Cooling component, package structure and method of forming same

Abstract

A package structure according to the present disclosure includes a package substrate, a package assembly disposed over the package substrate, a lid disposed over the package substrate and the package assembly, and an active cooling device embedded in the lid. Embodiments of the present disclosure also relate to a cooling component and a method of forming a package structure.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to cooling components, packaging structures, and methods of forming the same. Background Art

[0002] The semiconductor integrated circuit (IC) industry has experienced exponential growth. Technological advances in IC materials and design have produced multiple generations of ICs, each with smaller and more complex circuits than the previous generation. During IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased, while geometry size (i.e., the smallest component (or line) that can be created using a manufacturing process) has decreased. This scaling down process generally provides benefits by increasing production efficiency and reducing associated costs. This scaling down has also increased the complexity of processing and manufacturing ICs.

[0003] As ICs scale down, one of the challenges that comes with it is that thermal performance suffers. Smaller ICs can not only cause significant temperature increases, but can also hinder heat dissipation. In some cases, heat generation can be localized at certain locations, impacting performance and reliability. It is desirable to dissipate heat from these localized hot spots efficiently or even as needed. Summary of the invention

[0004] An embodiment of the present disclosure provides a packaging structure, including: a packaging substrate; a packaging component disposed above the packaging substrate; a cover disposed above the packaging substrate and the packaging component; and an active cooling device embedded in the cover.

[0005] Another embodiment of the present disclosure provides a cooling component, comprising: a cover portion; a ring portion extending continuously from a bottom surface of the cover portion to define a cavity configured to receive a packaging component; and an active cooling device embedded in the cover portion, wherein a bottom surface of the active cooling device and a bottom surface of the cover portion are coplanar.

[0006] Yet another embodiment of the present disclosure provides a method for forming a packaging structure, comprising: receiving a design of a packaging component; obtaining a thermal map of the packaging component to identify local hot spots; and manufacturing a lid, the lid comprising an embedded active cooling device, which is vertically aligned with the local hot spots when the lid is attached to the packaging component. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be emphasized that, in accordance with standard practice in the industry, the various components are not drawn to scale and are only used for illustrative purposes. In fact, the dimensions of the various components may be arbitrarily increased or reduced for clarity of discussion.

[0008] Figure 1A flow chart of a method of customizing a thermal solution for a package assembly according to various aspects of the present disclosure is shown.

[0009] Figures 2 to 8 Schematically shows various aspects of the present disclosure Figure 1 The operations at each step of the method.

[0010] Figures 9 to 16 Cross-sectional and top views of active cooling devices according to various aspects of the present disclosure are shown. DETAILED DESCRIPTION

[0011] The following disclosure provides many different embodiments or examples for implementing the different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. Of course, these are merely examples and are not intended to be limiting. For example, in the following description, forming a first component above or on a second component may include an embodiment in which the first component and the second component are directly contacted, and may also include an embodiment in which an additional component may be formed between the first component and the second component so that the first component and the second component may not be in direct contact. In addition, the present disclosure may repeat reference numbers and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the embodiments and / or configurations discussed.

[0012] Additionally, for ease of description, spatially relative terms such as "below," "beneath," "lower," "above," "upper," etc. may be used herein to describe the relationship of one element or component to another element or component as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should likewise be interpreted accordingly.

[0013] In addition, when "about," "approximately," or the like is used to describe a value or range of values, the term is intended to encompass values ​​within a reasonable range, taking into account variations inherent during manufacturing as understood by those of ordinary skill in the art. For example, based on known manufacturing tolerances associated with manufacturing components having the properties associated with the value, the value or range of values ​​encompasses a reasonable range that includes the described value, such as within + / - 10% of the described value. For example, a material layer having a thickness of "about 5 nm" may encompass dimensions within a range from 4.25 nm to 5.75 nm, where the manufacturing tolerance associated with depositing material layers is known to those of ordinary skill in the art to be + / - 15%.

[0014] Semiconductor packaging technology was once considered to be just a back-end process that facilitated the interface of chips with external circuits. Times have changed. Computing workloads have changed so much that it has brought packaging technology to the forefront of innovation. Modern packaging integrates multiple chips or tube cores into a single semiconductor device. Depending on the stacking level, modern semiconductor packages can have a 2.5D structure or a 3D structure. In a 2.5D structure, at least two tube cores are coupled to a redistribution layer (RDL) structure or an interposer that provides chip-to-chip communication. At least two tube cores in a 2.5D structure are not stacked vertically. In a 3D structure, at least two tube cores are stacked on top of each other and interact with each other through silicon vias (TSVs). Depending on the process adopted, the 2.5D structure and the 3D structure can have an integrated fan-out (InFO) configuration or a chip on wafer on a substrate. To dissipate heat from a 3D package, a heat sink may be placed on top of the top die to direct the heat upward and away from the top die.

[0015] The present disclosure provides a method for customizing a heat dissipation solution for a package assembly. In an example, a design of a package assembly is received. A thermal map of the package assembly is obtained to identify local hot spots. A lid including an embedded active cooling device is manufactured. When the lid is placed over the package structure, the embedded active cooling device is directly disposed over the local hot spot. After manufacturing the package assembly, the package assembly is bonded to a package substrate. The lid is placed over the package assembly and the package substrate. The active cooling device can be powered to improve heat dissipation with respect to the local hot spot. The present disclosure also provides an embodiment of an active cooling device embedded in a lid. The active cooling device according to the present disclosure is electrically powered and configured to dissipate heat radially from the local hot spot.

[0016] Various aspects of the present disclosure will now be described in more detail with reference to the accompanying drawings. In this regard, Figure 1 1 is a flow chart illustrating a method 100 for customizing a thermal solution for a package assembly according to various aspects of the present disclosure. The method 100 is merely an example and is not intended to limit the present disclosure to what is explicitly shown in the method 100. Additional steps may be provided before, during, and after the method 100, and some of the steps described may be replaced, eliminated, or rearranged for additional embodiments of the method. For simplicity, not all steps are described in detail. Figures 2 to 8 Describing method 100, Figures 2 to 8 The operations at different steps of the method 100 are schematically illustrated. Figures 9 to 16 A cross-sectional view and a top view of an active cooling device according to various aspects of the present disclosure are shown. For the avoidance of doubt, Figures 2 to 16 The X, Y and Z directions are perpendicular to each other. In the present disclosure, unless otherwise explicitly described, the same reference numerals denote the same components.

[0017] refer to Figure 1 and Figure 2 , the method 100 includes a block 102, in which a design of a package component 204 is received. In some embodiments, the package component 204 may include a plurality of dies bonded on a mold-based interposer, a silicon interposer, a redistribution layer (RDL), or a combination thereof and interconnected by a mold-based interposer, a silicon interposer, a redistribution layer (RDL), or a combination thereof. The plurality of dies in the package component 204 may be stacked vertically on top of each other, or bonded side-by-side on a mold-based interposer, a silicon interposer, or a redistribution layer. The plurality of dies in the package component 204 may include a system-on-chip (SoC) die, a logic die, an application-specific integrated circuit (ASIC) die, a high bandwidth memory (HBM) die, or a combination thereof. The HBM die may include a plurality of memory dies, such as a dynamic random access memory (DRAM) die. The mold-based interposer may include a local silicon interconnect (LSI) chip and / or an integrated passive device (IPD) embedded in a molding material. The mold-based interposer may also include a plurality of interposer through vias (TIVs) extending through the mold-based interposer to provide a circuit route through the interposer. The silicon interposer may include a plurality of substrate through vias (TSVs) extending through the silicon interposer. In some cases, the RDL may be disposed above the surface of the silicon interposer for rerouting. When the die is bonded to the mold-based interposer or the silicon interposer, an underfill is disposed between the die and the interposer. The die may be completely or partially surrounded by a molding material. According to the present disclosure, a package assembly includes a die disposed above its top surface. Each die on the top surface of the package assembly 204 includes a flip chip bond. As a result, the back side of the substrate of the die on the top surface of the package assembly 204 faces upward. Each of the plurality of dies of the package assembly 204 includes a plurality of transistors, such as a planar transistor, a fin field effect transistor (FinFET), a full-ring gate (GAA) transistor, a nanowire transistor, a nanosheet transistor, or other multi-gate transistors.

[0018] refer to Figure 1 and Figure 3 , the method 100 includes a block 104, in which a thermal map 220 of the package component 204 is obtained to identify hot spots 250. In one embodiment, the thermal map 220 of the package component 204 is obtained by simulation. In this embodiment, the package component 204 is not manufactured, and the simulation is performed based on the design of the package component 204. For example, the simulation can be performed by a computer or a server based on the thermal resistance of the package component 204 in the design, the reference temperature, and the power consumption of the package component. The data generated by the simulation is then compiled into Figure 3220 is shown. In an alternative embodiment, the thermal map 220 of the package component 204 is obtained by direct measurement. In an alternative embodiment, at least one package component 204 is manufactured according to the design. After the package component 204 is bonded to the test substrate, power is supplied to the package component 204, and a test process is performed on the package component 204. In some cases, once the surface temperature of the package component is allowed to reach an equilibrium state, a thermal infrared (IR) sensor or a thermal imaging device can be used to measure the surface temperature at different locations above the package component 204. The directly measured data can then be used to generate Figure 3 A heat map 220 is representatively shown in FIG. Figure 3 An isothermal diagram of the package assembly 204 is included. Figure 3 In the thermal map 220, isotherms or areas designated as darker sheds represent areas of localized higher temperatures. Hot spots 250 can be identified from the thermal map 220 based on predetermined temperatures that are considered or proven to be harmful to the component. Generally, the area of ​​the hot spot 250 increases as the predetermined temperature decreases. In some embodiments, the predetermined temperature can be between 95°C and about 105°C. The area of ​​the hot spot 250 can be significantly smaller than the top surface area of ​​the package component 204. In some cases, the area of ​​the hot spot 250 can be less than 50% of the top surface area of ​​the package component 204.

[0019] refer to Figure 1 , Figure 4 and Figure 5 , the method 100 includes a block 106, in which a lid 212 including an embedded active cooling device 300 is obtained. According to some embodiments of the present disclosure, the lid 212 needs to meet at least four criteria. First, the lid 212 should include a cavity to accommodate the package assembly 204 when the package assembly 204 is mounted on the package substrate. Figure 5 , the cover 212 may include a ring portion 212R and a cover portion 212C disposed above the ring portion 212R. In some embodiments, the ring portion 212R is attached to or extends from the periphery of the cover portion 212C to define a chamber 213 to accommodate the package assembly 204. Second, the cover 212 should include an active cooling device 300 configured to dissipate heat generated by the heat spot 250. Figure 5 In some embodiments shown, the active cooling device 300 is embedded in the cover portion 212C. The bottom surface of the active cooling device 300 is coplanar with the bottom surface 212B of the cover 212. Figure 4, along the Z direction perpendicular to the package assembly 204, the active cooling device 300 is disposed directly above the hot spot 250. In other words, the vertically projected area of ​​the active cooling device 300 in the lid 212 overlaps a majority of the vertically projected area of ​​the hot spot 250. The vertical alignment between the active cooling device 300 and the hot spot 250 allows the active cooling device 300 to precisely direct its heat dissipation capabilities to the hot spot 250. Third, the lid 212 is formed of a thermally conductive material and is configured to passively dissipate heat even in the absence of an embedded active cooling device 300. In some embodiments, the lid 212 may be formed of a metal or alloy, such as aluminum (Al), copper (Cu), iron (Fe), nickel (Ni), cobalt (Co), or alloys thereof. Example alloys may include aluminum-copper alloys, iron-nickel alloys, or iron-nickel-cobalt alloys. Because the lid 212 is formed of a metal or a metal alloy, it may be referred to as a metal lid 212. Fourth, the lid 212 should provide structural integrity for the package substrate and the package assembly 204 bonded to the package substrate. Reference Figure 5 The cover 212 includes a bottom surface 212B for engaging the top surface of the package component 204 and a lower edge 212E for engaging the package substrate (to which the package component 204 is bonded).

[0020] In order to include an embedded active cooling device 300, a groove may be formed in the cover portion 212C. The active cooling device 300 may be prefabricated and placed in the groove. To ensure good thermal conductivity, the interface between the surface of the active cooling device 300 and the inner surface of the groove may include a thermal interface material (TIM). The TIM is used to fill the gap between the active cooling device 300 and the cover 212 to reduce voids and gaps and improve thermal conductivity. The TIM between the active cooling device 300 and the cover 212 may be dispensed in liquid form or as a pre-cut tape. When the TIM is dispensed as a tape, the TIM may include a metal (i.e., copper or aluminum), graphite, or graphene. When the TIM is dispensed as a liquid, the TIM may include a base material and a thermally conductive filler. In some cases, the base material for the TIM may include a resin or epoxy resin, and the thermally conductive filler for the TIM may include beryllium oxide, aluminum oxide, zinc oxide, aluminum nitride, hexagonal boron nitride, a metal (i.e., copper or aluminum), diamond, graphene, or graphite.

[0021] As described above, the area of ​​the hot spot 250 may be substantially smaller than the area of ​​the top surface of the package assembly 204. Because the vertical projection area of ​​the active cooling device 300 substantially overlaps the vertical projection area of ​​the hot spot 250, the vertical projection area of ​​the active cooling device 300 may be substantially smaller than the area of ​​the top surface of the package assembly 204. In some cases, the vertical projection area of ​​the active cooling device 300 is less than 50% of the area of ​​the top surface of the package assembly 204.

[0022] refer to Figure 1 and Figure 6 , method 100 includes frame 108, wherein the package component 204 is manufactured based on the design of the package component 204. As described above, the package component 204 may include a plurality of tube cores, which are bonded on a mold-based interposer, a silicon interposer, a redistribution layer (RDL), or a combination thereof and interconnected by a mold-based interposer, a silicon interposer, a redistribution layer (RDL), or a combination thereof. In order to manufacture the package component 204, the tube core and the interposer in the package component 204 are manufactured separately. When the tube cores are bonded to each other, the tube cores can be bonded by direct bonding, wherein the bonding pads on one tube core are aligned with the bonding pads on the other tube core. Then, the tube cores (bonded to each other or individually) are bonded to the mold-based interposer, the silicon interposer, the redistribution layer (RDL) by connecting components (such as microbumps). The space between the tube core and the interposer is filled with bottom filler. The molding material can be deposited around the tube core and between the tube cores.

[0023] refer to Figure 1 and Figure 6 , the method 100 includes a block 110, in which a package component 204 is bonded to a package substrate 202. At block 110, the package component 204 is placed over the package substrate 202 so that the connection features 206 are vertically aligned with the contact pads on the front side surface 202F of the package substrate 202. A reflow process is performed so that the connection features 206 electrically couple the package component 204 to the package substrate 202. After the reflow process, a liquid precursor of an underfill 208 is allowed to fill the gap between the package component 204 and the front side surface 202F of the package substrate 202 by capillary action. The liquid precursor is then cured by annealing to form the underfill 208. In some embodiments, the connection features 206 may include controlled collapse chip connection (C4) bumps or other solder bumps.

[0024] refer to Figure 1 , Figure 7 and Figure 8 , method 100 includes block 112, where a lid 212 is attached to package assembly 204 and package substrate 202. Operations at block 112 may include dispensing a thermal interface material (TIM) 210 ( Figure 7 ), dispensing adhesive ( Figure 8 ), and placing the cover 212 over the package assembly 204 and the package substrate 202. First, refer to Figure 7. TIM 210 will be located between package component 204 and lid 212 to improve heat dissipation of package component 204. Because voids and gaps introduce air in the heat conduction path, and air has low thermal conductivity, the function of TIM 210 is to fill the gaps between package component 204 and lid 212 to reduce voids and gaps. In order to promote thermal conduction, TIM 210 or a precursor of TIM 210 should have sufficient thermal conductivity to promote thermal conduction. In order to reduce voids and gaps, TIM 210 or its precursor should have reasonable fluidity or flexibility. According to the present disclosure, TIM 210 can be dispensed in liquid form or as a pre-cut tape. When TIM 210 is dispensed as a tape, TIM 210 may include metal (i.e., copper or aluminum), graphite, or graphene. When TIM 210 is dispensed as a liquid, TIM 210 may include a base material and a thermally conductive filler. In some cases, the base material for TIM 210 may include resin or epoxy, and the thermally conductive filler for TIM 210 may include beryllium oxide, aluminum oxide, zinc oxide, aluminum nitride, hexagonal boron nitride, metal (ie, copper or aluminum), diamond, graphene, or graphite.

[0025] Adhesive 214 is used to attach lid 212 to package substrate 202. Because heat is generated by package component 204 rather than package substrate 202, adhesive 214 does not play a material role in heat dissipation. Therefore, adhesive 214 may not include any thermally conductive filler. In some embodiments, adhesive 214 may include a base material and a structural filler. In some cases, the base material for adhesive 214 may include silicone, nylon, epoxy, or resin, and the structural filler of adhesive 214 may include silicon dioxide or aluminum oxide. Adhesive 214 and TIM 210 may be distributed or applied in any order. For example, TIM 210 is distributed over package component 204, and then adhesive 214 is distributed over package substrate 202.

[0026] refer to Figure 8 After TIM 210 and adhesive 214 are dispensed over package component 204 and package substrate 202, lid 212 is placed over package component 204 and package substrate 202. Figure 8 As shown, when placed above the package component 204, in the cavity 213 ( Figure 5 2 ). The bottom surface 212B of the lid 212 is bonded to the top surface of the package component 204 through the TIM 210. The lower edge 212E of the lid 212 is bonded to the top surface of the package substrate 202 through the adhesive 214.

[0027] After placing lid 212 over package substrate 202 and package assembly 204, TIM 210 and adhesive 214 are cured. In some embodiments, TIM 210 and adhesive 214 are thermally cured. In these embodiments, Figure 8 The structure shown can be subjected to an annealing process. In some embodiments, the annealing process may include an annealing temperature between about 130° C. and about 180° C. In order to mount the package substrate 202 on another substrate, such as a printed circuit board (PCB). A solder component (not shown) may be formed on the backside surface 202B of the package substrate 202. As described above, the package substrate 202 may also include a plurality of contact pads or under-bump metallization (UBM) components located above the backside surface 202B. The solder component may be formed above the plurality of contact pads or UBM components. In some embodiments, the solder component may include an alloy of tin, lead, silver, copper, nickel, bismuth, or a combination thereof.

[0028] Figures 9 to 16 A cross-sectional view and a top view of a representative embodiment of an active cooling device 300 are shown. The active cooling device 300 according to the present disclosure includes a substrate plate to vertically engage the hot spot 250 of the package component 204 through the TIM 210. In the top view, the substrate plate can have a triangle, rectangle, square or polygon, so that the substrate plate includes multiple sides facing away from the geometric center of the substrate plate. A thermoelectric cooler (TEC) unit is arranged along each of the multiple sides of the substrate plate. The TEC unit can be powered by a direct current (DC) power supply controlled by a controller. The TEC units can be electrically connected in series or in parallel to meet design requirements. Each TEC unit has a cold side and a hot side. The cold side of each TEC unit is coupled to one side of the substrate plate, and the hot side faces away from the substrate plate. Configured in this way, the active cooling device 300 can vertically and radially guide heat away from the hot spot 250.

[0029] Fig. 9 A top view of an active cooling device 300 is provided, which includes a rectangular base plate 301R and TEC units connected in series. The active cooling device 300 includes a rectangular base plate 301R, which is connected in series. Fig. 9 It has a rectangular shape in the top view shown. Fig.10 , Fig.10 Provided along Fig. 9 2. In some embodiments, the rectangular substrate plate 301R is disposed directly above the hot spot 250. In other words, the vertical projection areas of the rectangular substrate plate 301R and the hot spot 250 may substantially overlap. Heat from the hot spot 250 may be conducted upward to the rectangular substrate plate 301R through the TIM 210. Fig.10As shown in the cross-sectional view in FIG. 3 , the rectangular base plate 301R has a thickness T. In some embodiments, the thickness T may be between about 1 mm and about 6 mm. As shown by the arrows, the thickness T allows the rectangular base plate 301R to conduct heat not only vertically into the cover 212 above the active cooling device 300, but also radially toward the four (4) sides of the rectangular base plate 301R. The radial heat conduction can be said to be away from the geometric center G of the rectangular base plate 301R. The rectangular base plate 301R can be made of a highly thermally conductive material, such as a metal, a metal alloy, or a non-metallic material. Example metals for constructing the rectangular base plate 301R may include aluminum (Al), copper (Cu), iron (Fe), nickel (Ni), cobalt (Co), or a combination thereof. Example metal alloys for constructing the rectangular base plate 301R may include aluminum-copper alloys, iron-nickel alloys, or iron-nickel-cobalt alloys. Example non-metallic materials for the rectangular base plate 301R may include beryllium oxide, aluminum oxide, zinc oxide, aluminum nitride, hexagonal boron nitride, diamond, or graphite. The bottom surface of the rectangular base plate 301R is the bottom surface of the active cooling device 300. As described above, the active cooling device 300 is embedded in the horizontal portion of the cover 212, and the bottom surface of the rectangular base plate 301R is aligned with the bottom surface 212B ( Figure 5 ) are flush or coplanar.

[0030] exist Fig. 9 In some embodiments shown, TEC units 302 are disposed along each of the four (4) sides of the rectangular base plate 301R. TEC units 302 are also known in the art as Peltier coolers and are solid-state active heat pumps. TEC units 302 are active heat pumps because they consume power to pump heat from the cold side to the hot side. Because the active cooling device 300 includes more than one TEC unit 302, the active cooling device 300 consumes power and is considered an active cooling device, hence the name. Still referring to Fig. 9 , each TEC unit 302 includes an n-type semiconductor core block 308N and a p-type semiconductor core block 308P. Away from the rectangular base plate 301R, the n-type semiconductor core block 308N and the p-type semiconductor core block 308P are coupled to the common conductive plate 310. Toward the rectangular base plate 301R, the n-type semiconductor core block 308N is coupled to the n-side conductive plate 306N, and the p-type semiconductor core block 308P is coupled to the p-side conductive plate 306P. In other words, the n-type semiconductor core block 308N is sandwiched between the common conductive plate 310 and the n-side conductive plate 306N, and the p-type semiconductor core block 308P is sandwiched between the common conductive plate 310 and the p-side conductive plate 306P. Fig. 9 In some embodiments shown, the common conductive plate 310 is thermally coupled to the outer ceramic plate 312. The n-side conductive plate 306N and the p-side conductive plate 306P are thermally coupled to the inner ceramic plate 304. Fig. 9The inner ceramic plate 304 and the outer ceramic plate 312 are shown, but they are optional. For example, when the rectangular base plate 301R is formed on a non-metallic material such as beryllium oxide, aluminum oxide, zinc oxide, aluminum nitride, hexagonal boron nitride, diamond, or graphite, the inner ceramic plate 304 can be omitted, and the n-side conductive plate 306N and the p-side conductive plate 306P are thermally coupled to one side of the rectangular base plate 301R. As another example, when the n-side conductive plate 306N and the p-side conductive plate 306P are insulated from the cover 212, the outer ceramic plate 312 can be omitted, and the common conductive plate 310 is thermally coupled to the inner wall of the groove defined in the cover 212.

[0031] In order to reduce power consumption and driving voltage, the common conductive plate 310, the n-side conductive plate 306N and the p-side conductive plate 306P are formed of a highly conductive metal. In some embodiments, the common conductive plate 310, the n-side conductive plate 306N and the p-side conductive plate 306P may include copper (Cu), aluminum (Al), silver (Ag) or their alloys. In one embodiment, they include copper (Cu). The p-type semiconductor core block 308P and the n-type semiconductor core block 308N may include bismuth telluride (BiTe), lead telluride (PdTe), bismuth selenide (BiSe), bismuth antimony telluride (BiSbTe), bismuth selenium telluride (BiSeTe), bismuth antimonide (BiSb), silicon (Si), silicon germanium (SiGe), germanium (Ge) or their alloys. In embodiments where the p-type semiconductor core block 308P and the n-type semiconductor core block 308N include silicon (Si), silicon germanium (SiGe), or germanium (Ge), they may include a p-type dopant to exhibit p-type conductivity or an n-type dopant to exhibit n-type conductivity. The p-type dopant may include boron (B). The n-type dopant may include phosphorus (P) or arsenic (As). When the p-type semiconductor core block 308P and the n-type semiconductor core block 308N include a metal alloy, no n-type or p-type dopant is required. For example, when the p-type semiconductor core block 308P and the n-type semiconductor core block 308N are formed of bismuth telluride, the p-type semiconductor core block 308P may include bismuth-rich bismuth telluride, and the n-type semiconductor core block 308N may include tellurium-rich bismuth telluride. As another example, the n-type semiconductor core block 308N may contain bismuth antimony telluride (BiSbTe), and the p-type semiconductor core block 308P may include bismuth selenium telluride (BiSeTe). In this example, bismuth antimony telluride (BiSbTe) and bismuth selenium telluride (BiSeTe) are both considered alloys. In this sense, antimony and selenium are not considered dopants. When present, the inner ceramic plate 304 and the outer ceramic plate 312 are formed of an insulating ceramic material. In some embodiments, the inner ceramic plate 304 and the outer ceramic plate 312 may include beryllium oxide, aluminum oxide, zinc oxide, aluminum nitride, hexagonal boron nitride, diamond, or graphite. In one embodiment, the inner ceramic plate 304 and the outer ceramic plate 312 include beryllium oxide.

[0032] To operate each TEC unit 302, the power supply 320 causes current to flow from the n-side conductive plate 306N to the p-side conductive plate 306P. The current flows through the n-type semiconductor core block 308N, the common conductive plate 310, and the p-type semiconductor core block 308P. The direction of the current or electrons is from the p-side conductive plate 306P to the n-side conductive plate 306N. Fig. 9 Four TEC cells 302 are shown connected in series. Current flows from one TEC cell 302 to another TEC cell 302 through traces 322 along adjacent sides of the rectangular base plate 301R. Fig. 9 Each trace 322 shown in FIG. 1 electrically connects the p-side conductive plate 306P and the n-side conductive plate 306N. Because the p-side conductive plate 306P and the n-side conductive plate 306N cannot be shorted together, the inner ceramic plate 304 is required when the rectangular base plate 301R is made of a conductive material. When the rectangular base plate 301R is formed of an insulating non-metal, the inner ceramic plate 304 can be omitted. In some embodiments, in order to keep the DC voltage of the power supply 320 below 20V, such as 10V or 15V, Fig. 9 The total resistance of the TEC unit 302 in is between about 4 ohms and about 10 ohms.

[0033] Fig.11 A top view of an active cooling device 300 is provided, which includes a polygonal base plate 301P and TEC units connected in series. Fig. 9 and Fig.10 The rectangular base plate 301R shown in FIG. Fig.11 The active cooling device 300 in FIG. 1 includes a polygonal base plate 301P. For purposes of illustration and not limitation, Fig.11 The polygonal base plate 301P in FIG. 3 is a hexagonal base plate that has a rectangular shape and 6 sides in the top view. It should be understood that the polygonal base plate 301P can have other polygonal shapes and include less than or more than 6 sides. Although not shown separately in the cross-sectional view, the polygonal base plate 301P also has a thickness T ( Fig.10 ), the thickness T may be between 2 mm and about 10 mm. Fig.10 Like the rectangular base plate 301R in FIG. 2 , the polygonal base plate 301P is disposed directly above the hotspot 250 when the lid 212 is attached to the package assembly 204. In other words, the vertically projected areas of the polygonal base plate 301P and the hotspot 250 substantially overlap. Fig.11 The polygonal base plate 301P shown in FIG. 1 has six (6) sides, so Fig.11 The active cooling device 300 in the embodiment includes six (6) TEC units 302 instead of four (4). The structure and construction of the TEC unit 302 have been described above in conjunction with Fig. 9 and Fig.10The TEC unit 302 has a cold side facing the side surface of the polygonal base plate 301P, and a hot side facing away from the side surface of the polygonal base plate 301P. This configuration allows the active cooling device 300 to direct heat radially away from the geometric center G of the polygonal base plate 301P. Fig.11 In some embodiments shown, six (6) TEC units 302 are connected in series and powered by a power supply 320. In order to keep the DC voltage of the power supply 320 below 20V, such as 10V or 15V, Fig.11 The total resistance of the TEC unit 302 in is between about 4 ohms and about 10 ohms.

[0034] Fig.12 A top view of an active cooling device 300 is provided, which includes a rectangular base plate 301R and TEC cells connected in parallel. In some embodiments, TEC cells 302 may be electrically connected in parallel to reduce voltage and increase current. Fig.12 The active cooling device 300 in FIG. 301 includes a rectangular base plate 301R. The n-side conductive plates 306N of the four (4) TEC units 302 are electrically coupled together through n-side interconnection lines 324N to the positive voltage output of the power supply 320, and the p-side conductive plates 306P of the four (4) TEC units 302 are electrically coupled together through p-side interconnection lines 324P to the negative voltage output of the power supply 320. Fig.12 In some of the illustrated embodiments, when the active cooling device 300 includes a rectangular base plate 301R, the active cooling device 300 may include four (4) n-side interconnect lines 324N and four (4) p-side interconnect lines 324P. Fig.12 The shapes and positions of the n-side interconnection lines 324N and p-side interconnection lines 324P shown in are examples. They may not have a 90-degree bend, and the shape may be substantially straight or curved. In order to reduce power consumption, the n-side interconnection lines 324N and p-side interconnection lines 324P are formed of a highly conductive material, such as copper (Cu), aluminum (Al), silver (Ag), or alloys thereof.

[0035] Fig.13 A top view of an active cooling device 300 is provided, which includes a polygonal base plate 301P and TEC cells connected in parallel. In some embodiments, TEC cells 302 may be electrically connected in parallel to reduce voltage and increase current. Fig.13The active cooling device 300 in FIG. 300 includes a polygonal base plate 301P. The n-side conductive plates 306N of the six (6) TEC units 302 are electrically coupled together through the n-side interconnection line 324N to the positive voltage output of the power supply 320, and the p-side conductive plates 306P of the six (6) TEC units 302 are electrically coupled together through the p-side interconnection line 324P to the negative voltage output of the power supply 320. Fig.13 In some of the illustrated embodiments, when the active cooling device 300 includes a polygonal base plate 301P, the active cooling device 300 may include six (6) n-side interconnect lines 324N and six (6) p-side interconnect lines 324P.

[0036] Fig.14 A top view of an active cooling device 300 is provided, which includes a rectangular base plate 301R and a TEC unit with a thermally conductive plate facing upward. Figures 9 to 13 In the active cooling device 300 shown, the cold side of the TEC unit 302 faces the rectangular base plate 301R or the polygonal base plate 301P, and the hot side of the TEC unit 302 is opposite to the cold side and faces away from the rectangular base plate 301R or the polygonal base plate 301P. This configuration allows the TEC unit 302 to absorb heat from the sidewalls of the rectangular base plate 301R or the polygonal base plate 301P and then radiate or conduct the heat radially away from the geometric center G of the rectangular base plate 301R or the polygonal base plate 301P. Fig.14 An active cooling device 300 is shown that includes an elbow TEC unit 350 coupled to four (4) sides of a rectangular base plate 301R. Referring first to Fig.14 As with the TEC unit 302, each elbow TEC unit 350 includes an inner ceramic plate 304, an n-type semiconductor core block 308N, a p-type semiconductor core block 308P, an n-side conductive plate 306N, and a p-side conductive plate 306P. Referring now to Fig.15 , Fig.15 Provided along Fig.14. The elbow TEC unit 350 includes a top conductive plate 314 thermally coupled to the top surfaces of the n-type semiconductor core block 308N and the p-type semiconductor core block 308P, instead of the common conductive plate 310 attached to the end surfaces of the n-type semiconductor core block 308N and the p-type semiconductor core block 308P. The elbow TEC unit 350 also includes a top ceramic plate 316 thermally coupled to the top conductive plate 314. Like the common conductive plate 310, the top conductive plate 314 may include copper (Cu), aluminum (Al), silver (Ag) or their alloys. In one embodiment, the top conductive plate 314 includes copper (Cu). The top ceramic plate 316 may include beryllium oxide, aluminum oxide, zinc oxide, aluminum nitride, hexagonal boron nitride, diamond or graphite. In one embodiment, the top ceramic plate 316 may include beryllium oxide. As described above, when the rectangular base plate 301R is formed of a non-metallic material, such as beryllium oxide, aluminum oxide, zinc oxide, aluminum nitride, hexagonal boron nitride, diamond, or graphite, the inner ceramic plate 304 of the elbow TEC unit 350 can be omitted. When the n-side conductive plate 306N and the p-side conductive plate 306P are insulated from the lid 212, the top ceramic plate 316 can be omitted. Omitting the top ceramic plate 316 allows the top conductive plate 314 to contact the lid 212 for better thermal conductivity. If the n-side conductive plate 306N and the p-side conductive plate 306P are not insulated from the lid 212, the power supply 320 will be short-circuited.

[0037] For the above-described TEC unit 302, the cold side is directly opposite the hot side to promote linear heat pumping radially away from the geometric center G of the rectangular base plate 301R or the polygonal base plate 301P. Fig.15 As shown, the cold side and the hot side of the elbow TEC unit 350 are not aligned. That is, the normal directions of the inner ceramic plate 304 and the top ceramic plate 316 are not aligned. Similarly, the normal directions of the n-side conductive plate 306N (or the p-side conductive plate 306P) and the top conductive plate 314 are not aligned. Instead, they form a 90 degree angle. Fig.15 As shown by the arrows in , each elbow TEC unit 350 can absorb heat radially away from the sidewalls of the rectangular base plate 301R and then radiate or conduct heat vertically away from the rectangular base plate 301R. The top ceramic plate 316 or the top conductive plate 314 can be thermally coupled to the lid 212.

[0038] Fig.16 A top view of an active cooling device 300 is provided, which includes a polygonal base plate 301P and a TEC unit with a thermally conductive plate facing upward. Fig.16 An active cooling device 300 is shown, which includes an elbow TEC unit 350 coupled to six (6) sides of a polygonal base plate 301P. Fig.14 and Fig.15As described, each elbow TEC unit 350 is configured to pump heat radially away from the sidewalls of the polygonal base plate 301P and vertically toward the lid 212 above the active cooling device 300 .

[0039] The present disclosure provides many embodiments. In one aspect, the present disclosure provides a packaging structure. The packaging structure includes: a packaging substrate; a packaging component disposed on the packaging substrate; a cover disposed on the packaging substrate and the packaging component; and an active cooling device embedded in the cover.

[0040] In some embodiments, the cover includes a lower edge and a bottom surface. The lower edge is attached to the top surface of the package substrate by an adhesive. The bottom surface is attached to the top surface of the package assembly by a thermal interface material layer. In some embodiments, the active cooling device includes a bottom surface, and the bottom surface of the active cooling device is coplanar with the bottom surface of the cover. In some embodiments, the package assembly includes a local hot spot, and the active cooling device is directly arranged above the local hot spot. In some embodiments, the active cooling device is powered by a direct current (DC) power supply. In some embodiments, the package assembly includes a top surface area, and the vertical projection area of ​​the active cooling device is less than 50% of the top surface area. In some embodiments, the active cooling device includes a base plate having a plurality of side walls and a plurality of thermoelectric cooling units arranged along the plurality of side walls, respectively. Each of the plurality of thermoelectric cooling units includes a first heat conducting plate thermally coupled to the base plate, a common conductor in contact with the first heat conducting plate, an n-type semiconductor component and a p-type semiconductor component arranged on the common conductor, a first conductor in contact with the n-type semiconductor component, a second conductor in contact with the p-type semiconductor component, and a second heat conducting plate in contact with the first conductor and the second conductor. In some embodiments, a plurality of thermoelectric cooling units are connected in parallel. In some embodiments, a plurality of thermoelectric cooling units are connected in series.

[0041] In another aspect, the present disclosure provides a packaging structure. The packaging structure includes: a cover portion; a ring portion extending continuously from a bottom surface of the cover portion to define a cavity configured to receive a packaging component; and an active cooling device embedded in the cover portion. The bottom surface of the active cooling device and the bottom surface of the cover portion are coplanar.

[0042] In some embodiments, the active cooling device is powered by a direct current (DC) power supply. In some embodiments, the bottom surface of the cover portion includes a surface area, and the vertical projection area of ​​the active cooling device is less than 50% of the surface area. In some embodiments, the active cooling device includes a base plate having a plurality of side walls and a plurality of thermoelectric cooling units respectively arranged along the plurality of side walls. Each of the plurality of thermoelectric cooling units includes a first heat conducting plate thermally coupled to the base plate, a common conductor in contact with the first heat conducting plate, an n-type semiconductor component and a p-type semiconductor component arranged on the common conductor, a first conductor in contact with the n-type semiconductor component, a second conductor in contact with the p-type semiconductor component, and a second heat conducting plate in contact with the first conductor and the second conductor. In some embodiments, a plurality of thermoelectric cooling units are connected in parallel. In some embodiments, a plurality of thermoelectric cooling units are connected in series.

[0043] In yet another aspect, the present disclosure provides a method that includes receiving a design of a package assembly, obtaining a thermal map of the package assembly to identify local hot spots, and manufacturing a lid that includes an embedded active cooling device that is vertically aligned with the local hot spots when the lid is attached to the package assembly.

[0044] In some embodiments, obtaining includes performing simulation based on a design of the package assembly. In some embodiments, obtaining includes manufacturing the package assembly based on the design of the package assembly, and measuring the temperature at different locations of the top surface of the package assembly during operation of the package assembly. In some embodiments, the method also includes manufacturing the package assembly based on the design of the package assembly, bonding the package assembly to a package substrate, and attaching a cover to the package assembly and the package substrate. In some embodiments, attaching includes depositing a layer of thermal interface material over the package assembly, dispensing an adhesive over the package substrate, placing the cover over the package assembly and the package substrate so that a bottom surface of the cover interfaces with the package assembly through the thermal interface material layer and a lower edge of the cover interfaces with the package substrate through the adhesive, and curing the thermal interface material layer and the adhesive.

[0045] The features of several embodiments are summarized above so that those skilled in the art can better understand aspects of the present disclosure. Those skilled in the art should understand that they can easily use the present disclosure as a basis to design or modify other processes and structures for implementing the same purpose and / or achieving the same advantages as the embodiments introduced herein. Those skilled in the art should also appreciate that such equivalent constructions do not deviate from the spirit and scope of the present disclosure, and that they can make various changes, substitutions, and modifications herein without departing from the spirit and scope of the present disclosure.

Claims

1. A packaging structure, comprising: Package substrate; A packaging component, disposed above the packaging substrate; A cover, disposed above the packaging substrate and the packaging assembly; as well as An active cooling device is embedded in the cover.

2. The packaging structure according to claim 1, in, The cover comprises a lower edge and a bottom surface, The lower edge is attached to the top surface of the package substrate by an adhesive, and the bottom surface is attached to the top surface of the package assembly by a thermal interface material layer.

3. The packaging structure according to claim 2, in, The active cooling device comprises a bottom surface, Wherein, the bottom surface of the active cooling device is coplanar with the bottom surface of the cover.

4. The packaging structure according to claim 1, in, The package assembly includes a local hot spot, Wherein, the active cooling device is arranged directly above the local hot spot.

5. The packaging structure according to claim 1, wherein: The active cooling device is powered by a direct current (DC) power source.

6. The packaging structure according to claim 1, in, The package assembly includes a top surface area, Wherein, the vertical projection area of ​​the active cooling device is less than 50% of the top surface area.

7. The packaging structure according to claim 1, in, The active cooling device comprises: a base plate including a plurality of side walls, A plurality of thermoelectric cooling units are respectively arranged along the plurality of side walls, Wherein, each of the plurality of thermoelectric cooling units comprises: a first heat conducting plate thermally coupled to the base plate, a common conductor in contact with the first heat conducting plate, An n-type semiconductor component and a p-type semiconductor component are disposed on the common conductor, a first conductor in contact with the n-type semiconductor component, a second conductor in contact with the p-type semiconductor component, and The second heat conducting plate is in contact with the first conductor and the second conductor.

8. The packaging structure according to claim 7, wherein: The plurality of thermoelectric cooling units are connected in parallel.

9. A cooling component, comprising: Cover part; a ring portion extending continuously from a bottom surface of the cover portion to define a cavity configured to receive a packaged component; as well as an active cooling device, embedded in said cover portion, Wherein, the bottom surface of the active cooling device and the bottom surface of the cover portion are coplanar.

10. A method for forming a packaging structure, comprising: Receive the design of the package assembly; obtaining a thermal map of the package assembly to identify local hot spots; as well as A lid is fabricated, the lid including an embedded active cooling device that is vertically aligned with the local hot spot when the lid is attached to the package assembly.

Images