A microchannel packaging structure capable of dissipating heat on six sides and a manufacturing method thereof

Abstract

The present invention discloses a microfluidic packaging structure capable of dissipating heat on six sides and a manufacturing method thereof, which belongs to the field of integrated circuit packaging, and includes a microfluidic cover plate, a two-dimensional heterogeneous integrated structural unit and a substrate assembled by a bonding process; the microfluidic cover plate includes a first microfluidic structural unit and a second microfluidic structural unit, and the first microfluidic structural unit and the second microfluidic structural unit are both made with microfluidic inlets and outlets; the two-dimensional heterogeneous integrated structural unit includes a transfer through hole, a groove and a microfluidic structure, a functional chip is buried in the groove, the microfluidic structure is distributed on the side wall and the bottom of the functional chip, the transfer through hole is filled with electroplated copper, and the signal interconnection with the functional chip is realized through a redistribution layer; a microfluidic inlet and a microfluidic outlet are provided in the substrate. The present invention realizes multi-dimensional and large-area active heat dissipation of a three-dimensional packaging system at the chip level by integrating a microfluidic structure around the chip, and effectively improves the chip heat dissipation capacity of the three-dimensional packaging system.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit packaging, and in particular to a microchannel packaging structure capable of dissipating heat on six sides and a manufacturing method thereof. Background Art

[0002] With the rapid development of three-dimensional heterogeneous integrated packaging, the integration of chips is increasing, and chip performance is improving. High-power chips will generate a lot of heat when working. In order to avoid the chips from burning due to high temperature and ensure the long-term stable operation of the chips, they must be cooled. Especially for chips that use three-dimensional heterogeneous integrated packaging, it is more difficult to dissipate heat for chips located in the middle of the stacked structure. Therefore, improving the heat dissipation efficiency of chip systems has become a major challenge in the research and development and application of three-dimensional integrated packaging systems.

[0003] For this type of packaging structure, liquid cooling or air cooling is generally used to dissipate heat from the chip. The heat generated by the chip during operation needs to pass through a large number of intermediate media such as the chip substrate, chip package, and packaging substrate to be effectively released. In addition, because multiple heterogeneous materials are integrated at the same time, thermal mismatch and other problems are prone to occur. Summary of the invention

[0004] The object of the present invention is to provide a microchannel packaging structure capable of dissipating heat on six sides and a manufacturing method thereof, so as to solve the problem of insufficient heat dissipation capacity of existing three-dimensional packaging system chips.

[0005] In order to solve the above technical problems, the present invention provides a microfluidic packaging structure capable of dissipating heat on six sides, comprising a microfluidic cover plate, a two-dimensional heterogeneous integrated structural unit and a substrate assembled by a bonding process;

[0006] The microfluidic cover plate is located at the top layer, and includes a first microfluidic structure unit and a second microfluidic structure unit, and the first microfluidic structure unit and the second microfluidic structure unit are both provided with microfluid inlets and outlets;

[0007] The two-dimensional heterogeneous integrated structural unit is located in the middle layer, and includes a transfer through hole, a groove and a microfluidic structure. The functional chip is buried in the groove, and the microfluidic structure is distributed on the side wall and bottom of the functional chip. The transfer through hole is filled with electroplated copper, and signal interconnection with the functional chip is achieved through the rewiring layer;

[0008] The substrate is located at the bottom layer and is provided with a microfluid inlet and a microfluid outlet.

[0009] Optionally, one side of the substrate has a double liquid inlet and outlet structure, and the other side has a single liquid inlet and outlet structure.

[0010] Optionally, the lower surface of the microfluidic cover plate and the upper surface of the two-dimensional heterogeneous integrated structural unit are both made with liquid inlet and outlet sealing rings and metal thermal conductive pads, and the lower surface of the microfluidic cover plate and the upper surface of the two-dimensional heterogeneous integrated structural unit are bonded;

[0011] Liquid inlet and outlet sealing rings are made on the lower surface of the two-dimensional heterogeneous integrated structural unit and the upper surface of the substrate, and the lower surface of the two-dimensional heterogeneous integrated structural unit is bonded to the upper surface of the substrate.

[0012] Optionally, the microfluidic channel cover plate is formed by combining a first microfluidic channel structure unit and a second microfluidic channel structure unit through a bonding process.

[0013] Optionally, the two-dimensional heterogeneous integrated structural unit and the microfluidic channel cover plate are made of the same material, such as silicon, glass or organic resin.

[0014] The present invention also provides a method for manufacturing a microchannel packaging structure capable of dissipating heat on six sides, comprising:

[0015] Step 1: providing a wafer, making a microfluidic inlet and outlet on the wafer to obtain a first microfluidic structure unit and a second microfluidic structure unit, and assembling the first microfluidic structure unit and the second microfluidic structure unit obtained above by a wafer-level bonding process to form a sealed microfluidic cover plate;

[0016] Step 2: using an electroplating process to manufacture an inlet and outlet sealing ring and a metal thermal pad on the lower surface of the microchannel cover plate;

[0017] Step 3: providing another wafer, making a transfer through hole on the wafer by using an etching process, filling the transfer through hole with electroplated copper by using an electroplating process, and making circuit layers on the upper and lower surfaces of the wafer;

[0018] Step 4: Making grooves on the wafer with the transfer vias, embedding the functional chip in the grooves, and integrating it through the wafer-level fan-out packaging process to form a two-dimensional heterogeneous integrated structure unit, making rewiring layers on the upper and lower surfaces to achieve signal interconnection between the transfer vias and the functional chip, and leading the chip signal to the lower surface of the two-dimensional heterogeneous integrated structure unit through the transfer vias;

[0019] Step 5: using an etching process to make microfluidic inlets and outlets on the lower surface of the two-dimensional heterogeneous integrated structural unit, distributed on the sidewalls and bottom of the embedded functional chip;

[0020] Step 6: Using electroplating or mounting technology to make liquid inlet and outlet sealing rings and metal thermal pads on the upper and lower surfaces of the two-dimensional heterogeneous integrated structural unit;

[0021] Step 7: providing a substrate, using a mechanical punching process or a laser punching process to make a microfluidic inlet and a microfluidic outlet, and making inlet and outlet sealing rings on the surface of the substrate;

[0022] Step 8: Assemble the microfluidic cover plate, two-dimensional heterogeneous integrated structural unit and substrate obtained above by a bonding process to form a microfluidic packaging structure capable of dissipating heat on six sides.

[0023] Optionally, the material of the wafer includes silicon, glass, and Group III-V compounds; the Group III-V compounds are gallium nitride and gallium arsenide.

[0024] Optionally, the materials of the liquid inlet and outlet sealing rings and the metal thermal pad include a low melting point metal single substance of tin, lead, bismuth, copper, or a compound of multiple metals.

[0025] The microchannel packaging structure capable of six-sided heat dissipation and the manufacturing method thereof provided by the present invention have the following beneficial effects:

[0026] (1) The microfluidic structure with micro-nano size is distributed on the top, bottom and sides of the chip, so that the coolant can dissipate heat on six sides of the chip, forming a microfluidic heat dissipation structure with a high heat exchange area, providing sufficient heat exchange area for the chip, greatly improving the heat dissipation rate of the chip;

[0027] (2) The present invention can directly realize the smooth injection and outflow of the coolant by directly integrating the liquid inlet and outlet structure on the substrate, omitting the metal module, and greatly reducing the package size;

[0028] (3) The liquid flowing into the substrate through the single inlet and outlet has a larger flow rate after entering the double inlet and outlet liquid, which accelerates the rapid release of heat;

[0029] (4) Adding a microchannel cover can not only enhance the heat dissipation function, but also protect the active chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of a microchannel packaging structure capable of six-sided heat dissipation provided by the present invention;

[0031] Figure 2 is a schematic diagram of making a microfluidic cover plate;

[0032] Figure 3 This is a schematic diagram of making inlet and outlet sealing rings and metal thermal pads on the microfluidic cover plate;

[0033] Figure 4 It is a schematic diagram of making a two-dimensional heterogeneous integrated structural unit;

[0034] Figure 5It is a schematic diagram of manufacturing a liquid outlet sealing ring and a metal thermal conductive pad on a two-dimensional heterogeneous integrated structural unit;

[0035] Figure 6 It is a schematic diagram of manufacturing a substrate and manufacturing liquid inlet and outlet sealing rings on its surface. DETAILED DESCRIPTION

[0036] The following is a further detailed description of a microfluidic package structure capable of six-sided heat dissipation and a method for manufacturing the same proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer according to the following description and claims. It should be noted that the accompanying drawings are in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0037] The present invention provides a microchannel packaging structure capable of dissipating heat on six sides, the structure of which is as follows: Figure 1 As shown, it includes a microfluidic cover plate, a two-dimensional heterogeneous integrated structure unit and a substrate assembled by a bonding process; the microfluidic cover plate is located at the top layer, the two-dimensional heterogeneous integrated structure unit is located at the middle layer, and the substrate is located at the bottom layer.

[0038] Please continue reading Figure 1 The microfluidic cover plate located at the top layer includes a first microfluidic structure unit 101 and a second microfluidic structure unit 102 bonded to each other, and the first microfluidic structure unit 101 and the second microfluidic structure unit 102 are both made with a microfluidic inlet and outlet 103; the two-dimensional heterogeneous integrated structure unit located at the middle layer includes a transfer through hole 106, a groove 107 and a microfluidic structure 109, a functional chip 108 is buried in the groove 107, and the microfluidic structure 109 is distributed on the side wall and bottom of the functional chip 108, and the transfer through hole 106 is filled with electroplated copper, and the signal interconnection with the functional chip 108 is realized through the rewiring layer 110; the substrate located at the bottom layer is provided with a microfluidic inlet 111 and a microfluidic outlet 112, and one side of the substrate is a double inlet and outlet structure, and the other side is a single inlet and outlet structure. The microfluidic cover plate and the two-dimensional heterogeneous integrated structure unit are made of the same material, silicon, glass or organic resin.

[0039] The lower surface of the microfluidic cover plate and the upper surface of the two-dimensional heterogeneous integrated structure unit are both made with liquid inlet and outlet sealing rings 104 and metal thermal pads 105, and the lower surface of the microfluidic cover plate is bonded to the upper surface of the two-dimensional heterogeneous integrated structure unit; the lower surface of the two-dimensional heterogeneous integrated structure unit and the upper surface of the substrate are both made with liquid inlet and outlet sealing rings 104, and the lower surface of the two-dimensional heterogeneous integrated structure unit is bonded to the upper surface of the substrate. The electrical signal is led out from the array external lead-out terminal on the surface of the bottom substrate.

[0040] The present invention uses microchannel active heat dissipation to embed microchannels around the chip to form a microchannel high heat exchange area heat dissipation structure, and uses the flow of cooling liquid to carry away a large amount of heat energy generated when the chip is working, ensuring that the chip works at a suitable temperature, thereby solving the heat dissipation problem of high heat flux density chips in a three-dimensional integrated packaging structure.

[0041] The microfluidic package structure capable of dissipating heat on six sides is prepared by the following method:

[0042] Step 1: Provide a wafer for making a microfluidic cover plate. The material of the wafer can be silicon, glass or other materials. A microfluidic inlet and outlet 103 with a depth-to-width ratio that meets the design requirements is made on the wafer by a dry etching process to obtain a first microfluidic structure unit 101 and a second microfluidic structure unit 102. The microfluidic inlet and outlet 103 is embedded in the microfluidic cover plate by an etching process to achieve active heat dissipation on the top of the chip; the first microfluidic structure unit 101 and the second microfluidic structure unit 102 obtained above are assembled by a wafer-level bonding process to obtain a sealed microfluidic cover plate, such as Figure 2 As shown;

[0043] Step 2: Use conventional electroplating process to make the inlet and outlet sealing ring 104 and the metal thermal pad 105 on the lower surface of the sealed microchannel cover plate obtained above, such as Figure 3 The material of the liquid inlet and outlet sealing ring 104 and the metal thermal pad 105 is a low melting point metal single substance among tin, lead, bismuth, and copper, or a compound of multiple metals;

[0044] Step 3: Provide another wafer, which can be made of silicon, glass or other materials, just like the wafer used to make the microchannel cover. Use an etching process to make a transfer through hole 106 with a diameter that meets the design requirements on the wafer, use an electroplating process to fill the transfer through hole 106 with electroplated copper, and make circuit layers on the upper and lower surfaces of the wafer;

[0045] Step 4: Use deep silicon etching process to make a groove 107 with a required aspect ratio, bury the functional chip 108 in the groove 107, and integrate it into a two-dimensional heterogeneous integrated structure unit through wafer-level fan-out packaging process. Make a rewiring layer 110 on the upper and lower surfaces of the two-dimensional heterogeneous integrated structure unit to realize the signal interconnection between the transfer via 106 and the functional chip 108, and lead the signal of the functional chip 108 to the lower surface of the two-dimensional heterogeneous integrated structure unit through the transfer via 106. Figure 4 As shown;

[0046] Step 5: Use an etching process to make a microchannel structure 109 with a diameter that meets the design requirements on the lower surface of the two-dimensional heterogeneous integrated structure unit obtained above, distributed on the side wall and bottom of the functional chip 108, so as to achieve active heat dissipation on the five sides of the chip. Figure 4As shown;

[0047] Step 6: Use electroplating or mounting technology to make the liquid inlet and outlet sealing ring 104 and the metal thermal pad 105 on the upper surface of the above-obtained two-dimensional heterogeneous integrated structural unit, and make the liquid inlet and outlet sealing ring 104 on the lower surface, such as Figure 5 The material of the liquid inlet and outlet sealing ring 104 and the metal thermal pad 105 is a low melting point metal single substance among tin, lead, bismuth, and copper, or a compound of multiple metals;

[0048] Step 7: Provide a substrate, use a mechanical punching process or a laser punching process to make a microfluidic inlet 111 and a microfluidic outlet 112 with diameters that meet the design requirements, and make an inlet and outlet sealing ring 104 on the surface of the substrate. One side of the substrate has a double inlet and outlet structure, and the other side has a single inlet and outlet structure, such as Figure 6 As shown;

[0049] Step 8: Assemble the microfluidic cover plate, the two-dimensional heterogeneous integrated structural unit and the substrate obtained above by bonding process to obtain Figure 1 A microfluidic packaging structure capable of dissipating heat on six sides is shown.

[0050] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A method for manufacturing a microfluidic package structure capable of dissipating heat on six sides, characterized in that: include: Step 1: providing a wafer, making a microfluidic inlet and outlet (103) on the wafer, obtaining a first microfluidic structure unit (101) and a second microfluidic structure unit (102), and assembling the first microfluidic structure unit (101) and the second microfluidic structure unit (102) obtained by a wafer-level bonding process to form a sealed microfluidic cover plate; Step 2: using an electroplating process to manufacture an inlet and outlet sealing ring (104) and a metal thermal conductive pad (105) on the lower surface of the microchannel cover plate; Step three: providing another wafer, forming a transfer through hole (106) on the wafer by using an etching process, and filling the transfer through hole (106) with electroplated copper by using an electroplating process, and forming circuit layers on the upper and lower surfaces of the wafer; Step 4: making a groove (107) on the wafer with the transfer through hole, burying the functional chip (108) in the groove (107), and integrating it through a wafer-level fan-out packaging process to form a two-dimensional heterogeneous integrated structural unit, and making a rewiring layer (110) on the upper and lower surfaces to achieve signal interconnection between the transfer through hole (106) and the functional chip (108), and leading the chip signal to the lower surface of the two-dimensional heterogeneous integrated structural unit through the transfer through hole (106); Step 5: using an etching process to fabricate a microchannel structure (109) on the lower surface of the two-dimensional heterogeneous integrated structural unit, distributed on the side wall and bottom of the embedded functional chip (108); Step 6: using electroplating or mounting technology to manufacture liquid inlet and outlet sealing rings (104) and metal thermal pads (105) on the upper and lower surfaces of the two-dimensional heterogeneous integrated structural unit; Step 7: providing a substrate, using a mechanical punching process or a laser punching process to make a microfluidic inlet (111) and a microfluidic outlet (112), and making an inlet and outlet sealing ring (104) on the surface of the substrate; Step 8: Assemble the microfluidic cover plate, two-dimensional heterogeneous integrated structural unit and substrate obtained above by a bonding process to form a microfluidic packaging structure capable of dissipating heat on six sides.

2. The method for manufacturing a microchannel packaging structure capable of six-sided heat dissipation as claimed in claim 1, characterized in that: The material of the wafer includes silicon, glass, and III-V compounds; the III-V compounds are gallium nitride and gallium arsenide.

3. The method for manufacturing a microfluidic package structure capable of six-sided heat dissipation as claimed in claim 1, characterized in that: The materials of the liquid inlet and outlet sealing rings (104) and the metal heat conductive pad (105) include a low melting point metal single substance of tin, lead, bismuth, copper, or a compound of multiple substances.

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