CN111384224A - CSP packaging structure, manufacturing method and light bar based on CSP packaging structure - Google Patents

Abstract

The invention discloses a CSP packaging structure, a manufacturing method, a light bar and a plastic packaging mold based on the CSP packaging structure. The CSP packaging structure includes a chip, a first packaging layer and a second packaging layer; the first packaging layer is covered on On the side and top surfaces of the chip, the top surface of the first encapsulation layer is in a protruding structure; the second encapsulation layer covers the top surface of the first encapsulation layer. In the technical solution provided by the present invention, the top surface of the first encapsulation layer is set as a raised structure to change the propagation direction of the light, which is beneficial to the extraction of light, so that the light emitted from the top surface of the first encapsulation layer is relatively uniform, and the light passes through the second encapsulation layer. The light emitting from the top surface of the first encapsulation layer is shielded, so that the top surface emitting light of the CSP package structure is similar to the side emitting light, so as to achieve the purpose of uniform light emitting.

Description

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

technical field

The present invention relates to the technical field of semiconductor lighting, in particular to a CSP packaging structure, a manufacturing method and a light bar based on the CSP packaging structure.

Background technique

CSP package refers to chip-level package, and its package size is basically the same as the core size of the chip. Therefore, CSP package has the advantages of small size. At the same time, CSP package structure also has the advantages of light weight and good electrical performance. Many advantages make CSP package structure be used. into various fields.

The current CSP package structure mainly includes flip-chip and encapsulant packaged on the flip-chip, and 60% of the light output of the CSP package structure of this structure will be concentrated directly above the chip, and less light will be emitted around the chip, that is, the existing CSP package structure. There is a disadvantage of uneven light distribution.

SUMMARY OF THE INVENTION

The invention provides a CSP packaging structure, a manufacturing method, a light bar and a plastic packaging mold based on the CSP packaging structure. The light emitted from the top surface is relatively uniform, and the light emitted from the top layer of the first packaging layer is shielded by the second packaging layer, so that the light emitted from the top surface of the CSP packaging structure is similar to the light emitted from the side surface, so as to achieve the purpose of uniform light output.

In a first aspect, the present invention provides a CSP packaging structure, comprising a chip, a first packaging layer and a second packaging layer;

The first encapsulation layer covers the side and top surface of the chip, and the top surface of the first encapsulation layer is in a raised structure;

The second encapsulation layer covers the top surface of the first encapsulation layer.

Preferably,

The side section of the protruding structure is zigzag.

Preferably,

In the protruding structure, the included angle between the inclined plane of a single protrusion and the horizontal plane ranges from 30° to 70°.

Preferably,

The included angle between the inclined surface of the single protrusion located in the central region and the horizontal plane in the protruding structure is greater than or equal to the included angle between the inclined surface of the single protrusion located in the edge region and the horizontal plane in the protruding structure.

Preferably,

The distance between the top surface of the first encapsulation layer and the top surface of the chip ranges from 0.25 mm to 0.6 mm.

Preferably,

The ratio of the length and width corresponding to a single protrusion in the protrusion structure to the distance between the top surface of the first encapsulation layer and the top surface of the chip ranges from 1/8 to 2/5.

Preferably,

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

Preferably,

The first encapsulation layer is a luminescent material layer or a transparent material layer.

Preferably,

The second encapsulation layer is a white glue layer.

Preferably,

The chip includes a horizontal structure chip or a flip-chip structure chip.

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

Performing the first plastic encapsulation on the fixed chip to form a first encapsulation layer on the side and top surface of the chip, and the top surface of the first encapsulation layer has a raised structure;

performing a second plastic encapsulation on the chip that has been encapsulated with the first encapsulation layer to form a second encapsulation layer on the top surface of the first encapsulation layer;

Bake, cut into individual devices.

In a third aspect, the present invention provides a light bar based on a CSP package structure, comprising: at least one of the CSP package structure described in the first aspect.

In a fourth aspect, the present invention provides a plastic sealing mold, comprising:

Upper mold and lower mold;

The bottom surface of the upper mold is in a convex structure, so that when the fixed chip is plastic-sealed by the plastic sealing mold, an encapsulation layer with a convex structure on the top surface is formed.

The invention provides a CSP packaging structure, a manufacturing method, a light bar and a plastic packaging mold based on the CSP packaging structure. The CSP packaging structure is composed of a chip, a first packaging layer and a second packaging layer, wherein the first packaging layer is wrapped in The side and top surfaces of the chip and the top surface of the first encapsulation layer have a protruding structure, which can change the propagation direction of the light, so that the top surface of the first encapsulation layer emits more uniform light in the central area and the edge area, avoiding The phenomenon that the light output of the CSP package structure is concentrated directly above the chip; the second package layer is further wrapped on the top surface of the first package layer to block the light output from the top surface of the first package layer, so that the top surface of the CSP package structure is The surface light is similar to the side light, so as to achieve the purpose of uniform light.

Description of drawings

In order to illustrate the embodiments of the present invention or the existing technical solutions more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the existing technology. Obviously, the accompanying drawings in the following description are only the For some embodiments described in the invention, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic structural diagram of a CSP packaging structure provided by an embodiment of the present invention;

2 is a schematic structural diagram of a CSP packaging structure provided by another embodiment of the present invention;

Fig. 3 is a partial parameter labeling diagram of a CSP packaging structure provided by an embodiment of the present invention;

4 is a schematic structural diagram of a chip after die bonding in a method for manufacturing a CSP packaging structure provided by an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a chip after first plastic packaging in a method for manufacturing a CSP packaging structure provided by an embodiment of the present invention;

6 is a schematic structural diagram of a chip after die bonding in a method for manufacturing a CSP packaging structure provided by another embodiment of the present invention;

7 is a schematic structural diagram of a chip after first plastic packaging in a method for manufacturing a CSP packaging structure provided by another embodiment of the present invention;

Among them, each reference sign in the figure:

1 - chip;

2- The first encapsulation layer;

21- convex structure;

3- The second encapsulation layer;

4- Substrate.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly or indirectly located on the other component. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element. Terms "top", "bottom", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outer", etc. The indicated orientation or position is based on the orientation or position shown in the drawings, which is only for the convenience of description, and should not be construed as a limitation on the technical solution. The terms "first" and "second" are only used for the purpose of description, and should not be understood as indicating or implying relative importance or implying indicating the number of technical features. "Plurality" means two or more, unless expressly specifically limited otherwise.

As shown in FIG. 1 , this embodiment provides a CSP packaging structure, including a chip 1 , a first packaging layer 2 and a second packaging layer 3 ;

The first encapsulation layer 2 covers the side and top surface of the chip 1, and the top surface of the first encapsulation layer 2 is in a raised structure;

The second encapsulation layer 3 covers the top surface of the first encapsulation layer 2 .

In the above-mentioned embodiment, the top surface of the first encapsulation layer 2 has a convex structure (as shown by 21 in FIG. 1 ), and the convex structure can change the propagation direction of the light, so that the top surface of the first encapsulation layer 2 is in the center The light output in the area and edge area is relatively uniform, avoiding the phenomenon that the light output of the CSP package structure is concentrated directly above the chip 1; further, the second package layer 3 is wrapped on the top surface of the first package layer 2, and the first package layer 2. The light output on the top surface is blocked, so that the light output on the top surface of the CSP package structure is similar to the light output on the side surface, so as to achieve the purpose of uniform light output.

It should be noted that, because the CSP package structure includes two common forms without substrate (as shown in FIG. 1 ) and with substrate 4 (as shown in FIG. 2 ), when the CSP package structure is a structure with a substrate, the CSP package structure includes a substrate 4. Chip 1, first encapsulation layer 2 and second encapsulation layer 3, the chip 1 is fixed on the substrate 4, the first encapsulation layer 2 covers the side and top surface of the chip 1, and the top surface of the first encapsulation layer 2 is In the protruding structure, the second encapsulation layer 3 covers the top surface of the first encapsulation layer 1 .

In an embodiment of the present invention, the side cross section of the protruding structure is zigzag. Wherein, the side section of the protruding structure is a plane parallel to the side surface of the chip. Specifically, the raised structure includes a plurality of single protrusions, and each single protrusion can be a structure such as a micro-pyramid or a short concentric circular prism. The purpose of the raised structure is to change the propagation direction of the light and diffuse the light, so that the After passing through the raised structure, the light emits uniformly and has a large light-emitting angle. Therefore, the side section of the raised structure can also be in other shapes, such as wavy shapes, as long as the purpose of uniform light emission can be achieved. Users can set according to the actual business scenario. .

In an embodiment of the present invention, the angle between the inclined surface of a single protrusion and the horizontal plane in the protrusion structure (A or B in FIG. 3 ) ranges from 30° to 70°, and the protrusion passes through the protrusion within this angle range. The light emitted by the structure is relatively uniform.

In an embodiment of the present invention, the included angle between the slope of a single bulge located in the central region and the horizontal plane of the bulge structure is greater than or equal to the angle between the slope of the single bulge located in the edge region of the bulge structure and the horizontal plane. angle. Usually, the CSP package structure emits light directly above the chip, and the peripheral area emits less light. Therefore, in order to make the light output in the center area and edge area of the first package layer more uniform, the slope and horizontal plane of a single protrusion located in the center area of the raised structure are made. The included angle between the protruding structures is greater than or equal to the included angle between the inclined plane and the horizontal plane of a single protruding surface located in the edge region of the protruding structure. By arranging the protruding structure in this way, the light output from each region of the top surface of the first encapsulation layer is relatively uniform.

In an embodiment of the present invention, the distance between the top surface of the first encapsulation layer and the top surface of the chip (t in FIG. 3 ) ranges from 0.25 mm to 0.6 mm, for example, the value of t may be 0.25 mm , 0.4mm, 0.45mm, 0.5mm or 0.6mm, etc. When the value of t is large, the volume of the CSP package structure will be large, thereby limiting the application of the CSP package 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 a range of 0.25 mm to 0.6 mm, so that the volume of the entire packaging structure is small.

In an embodiment of the present invention, the length and width dimensions corresponding to a single protrusion in the protrusion structure (a in FIG. 3 ) and the distance from the top surface of the first encapsulation layer to the top surface of the chip The range of the ratio (t in Figure 3) includes 1/8 to 2/5, for example, the value of a is 1/8, 1/5, 1/4, 3/10 or 2/5 of the value of t, etc. Within the value range of the embodiment, the light emitted after passing through the protruding structure can be made relatively uniform.

In an embodiment of the present invention, the height dimension (h in Figure 3) corresponding to a single projection in the projection structure is less than or equal to the length and width dimensions (a in Figure 3), if the height of a single projection is larger, The effect of uniform light emission from the top surface of the first encapsulation layer 2 will be poor. Therefore, by controlling the height dimension corresponding to a single protrusion to be less than or equal to the length and width dimensions, a better uniform light emission effect can be achieved.

In an embodiment of the present invention, the first encapsulation layer 2 is a luminescent material layer or a transparent material layer. When the color of the light emitted by the chip 1 needs to be changed, a luminescent material with a luminescent function, such as phosphor glue, can be selected. Specifically, when the chip 1 is a blue light chip, the phosphor glue is used as the material of the first encapsulation layer 2, and the light emitted from the phosphor glue will be white light; if it is not necessary to change the color of the light emitted by the chip 1, a transparent material can be selected as The material of the first encapsulation layer, such as transparent silica gel, epoxy glue, etc. Of course, the first encapsulation layer can also be quantum dot glue, etc. The user can choose the material used for the encapsulation glue according to the actual scene.

In an embodiment of the present invention, the material used in 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 emitted by the CSP encapsulation device is relatively uniform. Of course, other opaque adhesives can also be used for the material of the second encapsulation layer 3 to achieve the purpose of blocking the light emitted from the top surface of the first encapsulation layer 2 , and the user can choose according to the actual situation.

In an 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 according to the actual situation.

In a second aspect, this embodiment provides a method for manufacturing a CSP package structure, including:

Performing the first plastic encapsulation on the fixed chip to form a first encapsulation layer on the side and top surface of the chip, and the top surface of the first encapsulation layer has a raised structure;

performing a second plastic encapsulation on the chip that has been encapsulated with the first encapsulation layer to form a second encapsulation layer on the top surface of the first encapsulation layer;

Bake, cut into individual devices.

In the above embodiment, the top surface of the first encapsulation layer has a protruding structure (as shown by 21 in FIG. 1 ), and the protruding structure can change the propagation direction of light, so that the top surface of the first encapsulation layer is in the central area and The light output in the edge area is relatively uniform, avoiding the phenomenon that the light output of the CSP packaging structure is concentrated directly above the chip; further, the second packaging layer is wrapped on the top surface of the first packaging layer, and the light output on the top surface of the first packaging layer is carried out. The occlusion makes the top surface light output of the CSP package structure similar to the side light output, so as to achieve the purpose of uniform light output.

In a possible implementation manner, the manufacturing method of the CSP package structure includes the following steps:

Step 10, bonding wire for die bonding: fixing the chip 1 on the substrate 4 in a die-bonding manner, and connecting the chip 1 and the substrate 4 (to form the structure shown in FIG. 4 ).

Step 11, the first molding (molding): the substrate 4 with the chip 1 fixed is coated with transparent glue or phosphor glue on the substrate 4 and the chip 1 by plastic sealing, so as to form on the side and top surface of the chip 1 The first encapsulation layer 2, and the top surface of the first encapsulation layer 2 is a protruding structure, and the side cross section of the protruding structure is zigzag (the structure shown in FIG. 5).

Step 12, the second plastic sealing: the white glue is coated on the transparent glue or phosphor glue in a plastic sealing manner to form a second packaging layer 3 on the top surface of the first packaging layer 2 (as shown in FIG. 2 ). structure).

Step 13, curing: baking and curing the product after twice plastic sealing.

Step 14, cutting: cutting the cured product into a single product.

In another possible implementation manner, the manufacturing method of the CSP package structure includes the following steps:

Step 20, die bonding: the chip 1 is fixed on the reusable adhesive film by die bonding (to form the structure shown in FIG. 6).

Step 21, the first plastic encapsulation: apply transparent glue or phosphor glue over the chip 1 in a plastic encapsulation manner to form a first encapsulation layer 2 on the side and top surfaces of the chip 1, and the top of the first encapsulation layer 2 The surface is a convex structure, and the side cross section of the convex structure is zigzag (structure shown in FIG. 7 ).

Step 22, the second plastic sealing: the white glue is coated on the transparent glue or phosphor glue in a plastic sealing manner to form a second packaging layer 3 on the top surface of the first packaging layer 2 (as shown in FIG. 1 ). structure).

Step 23, curing: baking and curing the product after twice plastic sealing.

Step 24, cutting: cutting the cured product into a single product.

In a third aspect, this embodiment provides a light bar based on a CSP package structure, including: at least one CSP package structure according to the first aspect, the light bar can achieve the effect of uniform light output.

In the fourth aspect, this embodiment provides a plastic sealing mold, including an upper mold and a lower mold; the bottom surface of the upper mold is in a convex structure, so that when the fixed chip is plastic-sealed by the plastic sealing mold, a top mold is formed. An encapsulation layer with a raised surface. Specifically, the side section of the protruding structure can be saw-toothed.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (10)

1. A CSP packaging structure is characterized by comprising a chip, a first packaging layer and a second packaging layer;

the first packaging layer is coated on the side face and the top face of the chip, and the top face of the first packaging layer is of a protruding structure;

the second packaging layer is coated on the top surface of the first packaging layer.

2. The CSP package structure of claim 1,

the side section of the protruding structure is in a sawtooth shape.

3. The CSP package structure of claim 2,

the included angle range between the inclined plane of each single protrusion in the protrusion structure and the horizontal plane is 30-70 degrees.

4. The CSP package structure of claim 2,

the included angle between the inclined plane of the single bulge positioned in the central area and the horizontal plane in the bulge structure is more than or equal to the included angle between the inclined plane of the single bulge positioned in the edge area and the horizontal plane in the bulge structure.

5. The CSP package structure of claim 1,

the distance range between the top surface of the first packaging layer and the top surface of the chip comprises 0.25 mm-0.6 mm.

6. The CSP package structure of claim 1,

the ratio of the length and width corresponding to a single bump in the bump structure to the distance from the top surface of the first packaging layer to the top surface of the chip is 1/8-2/5;

and/or the presence of a gas in the gas,

the height dimension corresponding to a single bump in the bump structure is less than or equal to the length dimension and the width dimension.

7. The CSP package structure as claimed in any one of claims 1 to 6,

the first packaging layer is a luminescent material layer or a transparent material layer;

and/or the second packaging layer is a white glue layer;

and/or the chip comprises a horizontal structure chip or a flip structure chip.

8. A method for manufacturing a CSP packaging structure is characterized by comprising the following steps:

carrying out primary plastic package on the fixed chip to form a first packaging layer on the side surface and the top surface of the chip, wherein the top surface of the first packaging layer is of a convex structure;

carrying out secondary plastic packaging on the chip subjected to the plastic packaging of the first packaging layer so as to form a second packaging layer on the top surface of the first packaging layer;

baking and cutting into independent devices.

9. A kind of light strip based on CSP packaging structure, comprising: at least one CSP package structure defined by any one of claims 1 to 7.

10. A plastic package mold is characterized by comprising:

an upper die and a lower die;

the bottom surface of the upper die is of a convex structure, so that when the fixed chip is plastically packaged by the plastic packaging die, a packaging layer with the top surface of the convex structure is formed.

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