A CSP packaging structure, a manufacturing method and a light bar based on the CSP packaging structure

Abstract

The present invention discloses a CSP packaging structure, a manufacturing method, a light bar based on the CSP packaging structure, and a plastic packaging mold. The CSP packaging structure includes a chip, a first packaging layer, and a second packaging layer; the first packaging layer is coated on the side and top surface of the chip, and the top surface of the first packaging layer is a convex structure; the second packaging layer is coated on the top surface of the first packaging layer. The technical solution provided by the present invention changes the propagation direction of light by setting the top surface of the first packaging layer as a convex structure, which is beneficial to the extraction of light, so that the light output from the top surface of the first packaging layer is more uniform, and the light output from the top surface of the first packaging layer is shielded by the second packaging layer, so that the light output from the top surface of the CSP packaging structure is similar to the light output from the side surface, thereby achieving the purpose of uniform light output.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor lighting technology, and in particular to a CSP packaging structure, a manufacturing method and a light bar based on the CSP packaging structure. Background Art

[0002] CSP packaging refers to chip-scale packaging, and its packaging size is basically the same as the chip core size. Therefore, CSP packaging has the advantage of small size. At the same time, CSP packaging structure also has the advantages of light weight and good electrical performance. These numerous advantages make CSP packaging structure applied to various fields.

[0003] The current CSP packaging structure mainly includes a flip chip and a packaging glue encapsulated on the flip chip. In this CSP packaging structure, 60% of the light output is concentrated directly above the chip, and less light is output around it. That is, the existing CSP packaging structure has the disadvantage of uneven light distribution. Summary of the invention

[0004] The present invention provides a CSP packaging structure, a manufacturing method, a light bar based on the CSP packaging structure, and a plastic packaging mold. The top surface of a first packaging layer is set as a convex structure to change the propagation direction of light, so that the light output from the top surface of the first packaging layer is more uniform, and the light output from the top layer of the first packaging layer is shielded by a second packaging layer, so that the light output from the top surface of the CSP packaging structure is similar to the light output from the side surface, thereby achieving the purpose of uniform light output.

[0005] In a first aspect, the present invention provides a CSP packaging structure, including a chip, a first packaging layer and a second packaging layer;

[0006] The first packaging layer covers the side surface and top surface of the chip, and the top surface of the first packaging layer is a convex structure;

[0007] The second packaging layer covers the top surface of the first packaging layer.

[0008] Preferably,

[0009] The side cross-section of the protruding structure is sawtooth-shaped.

[0010] Preferably,

[0011] The angle between the inclined surface of a single protrusion in the protrusion structure and the horizontal plane ranges from 30° to 70°.

[0012] Preferably,

[0013] The angle between the inclined surface of a single protrusion located in the central area of ​​the protrusion structure and the horizontal plane is greater than or equal to the angle between the inclined surface of a single protrusion located in the edge area of ​​the protrusion structure and the horizontal plane.

[0014] Preferably,

[0015] The distance between the top surface of the first packaging layer and the top surface of the chip ranges from 0.25 mm to 0.6 mm.

[0016] Preferably,

[0017] The ratio of the length and width of a single protrusion in the protrusion structure to the distance from the top surface of the first packaging layer to the top surface of the chip ranges from 1 / 8 to 2 / 5.

[0018] Preferably,

[0019] The height dimension corresponding to a single protrusion in the protrusion structure is less than or equal to the length and width dimensions.

[0020] Preferably,

[0021] The first encapsulation layer is a light-emitting material layer or a transparent material layer.

[0022] Preferably,

[0023] The second encapsulation layer is a white glue layer.

[0024] Preferably,

[0025] The chip includes a horizontal structure chip or a flip-chip structure chip.

[0026] In a second aspect, the present invention provides a method for manufacturing the CSP packaging structure as described in the first aspect, comprising:

[0027] Performing a first plastic encapsulation on the fixed chip to form a first encapsulation layer on the side and top surface of the chip, wherein the top surface of the first encapsulation layer is a convex structure;

[0028] Performing a second plastic packaging on the chip that has been plastic-sealed with the first packaging layer to form a second packaging layer on the top surface of the first packaging layer;

[0029] Bake and cut into individual devices.

[0030] In a third aspect, the present invention provides a light bar based on a CSP packaging structure, comprising: at least one CSP packaging structure according to the first aspect.

[0031] In a fourth aspect, the present invention provides a plastic packaging mold, comprising:

[0032] An upper mold and a lower mold;

[0033] The bottom surface of the upper mold is a convex structure, so that when the fixed chip is encapsulated by the encapsulation mold, a packaging layer with a convex structure on the top surface is formed.

[0034] The present invention provides a CSP packaging structure, a manufacturing method, a light bar based on the CSP packaging structure and a plastic packaging mold. The CSP packaging structure consists of a chip, a first packaging layer and a second packaging layer, wherein the first packaging layer is coated on the side and top surface of the chip, and the top surface of the first packaging layer is a convex structure. The convex structure can change the propagation direction of light, so that the light emission of the top surface of the first packaging layer in the central area and the edge area is more uniform, and the phenomenon that the light emission of the CSP packaging structure is concentrated directly above the chip is avoided; further, the second packaging layer is coated on the top surface of the first packaging layer to block the light emission of the top surface of the first packaging layer, so that the light emission of the top surface of the CSP packaging structure is similar to the light emission of the side surface, thereby achieving the purpose of uniform light emission. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the existing technical solutions, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 A schematic diagram of a CSP packaging structure provided by an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of a CSP packaging structure provided by another embodiment of the present invention;

[0038] Figure 3 A diagram of some parameters of a CSP packaging structure provided by an embodiment of the present invention;

[0039] Figure 4 A schematic diagram of the structure of a chip after die bonding in a method for manufacturing a CSP packaging structure provided by an embodiment of the present invention;

[0040] Figure 5 A schematic diagram of the structure of a chip after the first plastic encapsulation in a method for manufacturing a CSP packaging structure provided by an embodiment of the present invention;

[0041] Figure 6 A schematic diagram of the structure of a chip after die bonding in a method for manufacturing a CSP packaging structure provided by another embodiment of the present invention;

[0042] Figure 7 A schematic diagram of the structure of a chip after the first plastic encapsulation in a method for manufacturing a CSP packaging structure provided by another embodiment of the present invention;

[0043] Among them, the reference numerals in the figure are:

[0044] 1- Chip;

[0045] 2- first encapsulation layer;

[0046] 21- convex structure;

[0047] 3- second encapsulation layer;

[0048] 4-Substrate. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly or indirectly located on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and cannot be understood as limitations on the present technical solution. The terms "first" and "second" are only used for the convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0051] like Figure 1 As shown, this embodiment provides a CSP packaging structure, including a chip 1, a first packaging layer 2 and a second packaging layer 3;

[0052] The first packaging layer 2 covers the side surface and top surface of the chip 1, and the top surface of the first packaging layer 2 is a convex structure;

[0053] The second encapsulation layer 3 is coated on the top surface of the first encapsulation layer 2 .

[0054] In the above embodiment, the top surface of the first encapsulation layer 2 is a convex structure (eg Figure 121), the raised structure can change the propagation direction of the light, so that the light emission in the center area and the edge area of ​​the top surface of the first packaging layer 2 is more uniform, avoiding the phenomenon that the light emission of the CSP packaging structure is concentrated directly above the chip 1; further, the second packaging layer 3 is coated on the top surface of the first packaging layer 2 to block the light emission from the top surface of the first packaging layer 2, so that the light emission from the top surface of the CSP packaging structure is close to the light emission from the side, thereby achieving the purpose of uniform light emission.

[0055] It should be noted that since the CSP packaging structure includes a substrate-free (such as Figure 1 As shown) and a substrate 4 (as Figure 2 There are two common forms of CSP packaging structure (as shown in the figure). When the CSP packaging structure is a substrate structure, the CSP packaging structure includes a substrate 4, a chip 1, a first packaging layer 2 and a second packaging layer 3. The chip 1 is fixed on the substrate 4, the first packaging layer 2 is coated on the side and top surface of the chip 1, the top surface of the first packaging layer 2 is a convex structure, and the second packaging layer 3 is coated on the top surface of the first packaging layer 1.

[0056] In one embodiment of the present invention, the side section of the raised structure is sawtooth-shaped. The side section of the raised structure is a plane parallel to the side of the chip. Specifically, the raised structure includes a plurality of individual protrusions, each of which can be a micro-pyramid or a short concentric prism. The purpose of the raised structure is to change the propagation direction of light and diffuse the light so that the light is uniform after passing through the raised structure and has a large light-emitting angle. Therefore, the side section of the raised structure can also be other shapes, such as a wave shape, as long as the purpose of uniform light emission can be achieved. Users can set it according to actual business scenarios.

[0057] In one embodiment of the present invention, the angle between the inclined surface of a single protrusion in the protrusion structure and the horizontal plane (e.g. Figure 3 The range of A or B) includes 30° to 70°, and the light emitted through the protruding structure within this angle range is relatively uniform.

[0058] In one embodiment of the present invention, the angle between the inclined surface of a single protrusion located in the center area of ​​the protrusion structure and the horizontal plane is greater than or equal to the angle between the inclined surface of a single protrusion located in the edge area of ​​the protrusion structure and the horizontal plane. Usually, the light emission of the CSP packaging structure is concentrated directly above the chip, and the light emission in the peripheral area is less. Therefore, in order to make the light emission in the center area and the edge area of ​​the first packaging layer more uniform, the angle between the inclined surface of a single protrusion located in the center area of ​​the protrusion structure and the horizontal plane is made greater than or equal to the angle between the inclined surface of a single protrusion located in the edge area of ​​the protrusion structure and the horizontal plane. By setting the protrusion structure in this way, the light emission in each area of ​​the top surface of the first packaging layer is more uniform.

[0059] In one embodiment of the present invention, the distance between the top surface of the first packaging layer and the top surface of the chip ( Figure 3 The range of t) in the figure includes 0.25 mm to 0.6 mm. For example, the value of t may be 0.25 mm, 0.4 mm, 0.45 mm, 0.5 mm or 0.6 mm. When the value of t is large, the volume of the CSP packaging structure will be large, thereby limiting the application of the CSP packaging structure in ultra-thin display products. In this embodiment, the distance between the top surface of the first packaging layer and the top surface of the chip is controlled within the range of 0.25 mm to 0.6 mm, so that the volume of the entire packaging structure is small.

[0060] In one embodiment of the present invention, the length and width of a single protrusion in the protrusion structure (eg Figure 3 a) and the distance between the top surface of the first packaging layer and the top surface of the chip (such as Figure 3 The ratio range of t) includes 1 / 8 to 2 / 5, for example, the a value is 1 / 8, 1 / 5, 1 / 4, 3 / 10 or 2 / 5 of the t value. Within the value range of this embodiment, the light emitted after passing through the protruding structure can be made more uniform.

[0061] In one embodiment of the present invention, the height dimension corresponding to a single protrusion in the protrusion structure (eg Figure 3 h) is less than or equal to the length and width (such as Figure 3 In a), if the height of a single protrusion is too large, the uniform light emission effect on the top surface of the first packaging layer 2 will be poor. Therefore, controlling the height dimension corresponding to the single protrusion to be less than or equal to the length and width dimensions can achieve a better uniform light emission effect.

[0062] In one embodiment of the present invention, the first packaging layer 2 is a luminescent material layer or a transparent material layer. When it is necessary to change the color of the light emitted by the chip 1, a luminescent material with a luminescent function can be selected, such as phosphor glue. Specifically, when the chip 1 is a blue light chip, phosphor glue is used as the material of the first packaging layer 2, and the light emitted from the phosphor glue will be white light. If there is no need to change the color of the light emitted by the chip 1, a transparent material can be selected as the material of the first packaging layer, such as transparent silicone, epoxy glue, etc. Of course, the first packaging layer can also be quantum dot glue, etc. The user can choose the material used for the packaging glue according to the actual scenario.

[0063] In one embodiment of the present invention, the material used for the second encapsulation layer 3 is white glue, and the second encapsulation layer 3 is used to block the light emitted from the top surface of the first encapsulation layer 2, so that the light emission of the CSP packaged device is more uniform. Of course, the material used for the second encapsulation layer 3 can also be other opaque glues to achieve the purpose of blocking the light emitted from the top surface of the first encapsulation layer 2. Users can choose according to actual conditions.

[0064] In one embodiment of the present invention, the chip 1 includes a horizontal structure chip or a flip-chip structure chip. Specifically, the chip 1 includes a blue light chip, an ultraviolet chip, a green light chip or a red light chip. The user can choose the chip installation method and chip selection according to actual conditions.

[0065] In a second aspect, this embodiment provides a method for manufacturing a CSP packaging structure, including:

[0066] Performing a first plastic encapsulation on the fixed chip to form a first encapsulation layer on the side and top surface of the chip, wherein the top surface of the first encapsulation layer is a convex structure;

[0067] Performing a second plastic packaging on the chip that has been plastic-sealed with the first packaging layer to form a second packaging layer on the top surface of the first packaging layer;

[0068] Bake and cut into individual devices.

[0069] In the above embodiment, the top surface of the first packaging layer is a convex structure (such as Figure 1 21), the raised structure can change the propagation direction of the light, so that the light emission from the top surface of the first packaging layer in the central area and the edge area is more uniform, avoiding the phenomenon that the light emission of the CSP packaging structure is concentrated directly above the chip; further, the second packaging layer is coated on the top surface of the first packaging layer to block the light emission from the top surface of the first packaging layer, so that the light emission from the top surface of the CSP packaging structure is close to the light emission from the side, thereby achieving the purpose of uniform light emission.

[0070] In a possible implementation, a method for manufacturing a CSP packaging structure includes the following steps:

[0071] Step 10, bonding wire: fix the chip 1 on the substrate 4 by bonding, and connect the chip 1 and the substrate 4 (forming a bonding wire as shown in FIG. Figure 4 structure shown).

[0072] Step 11, first molding: The substrate 4 with the chip 1 fixed thereon is molded by coating the substrate 4 and the chip 1 with transparent glue or phosphor glue to form a first packaging layer 2 on the side and top surface of the chip 1, and the top surface of the first packaging layer 2 is a convex structure, and the side cross-section of the convex structure is a sawtooth shape (such as Figure 5 structure shown).

[0073] Step 12, second plastic sealing: coating the white glue on the transparent glue or the phosphor glue in a plastic sealing manner to form a second packaging layer 3 (such as Figure 2 structure shown).

[0074] Step 13, curing: the product after two plastic sealings is baked and cured.

[0075] Step 14, cutting: cutting the cured product into individual products.

[0076] In another possible implementation, the manufacturing method of the CSP packaging structure includes the following steps:

[0077] Step 20, die bonding: The chip 1 is fixed on a reusable adhesive film by die bonding (forming a Figure 6 structure shown).

[0078] Step 21, first plastic encapsulation: transparent glue or phosphor glue is applied on the chip 1 in a plastic encapsulation manner to form a first encapsulation layer 2 on the side and top surface of the chip 1, and the top surface of the first encapsulation layer 2 is a convex structure, and the side cross-section of the convex structure is a sawtooth shape (such as Figure 7 structure shown).

[0079] Step 22, second plastic sealing: coating the white glue on the transparent glue or the phosphor glue in a plastic sealing manner to form a second packaging layer 3 (such as Figure 1 structure shown).

[0080] Step 23, curing: the product after the two plastic sealings is baked and cured.

[0081] Step 24, cutting: cutting the solidified product into individual products.

[0082] In a third aspect, the present embodiment provides a light bar based on a CSP packaging structure, comprising: at least one CSP packaging structure as described in the first aspect, and the light bar can achieve a uniform light output effect.

[0083] In a fourth aspect, this embodiment provides a plastic encapsulation mold, comprising an upper mold and a lower mold; the bottom surface of the upper mold is a convex structure, so that when the fixed chip is encapsulated by the plastic encapsulation mold, a packaging layer with a convex structure on the top surface is formed. Specifically, the side cross-section of the convex structure can be sawtooth-shaped.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A CSP packaging structure, characterized in that: comprising a chip, a first packaging layer and a second packaging layer; The first packaging layer covers the side surface and top surface of the chip, and the top surface of the first packaging layer is a convex structure; The second encapsulation layer is coated on the top surface of the first encapsulation layer, wherein the second encapsulation layer blocks light emitted from the top surface of the first encapsulation layer; The ratio of the length and width of a single protrusion in the protrusion structure to the distance from the top surface of the first packaging layer to the top surface of the chip is in the range of 1 / 8 to 2 / 5; and / or, The height dimension corresponding to a single protrusion in the protrusion structure is less than or equal to the length and width dimensions.

2. The CSP packaging structure according to claim 1, characterized in that: The side cross-section of the protruding structure is sawtooth-shaped.

3. The CSP packaging structure according to claim 2, characterized in that: The angle between the inclined surface of a single protrusion in the protrusion structure and the horizontal plane ranges from 30° to 70°.

4. The CSP packaging structure according to claim 2, characterized in that: The angle between the inclined surface of a single protrusion located in the central area of ​​the protrusion structure and the horizontal plane is greater than or equal to the angle between the inclined surface of a single protrusion located in the edge area of ​​the protrusion structure and the horizontal plane.

5. The CSP packaging structure according to claim 1, characterized in that: The distance between the top surface of the first packaging layer and the top surface of the chip ranges from 0.25 mm to 0.6 mm.

6. The CSP packaging structure according to any one of claims 1 to 5, characterized in that: The first encapsulation layer is a luminescent material layer or a transparent material layer; And / or, the second encapsulation layer is a white glue layer; And / or, the chip includes a horizontal structure chip or a flip-chip structure chip.

7. A method for manufacturing a CSP packaging structure, characterized in that: include: Performing a first plastic encapsulation on the fixed chip to form a first encapsulation layer on the side and top surface of the chip, wherein the top surface of the first encapsulation layer is a convex structure; Performing a second plastic encapsulation on the chip that has been plastic encapsulated with the first packaging layer to form a second packaging layer on the top surface of the first packaging layer, wherein the second packaging layer shields light from the top surface of the first packaging layer; The ratio of the length and width of a single protrusion in the protrusion structure to the distance from the top surface of the first packaging layer to the top surface of the chip is in the range of 1 / 8 to 2 / 5; and / or, The height dimension corresponding to a single protrusion in the protrusion structure is less than or equal to the length and width dimensions; Bake and cut into individual devices.

8. A light bar based on a CSP packaging structure, characterized in that: include: At least one CSP package structure according to any one of claims 1 to 7.

9. A plastic encapsulation mold, applied to the CSP packaging structure according to claims 1 to 7, characterized in that: include: An upper mold and a lower mold; The bottom surface of the upper mold is a convex structure, so that when the fixed chip is encapsulated by the encapsulation mold, a packaging layer with a convex structure on the top surface is formed.

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