transmissive cover plate 12 is provided, a plurality ofsupport structures 14 are formed on one surface of the light-transmissive cover plate 12, and then bonding is performed between thesupport structures 14 and thefront surface 111 of thechip unit 11.

Step s 3: as shown in fig. 6, thebonding pads 114 on thechip units 11 are exposed by cutting or cutting plus etching, and then thewafer 100 is divided by a cutting process, wherein during the cutting, the cutting is performed along the direction of the cuttingchannels 110, so as to form a plurality ofpackage structures 10. Thewafer 100 may be cut by a dicing blade, which may be a metal blade or a resin blade, or by a laser.

Wherein the light-transmitting cover plate can be cut by a profiled blade to form theinclined side walls 121 shown in fig. 1.

The light-transmitting cover plate can be cut by blades with different widths to form the structure of thestep portion 122 shown in fig. 2.

Step s 4: referring to fig. 7, acircuit board 13 is provided, and thecircuit board 13 has a front surface and a back surface opposite to each other. The front face is used for fixing thechip unit 11. Specifically, the back surface of thechip unit 11 is disposed toward the front surface of thecircuit board 13. The back surface of thecircuit board 13 hassolder balls 131, and thesolder balls 131 are used for connection with an external circuit. An interconnection circuit is arranged in thecircuit board 13, and the interconnection circuit is connected with thesolder balls 131.

Thechip unit 11 and thecircuit board 13 may be bonded and fixed by an adhesive layer or may be welded and fixed by a welding process.

Then, thechip unit 11 is electrically connected to thecircuit board 13 through the metal leads 15.

The electrical connection between thechip unit 11 and thecircuit board 13 is not limited to the connection of the metal leads 15. An interconnection structure may also be formed on the surface of thechip unit 11 through a TSV (through silicon via) process, and thecircuit board 13 is electrically connected directly through the interconnection structure.

Step s 5: as shown in fig. 8, the sidewall of the transparent cover plate, the exposedbonding pads 114 and the metal leads 15 are subjected to an injection molding process.

Step s 6: thecircuit board 13 is cut and divided into individual packages, as shown in fig. 1 and 2.

The aspects, embodiments, features and examples of the present invention should be considered as illustrative in all respects and not intended to be limiting of the invention, the scope of which is defined only by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

Unless specifically stated otherwise, use of the terms "comprising", "including", "having" or "having" is generally to be understood as open-ended and not limiting.

The use of the singular herein includes the plural (and vice versa) unless specifically stated otherwise. Furthermore, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. In addition, where the term "about" is used before a quantity, the present teachings also include the particular quantity itself unless specifically stated otherwise.

It should be understood that the order of steps or the order in which particular actions are performed is not critical, so long as the teachings of the invention remain operable. Further, two or more steps or actions may be performed simultaneously.

While the invention has been described with reference to illustrative embodiments, it will be understood by those skilled in the art that various other changes, omissions and/or additions may be made and substantial equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.

Claims (10)

Translated fromChinese

1.一种封装结构，其特征在于，包括：1. a package structure, is characterized in that, comprises:芯片单元，具有相对的正面和背面，其正面具有感应区域；A chip unit, with opposing front and back sides, the front side of which has a sensing area;透光盖板，覆盖所述芯片单元的正面；a light-transmitting cover plate covering the front side of the chip unit;塑封层，在垂直所述感应区域的方向上对所述透光盖板的侧壁进行遮光，并暴露出与所述感应区域相对的区域。The plastic sealing layer shields the side wall of the light-transmitting cover plate from light in the direction perpendicular to the sensing area, and exposes the area opposite to the sensing area.2.根据权利要求1所述的封装结构，其特征在于：所述透光盖板的侧壁为斜面，2 . The packaging structure according to claim 1 , wherein the side wall of the light-transmitting cover plate is an inclined plane, 3 .所述塑封层结合于所述斜面上。The plastic sealing layer is combined with the inclined surface.3.根据权利要求1所述的封装结构，其特征在于：所述透光盖板的四周边缘开设形成有台阶部，3 . The packaging structure according to claim 1 , wherein a step portion is formed on the peripheral edge of the light-transmitting cover plate,所述塑封层填充于所述台阶部上。The plastic sealing layer is filled on the stepped portion.4.根据权利要求1所述的封装结构，其特征在于：所述塑封层不凸伸出所述透光盖板背离所述芯片单元的表面。4 . The packaging structure of claim 1 , wherein the plastic sealing layer does not protrude from the surface of the transparent cover plate away from the chip unit. 5 .5.根据权利要求1所述的封装结构，其特征在于：所述透光盖板通过支撑结构支撑于所述芯片单元的表面，5 . The package structure according to claim 1 , wherein the light-transmitting cover plate is supported on the surface of the chip unit by a supporting structure, 6 .所述感应区域位于所述支撑结构围成的空腔内。The sensing area is located in the cavity enclosed by the support structure.6.根据权利要求1所述的封装结构，其特征在于：还包括一电路板，所述芯片单元的背面贴合固定于所述电路板上，6 . The package structure according to claim 1 , further comprising a circuit board, and the back of the chip unit is attached and fixed on the circuit board, 6 .所述芯片单元的焊垫与电路板之间通过金属引线电性连接，The bonding pads of the chip unit and the circuit board are electrically connected through metal leads,所述塑封层设置在所述电路板固定所述芯片单元的表面，并对芯片单元和金属引线进行包围。The plastic packaging layer is arranged on the surface of the circuit board on which the chip unit is fixed, and surrounds the chip unit and the metal leads.7.根据权利要求1所述的封装结构，其特征在于：所述透光盖板为干膜、无机玻璃或有机玻璃。7 . The package structure according to claim 1 , wherein the light-transmitting cover plate is dry film, inorganic glass or organic glass. 8 .8.一种权利形成如权利要求1-7任一所述的封装结构的封装方法，其特征在于，包括：8. An encapsulation method for forming the encapsulation structure according to any one of claims 1-7, characterized in that, comprising:提供所述的芯片单元；providing the chip unit;将透光盖板覆盖所述芯片单元的正面；Covering the front side of the chip unit with a light-transmitting cover plate;对芯片单元和透光盖板进行塑封，所形成的塑封层在垂直所述感应区域的方向上对所述透光盖板的侧壁进行遮光，并暴露出与所述感应区域相对的区域。The chip unit and the light-transmitting cover plate are plastic-sealed, and the formed plastic-sealing layer shields the sidewall of the light-transmitting cover plate from light in the direction perpendicular to the sensing area, and exposes the area opposite to the sensing area.9.一种权利形成如权利要求1-7任一所述的封装结构的封装方法，其特征在于，包括：9. An encapsulation method for forming the encapsulation structure according to any one of claims 1-7, characterized in that, comprising:提供一晶圆，该晶圆具有多个所述的芯片单元；providing a wafer, the wafer has a plurality of the chip units;提供一透光盖板，将该透光盖板覆盖所述芯片单元的正面；A light-transmitting cover plate is provided, and the light-transmitting cover plate covers the front surface of the chip unit;通过切割工艺，切割所述晶圆和透光盖板，形成多个单粒的封装结构；Through a cutting process, the wafer and the light-transmitting cover plate are cut to form a plurality of single-grain packaging structures;对单粒的封装结构进行塑封，所形成的塑封层在垂直所述感应区域的方向上对所述透光盖板的侧壁进行遮光，并暴露出与所述感应区域相对的区域。The single-particle encapsulation structure is plastic-encapsulated, and the formed plastic encapsulation layer shields the sidewall of the light-transmitting cover plate from light in the direction perpendicular to the sensing area, and exposes the area opposite to the sensing area.10.根据权利要求9所述的封装结构的封装方法，其特征在于，还包括：10. The packaging method of the packaging structure according to claim 9, characterized in that, further comprising:将多颗单粒的封装结构粘合在电路板上，然后再对单粒的封装结构进行塑封；Adhere the multi-grain single-grain package structure to the circuit board, and then plastic-encapsulate the single-grain package structure;以及在塑封后，切割电路板形成多个单粒的封装体。And after plastic sealing, the circuit board is cut to form a plurality of single-particle packages.

Images