Liquid cooling adapter plate for chip packaging

Abstract

The invention provides a liquid cooling adapter plate for chip packaging, which is composed of a plurality of layers of prefabricated cooling sheets, and is characterized in that the plurality of layers of cooling sheets are processed in advance, then arranged in a certain space according to a specific sequence, aligned and then connected into a whole in one or more modes such as bonding, welding, sintering or bonding. All or part of the cooling sheets are provided with a certain number of through structures in a certain shape, after the multiple layers of cooling sheets are connected into a whole, the through structures are communicated with one another to form a flow channel which is communicated completely or partially, and the flow channel is used for cooling working media to flow and take away heat generated on the chip and / or the adapter plate. According to the invention, the problems of difficulty in manufacturing a complex runner structure, high processing cost, low reliability and the like in the prior art can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor technology, and in particular to a liquid cooling adapter plate for chip packaging. BACKGROUND

[0002] The continuous advancement of Moore's Law has led to the continuous reduction of transistor size within logic chips, while the number is growing exponentially. As integrated circuit (IC) design continues to develop towards high performance, high integration and miniaturization, the power density and total heat dissipation of chips are growing rapidly. Currently, the power consumption of a single logic chip package can reach hundreds to thousands of watts, and traditional chip external cooling technology and air cooling technology cannot fully meet the cooling demand. Chip packaging thermal management problems are becoming increasingly severe.

[0003] On the other hand, the widespread application of advanced packaging technologies (such as 2.5D / 3D IC, Chiplet, etc.) further exacerbates the complexity of thermal management. These technologies achieve higher performance through stacked chips or heterogeneous integration, but also cause heat to be highly concentrated in a small space, forming local hotspots, which pose a serious threat to the reliability, performance and lifespan of the chip.

[0004] Under this background, microfluidic liquid cooling technology integrated inside the package has become a research hotspot. Unlike traditional macroscopic liquid cooling solutions, microfluidic liquid cooling integrates microfluidic channels directly inside the chip through direct packaging, and uses the high specific heat capacity, high density thermal physical properties and forced convection of liquids (such as deionized water, freon or nanofluid, etc.) to achieve more direct and efficient cooling of high power density areas.

[0005] In addition to logic chips, microfluidic liquid cooling technology inside the package can also be applied to other chip packaging fields with urgent cooling needs, such as various power chips, memory chips and detection chips, etc.

[0006] In the future, as IC process nodes approach physical limits, microfluidic liquid cooling inside the package will become one of the key technologies to break through the "power wall" and drive the development of the next generation of high-performance chips.

[0007] In recent years, academic and industrial circles have proposed microfluidic liquid cooling solutions, however, these technologies still face challenges such as manufacturing process complexity, two-phase flow stability, long-term reliability, and high manufacturing cost, etc. SUMMARY

[0008] To this end, the present application provides a liquid cooling adapter plate for chip packaging, which is used for placing chip packaging to quickly release the heat generated by the chip packaging in the operation process, and the liquid cooling adapter plate for chip packaging is composed of a plurality of prefabricated cooling sheets which are stacked in sequence, and a micro flow channel for flowing cooling liquid is formed between the plurality of prefabricated cooling sheets of the liquid cooling adapter plate for chip packaging, wherein the micro flow channel is formed by the through structure in the plurality of prefabricated cooling sheets.

[0009] In addition, preferably, in the liquid cooling adapter plate for chip packaging provided by the present application, the plurality of prefabricated cooling sheets are integrated by being connected in one of the following manners or a combination of two or more of the following manners after being aligned: bonding, welding, sintering or bonding.

[0010] In addition, preferably, in the liquid cooling adapter plate for chip packaging provided by the present application, at least one inlet for cooling medium and at least one outlet for cooling medium are arranged on the uppermost and / or lowermost two layers of surface prefabricated cooling sheets.

[0011] In addition, preferably, in the liquid cooling adapter plate for chip packaging provided by the present application, the internal fluid cavity region between the opposite upper and lower surfaces of the outer surface is connected by the through conductive via to form the electrical connection of the corresponding regions of the upper and lower surfaces.

[0012] In addition, preferably, in the liquid cooling adapter plate for chip packaging provided by the present application, the cooling sheets have longitudinal and / or transverse electrical connection structures in a certain number and shape.

[0013] In addition, preferably, in the liquid cooling adapter plate for chip packaging provided by the present application, each prefabricated cooling sheet is an integral layer or a combination of multiple layers with the same thickness.

[0014] In addition, preferably, in the liquid cooling adapter plate for chip packaging provided by the present application, each prefabricated cooling sheet is processed as a single piece or is formed by large piece processing and then divided into multiple pieces.

[0015] In addition, preferably, in the liquid cooling adapter plate for chip packaging provided by the present application, each layer of the plurality of prefabricated cooling sheets has the same thickness or does not have the same thickness.

[0016] In addition, preferably, in the liquid cooling adapter plate for chip packaging provided by the present application, the micro flow channel is connected to the first and second opposite surfaces of the cooling sheet on each layer of the cooling sheet.

[0017] In addition, preferably, in the liquid cooling adapter plate for chip packaging provided by the present application, the micro flow channel is one-dimensional or two-dimensional array and / or has a mirror symmetry structure.

[0018] By means of the present application, the problems of difficulty in manufacturing complex flow channel structure, high processing cost and low reliability in prior art can be solved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1A is a schematic view that schematically shows a cross section of a liquid-cooled adapter plate for chip packaging according to the prior art.

[0020] Figure 1B is a top view that schematically shows a micro groove structure in a liquid-cooled adapter plate for chip packaging according to the prior art.

[0021] Figure 1C is a schematic view that schematically shows a three-dimensional shape of a liquid-cooled adapter plate for chip packaging according to the prior art, in which a wire frame display is used to better present the internal structure.

[0022] Figure 2A is a schematic view that schematically shows a cross section of a liquid-cooled adapter plate for chip packaging according to an embodiment of the present application.

[0023] Figure 2B is a schematic view that schematically shows a three-dimensional shape of a liquid-cooled adapter plate for chip packaging according to an embodiment of the present application, and a wire frame display is used to better present the internal structure.

[0024] Figure 2C is a plan view that schematically shows a multi-layer cooling sheet of a liquid-cooled adapter plate for chip packaging according to an embodiment of the present application.

[0025] Figure 3A is a schematic view that schematically shows a cross section of a liquid-cooled adapter plate for chip packaging according to another embodiment of the present application.

[0026] Figure 3B is a schematic view that schematically shows a three-dimensional shape of a liquid-cooled adapter plate for chip packaging according to another embodiment of the present application, in which a wire frame display is used to better present the internal structure.

[0027] Figure 3C is a plan view that schematically shows a multi-layer cooling sheet of a liquid-cooled adapter plate for chip packaging according to another embodiment of the present application.

[0028] Figure 4A is a schematic view that schematically shows a cross section of a liquid-cooled adapter plate for chip packaging according to another embodiment of the present application.

[0029] Figure 4B is a schematic view that schematically shows a three-dimensional shape of a liquid-cooled adapter plate for chip packaging according to another embodiment of the present application, in which a wire frame display is used to better present the internal structure.

[0030] Figure 4C is a plan view schematically showing a multi-layer cooling sheet of a liquid-cooled adapter plate for a chip package according to another embodiment of the present application.

[0031] Figure 5A is a schematic view of a cross section schematically showing a liquid-cooled adapter plate for a chip package according to another embodiment of the present application.

[0032] Figure 5B is a schematic view of a three-dimensional shape schematically showing a liquid-cooled adapter plate for a chip package according to another embodiment of the present application, in which a wire frame display is used to better present its internal structure.

[0033] Figure 6A is a schematic view of a three-dimensional shape schematically showing a liquid-cooled adapter plate for a chip package according to another embodiment of the present application, in which a wire frame display is used to better present its internal structure.

[0034] Figure 6B is a plan view schematically showing a multi-layer cooling sheet of a liquid-cooled adapter plate for a chip package according to another embodiment of the present application.

[0035] Figure 7A is a schematic view of a three-dimensional shape schematically showing a liquid-cooled adapter plate for a chip package according to another embodiment of the present application, in which a wire frame display is used to better present its internal structure.

[0036] Figure 7B is a plan view schematically showing a multi-layer cooling sheet of a liquid-cooled adapter plate for a chip package according to another embodiment of the present application. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, other embodiments or variants obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0038] The microfluidic liquid cooling structure is generally composed of a substrate containing microgrooves and a cover plate containing fluid inlets and outlets, and the material is generally silicon or glass. In the process of processing and preparation, first, the etching of the substrate cavity and the heat dissipation fins in the cavity is completed, then the etching of the fluid inlets and outlets on the cover plate is completed, and then the substrate and the cover plate are bonded (the traditional bonding method is silicon-glass anodic bonding or silicon-silicon direct bonding) to seal, that is, the microgrooves on the substrate are closed by the cover plate to realize the cooling microfluid channel structure.

[0039] And the existing processing method for forming a substrate containing micro-grooves by etching needs to define a pattern through a photolithography process. Therefore, when forming a micro-channel structure, the prior art generally must use photolithography, etching, bonding and other semiconductor processes, which are high-cost process methods. In addition, the 3D printing method is also used to form a micro-channel structure, which still has the problems of high cost and unsuitability for large-scale manufacturing.

[0040] In the prior art, the main shortcomings of the micro-fluid liquid cooling structure and the forming method are the lack of a simpler and faster processing method suitable for batch manufacturing, and it is also difficult to process and manufacture complex flow channel structures, especially in the thickness direction, the structure can only be very simple, and the profile is not easy to control. The root cause is that there is a lack of better design methods and forming methods.

[0041] In addition, the main advantages of the micro-fluid liquid cooling technology inside the package are:

[0042] (1) Junction-level cooling: The cooling liquid is directly delivered to the vicinity of the heat source, which maximizes the reduction of thermal resistance and eliminates the thermal interface resistance, thereby achieving the purpose of reducing the total thermal resistance.

[0043] (2) High-efficiency heat dissipation: By optimizing the micro-channel topology structure and fluid parameters, the minimum power consumption can be used to maximize and customize the heat dissipation of different power consumption distributions of the chip.

[0044] (3) Efficient use of space: The micro-channel structure can be integrated with the interposer or the back of the chip, etc., to adapt to the compact space of advanced packaging.

[0045] The present application provides a cooling structure and a forming method, which can be briefly described as follows: first, a multi-layer cooling sheet is prepared, then a through structure is formed on the thin cooling sheet, and then the multi-layer cooling sheet is formed into an integrated structure.

[0046] There are many processing methods for forming thin sheets and through structures of various materials, and the method for forming an integrated structure is also common. From a broad classification, the processing method for forming a thin sheet includes cutting, grinding, calendering, sintering, etc. The processing method for forming a through structure includes mechanical processing, laser processing, electrical processing, chemical processing or electrochemical processing, etc. The method for forming an integrated structure includes bonding, welding, sintering or bonding, etc. Therefore, the structure and the forming method provided by the present application have many implementation paths and can be applied to the liquid cooling interposer for manufacturing chip packages of various design targets and various materials.

[0047] In summary, the purpose of the present application can be achieved by the following technical solutions:

[0048] A liquid-cooled adapter plate structure for chip packaging, wherein the liquid-cooled adapter plate is composed of a plurality of pre-fabricated cooling sheets, the plurality of cooling sheets are arranged in a certain order in a certain space, each of the plurality of cooling sheets comprises a first surface and a second surface opposite to the first surface, except for the uppermost and lowermost cooling sheets, each of the intermediate cooling sheets is connected by the first surface of itself and the second surface of the adjacent cooling sheet above itself, and connected by the second surface of itself and the first surface of the adjacent cooling sheet below itself, the whole or part of the cooling sheets comprises a certain number and shape of through structures, the through structures on the plurality of cooling sheets are connected to each other to form a whole or partial flow channel.

[0049] The liquid-cooled adapter plate structure, wherein the plurality of cooling sheets are aligned to form a cooling liquid flow path comprising an interlayer flow path and an intra-layer flow path, and then connected by any one or more of bonding, welding, sintering or bonding to form an integral structure.

[0050] The liquid-cooled adapter plate structure, wherein at least one inlet for the cooling working medium and at least one outlet for the cooling working medium are provided on the uppermost and / or lowermost surface cooling sheets.

[0051] The liquid-cooled adapter plate structure, wherein the electrically conductive through holes are connected between the opposite upper and lower surfaces of the outer surface and the internal fluid cavity region to form an electrical connection of the corresponding regions of the upper and lower surfaces.

[0052] The plurality of pre-fabricated cooling sheets, wherein the whole or part of the cooling sheets further comprise a certain number and shape of longitudinal and / or transverse electrical connection structures.

[0053] The plurality of pre-fabricated cooling sheets, wherein each layer can be a whole or a plurality of parts of the same thickness.

[0054] The plurality of pre-fabricated cooling sheets, wherein the sheets can be processed as a single piece or divided into multiple pieces after being processed as a large piece.

[0055] The plurality of pre-fabricated cooling sheets, wherein each layer can be of the same thickness, or different thickness, or not exactly the same thickness.

[0056] The plurality of pre-fabricated cooling sheets, wherein the materials of each layer or each part of each layer include but are not limited to glass, ceramic (silicon carbide, aluminum oxide, aluminum nitride, etc.), semiconductor (silicon, germanium, gallium nitride, etc.), metal (copper, aluminum, molybdenum copper, tungsten copper, etc.), diamond, organic polymer, etc., or composite materials including but not limited to the above materials.

[0057] The multi-layer pre-cooling sheet, wherein the material of each part of each layer can be the same, different, or not exactly the same.

[0058] The through structure on the multi-layer pre-cooling sheet, wherein the through structure on each layer of the cooling sheet connects the first face and the second face opposite to the first face of the cooling sheet.

[0059] The through structure on the cooling sheet, wherein the through structure is processed by any one or more of mechanical processing (cutting, milling, punching, etc.), laser processing, electrical processing, chemical processing, electrochemical processing, or semiconductor processing, etc.

[0060] The through structure on the cooling sheet, wherein the through structure can be one or more parts, preferably all or part of a one-dimensional / two-dimensional array and / or mirror image of a simple structure.

[0061] The through structure on the cooling sheet, wherein the profile can be various planar shapes, and the through structures on the multi-layer cooling sheet are connected to each other to form various complex three-dimensional flow channel structures, including but not limited to straight lines, broken lines, curves, one-to-many, many-to-one, cross grids, etc.

[0062] The through structure, wherein all or part of the feature size is microscale, and thus the flow channel formed is all or part of a micro flow channel. For example, the flow path diameter of the micro flow channel is 10 nm-100 μm, and the thickness of the cooling sheet is 5 μm-500 μm.

[0063] The flow channel is a flow passage for a cooling working medium, which includes various pure substance coolants, or a solution or liquid mixture composed of two or more substances, or a gas-liquid / solid-liquid two-phase mixture composed of the same / different substances. The substances include but are not limited to water, oil, organic compound coolants (freon, ethanol, ethylene glycol, glycerol, etc.), and nanoparticles, etc.

[0064] A method for forming a liquid-cooled adapter plate structure of a chip package, wherein the liquid-cooled adapter plate is composed of a multi-layer pre-cooling sheet, the multi-layer cooling sheet is arranged in a certain order in a certain space, each layer of the multi-layer cooling sheet includes a first face and a second face opposite to the first face, and each intermediate layer of the cooling sheet is connected to the second face of the adjacent cooling sheet above it and the first face of the adjacent cooling sheet below it, a certain number and shape of through structures are arranged on all or part of the cooling sheet, the through structures on the multi-layer cooling sheet are connected to each other to form all or part of the connected flow channel.

[0065] The method for forming the liquid-cooled adapter plate structure, wherein the through structure on the cooling sheet is processed by any one or more of mechanical processing (cutting, milling, punching, etc.), laser processing, electrical processing, chemical processing, electrochemical processing, or semiconductor processing.

[0066] The method for forming the liquid-cooled adapter plate structure, wherein the multi-layer cooling sheet is integrated by any one or more of bonding, welding, sintering, or bonding after being aligned.

[0067] The method for forming the liquid-cooled adapter plate structure, wherein the conductive via and other electrical connection structures are processed after the cooling channel structure is completed. Alternatively, the conductive via and other electrical connection structures are processed in each layer in advance, and then the multi-layer cooling sheet is integrated by any one or more of bonding, welding, sintering, or bonding after being aligned.

[0068] The method for forming the liquid-cooled adapter plate structure, wherein the multi-layer cooling sheet can be integrated by connecting a single piece to another, or by connecting a large piece of cooling sheet to another and then dividing it into multiple pieces.

[0069] The present application has at least the following advantages.

[0070] 1. The internal channel formed by the combination of multi-layer cooling sheets has a relatively simple structure and design, and the combination is easy to form a complex three-dimensional structure, such as a geometric fractal structure, a jet impact array, a multi-manifold structure, a Tesla valve, etc. Through various designs, it is easy to achieve heat transfer enhancement, easy to achieve shunt flow control, and easy to achieve flow resistance control.

[0071] 2. There are many methods for forming through structures on thin cooling sheets, including mechanical processing, laser processing, electrical processing, or chemical processing, or a combination of two or more processing methods, so the manufacturing is relatively easy and flexible, the cost is relatively low, the high-difficulty / high-cost whole etching process is avoided, and it is suitable for large-scale manufacturing.

[0072] The technical content of the present application will be further described below with reference to the accompanying drawings. Figure 1A 、 1B 、1C is a schematic cross-sectional view of a liquid-cooled adapter plate for chip packaging, a top view of a micro-groove structure, and a schematic view of a three-dimensional shape.

[0073] Figure 2A 、 2B2C is a schematic cross-sectional view, a three-dimensional shape view, and a plan view of the multilayer cooling sheets (as shown by reference numerals 101 to 106) therein of a liquid-cooled adapter plate for chip packaging according to an embodiment of the present invention. Figure 3A , 3B 3C is a schematic cross-sectional view, a three-dimensional shape view, and a plan view of the multilayer cooling sheets (as shown by reference numerals 201 to 204) therein of a liquid-cooled adapter plate for chip packaging according to one embodiment of the present invention. Figure 4A , 4B 4C is a schematic cross-sectional view, a three-dimensional shape view, and a plan view of the multilayer cooling sheets (as shown by reference numerals 301 to 304) therein of a liquid-cooled adapter plate for chip packaging according to one embodiment of the present invention. Figure 5A , 5B This schematically illustrates a cross-sectional view and a three-dimensional shape view of a liquid-cooled adapter board for chip packaging according to one embodiment of the present invention. Figure 6A , 6B This is a schematic diagram illustrating a three-dimensional shape of a liquid-cooled adapter plate for chip packaging according to an embodiment of the present invention, and a plan view of the multilayer cooling sheets therein (as shown by reference numerals 501 to 505). Figure 7A , 7B This is a schematic three-dimensional shape diagram of a liquid-cooled adapter plate for chip packaging according to one embodiment of the present invention, and a plan view of the multilayer cooling sheets therein (as shown by reference numerals 601 to 608).

[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0075] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0076] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any modification or replacement within the technical range disclosed by the present application can be easily thought by those skilled in the art, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0077] The above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted. Any modification, equivalent replacement and improvement within the spirit and principle of the present application should be covered within the protection scope of the claims of the present application.

Claims

1. A liquid-cooled adapter plate for chip packaging, used to remove heat generated during chip packaging operation, characterized in that, The liquid-cooled adapter board for chip packaging is composed of multiple pre-fabricated cooling sheets stacked sequentially. The liquid-cooled adapter plate for chip packaging has microchannels formed between multiple pre-fabricated cooling sheets for coolant to flow through, wherein the microchannels are formed by through-structures in the multiple pre-fabricated cooling sheets.

2. The liquid-cooled adapter board for chip packaging according to claim 1, characterized in that, After aligning the multi-layer pre-fabricated cooling sheets, they are then connected to form a whole by one or more of the following methods: bonding, welding, sintering, or bonding.

3. The liquid-cooled adapter board for chip packaging according to claim 1, characterized in that, At least one inlet for the cooling medium and at least one outlet for the cooling medium are provided on the top and / or bottom two pre-fabricated cooling sheets.

4. The liquid-cooled adapter board for chip packaging according to claim 3, characterized in that, Between the opposing upper and lower surfaces of the outer surface, there is an internal fluid-free cavity region, which is connected by a through conductive via to form an electrical connection between the corresponding regions of the upper and lower surfaces.

5. The liquid-cooled adapter board for chip packaging according to claim 3, characterized in that, The cooling sheets, in whole or in part, also include a certain number of longitudinal and / or transverse electrical connection structures of a certain shape.

6. The liquid-cooled adapter board for chip packaging according to claim 3, characterized in that, Each pre-formed cooling sheet is either a single, integral layer or a combination of multiple parts of the same thickness.

7. The liquid-cooled adapter board for chip packaging according to claim 3, characterized in that, Each pre-formed cooling sheet is processed as a single piece or divided into multiple pieces after being formed from a large sheet.

8. The liquid-cooled adapter board for chip packaging according to claim 3, characterized in that, The layers of multiple pre-formed cooling sheets may have the same thickness or different thicknesses.

9. The liquid-cooled adapter board for chip packaging according to claim 1, characterized in that, The microchannels connect the upper and lower opposing first and second surfaces of each cooling sheet.

10. The liquid-cooled adapter board for chip packaging according to claim 1, characterized in that, The microchannels are all or part of a one-dimensional or two-dimensional array and / or have a mirror-symmetric structure.

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