A heat dissipation packaging structure and its forming method

Abstract

This invention relates to a heat dissipation package structure, comprising: a substrate; metal pillars penetrating the substrate; a first pad disposed on the front side of the substrate and connected to the metal pillar; wire bonding fingers disposed on the front side of the substrate and connected to a chip via wires; a first solder ball connected to the first pad; a chip disposed on the front side of the substrate; a second pad disposed on the back side of the substrate and connected to the metal pillar; an insulating layer disposed on the back side of the substrate; a second solder ball connected to the second pad; and a molding compound layer encapsulating the chip. This invention also relates to a method for forming a heat dissipation package structure. In this package structure, the chip and substrate are connected via solder balls, solving the delamination problem. The metal pillars in the substrate and the pads on the front and back sides of the substrate are perforated, improving the heat dissipation capacity of the package structure and enabling the device to dissipate heat quickly during operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor packaging, and particularly relates to a packaging structure with a heat dissipation function and a forming method thereof. BACKGROUND

[0002] With the rapid development of IC packaging technology, the packaging size is getting smaller and smaller, and the integration is getting higher and higher. As a carrier of the chip, the heat dissipation effect of the substrate has become an important factor to determine the stability and reliability of the product. The conventional heat dissipation scheme mainly improves the heat dissipation capacity of the chip and the outside of the packaging through the form of attaching a heat dissipation cover and the like. The wire bonding (WB) product mainly solves the heat dissipation problem by attaching a heat dissipation sheet above the chip, and the heat dissipation of the lower part of the chip is mainly solved by punching or mainly relies on the large copper sheet exposed below the chip. This kind of way has limited heat dissipation effect, and the exposed large copper sheet may cause poor bonding with the solder after gold plating, resulting in delamination below the chip. Therefore, it is necessary to design new research ideas and solutions to improve the heat dissipation problem of the wire bonding packaging structure. SUMMARY

[0003] The task of the present application is to provide a packaging structure with a heat dissipation function and a forming method thereof, which connects the chip and the substrate through the solder ball, solves the delamination problem, punches the metal column in the substrate and the pads on the front and back surfaces of the substrate, improves the heat dissipation capacity of the packaging structure, and enables the device to quickly dissipate heat during the working process.

[0004] In the first aspect of the present application, in order to solve the problems in the prior art, the present application provides a packaging structure with a heat dissipation function, which comprises:

[0005] a substrate;

[0006] a metal column penetrating through the substrate;

[0007] a first pad arranged on the front surface of the substrate and connected with the metal column;

[0008] a wire finger arranged on the front surface of the substrate and connected with the chip through a wire;

[0009] a first solder ball connected with the first pad;

[0010] a chip arranged on the front surface of the substrate;

[0011] a second pad arranged on the back surface of the substrate and connected with the metal column;

[0012] an insulating layer arranged on the back surface of the substrate;

[0013] a second solder ball connected with the second pad; and

[0014] a plastic encapsulation layer encapsulating the chip.

[0015] In one embodiment of the present application, an ink layer is further included on the front side of the substrate, wherein the first pad and the wire bonding finger are not covered by the ink layer.

[0016] In one embodiment of the present application, the first pad is located in the middle of the front side of the substrate and has a through hole;

[0017] The metal pillar and the second pad have a through hole, wherein the through holes of the first pad, the metal pillar and the second pad are communicated.

[0018] In one embodiment of the present application, the first pad is connected with the back side of the chip through the first solder ball, and the chip is arranged on the front side of the substrate.

[0019] In one embodiment of the present application, the wire bonding finger is located around the first pad.

[0020] The front side of the chip has a lead connection point, and the wire bonding finger is connected with the lead connection point through a lead.

[0021] In the second aspect of the present application, in order to solve the problems existing in the prior art, the present application provides a forming method of a packaging structure with heat dissipation function, comprising:

[0022] forming a metal pillar penetrating through the substrate;

[0023] arranging a first pad and a wire bonding finger on the front side of the substrate;

[0024] arranging an insulating layer and a second pad on the back side of the substrate;

[0025] making a through hole in the first pad, the metal pillar and the second pad;

[0026] arranging a first solder ball on the back side of the chip, and the front side of the chip has a lead connection point;

[0027] arranging a first solder ball on the back side of the chip;

[0028] arranging the chip on the front side of the substrate;

[0029] connecting the wire bonding finger and the lead connection point by a lead; and

[0030] encapsulating the chip to form a plastic encapsulation layer, and arranging a second solder ball on the second pad.

[0031] In one embodiment of the present application, an ink layer is further included on the front side of the substrate.

[0032] In one embodiment of the present application, the chip is arranged on the front surface of the substrate by soldering the first soldering ball on the back surface of the chip with the first soldering pad.

[0033] In one embodiment of the present application, the metal column is connected with the first soldering pad and the second soldering pad, and the through hole of the first soldering pad, the metal column and the second soldering pad is in communication.

[0034] In one embodiment of the present application, the first soldering pad is located in the middle of the front surface of the substrate, and the wire bonding fingers are located around the first soldering pad.

[0035] The present application has at least the following advantages: the packaging structure with heat dissipation function and the forming method thereof disclosed by the present application solve the delamination problem by connecting the chip and the substrate through soldering balls; the chip is connected with the soldering pad on the front surface of the substrate through soldering balls, thereby enhancing the heat dissipation capacity between the chip and the substrate; the metal column in the substrate and the soldering pads on the front surface and the back surface of the substrate are punched, and if the substrate is connected with a PCB in the future, the heat dissipation capacity from the substrate to the PCB can be effectively enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0036] To further clarify the above and other advantages and features of the embodiments of the present application, a more particular description of embodiments of the present application will be rendered by reference to specific embodiments thereof which are illustrated in the drawings. It is appreciated that these drawings depict only typical embodiments of the application and are therefore not to be considered limiting of its scope. The same or corresponding elements in the drawings are denoted by the same or similar reference signs.

[0037] Figure 1 A schematic diagram of a packaging structure with heat dissipation function according to one embodiment of the present application is shown.

[0038] Figure 2 A top view of a substrate according to one embodiment of the present application is shown.

[0039] Figures 3A to 3F A cross-sectional schematic diagram of a process of forming a packaging structure with heat dissipation function according to one embodiment of the present application is shown.

[0040] Figure 4 A flowchart of forming a heat dissipation substrate according to one embodiment of the present application is shown. DETAILED DESCRIPTION

[0041] It should be noted that the components in the drawings can be exaggerated for the purpose of illustration and are not necessarily to scale.

[0042] In the present application, the embodiments are merely intended to illustrate the scheme of the present application and should not be understood as limiting.

[0043] In the present application, the quantifier "one", "a" does not exclude the scenario of multiple elements, unless specifically indicated.

[0044] It should also be noted that, in the embodiments of the present application, only a part of components or assemblies can be shown for the sake of clarity and simplicity, but those skilled in the art can understand that, under the teaching of the present application, the required components or assemblies can be added according to the specific scene.

[0045] It should also be noted that, in the scope of the present application, the words "same", "equal", "equal to" and the like do not mean that the numerical values of the two are absolutely equal, but allow a certain reasonable error, that is, the words also cover "substantially the same", "substantially equal", "substantially equal".

[0046] It should also be noted that, in the description of the present application, the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not mean that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating relative importance.

[0047] In addition, the embodiments of the present application describe the process steps in a specific order, however, this is only for the convenience of distinguishing between steps, and is not limited to the order of the steps, and in different embodiments of the present application, the order of the steps can be adjusted according to the adjustment of the process.

[0048] Figure 1 A schematic diagram of a packaging structure with heat dissipation function according to an embodiment of the present application is shown. Figure 2 A top view of a heat dissipation substrate according to an embodiment of the present application is shown.

[0049] As shown in Figure 1 and Figure 2 , the packaging structure with heat dissipation function includes a substrate 101, a metal column 102, a first pad 103, a wire finger 104, an ink layer 105, a first solder ball 106, a chip 107, a lead 108, a second pad 109, an insulating layer 110, a second solder ball 111 and a plastic encapsulation layer 112.

[0050] The metal column 102 penetrates the substrate 101. The metal column 102 is a hollow column with a through hole.

[0051] A first pad 103 is disposed on the front side of the substrate 101 and connected to a metal pillar 102. The first pad 103 has a through-hole 1031. A plurality of first pads 103 are located in the center of the front side of the substrate 101.

[0052] The wire bonding fingers 104 are arranged on the front side of the substrate 101 and are located around the first pad 103.

[0053] An ink layer 105 is located on the front side of the substrate 101. The first pad 103 and the bonding fingers 104 are not covered by the ink layer. The bonding fingers 104 are exposed at the ink opening 1051.

[0054] The first solder ball 106 is connected to the first solder pad 103.

[0055] Chip 107 is disposed on the front side of substrate 101. The back side of chip 107 and the first pad 103 are connected by first solder balls 106, thus disposing chip 107 on the front side of substrate 101. The back side of chip 107 and the first pad 103 are soldered together by the first solder balls 106, which can effectively solve the delamination problem and also enhance the heat dissipation between the chip and the substrate.

[0056] The front side of the chip 107 has a lead connection point 1071, which is connected to the bonding finger 104 via a lead 108. The lead 108 can be a metal wire such as gold wire, lead wire, or copper wire, and the wire diameter of the lead 108 is determined by the size of the bonding finger 104.

[0057] The second pad 109 is disposed on the back side of the substrate 101 and connected to the metal pillar 102. The second pad 109 has a through hole. The through hole in the metal pillar 102, the first pad 103, and the second pad 109 is connected, which can enhance the heat dissipation capacity of the substrate. If the substrate is subsequently connected to the PCB board, the heat dissipation capacity from the substrate to the PCB board can be effectively enhanced.

[0058] An insulating layer 110 is disposed on the back side of the substrate 101. A second pad 109 is located in the insulating layer 110 and partially exposes the insulating layer 110.

[0059] The second solder ball 111 is connected to the second solder pad 109.

[0060] A molding compound 112 encapsulates the chip 107. The molding compound 112 encapsulates the first pad 103, wire bonding fingers 104, first solder balls 106, chip 107, and leads 108.

[0061] Figures 3A to 3F A cross-sectional schematic diagram of the process of forming a heat dissipation package structure according to an embodiment of the present invention is shown. Figure 4 A flowchart illustrating the formation of a heat dissipation substrate according to an embodiment of the present invention is shown.

[0062] The process of forming a package structure with heat dissipation function includes:

[0063] In step 1, as Figure 3A and Figure 4 As shown, the heat dissipation substrate includes:

[0064] In step 1.1, a substrate 201 is provided.

[0065] In step 1.2, a metal pillar 202 is formed penetrating the substrate 201. First, the substrate 201 is etched to form a substrate through-hole, and then metal is filled to form the metal pillar 202. The metal pillar 202 is located in the middle of the substrate.

[0066] In step 1.3, a first pad 203 and wire bonding fingers 204 are arranged on the front side of the substrate 201. The first pad 203 is located in the center of the front side of the substrate 201 and is connected to the metal pillar 202. The wire bonding fingers 204 are located around the first pad 203. First, a dry film is laminated on the front side of the substrate, and then the first pad pattern and the wire bonding finger pattern are formed through processes such as exposure, development, and etching. Electroplating filler metal is then performed in the first pad pattern to form the first pad and the wire bonding fingers.

[0067] In step 1.4, an ink layer 205 is applied to the front side of the substrate 201. The first pad 203 and the wire bonding fingers 204 are not covered by the ink layer 205. Here, the ink layer 205 can be applied by coating.

[0068] In step 1.5, an insulating layer 206 and a second pad 207 are disposed on the back side of the substrate 201. The second pad 207 is located in the insulating layer 206, and the surface of the second pad 207 exposes the insulating layer 206. Part of the second pad 207 is connected to the metal pillar 202. First, the insulating layer 206 is disposed on the back side of the substrate 201 by coating, deposition, or other methods. Then, the insulating layer 206 is etched to form a pad pattern, and metal is electroplated in the pad pattern to form the second pad 207. The insulating layer 206 can be an inorganic material such as silicon oxide, silicon oxynitride, borosilicate glass, phosphosilicate glass (PSG), borosilicate glass (BPSG), fluorinated glass silicate glass (FSG), or low-K dielectric; or it can be an organic material such as polyimide, photosensitive epoxy resin, solder resist ink, green paint, dry film, photosensitive additive material, BCB (bisphenylcyclobutene resin), or PBO (phenylbenzodioxazole resin).

[0069] In step 1.6, through-holes are fabricated in the first pad 203, the metal pillar 202, and the second pad 207. By drilling, through-holes are formed from the first pad 203 to the second pad 207, creating interconnected through-holes in the first pad 203, the metal pillar 202, and the second pad 207. The interconnected through-holes in the first pad 203, the metal pillar 202, and the second pad 207 enhance the heat dissipation capacity of the substrate. If the substrate is subsequently connected to the PCB board, the heat dissipation capacity between the substrate and the PCB board will be effectively enhanced.

[0070] In step 2, as Figure 3B As shown, a chip 208 is provided with lead connection points 2081 on the front side.

[0071] In step 3, as Figure 3C As shown, a first solder ball 209 is arranged on the back side of chip 208.

[0072] In step 4, as Figure 3D As shown, chip 208 is arranged on the front side of substrate 201. The first solder ball 209 on the back side of chip 208 is soldered to the first solder pad 203. The chip 208 and substrate 201 are connected by the first solder ball, which solves the delamination problem and also enhances the heat dissipation capacity between the chip and the substrate.

[0073] In step 5, as Figure 3E As shown, the lead wire 210 is used to connect the bonding finger 204 and the lead wire connection point 2081.

[0074] In step 6, as Figure 3F As shown, chip 208 is encapsulated to form encapsulation layer 211, and second solder balls 212 are arranged on second pad 207. The second solder balls 212 are arranged on second pad 207 using a ball-mounting process. Encapsulation layer 211 encapsulates first pad 203, wire bonding fingers 204, first solder balls 209, chip 208, and leads 210.

[0075] The present invention has at least the following beneficial effects: The present invention discloses a packaging structure with heat dissipation function and a method for forming the same. The chip and the substrate of the packaging structure are connected by solder balls, which solves the delamination problem; the chip is connected to the pads on the front side of the substrate by solder balls, which enhances the heat dissipation capacity between the chip and the substrate; the metal pillars in the substrate and the pads on the front and back sides of the substrate are perforated, which can effectively enhance the heat dissipation capacity from the substrate to the PCB board if the substrate is subsequently connected to the PCB board.

[0076] While some embodiments of the present invention have been described in this application, those skilled in the art will understand that these embodiments are merely illustrative. Numerous variations, alternatives, and improvements will arise in those skilled in the art under the teachings of this invention without departing from its scope. The appended claims are intended to define the scope of the invention and thereby cover methods and structures within the scope of the claims themselves and their equivalents.

Claims

1. A packaging structure with heat dissipation function, characterized in that, The method comprises: forming a metal pillar through a substrate; arranging a first solder pad and a wire finger on a front surface of the substrate; arranging an insulating layer and a second solder pad on a back surface of the substrate; making a through hole in the first solder pad, the metal pillar and the second solder pad; the metal pillar is connected with the first solder pad and the second solder pad, and the through holes of the first solder pad, the metal pillar and the second solder pad are communicated; arranging a first solder ball on a back surface of a chip; the chip is arranged on the front surface of the substrate by soldering the first solder ball on the back surface of the chip with the first solder pad; arranging a second solder ball on the second solder pad; the metal pillar and the second solder pad have through holes, wherein the through holes of the first solder pad, the metal pillar and the second solder pad are communicated; and encapsulating the chip to form an encapsulation layer. Further comprising an ink layer on the front surface of the substrate, wherein the first solder pad and the wire finger are not covered by the ink layer. The wire finger is located around the first solder pad. The front surface of the chip has a lead connection point, and the wire finger is connected with the lead connection point by a lead.

2. The package structure with heat dissipation function according to claim 1, wherein, The method comprises:

3. The package structure with heat dissipation function according to claim 1, wherein, forming a metal pillar through a substrate; arranging a first solder pad and a wire finger on a front surface of the substrate; 4. A method of forming a package structure having a heat dissipation function, characterized by, arranging an insulating layer and a second solder pad on a back surface of the substrate; making a through hole in the first solder pad, the metal pillar and the second solder pad; the metal pillar is connected with the first solder pad and the second solder pad, and the through holes of the first solder pad, the metal pillar and the second solder pad are communicated; arranging a first solder ball on a back surface of a chip; the chip has a lead connection point on a front surface of the chip; arranging a first solder ball on a back surface of a chip; arranging the chip on the front surface of the substrate by soldering the first solder ball on the back surface of the chip with the first solder pad; connecting the wire finger and the lead connection point by a lead; and encapsulating the chip to form an encapsulation layer, and arranging a second solder ball on the second solder pad. Further comprising: arranging an ink layer on the front surface of the substrate. The first solder pad is located in the middle of the front surface of the substrate, and the wire finger is located around the first solder pad.

5. The method of claim 4, wherein the method further comprises forming a thermal pad on the first surface of the semiconductor die. ​ ​ 6. The method of claim 4, wherein the method further comprises forming a thermal pad on the first surface of the semiconductor die. ​

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