cooling system

Abstract

A cooling system comprising a die; a bonding layer disposed over the die; an integrated micro-cooler disposed over the bonding layer; and a cooling lid disposed over the integrated micro-cooler, wherein the integrated micro-cooler comprises a first portion on the bonding layer and a second portion over the first portion, wherein the second portion comprises a plurality of trenches and a partition wall surrounding the plurality of trenches, wherein the integrated micro-cooler comprises a material of single-crystal diamond, and wherein the cooling lid comprises a fluid inlet conduit and a fluid outlet conduit through the cooling lid, the fluid inlet conduit and the fluid outlet conduit disposed over and open to the plurality of trenches.

Description

Technical Field

[0001] This utility model relates to a cooling system. Background Technology

[0002] The semiconductor integrated circuit (IC) industry has experienced exponential growth. Technological advancements in IC materials and design have resulted in generation after generation of ICs, each generation smaller and more complex than the last. This scaling down process typically benefits production efficiency and reduces associated costs. However, this scaling down also impacts the efficiency and complexity of IC heat dissipation. Therefore, while existing IC heat dissipation systems and their manufacturing methods are generally sufficient for their intended purpose, they are not entirely satisfactory in all aspects. Utility Model Content

[0003] The purpose of this invention is to provide a cooling system to solve at least one of the above-mentioned problems.

[0004] This utility model provides a cooling system in several embodiments. The cooling system includes a grain, a bonding layer disposed on the grain, an integrated microcooler disposed on the bonding layer, and a cooling cap disposed on the integrated microcooler. The integrated microcooler includes a first portion on the bonding layer and a second portion above the first portion. The second portion includes a plurality of trenches and partition walls surrounding the trenches. The integrated microcooler is made of a single-crystal diamond material, and the cooling cap includes a fluid inlet conduit and a fluid outlet conduit disposed above and open to the trenches.

[0005] According to one embodiment of the present invention, it further includes: a fluid path between the fluid inlet conduit and the fluid outlet conduit and located outside the cooling cover; and a heat exchanger on the fluid path, wherein the heat exchanger is configured to cool a coolant in the fluid path.

[0006] According to one embodiment of the present invention, a sealing layer is further included to join the integrated microcooler and the cooling cover, wherein the sealing layer comprises a polymer-based material or a silicone-based material.

[0007] According to one embodiment of the present invention, the bonding layer has a thickness equal to or less than about 0.05 mm. 2 Thermal resistance of C / W.

[0008] According to one embodiment of the present invention, the cooling cap comprises single-crystal diamond or copper.

[0009] According to one embodiment of the present invention, the fluid inlet conduit and the fluid outlet conduit each include a T-shaped portion.

[0010] According to one embodiment of the present invention, from a top view, the plurality of grooves are connected to form a sawtooth shape.

[0011] According to one embodiment of the present invention, the plurality of grooves include a plurality of side grooves near the side of the integrated micro-cooler and a plurality of central grooves located between the plurality of side grooves, wherein the width of the plurality of side grooves is greater than the width of the plurality of central grooves.

[0012] According to one embodiment of the present invention, the cooling cover is joined to the partition wall.

[0013] According to one embodiment of the present invention, the second part further includes a plurality of walls that divide the plurality of grooves, wherein the height of the plurality of walls is equal to or less than the height of the dividing wall. Attached Figure Description

[0014] The concept of embodiments of this utility model will be better understood by referring to the following detailed description and the accompanying drawings. It should be noted that, according to standard industry practice, the various features in the drawings are not necessarily drawn to scale. In fact, the dimensions of various features may be arbitrarily enlarged or reduced for clarity of illustration.

[0015] Figure 1 A schematic diagram of a cooling system with a cooling unit constructed according to some embodiments of the present invention is shown.

[0016] Figure 2A An exploded perspective view of a cooling unit according to some embodiments of the present invention is shown.

[0017] Figure 2B A perspective view of the cooling cover of a cooling unit according to some embodiments of the present invention is shown.

[0018] Figure 3 A perspective view of a cooling unit according to some embodiments of the present invention is shown.

[0019] Figure 4 A top view showing a portion of a cooling unit according to some embodiments of the present invention.

[0020] Figure 5 Along some embodiments of the present invention are shown. Figure 4 A schematic cross-sectional view of a portion of the cooling unit along line A-A'.

[0021] Figure 6A , Figure 6B , Figure 6C , Figure 6D , Figure 6E and Figure 6F A top view of a portion of an integrated micro cooler (IMC) of a cooling unit according to some embodiments of the present invention is shown.

[0022] Figure 7 This is a flowchart illustrating a method for forming a cooling unit according to some embodiments of the present invention.

[0023] Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 , Figure 13 , Figure 14 and Figure 15 Based on various aspects of this utility model Figure 7 Partial cross-sectional views of exemplary workpieces associated with various manufacturing stages of the method.

[0024] The attached figures are labeled as follows:

[0025] 100: Cooling System

[0026] 105: Heat Exchanger

[0027] 110: Cooling water supply

[0028] 115: First catheter

[0029] 120: Second catheter

[0030] 125: First cooling water conduit

[0031] 128: Second cooling water conduit

[0032] 130: Pump

[0033] 132: First Pipeline

[0034] 134: Entrance connection stand

[0035] 136: Branch Unit

[0036] 138: Branch catheter

[0037] 140: Pressure gauge

[0038] 142: Flow meter

[0039] 144: Second Pipeline

[0040] 146: Export connection stand

[0041] 148: Branch Unit

[0042] 150: Branch catheter

[0043] 152: Pressure gauge

[0044] 154: Arrow

[0045] 156: Arrow

[0046] 200: Cooling unit / precursor / workpiece

[0047] 205: Integrated Microcooler

[0048] 205a: Integrated microcooler precursor

[0049] 210: Grain

[0050] 210a: Grain

[0051] 215: Cooling cap

[0052] 216: Inlet catheter

[0053] 216a: T-shaped section / dashed T-shape

[0054] 216b: Rectangular section / Dashed rectangle

[0055] 218: Outlet conduit

[0056] 218a: T-shaped section / dashed T-shape

[0057] 218b: Rectangular section / Dashed rectangle

[0058] 220: Calories

[0059] 222in: Fluid inlet port

[0060] 222out: Fluid outlet port

[0061] 224: Area

[0062] 226: Partition wall

[0063] 228: Features

[0064] 230: Arrow

[0065] 232: Arrow

[0066] 234: Arrow

[0067] 236:Outer wall

[0068] 238: Upper sidewall

[0069] 240: Top surface

[0070] 242: Lower sidewall

[0071] 244:Wall

[0072] 246: Trench

[0073] 246a: Groove / Side Groove

[0074] 246b: Groove / Central Groove

[0075] 250: Top section

[0076] 252: Bottom section

[0077] 260: Bonding layer

[0078] 262: Sealing layer

[0079] 266: Merging openings

[0080] 268:Substrate

[0081] 270: Interconnection Structure

[0082] 272: Multilayer interconnect structure

[0083] 276: Passivation Structure

[0084] 280: Electrical conductivity characteristics

[0085] 282: Dielectric layer

[0086] 286: Passivation layer

[0087] 288: Conductive pad / contact pad

[0088] 290: First load-bearing component

[0089] 292: Bonding layer

[0090] 293: Flat surface

[0091] 294: Second load-bearing component

[0092] 296: Adhesive layer

[0093] 298: Hard mask layer

[0094] 298a: Part One

[0095] 298b: Part Two

[0096] 300: Method

[0097] 312, 314, 316, 318, 320, 322, 324, 326, 328, 330: Blocks; X, Y, Z: Axes

[0098] A-A': line

[0099] H1: Thickness / (Total) Height

[0100] H2, H2', H3, H4, H5, H5', H6: Height; H7, H8, H9: Thickness

[0101] W1: Width

[0102] W2: Total width

[0103] W3, W4, W5, W6, W7, W8, W9: Width

[0104] FS: Front Surface

[0105] BS: Back surface Detailed Implementation

[0106] The following disclosure provides many different embodiments or examples to implement different features of the present invention. Specific examples of components and configurations are described below to simplify the description of the present invention. Of course, these specific examples are merely illustrative and not intended to limit the present invention. For example, in the following description, reference to a first feature being formed on or above a second feature indicates that it may include embodiments where the first and second features are in direct contact, or embodiments where an additional feature is formed between the first and second features, so that the first and second features may not be in direct contact.

[0107] Additionally, reference numerals and / or letters may be repeated in various embodiments of this invention. Such repetition is for simplicity and clarity and does not in itself limit the relationship between the various embodiments and / or configurations described. Furthermore, references in the following description to the formation of one feature, connected to, and / or coupled to another feature may include embodiments in which these features are formed in direct contact, and may also include embodiments in which additional features are formed inserted into these features such that these features are not in direct contact. Additionally, spatially related terms such as “lower,” “higher,” “horizontal,” “vertical,” “above,” “above,” “below,” “under,” “up,” “bottom,” etc., and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) may be used herein to describe the relationship between one feature and another shown in the figures. These spatially related terms are intended to cover different orientations of the device including these features. Furthermore, when numbers or ranges of numbers are described using terms such as “about,” “approximately,” etc., unless otherwise stated, these terms are intended to cover numbers within + / - 10% of the described number; for example, “about 5nm” covers a size range from 4.5nm to 5.5nm.

[0108] Typically, an IC chip comprises multiple active devices formed on a semiconductor substrate and interconnect structures for functionally interconnecting these active elements. An IC chip can also be called an IC die or simply a die. A typical problem with dies is heat dissipation during operation. Operating at excessively high temperatures and exposing the die to such environments for extended periods can reduce its reliability and lifespan. This problem can be exacerbated if the die is a computational die, such as a central processing unit (CPU), that generates a significant amount of heat. Therefore, improvements in heat transfer remain necessary.

[0109] This invention provides various embodiments of a cooling system. In particular, this invention provides a cooling system having a cooling unit. The cooling unit includes a grain, an integrated microcooler (IMC) integrated with the grain, and a cooling cap disposed on the integrated microcooler. The integrated microcooler can be bonded to the grain via a bonding layer comprising a thermal interface material (TIM). The bonding layer may have a thickness equal to or less than about 0.05 mm. 2 • Thermal resistance (C / W). The integrated microcooler includes a trench open to the inlet conduit and outlet conduit of the cooling cap. The integrated microcooler includes more than about 90 wt% single-crystal diamond (SCD). During operation, coolant can flow sequentially through the inlet conduit in the cooling cap, the trench in the integrated microcooler, and the outlet conduit in the cooling cap. Heat generated by the grains can be transferred to the coolant in the trench. By having the integrated microcooler, bonding layer, and cooling cap of this invention, the heat transfer efficiency from the grains to the coolant can be improved. Therefore, heat accumulation in the grains can be reduced and thermal damage to the grains can be prevented. The cooling system may also include a heat exchanger for cooling the coolant flowing out of the cooling unit and a pump for driving the coolant flow. By using the cooling unit of this invention, the power consumption of the pump can be reduced.

[0110] Various aspects of the present invention will now be described in more detail with reference to the accompanying drawings. To avoid ambiguity, Figures 2A to 6F and Figures 8 to 15 The X, Y, and Z directions are perpendicular to each other. Furthermore, the same reference numerals are used throughout the disclosure to represent the same features.

[0111] Figure 1This diagram illustrates a cooling system 100 constructed according to some embodiments of the present invention. In some embodiments, the cooling system 100 includes a cooling unit 200, a heat exchanger 105, a cooling water supply 110, a first conduit 115 and a second conduit 120 connecting the heat exchanger 105 and the cooling unit 200, a first cooling water conduit 125 connecting the cooling water supply 110 and the heat exchanger 105, and a second cooling water conduit 128 connected to the heat exchanger 105. In the present invention, a conduit is one or more channels providing a path for conveying water or other fluids (e.g., coolant). A conduit may include a pipe, tube, valve, any other suitable device, or any combination thereof. The cooling system 100 may include any suitable number of cooling units 200, such as one, two, three, four, five, etc. In some embodiments, the cooling system 100 also includes a pump 130 on the first conduit 115.

[0112] In some embodiments, the cooling unit 200 includes a die 210, an integrated microcooler (IMC) 205 disposed above and attached to the die 210, and a cooling cap 215 disposed above and attached to the integrated microcooler 205.

[0113] The cooling cap 215 may include a plurality of inlet conduits 216 and outlet conduits 218 respectively connected to the first conduit 115 and the second conduit 120. The inlet conduits 216 and outlet conduits 218 are shown with arrows to indicate the direction of coolant flow in the inlet conduits 216 and outlet conduits 218. It should be noted that the location and number of inlet conduits 216 and outlet conduits 218 are for illustrative purposes only. Details will be described later in this invention.

[0114] In some embodiments, the first conduit 115 includes a first pipe 132 and an inlet connection skid 134 connected to the first pipe 132. The first pipe 132 is connected to a heat exchanger 105. The inlet connection skid 134 is connected to a cooling unit 200. In some embodiments, a pump 130 is connected to the first pipe 132. The inlet connection skid 134 may include a branch unit 136 connected to the first pipe 132 and a plurality of branch conduits 138. The branch unit 136 may include a main pipe connected to the first pipe 132 and a plurality of side openings. Each of the plurality of side openings is connected to one of the plurality of branch conduits 138. One of the plurality of branch conduits 138 may be connected to one of a plurality of inlet conduits 216. In some embodiments, the inlet connection skid 134 further includes a pressure gauge 140 on each branch conduit 138. The pressure gauge 140 is used to measure the fluid pressure within the branch conduit 138. The inlet connection skid 134 may also include a flow meter 142 on each branch conduit 138. The flow meter 142 is used to measure the flow rate of the fluid within the branch conduit 138.

[0115] The second conduit 120 may have a similar structure to the first conduit 115. In some embodiments, the second conduit 120 includes a second pipe 144 and an outlet connection stand 146 connected to the second pipe 144. The second pipe 144 is connected to a heat exchanger 105. The outlet connection stand 146 is connected to a cooling unit 200. The outlet connection stand 146 may include a branch unit 148 connected to the second pipe 144 and a plurality of branch conduits 150. The branch unit 148 may include a main pipe connected to the second pipe 144 and a plurality of side openings. Each of the plurality of side openings is connected to one of the plurality of branch conduits 150. One of the plurality of branch conduits 150 may be connected to one of the plurality of outlet conduits 218. In some embodiments, the outlet connection stand 146 also includes a pressure gauge 152 on each branch conduit 150. The pressure gauge 152 can be used to measure the fluid pressure within the branch conduit 150.

[0116] Heat exchanger 105 may include any type of heat exchanger, such as a shell-and-tube heat exchanger or a plate heat exchanger. In some embodiments, cooling water supply 110 supplies cooling water to heat exchanger 105. Used cooling water then enters a second cooling water conduit 128 and can be cooled by any suitable method. In some embodiments, used cooling water is cooled and circulated back to cooling water supply 110.

[0117] For clarity, Figure 1 The description has been simplified for better understanding of the concept of this utility model. Additional features can be added to the cooling system 100, and some of the features described above can be replaced, modified, or eliminated in other embodiments of the cooling system 100. For example, Figure 1Some features (e.g., valves, pumps, temperature sensors, controllers, filters) have been omitted.

[0118] Methods of using cooling system 100 may include circulating a coolant in a first conduit 115, cooling unit 200, second conduit 120, and heat exchanger 105. The coolant may include any suitable coolant, such as water, propylene glycol, 25% propylene glycol (PG25), or combinations thereof. In some embodiments, the coolant is a water-based coolant. In some embodiments, additives are added to water to produce the coolant. Examples of additives include surfactants, corrosion inhibitors, biocides, antifreeze, etc. The coolant may remain in the liquid phase during operation of cooling system 100.

[0119] In some embodiments, the coolant in the first conduit 115 has a first temperature and flows from the heat exchanger 105 to the cooling unit 200. Arrow 154 indicates the direction of coolant flow. The coolant flow in the first conduit 132 is branched into branch conduits 138 by branch unit 136. The temperature, pressure, flow rate, etc. of the coolant in the branch conduits 138 can be monitored and / or controlled.

[0120] Coolant from branch conduit 138 then enters inlet conduit 216 and flows into the trench of integrated microcooler 205. In the trench of integrated microcooler 205, the coolant exchanges heat with the grains 210. For example, heat 220 generated by the grains 210 during operation is transferred from the grains 210 to the coolant in the trench of integrated microcooler 205. After heat exchange, the coolant flows from the trench of integrated microcooler 205 through outlet conduit 218 to branch conduit 150. The coolant in the second conduit 120 may have a second temperature higher than the first temperature. The coolant flows out of branch conduit 150, converges at branch unit 148, and then flows through second conduit 144 to heat exchanger 105. Arrow 156 indicates the direction of coolant flow. The temperature, pressure, flow rate, etc., of the coolant in branch conduit 150 can be monitored and / or controlled.

[0121] The coolant from the second conduit 120 then flows through the heat exchanger 105 and into the first conduit 115. In the heat exchanger 105, the coolant is cooled by cooling water from the cooling water supply 110 (e.g., from a second temperature to a first temperature).

[0122] Figure 2A An exploded perspective view of a cooling unit 200 according to some embodiments of the present invention is shown, and Figure 2B A perspective view of a cooling cover 215 according to some embodiments of the present invention is shown.

[0123] exist Figure 2AIn the diagram, for clarity, the cooling cap 215, integrated microcooler 205, and grain 210 are vertically separated. Components of the cooling cap 215 are shown, although the cooling cap 215 may not necessarily be transparent. The cooling cap 215 may have an inverted T-shape in a cross-sectional view in the XZ plane. Each inlet conduit 216 may include a T-shaped portion 216a (e.g., dashed T-shape 216a) opening to a fluid inlet port 222in. The T-shape can be viewed from a top view. In such embodiments, the inlet conduit 216 may also include a rectangular portion 216b (e.g., dashed rectangle 216b). The rectangular portion 216b may be connected to a topbar of the T-shaped portion 216a. The rectangular portion 216b may extend vertically to and open to the integrated microcooler 205 below it. In some other embodiments, the T-shape can be viewed from a cross-sectional view in the YZ plane. In such an embodiment, the inlet conduit 216 may not include the rectangular portion; instead, the top rod of the T-shaped portion 216a may extend vertically to and open onto the integrated microcooler 205 below it. The outlet conduit 218 has a similar structure to the inlet conduit 216. For example, each outlet conduit 218 may include a T-shaped portion 218a (e.g., dashed T-shape 218a) similar to the T-shaped portion 216a, and the T-shaped portion 218a opens onto the fluid outlet port 222out. In some embodiments, the outlet conduit 218 also includes a rectangular portion 218b (e.g., dashed rectangle 218b) similar to the rectangular portion 216b. Each outlet conduit 218 may open onto the integrated microcooler 205 below it.

[0124] The top portion (also known as the top surface portion) of the integrated microcooler 205 can be divided into nine zones 224 by partition walls 226, such as Figure 2A and Figure 4 As shown. A pair of inlet conduits 216 and outlet conduits 218 are open (or connected to) each region 224. In some embodiments, arrow 230 in the inlet conduit 216, arrow 232 in the region 224, and arrow 234 in the outlet conduit 218 indicate the flow direction of coolant from the fluid inlet port 222in to the corresponding fluid outlet port 222out.

[0125] The inlet conduit 216 and outlet conduit 218 extend beyond the outer wall 236 of the cooling cap 215 and include features designed to accommodate screws (e.g., for connection). Figure 1 Characteristic 228 of branch catheter 138 or branch catheter 150, such as Figure 2B As shown.

[0126] Figure 3 A perspective view of a cooling unit 200 according to some embodiments of the present invention is shown. Figure 3In the illustration, the internal components of the cooling cap 215 (e.g., inlet conduit 216 and outlet conduit 218) are not shown. In the depicted example, fluid inlet ports 222in are located on opposite upper sidewalls 238 and top surface 240 of the cooling cap 215, and fluid outlet ports 222out are located on opposite lower sidewalls 242 and top surface 240 of the cooling cap 215. The cooling cap 215 includes nine (9) fluid inlet ports 222in and nine (9) fluid outlet ports 222out.

[0127] It should be noted that, in Figure 2A and Figure 3 In this illustration, the positions of the fluid inlet port 222in, the fluid outlet port 222out, the inlet conduit 216, and the outlet conduit 218 are for illustrative purposes only and should not be construed as limiting the scope of this invention. For example, the positions of the inlet conduit 216 and the corresponding outlet conduit 218 may be interchanged.

[0128] Figure 4 The figure illustrates a top view of a cooling unit 200 according to some embodiments of the present invention. In the depicted embodiments, a plurality of regions 224 have a rectangular shape of similar dimensions. The top surface 240 of the cooling cap 215 may have a width W1 along the X direction. The cooling cap 215 may have a total width W2 along the X direction. The integrated microcooler 205 may have a width W3 along the X direction, which is greater than the width W1 and less than the total width W2. The width W3 may be from about 20 mm to about 30 mm. The cooling cap 215 and the integrated microcooler 205 may have a width W4 along the Y direction, which is in the range of about 15 mm to about 30 mm. The grains 210 may have a similar size to the depicted integrated microcooler 205, or have widths along the X and Y directions greater than the widths W3 and W4, respectively.

[0129] Figure 5 Along some embodiments of the present invention are shown. Figure 4 A cross-sectional view of the cooling unit 200 along line A-A'. Figure 5 For clarity, features of the cooling cap 215 (e.g., inverted T-shape, inlet conduit 216, outlet conduit 218) have been simplified or omitted to better understand the concept of this invention. Similar to that shown in Figures 2A and 3, the inlet conduit 216 and the corresponding outlet conduit 218 may interchange their positions. The coolant flowing in the inlet conduit 216 and outlet conduit 218 of the cooling cap 215 is indicated by arrows 230 and 234, respectively. In the depicted embodiment, arrow 232 indicates the direction of coolant flow in the integrated microcooler 205. Heat 220 is transferred from the grains 210 to the coolant flowing in the integrated microcooler 205.

[0130] Die 210 can be an IC chip, a system-on-a-chip (SoC), or a portion thereof, and may include various passive and active microelectronic devices, such as resistors, capacitors, inductors, diodes, p-type field-effect transistors (PFETs), n-type field-effect transistors (NFETs), metal-oxide-semiconductor field-effect transistors (MOSFETs), complementary metal-oxide-semiconductor (CMOS) transistors, bipolar junction transistors (BJTs), laterally diffused metal-oxide-semiconductor (LDMOS) transistors, high-voltage transistors, high-frequency transistors, other suitable components, or combinations thereof. Die 210 can be any suitable chip, such as a memory chip, a central processing unit (CPU) chip, a graphics processing unit (GPU) chip, an input / output (I / O) chip, or combinations thereof.

[0131] In some embodiments, an integrated microcooler 205 is disposed on a die 210. The integrated microcooler 205 may be bonded to the die 210 via a bonding layer 260. The bonding layer 260 is used to improve electrical and / or thermal conduction by filling microcavities created between minute uneven surfaces (e.g., the region between the surfaces of the integrated microcooler 205 and the die 210). In some embodiments, the thickness of the bonding layer 260 is from about 0.1 μm to about 10 μm. The bonding layer 260 may include a first thermal interface material (TIM) layer or a second TIM layer, which will be described below. In some embodiments, the bonding layer 260 includes a first TIM layer and a second TIM layer. In some embodiments, the second TIM layer is disposed on top of the first TIM layer to improve bonding.

[0132] In some embodiments, the bonding layer 260 includes a first TIM layer. In such embodiments, the bonding layer 260 may have a thickness of approximately 0.5 mm. 2 •C / W to approximately 5mm 2• Thermal resistance (C / W). In some embodiments, the first TIM comprises an oxide, such as silicon oxide. The first TIM may be a viscous organosilicon compound with mechanical properties similar to a grease or gel. The first TIM may have a thermal conductivity of about 1 W / m·K to about 30 W / m·K, for example, about 4 W / m·K.

[0133] In some embodiments, the bonding layer 260 includes a second TIM layer. In such embodiments, the bonding layer 260 may have a thickness equal to or less than about 0.05 mm. 2 • Thermal resistance of C / W. In some embodiments, the bonding layer 260 has a thickness of approximately 0.01 mm. 2 • Thermal resistance (C / W). In some embodiments, the second TIM is a metal-based thermal paste containing silver, nickel, or aluminum particles suspended in a silicone grease. In other embodiments, non-conductive ceramic-based pastes filled with ceramic powders such as beryllium oxide, aluminum nitride, aluminum oxide, or zinc oxide can be used. In other embodiments, the second TIM can be a solid material rather than a paste with a gel-like or grease-like consistency. In this embodiment, the second TIM can be a sheet of thermally conductive solid material. In a particular embodiment, the solid second TIM can be a sheet of indium, nickel, silver, aluminum, combinations and alloys thereof, or other thermally conductive solid materials. The second TIM can have a thermal conductivity of about 50 W / m·K to about 500 W / m·K, for example, about 400 W / m·K.

[0134] In some embodiments, the integrated microcooler (IMC) 205 comprises single crystal diamond (SCD). The integrated microcooler 205 may comprise more than about 90 wt% SCD and less than about 10% other materials (e.g., impurities, dopants). The single crystal diamond can be a single, continuous diamond crystal. The single crystal diamond can be formed by any suitable method, such as chemical vapor deposition (CVD) or high-pressure high-temperature (HPHT) processes. In some embodiments, the integrated microcooler 205 is doped with dopants (e.g., boron and phosphorus). The integrated microcooler 205 may have a thermal conductivity greater than about 2,000 W / m·K. In some embodiments, the integrated microcooler 205 has a thermal conductivity from about 2,000 W / m·K to about 3,000 W / m·K. In some embodiments, the integrated microcooler 205 has a thermal conductivity from about 2,100 W / m·K to about 2,300 W / m·K. By having increased thermal conductivity compared to conventional IMCs, the heat transfer efficiency (e.g., heat transfer from grain 210 to the coolant) in the integrated microcooler 205 can be increased. In some embodiments, the integrated microcooler 205 has a Young's modulus greater than about 900 GPa. In some embodiments, the integrated microcooler 205 has a Young's modulus from about 900 GPa to about 1100 GPa. In some embodiments, the hardness of the integrated microcooler 205 is equal to or greater than the Mohs scale of mineral hardness 9. For example, the Mohs scale of mineral hardness of the integrated microcooler 205 is 10. Compared to conventional IMCs, the Young's modulus and hardness of the integrated microcooler 205 can be greater. By having the above-described mechanical properties, the mechanical integrity of the integrated microcooler 205 is improved. Therefore, the thickness H1 of the integrated microcooler 205 along the Z direction can be reduced, which further reduces the thermal resistance of the integrated microcooler 205. The thickness in this invention can also be referred to as the height and is along the Z direction.

[0135] In some embodiments, reference Figure 5 and Figures 6A to 6FEach region 224 in the top portion 250 of the integrated microcooler 205 includes a plurality of walls 244 and a plurality of grooves 246 divided by the plurality of walls 244. The grooves 246 located on the sides (also referred to as side grooves 246a) may each have a width W5 greater than the width W6 of the groove 246 located between the side grooves 246a (also referred to as the central groove 246b), wherein the widths W5 and W6 are along the X direction. The reasons for the width W5 being greater than the width W6 include: the coolant in the side grooves 246a carries away additional heat from the adjacent partition walls 226, and the inlet conduit 216 or outlet conduit 218 being open to the side grooves 246a. Depending on the context, the side grooves 246a and the central groove 246b may be referred to individually or collectively as grooves 246. In some embodiments, the width W6 is from about 50 μm to about 500 μm. If the width W6 is too small, heat may accumulate in the portion of the integrated microcooler 205 located directly below the central trench 246b. If the width W6 is too large, the number of central trenches 246b may be too small, thus reducing the heat transfer efficiency to the coolant. The ratio of width W5 to width W6 (W5 / W6) can be from about 1.1 to about 1.5. If the ratio (W5 / W6) is too small, the width W5 may be too small, and heat may accumulate in the adjacent partition wall 226. If the ratio (W5 / W6) is too large, the width W5 may be too large, resulting in the number of central trenches 246b being too small, thus reducing the heat transfer efficiency to the coolant.

[0136] Wall 244 may have a width W7 of about 50 μm to about 300 μm. The ratio of width W7 to width W6 (W7 / W6) is about 0.1 to about 1. If the ratio (W7 / W6) is too small, the width W7 may be too small and wall 244 may crack during operation. If the ratio (W7 / W6) is too large, the width W7 may be too large, thus making the available space for trench 246 too small. In some embodiments, partition wall 226 has a width W8 of about 100 μm to about 1,000 μm. Width W8 may be equal to or greater than width W7, and the ratio of width W8 to width W7 (W8 / W7) may be about 1 to about 10. If width W8 is too small, the mechanical support provided by partition wall 226 may be too small. If width W8 is too large, the available space for trench 246 may be too small. In some embodiments, the partition wall 226 (or the top portion 250 of the integrated microcooler 205) has a height H2 of about 100 μm to about 250 μm. The wall 244 may have a height H2' of about 100 μm to about 230 μm. The height H2' may be equal to or less than the height H2. If the height H2 or the height H2' is too small, the volume of the trench 246 may be too small, thereby reducing the amount of coolant in the trench 246. If the height H2 or the height H2' is too large, the coolant in the bottom of the trench 246 may remain there for too long, which may reduce heat transfer efficiency.

[0137] In some embodiments, the integrated microcooler 205 includes a bottom portion 252 located below the top portion 250. The bottom portion 252 may have a height H3 of about 180 μm to about 600 μm. In some embodiments, the height H3 is about 200 μm to about 300 μm. The total height H1 of the integrated microcooler 205 may be about 300 μm to about 750 μm. If the total height H1 is too small, the height H3 of the bottom portion 252 of the integrated microcooler 205 may be too small, thereby affecting the mechanical integrity of the integrated microcooler 205 (e.g., increasing the likelihood of the integrated microcooler 205 breaking during the manufacture or operation of the cooling unit 200); or, the height H2 of the partition wall 226 may be too small, thereby reducing the available space for coolant in the integrated microcooler 205 and its heat dissipation efficiency. If the total height H1 is too large, the thermal resistance of the integrated microcooler 205 may be too large, which reduces the benefits of having single-crystal diamond in the integrated microcooler 205.

[0138] By including the aforementioned bonding layer 260 and the integrated microcooler 205, heat dissipation of the grain 210 is improved. Therefore, the flow rate of the coolant in the cooling system 100 can be reduced while removing the same amount of heat from the grain 210. This reduces the power consumption of the pump 130 in the cooling system 100. At the same power consumption, the heat removed from the grain 210 can be increased by more than about 50%. Additionally, any hot spots on the grain 210 during operation (e.g., below the partition wall 226) can be reduced and / or eliminated.

[0139] In some embodiments, the integrated microcooler 205 is joined to the cooling cap 215 via a sealing layer 262. In some embodiments, the sealing layer 262 is disposed between the partition wall 226 and the cooling cap 215. The partition wall 226 can provide support for the cooling cap 215. The sealing layer 262 can be used for sealing purposes, such as preventing coolant leakage into the environment and / or between adjacent areas 224. Thus, coolant in one area 224 can be separated from coolant in adjacent areas 224 by the partition wall 226 and the sealing layer 262. The sealing layer 262 may comprise a polymer-based material, a silicone-based material, or a combination thereof. In some embodiments, the sealing layer 262 includes silicon oxide, tetraethyl orthosilicate (TEOS) oxide, un-doped silicate glass (USG), or doped silicate glass, such as borophosphosilicate glass (BPSG), fused silicate glass (FSG), phosphosilicate glass (PSG), boron doped silicate glass (BSG), and / or other suitable dielectric materials.

[0140] Sealing layer 262 and bonding layer 260 may have different compositions. In some embodiments, sealing layer 262 does not include the second thermal interface material as described above. Sealing layer 262 may have a thickness equal to or greater than about 1 mm. 2 • Thermal resistance of C / W, for example, about 5mm 2 • C / W. In some embodiments, the bonding layer 260 comprises a sheet of indium, nickel, silver, aluminum, combinations thereof, and alloys thereof, and has a thickness equal to or less than about 0.03 mm. 2The thermal resistance is C / W. Therefore, the first thermal conductivity rate in the sealing layer 262 is less than the second thermal conductivity rate in the bonding layer 260. The ratio of the first thermal conductivity rate to the second thermal conductivity rate can be approximately 1:50 to approximately 1:500. Therefore, most of the heat 220 generated from the grain 210 can be transferred to region 224 and removed by the coolant, which is more efficient than transferring it through the sealing layer 262 and then through the environment and / or the cooling cap 215.

[0141] In some embodiments, the thickness H4 of the sealing layer 262 is from about 20 μm to about 200 μm. If the thickness H4 is too small, the connection and seal between the cooling cap 215 and the integrated microcooler 205 may be too weak. If the thickness H4 is too large, it may affect heat dissipation.

[0142] In some embodiments, the cooling cap 215 comprises more than about 90 wt% copper (Cu) and less than about 10 wt% other materials (e.g., impurities, other metals). Copper provides mechanical integrity for the cooling cap 215. In some embodiments, the cooling cap 215 has a thermal conductivity of about 350 W / m·K to about 450 W / m·K. In some embodiments, the inlet conduit 216 and the outlet conduit 218 each have a width W9 of about 30 μm to about 500 μm. The width W9 may be less than the width W5. The ratio of width W9 to width W5 (W9 / W5) may be about 0.3 to about 1. If the ratio (W9 / W5) is too small or the width W9 is too small, the pressure drop in the inlet conduit 216 and the outlet conduit 218 may be too large, which increases the power consumption of the pump 130. If the ratio (W9 / W5) is too large or the width W9 is too large, coolant may flow into the central trench 246b instead of the side trench 246a, and therefore the heat transfer time may be too short.

[0143] In some alternative embodiments, the cooling cap 215 comprises more than about 50 wt% single-crystal diamond (SCD) and less than about 50 wt% other materials (e.g., metals, such as copper). For example, the cooling cap 215 comprises more than about 70 wt% SCD. In some embodiments, the cooling cap 215 comprises more than about 90 wt% SCD. In some embodiments, the cooling cap 215 comprises SCD, copper, or a combination thereof. By including SCD, the cooling cap 215 can have increased mechanical integrity and thermal conductivity. In some embodiments, the cooling cap 215 comprises more than about 70 wt% SCD and the bonding layer 260 comprises more than about 95 wt% a first thermal interface material. In some embodiments, the cooling cap 215 comprises more than about 70 wt% SCD and the bonding layer 260 comprises more than about 95 wt% a second thermal interface material.

[0144] Figures 6A to 6FA top view is shown of one of the regions 224 surrounded by a portion of a partition wall 226 according to some embodiments of the present invention. One of the regions 224 can be any region 224 in the integrated microcooler 205. In other words, the plurality of regions 224 in the integrated microcooler 205 can have... Figures 6A to 6F Any combination of the embodiments shown. Figure 6A In the middle, wall 244 extends along the Y direction, and the two ends of each wall 244 contact the partition wall 226. From the top view, the groove 246 is completely separated from each other by the walls 244. Figure 6B In, with Figure 6A The difference lies in that each wall 244 contacts the partition wall 226 at only one end, and the grooves 246b and 246a are joined end-to-end to form a serrated groove. Figure 6C In, with Figure 6B The difference lies in that each wall 244 is divided into multiple segments (e.g., two segments), such that adjacent trenches 246 have two merged openings 266, as shown in the figure. Figure 6D In, with Figure 6B The difference lies in the fact that the two ends of each wall 244 are spaced apart from the partition wall 226. Figure 6E In, with Figure 6D The difference lies in that each wall 244 is divided into multiple segments (e.g., two segments), such that adjacent trenches 246 have three merged openings 266, as shown in the figure. Figure 6F In, with Figure 6A The difference is that wall 244 also includes a portion extending along the X direction, making Figure 6A Each groove 246b is further divided into smaller grooves 246b, such as Figure 6F As shown. In Figures 6A to 6F In this context, it should be understood that wall 244 and partition wall 226 can be combined into a continuous feature.

[0145] Figure 7 This is a flowchart illustrating a method 300 for forming a cooling unit 200 according to some embodiments of the present invention. Method 300 is merely exemplary and is not intended to limit the present invention to what is explicitly shown in method 300. Additional steps may be provided before, during, and after method 300, and some steps described may be replaced, eliminated, or moved for additional embodiments of this method. For simplicity, not all steps are described in detail herein. The following is in conjunction with... Figures 8 to 15 To describe method 300, Figures 8 to 15 It is based on some embodiments of this utility model along Figure 4A partial cross-sectional view of the precursor of the cooling unit 200 at different manufacturing stages, along line A-A'. Since the precursor will be manufactured into the cooling unit 200 as described above, it may also be referred to herein as precursor 200, workpiece 200, or cooling unit 200, depending on the context.

[0146] refer to Figure 7 and Figure 8 Method 300 includes block 312, in which a die 210a is provided. Die 210a is a precursor to die 210 as described above. In some embodiments, die 210a is an IC wafer, a system-on-a-chip (SoC), or a portion thereof, which includes various passive and active microelectronic devices, such as resistors, capacitors, inductors, diodes, p-type field-effect transistors (PFETs), n-type field-effect transistors (NFETs), fin field-effect transistors (FinFETs), nanosheet field-effect transistors (nanosheet FETs), nanowire FETs, other types of multi-gate field-effect transistors, metal-oxide-semiconductor field-effect transistors (MOSFETs), complementary metal-oxide-semiconductor (CMOS) transistors, bipolar junction transistors (BJTs), laterally diffused metal-oxide-semiconductor (LDMOS) transistors, high-voltage transistors, high-frequency transistors, memory devices, other suitable components, or combinations thereof.

[0147] In some embodiments, die 210a includes a substrate 268 and an interconnect structure 270 on the substrate 268. As shown, die 210a has a front surface FS and a rear surface BS opposite to the front surface FS.

[0148] In some embodiments, substrate 268 may include a semiconductor material, such as a group III-V semiconductor material of the periodic table. In some embodiments, substrate 268 may include an elemental semiconductor material (e.g., silicon or germanium), a compound semiconductor material (e.g., silicon carbide, gallium arsenide, indium arsenide, or indium phosphide), or an alloy semiconductor material (e.g., silicon germanium, silicon germanium carbide, gallium arsenide phosphide, or gallium indium phosphide). For example, substrate 268 may be a silicon bulk substrate. Die 210a may include active components (e.g., transistors, etc.) and optional passive components (e.g., resistors, capacitors, inductors, etc.) formed in substrate 268. Die 210a may be a logic die, such as a central processing unit (CPU) die, a graphics processing unit (GPU) die, a microcontroller unit (MCU) die, an input / output (I / O) die, a baseband (BB) die, or an application processor (AP) die. In some alternative embodiments, die 210a may be a memory die, such as a high-bandwidth memory die. In some embodiments, the substrate 268 has a height H5 of about 700 μm to about 850 μm.

[0149] In some embodiments, the interconnect structure 270 includes a multi-layer interconnect (MLI) structure 272 and a passivation structure 276 on top of the multi-layer interconnect structure 272.

[0150] The multilayer interconnect structure 272 may include a plurality of patterned dielectric layers and conductive layers, the conductive layers providing interconnections (e.g., wiring) between various microelectronic components formed within the substrate 268 and upper conductive features (e.g., conductive pads 288) in the passivation structure 276. As noted, the multilayer interconnect structure 272 may include a plurality of conductive features 280 connected to components in the substrate 268 and a plurality of dielectric layers 282 for providing isolation between the conductive features 280. In some embodiments, the dielectric layers 282 may include silicon oxide or a silicon oxide-containing material, wherein silicon is present in various suitable forms. In some examples, dielectric layer 282 may include a low-k dielectric layer (e.g., having a dielectric constant of about 3.9, less than that of SiO2), such as an oxide formed from tetraethyl orthosilicate (TEOS), undoped silicate glass (USG), or doped silicon oxide, such as borosilicate glass (BPSG), fluorosilicate glass (FSG), phosphosilicate glass (PSG), boron-doped silicon glass (BSG), and / or other suitable low-k dielectric materials.

[0151] In some embodiments, conductive feature 280 may include contacts, vias, or metal wires to provide horizontal and vertical interconnections. In some cases, conductive feature 280 includes copper (Cu), aluminum (Al), aluminum-copper (AlCu) alloys, ruthenium (Ru), cobalt (Co), tungsten (W), or other suitable materials. In some embodiments, conductive feature 280 includes a barrier layer and a bulk metal layer above the barrier layer.

[0152] The present invention anticipates that the multilayer interconnect structure 272 has more or fewer interconnect layers and / or levels, for example, the total number of interconnect layers (levels) is N, where N is an integer ranging from 1 to 10.

[0153] In some embodiments, a passivation structure 276 is formed on the multilayer interconnect structure 272. The passivation structure 276 can be used to protect devices in the substrate 268 and / or the multilayer interconnect structure 272 from exposure to, for example, contaminant particles, moisture, oxygen, etc. In some embodiments, the passivation structure 276 includes a passivation layer 286. The passivation layer 286 can be formed on the multilayer interconnect structure 272 using suitable processes, such as processes including deposition processes (e.g., CVD processes) and chemical mechanical polishing (CMP) processes. In some embodiments, the passivation layer 286 comprises a dielectric material, such as silicon oxide, silicon nitride, silicon oxynitride (SiON), silicon carbide (SiCN), silicon oxycarbonate (SiOC), silicon carbide (SiC), silicon carbon oxynitride (SiOCN), epoxy resin, polyimide (PI), benzocyclobutene (BCB), polybenzoxazole (PBO), tetraethyl orthosilicate (TEOS) oxide, or combinations thereof, and may comprise one layer or multiple layers of dielectric material. In some embodiments, the passivation layer 286 comprises tetraethyl orthosilicate (TEOS) oxide.

[0154] In some embodiments, the passivation structure 276 includes a plurality of contact pads 288 embedded in the passivation layer 286 and electrically connected to conductive features 280 in the multilayer interconnect structure 272. In some embodiments, each contact pad 288 includes a pad portion and a plurality of via portions. The contact pads 288 may include aluminum, tungsten, some other metal or conductive material, or a combination thereof. In some embodiments, the contact pads 288 include aluminum. The passivation layer 286 may include a portion located above the top surface of the contact pads 288. The portion may have a height H6 of about 1 μm to about 5 μm.

[0155] refer to Figure 7 and Figure 9Method 300 includes block 314, in which a first carrier 290 is bonded to the front surface FS of a die 210a to provide mechanical strength, while a substrate 268 is thinned and subsequently partially removed. The bonding of the first carrier 290 allows the die 210a to be flipped for further processing, and the first carrier 290 provides mechanical strength to the die 210a. To achieve this, a bonding layer 292 is deposited on a passivation layer 286 to bond with the first carrier 290 in a direct bonding process. In some embodiments, the first carrier 290 comprises an elemental semiconductor, such as silicon (Si) or germanium (Ge); a compound semiconductor, such as silicon carbide (SiC), gallium arsenide (GaAs), gallium phosphide (GaP), indium phosphide (InP), indium arsenide (InAs), and / or indium antimonide (InSb); an alloy semiconductor, such as silicon germanium (SiGe), gallium arsenide phosphide (GaAsP), aluminum indium arsenide (AlInAs), aluminum gallium arsenide (AlGaAs), gallium indium arsenide (GaInAs), gallium indium phosphide (AlInP), and / or gallium indium arsenide phosphide (GaInAsP); or a combination thereof. In some embodiments, the first carrier 290 comprises silicon (Si). In some alternative embodiments, the first carrier 290 comprises glass. In some examples, the first carrier 290 has a thickness H7 of about 750 μm to about 800 μm.

[0156] In some embodiments, the bonding layer 292 is an oxide layer, such as a silicon oxide layer (e.g., a SiO2 layer). In some embodiments, the bonding layer 292 is another suitable material that facilitates bonding of the first carrier 290 to the front side of the grain 210a.

[0157] refer to Figure 7 and Figure 10 Method 300 includes block 316, in which substrate 268 of grain 210a is thinned. In some embodiments, grain 210a and first carrier 290 are flipped, as shown. Thinning of substrate 268 begins from the back surface BS of grain 210a. Thinning may include mechanical polishing and chemical mechanical polishing (CMP). During the mechanical polishing process, a significant amount of substrate material may be removed from substrate 268. Subsequently, a CMP process is performed to further thin substrate 268 and provide a flat back surface BS. The mechanical polishing process can reduce the height of substrate 268 to about 25 μm to about 35 μm. The CMP process can further reduce the height H5' of substrate 268 to about 15 μm to about 25 μm.

[0158] refer to Figure 7 and Figure 11Method 300 includes block 318, in which an integrated microcooler precursor (IMCprecursor) 205a is bonded to a grain 210a (e.g., via bonding layer 260). Bonding may include any suitable method, such as deposition, applying heat (e.g., annealing process), applying pressure, sintering, diffusion, or a combination thereof. In some embodiments, a thermal interface material (e.g., a first thermal interface material and a second thermal interface material as described above) is conformally deposited on the rear surface BS of the grain 210a. The integrated microcooler precursor 205a is disposed on the thermal interface material. In some embodiments, operation of block 318 further includes applying heat and / or pressure to the thermal interface material between the integrated microcooler precursor 205a and the grain 210a for a period of time (e.g., from about 1 minute to about 30 minutes) to bond the integrated microcooler precursor 205a and the grain 210a. The thermal interface material may be heated at a temperature of about 300°F to about 600°F. Pressure can be applied to the thermal interface material along the Z direction, and the pressure is from about 15 MPa to about 30 MPa. After applying heat and / or pressure, the thickness of the thermal interface material can be reduced (e.g., by more than 50%) to the thickness of the bonding layer 260 as described above.

[0159] Still referencing Figure 7 and Figure 11 Method 300 includes block 320, wherein the thickness of the integrated microcooler precursor 205a is reduced. Thickness reduction (also known as thinning) may include a mechanical polishing process and a CMP process. During the mechanical polishing process, a significant amount of SCD may be removed from the integrated microcooler precursor 205a. Subsequently, a CMP process is performed to further thin the integrated microcooler precursor 205a and provide a flat surface 293. The thinning process can reduce the height of the integrated microcooler precursor 205a from an initial height (e.g., about 750 μm to about 800 μm) to a height H1 as described above.

[0160] refer to Figure 7 and Figure 12 Method 300 includes block 322 in which a portion of the first carrier 290, bonding layer 292, and passivation structure 276 are removed. Following the operation of block 322, grain 210a is formed as described above. The operation of block 322 removes a portion of the passivation layer 286 above the top surface of the contact pad 288, thus exposing the top surface of the contact pad 288 thereafter. The operation of block 322 can include any suitable process, such as mechanical polishing and CMP. In some examples, a significant amount of material from the first carrier 290 may be removed during the mechanical polishing process. Subsequently, a CMP process is performed to completely remove the first carrier 290 and bonding layer 292, and to remove a portion of the passivation structure 276 to provide a flat front surface FS.

[0161] refer to Figure 7 and Figure 13 Block 300 includes block 324, in which a second carrier 294 is bonded to grain 210 to provide mechanical strength, while the integrated microcooler precursor 205a is subsequently etched. The second carrier 294 can be bonded to the front surface FS of grain 210 via an adhesive layer 296. The bonding of the second carrier 294 allows workpiece 200 to be flipped for further processing, and the second carrier 294 provides mechanical strength to workpiece 200. To achieve this, an adhesive layer 296 is deposited on passivation structure 276 to bond with the second carrier 294 in a direct bonding process. The second carrier 294 may comprise a material similar to the first carrier 290 as described above. In some embodiments, the second carrier 294 comprises glass. In some examples, the second carrier 294 has a thickness H8 of about 450 μm to about 550 μm.

[0162] In some embodiments, the adhesive layer 296 is an oxide layer, such as a silicon oxide layer (e.g., a SiO2 layer). In some embodiments, the adhesive layer 296 is another suitable material that facilitates bonding of the second carrier 294 to the front surface FS of the grain 210. The adhesive layer 296 may have a thickness H9 of about 50 μm to about 80 μm.

[0163] refer to Figure 7 and Figure 14 Method 300 includes block 326, wherein the integrated microcooler precursor 205a is patterned to form the integrated microcooler (IMC) 205 as described above. Prior to patterning, the workpiece 200 can be as follows: Figure 14 The image shown has been flipped.

[0164] Forming trench 246 may include forming a hard mask layer 298 over the integrated microcooler precursor 205a, and performing photolithography and etching processes to pattern the hard mask layer 298. The hard mask layer 298 may include SiO, HfSi, SiOC, AlO, ZrSi, AlON, ZrO, HfO, TiO, ZrAlO, ZnO, TaO, LaO, YO, TaCN, SiN, SiOCN, Si, SiOCN, ZrN, SiCN, SiO2, metals (e.g., aluminum, nickel), or other suitable materials. In some embodiments, the hard mask layer 298 comprises aluminum or nickel. The patterning of the hard mask layer 298 forms an opening directly above the designed trench region of the integrated microcooler precursor 205a.

[0165] In some alternative embodiments, instead of lithography patterning, the hard mask layer 298 can be patterned using a pre-made mode with a designed shape. In some alternative embodiments, the hard mask layer 298 is pre-fabricated and used as a mask in a subsequent etching process to form the trench 246.

[0166] Then, one or more etching processes are performed using a hard mask layer 298 as a mask to form trench 246. The one or more etching processes may include multiple steps and involve various etching fluids. The one or more etching processes may include any suitable method, such as dry etching, wet etching, reactive ion etching (RIE), inductively coupled plasma (ICP) etching, and / or other suitable processes. For example, a dry etching process may be performed using oxygen-containing gases, fluorine-containing gases (e.g., CF4, SF6, CH2F2, CHF3, and / or C2F6), chlorine-containing gases (e.g., Cl2, CHCl3, CCl4, and / or BCl3), bromine-containing gases (e.g., HBr and / or CHBr3), iodine-containing gases, hydrogen-containing gases, other suitable gases, and / or plasma and / or combinations thereof. The etching process may use one or more etchants. Wet etching processes may include etching in diluted hydrofluoric acid (DHF); potassium hydroxide (KOH) solution; ammonia; solutions containing hydrofluoric acid (HF), nitric acid (HNO3) and / or acetic acid (CH3COOH); or other suitable wet etchants.

[0167] In some embodiments, under the same etching conditions (e.g., etchant, power, etc.) of a dry etching process, the ratio of the first etching rate of the integrated microcooler precursor 205a to the second etching rate of the silicon substrate (not shown) may be equal to or less than about 1:10. In some embodiments, the ratio is from about 1:10 to about 1:50. In some embodiments, the one or more etching processes require from about 30 minutes to about 24 hours.

[0168] In some embodiments, a first portion 298a of the hard masking layer 298 directly above region 224 is removed, while a second portion 298b of the hard masking layer 298 directly above partition wall 226 remains. This can be done using any suitable method, such as patterning the hard masking layer 298. An additional etching process, such as that described above with respect to one or more etching processes, can then be applied to region 224 of the integrated microcooler precursor 205a. The second portion 298b of the hard masking layer 298 is then removed. In such embodiments, the height H2' may be less than the height H2 due to the additional etching process. In some other embodiments, after the one or more etching processes, the first portion 298a and the second portion 298b of the hard masking layer 298 are removed from the integrated microcooler precursor 205a. In such embodiments, the height H2' is approximately equal to the height H2 as described above.

[0169] refer to Figure 7 and Figure 15 Method 300 includes a block 328 in which a cooling cap 215 is provided and bonded to an integrated microcooler 205. After operation of block 328, workpiece 200 becomes cooling unit 200. Sealing layer 262 may be deposited onto the top surface of partition wall 226, and cooling cap 215 may be placed on and bonded to sealing layer 262 using any suitable method (e.g., direct bonding process).

[0170] The cooling cap 215 is designed to include an inlet conduit 216 and an outlet conduit 218 as described above. Attaching the cooling cap 215 to the integrated microcooler 205 results in the inlet conduit 216 and the outlet conduit 218 having openings leading to corresponding side grooves 246a below them.

[0171] refer to Figure 7 Method 300 includes block 330, in which further processes can be performed, such as connecting cooling unit 200 to other components in cooling system 100 (e.g., branch conduit 138 and branch conduit 150).

[0172] While not intended to be limiting, one or more embodiments of this invention offer numerous benefits for cooling systems and their manufacture. For example, embodiments of this invention improve heat dissipation generated by the grain by integrating the grain with the integrated microcooler (IMC) and cooling cap disclosed herein. The integrated microcooler can be bonded to the grain via the bonding layer disclosed herein, which can further improve heat dissipation. Improved heat dissipation reduces and / or prevents heat buildup and thermal damage within the grain, and reduces the power consumption of the cooling system's pump.

[0173] In one exemplary aspect, the present invention relates to a method of manufacturing a cooling unit. The method includes providing a workpiece, including a device substrate and a passivation structure disposed on the device substrate. The method includes bonding a first carrier to the passivation structure. The method includes bonding an integrated microcooler (IMC) precursor to the device substrate via a bonding layer. The method includes removing the first carrier. The method includes bonding a second carrier to the passivation structure. The method includes etching the integrated microcooler precursor to form a plurality of trenches and partition walls surrounding the plurality of trenches, thereby forming an integrated microcooler. The method further includes bonding a cooling cap to the integrated microcooler. The integrated microcooler precursor includes single-crystal diamond (SCD). The cooling cap includes a fluid inlet port and a fluid outlet port connected to the plurality of trenches via a plurality of fluid conduits.

[0174] In some embodiments, the bonding layer has a thickness equal to or less than about 0.05 mm. 2 • Thermal resistance of C / W. In some embodiments, removing the first carrier also removes a portion of the passivation structure. In some embodiments, the cooling cap comprises single-crystal diamond, copper, or a combination thereof, and each of the fluid conduits comprises a T-shaped portion. In some embodiments, the cooling cap is joined to the integrated microcooler using a sealing layer comprising a polymer-based material, a silicone-based material, or a combination thereof. In some embodiments, from a top view, the plurality of trenches are connected in a zigzag shape. In some embodiments, the plurality of trenches are a plurality of first trenches, a partition wall is a first partition wall, a fluid inlet port is a first fluid inlet port, and a fluid outlet port is a first fluid outlet port; etching the integrated microcooler precursor also forms a plurality of second trenches and a second partition wall separating the plurality of second trenches from the plurality of first trenches, the plurality of second trenches and the second partition wall being surrounded by the first partition wall; and the cooling cap also includes a second fluid inlet port and a second fluid outlet port connected to the plurality of second trenches via the fluid conduits.

[0175] In another exemplary aspect, the present invention relates to a method of manufacturing a cooling unit. The method includes providing a grain having a first surface and a second surface opposite to the first surface. The method includes bonding the second surface of the grain to a third surface of an integrated microcooler precursor via a bonding layer, wherein the integrated microcooler precursor comprises a single-crystal diamond. The method includes etching from a fourth surface of the integrated microcooler precursor to form a plurality of trenches, thereby transforming the integrated microcooler precursor into an integrated microcooler, wherein the fourth surface of the integrated microcooler precursor is opposite to the third surface of the integrated microcooler precursor. The method further includes bonding a cooling cap to the fourth surface of the integrated microcooler, wherein the cooling cap includes a fluid inlet conduit and a fluid outlet conduit disposed over and open to the plurality of trenches.

[0176] In some embodiments, the cooling cap comprises single-crystal diamond, copper, or a combination thereof. In some embodiments, the cooling cap is bonded to a fourth surface of the integrated microcooler via a sealing layer, and the sealing layer comprises a polymer-based material, a silicone-based material, or a combination thereof. In some embodiments, the thermal resistance of the bonding layer is equal to or less than about 0.05 mm. 2 •C / W, and the thermal resistance of the sealing layer is equal to or greater than approximately 1 mm. 2 • C / W. In some embodiments, the method further includes reducing the thickness of the integrated microcooler precursor, wherein the thickness of the integrated microcooler is about 300 μm to about 750 μm, before etching from the fourth surface of the integrated microcooler precursor. In some embodiments, etching from the fourth surface of the integrated microcooler precursor includes depositing a hard mask layer on the integrated microcooler precursor, patterning the hard mask layer to form a patterned hard mask, and using the patterned hard mask as an etching mask to etch the fourth surface of the integrated microcooler precursor. In some embodiments, etching from the fourth surface of the integrated microcooler precursor also forms partition walls surrounding the plurality of trenches, and a cooling cap is attached to the partition walls. In some embodiments, from a top view, the integrated microcooler includes multiple regions, the multiple trenches being multiple first trenches, a fluid inlet conduit being a first fluid inlet conduit, a fluid outlet conduit being a first fluid outlet conduit, the multiple first trenches being in the first region of the multiple regions, and multiple second trenches being etched from a fourth surface of the integrated microcooler precursor into a second region of the multiple regions, the multiple second trenches being separated from the multiple first trenches by partition walls, and the cooling cap also including a second fluid inlet conduit and a second fluid outlet conduit open to the multiple second trenches.

[0177] In yet another exemplary aspect, the present invention relates to a cooling system. The cooling system includes a grain, a bonding layer disposed on the grain, an integrated microcooler disposed on the bonding layer, and a cooling cap disposed on the integrated microcooler. The integrated microcooler includes a first portion on the bonding layer and a second portion above the first portion, the second portion including a plurality of trenches and partition walls surrounding the plurality of trenches. The integrated microcooler is made of a single-crystal diamond material, and the cooling cap includes a fluid inlet conduit and a fluid outlet conduit disposed above and open to the plurality of trenches.

[0178] In some embodiments, the cooling system further includes a fluid path between a fluid inlet conduit and a fluid outlet conduit and located outside the cooling cap, and a heat exchanger along the fluid path, wherein the heat exchanger is configured to cool the coolant in the fluid path. In some embodiments, the cooling system further includes a sealing layer that bonds the integrated microcooler and the cooling cap, and the sealing layer comprises a polymer-based material, a silicone-based material, or a combination thereof. In some embodiments, the bonding layer has a thickness equal to or less than about 0.05 mm. 2 • Thermal resistance of C / W. In some embodiments, the cooling cap comprises monocrystalline diamond, copper, or a combination thereof.

[0179] The foregoing outlines the features of numerous embodiments to enable those skilled in the art to better understand the various embodiments of this utility model. Those skilled in the art should understand that other processes and structures can be easily designed or modified based on the embodiments of this utility model to achieve the same objectives and / or advantages as the embodiments described herein. Those skilled in the art should also understand that these equivalent structures do not depart from the spirit and scope of this utility model. Various changes, substitutions, and modifications can be made to the embodiments of this utility model without departing from the spirit and scope of the appended claims.

Claims

1. A cooling system, characterized in that, The cooling system includes: One grain; A bonding layer is disposed on the grain; An integrated micro-cooler is disposed on the bonding layer; and A cooling cap is installed on top of this integrated microcooler. The integrated microcooler includes a first portion on the bonding layer and a second portion above the first portion. The second part includes a plurality of trenches and a partition wall surrounding the plurality of trenches. The integrated microcooler incorporates single-crystal diamond material, and The cooling cover includes a fluid inlet conduit and a fluid outlet conduit, which are disposed above and open to the plurality of grooves.

2. The cooling system as described in claim 1, characterized in that, Also includes: A fluid path is provided between the fluid inlet conduit and the fluid outlet conduit and is located outside the cooling cover; as well as A heat exchanger in the fluid path, wherein the heat exchanger is configured to cool a coolant in the fluid path.

3. The cooling system as described in claim 1, characterized in that, It also includes a sealing layer that joins the integrated microcooler and the cooling cap, wherein the sealing layer comprises a polymer-based material or a silicone-based material.

4. The cooling system as described in claim 1, characterized in that, The bonding layer has a thickness equal to or less than approximately 0.05 mm. 2 Thermal resistance of C / W.

5. The cooling system as described in claim 1, characterized in that, The cooling cap may consist of single-crystal diamond or copper.

6. The cooling system as claimed in claim 1, characterized in that, The fluid inlet conduit and the fluid outlet conduit each include a T-shaped section.

7. The cooling system as claimed in claim 1, characterized in that, From a top view, the multiple grooves are connected to form a sawtooth shape.

8. The cooling system as claimed in claim 1, characterized in that, The plurality of grooves includes a plurality of side grooves near the side of the integrated microcooler and a plurality of central grooves located between the plurality of side grooves, wherein the width of the plurality of side grooves is greater than the width of the plurality of central grooves.

9. The cooling system as claimed in claim 1, characterized in that, The cooling cover is attached to the partition wall.

10. The cooling system as claimed in claim 1, characterized in that, The second part also includes a plurality of walls that divide the plurality of said trenches, wherein the height of the plurality of said walls is equal to or less than the height of the dividing wall.

Images