Packaged built-in current sharing and heating device

Abstract

This invention provides a packaged internal current and heat equalization device, including a substrate, a chip, a current guiding component, and a heat equalization component. The chip is connected to the substrate, and the chips are vertically interconnected to form multiple stacked chip groups with different heights. The current guiding component includes a current guiding ramp inclined relative to the substrate and the chip, and a connecting plate parallel to the substrate and the chip. The heat equalization component includes a bridging plate and a heat transfer plate. The bridging plate is parallel to the substrate and the chip, and the heat transfer plate is disposed on the side of each stacked chip group. This invention can balance internal flow resistance differences, thereby reducing pressure differences and reducing the generation of molding voids and holes. It can form a large heat dissipation plane above the stacked chips, which can accelerate the removal of heat from the lower layers and improve the packaging performance of three-dimensional stacked chips.

Description

Technical Field

[0001] This invention relates to the field of microelectronic packaging technology, and in particular to a package-integrated heat and flow equalization device. Background Technology

[0002] With the development of integrated circuit technology, integrated circuit packaging technology is also constantly improving, and the requirements for integration are becoming increasingly stringent. For example, there is a need to integrate more chip devices in a given space, and in order to shorten the interconnection distance between chips and improve signal integrity, multi-chip stacking packaging has emerged. This type of packaging contains multiple chip stacks inside, which are protected by external epoxy resin molding compound.

[0003] Multi-chip stacked packaging has two main problems. First, during the molding process, the height difference creates inconsistent flow resistance, resulting in significant pressure differences downstream, which can lead to cavitation and voids. Second, when multiple chips are stacked, heat can accumulate at the bottom and cannot be dissipated in time, causing a significant temperature difference within the molding cavity. This not only affects the flow and curing process of the molding compound, but may also cause deformation and warping of the chips and substrate, ultimately affecting the packaging quality.

[0004] Therefore, a method is needed to ensure uniform flow and heat distribution within the internal plastic package during multi-chip stacking and packaging. Summary of the Invention

[0005] The purpose of this invention is to provide a solution that improves the internal molding flow field, thereby making the molding material flow and heat more uniform, in order to address the shortcomings of the above-mentioned background technology.

[0006] To achieve the above objectives, the present invention provides a packaged built-in flow and heat equalization device, including a substrate, a chip, a flow guiding component, and a heat equalization component.

[0007] The chip is connected to the substrate, and the chips are vertically interconnected to form multiple stacked chip groups with different heights.

[0008] The flow guiding assembly includes a flow guiding ramp that is inclined relative to the substrate and the chip, and a connecting plate that is parallel to the substrate and the chip. The connecting plate is connected to the flow guiding ramp. The flow guiding ramp is used to allow the molding compound to flow upward along the ramp. The flow guiding ramp has multiple through holes for the molding compound to pass through, so that when the molding compound flows toward the area where the stacked chips are located, it can smoothly enter the back side of the flow guiding ramp through the through holes and fill the area above the first set of stacked chips.

[0009] The heat dissipation assembly includes a bridging plate and a heat transfer plate. The bridging plate is arranged parallel to the substrate and the chip. A first end of the bridging plate is connected to the connecting plate. The lower surface of the second end of the bridging plate contacts the upper surface of the second group of stacked chips. The heat transfer plate is disposed on the side of each group of stacked chips. The bottom of the heat transfer plate is connected to the substrate. The top of the heat transfer plate is connected to the bridging plate and / or the connecting plate.

[0010] Furthermore, the flow guide plate is welded to the chip, and the connecting plate is integrally formed with or welded to the flow guide plate.

[0011] Furthermore, the tilt angle of the guide plate is set to 30~60°.

[0012] Furthermore, the shape of the through hole is set to be circular or rectangular.

[0013] Furthermore, the bridging plate and the connecting plate are set at the same height.

[0014] Furthermore, the bridging plate and the connecting plate are set to have the same thickness.

[0015] Furthermore, the upper surface of the bridging plate and the connecting plate is a heat dissipation plane, and the bridging plate and the connecting plate are made of a high thermal conductivity metal material.

[0016] Furthermore, the heat transfer plate is a thermoelectric vapor chamber, which has multiple pairs of P-type and N-type semiconductors built in it. The thermoelectric vapor chamber is connected to the substrate by solder balls, and the part of the thermoelectric vapor chamber near the substrate is the cold end, while the part near the bridging plate or the connecting plate is the hot end.

[0017] Furthermore, when the chip's workload exceeds the maximum load preset ratio, the thermoelectric vapor chamber is turned on, and electron-hole pairs are generated inside the cold end, reducing the internal energy and lowering the temperature, thus carrying away the heat from the lower layer. At the hot end, due to the recombination of electron-hole pairs, the internal energy increases and the temperature rises, transferring the heat to the bridge board and the connecting board for heat dissipation.

[0018] When the chip's workload falls below a preset percentage of the maximum load, the thermoelectric vapor chamber is shut off.

[0019] The above-described solution of the present invention has the following beneficial effects:

[0020] The built-in flow and heat equalization device provided by this invention has the following two advantages: First, the flow guides and connecting plates in the flow guide assembly allow for more uniform flow of the molding compound during the molding process, balancing internal flow resistance differences and reducing pressure differences, thereby minimizing the formation of molding voids and pores. Second, the bridging plate and thermoelectric vapor chamber in the heat equalization assembly ensure reliable overall structural support while forming a large heat dissipation plane above the stacked chips. This plane can directly contact the system's heat dissipation structure, accelerating the removal of heat generated by the chips and improving packaging performance. Third, the thermoelectric vapor chamber can accelerate the removal of heat from the lower layers during high-load operation and can be shut down during low-load operation to save energy, further enhancing the packaging performance of the stacked chips.

[0021] Other beneficial effects of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 This is another schematic diagram of the overall structure of the present invention;

[0024] Figure 3 This is a schematic diagram showing the flow direction of the molding compound.

[0025] [Explanation of Labels in the Attached Image]

[0026] 1-Substrate; 2-Chip; 2a-First stacked chip group; 2b-Second stacked chip group; 3-Guiding slant plate; 4-Connecting plate; 5-Through hole; 6-Bridging plate; 7-Thermoelectric heat spreader. Detailed Implementation

[0027] To make the technical problems, solutions, and advantages of this invention clearer, a detailed description will be provided below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0028] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a locking connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] like Figures 1-3 As shown, an embodiment of the present invention provides a packaged built-in current and heat equalization device, including a substrate 1, a chip 2, a current guiding component, and a heat equalization component. The chip 2 is connected to the substrate 1 via solder balls or leads. For each stacked chip 2, the vertical interconnections between chips 2 are achieved using through-silicon vias (TSVs) or solder balls, which improves signal transmission speed compared to numerous long-distance interconnections. After the chips 2 are connected to the substrate 1 and to each other, the solder joints and gaps between the chips 2 and the substrate 1, and between the chips 2 and each other, need to be filled with molding compound to protect the stacked chips 2.

[0031] In actual packaging, the heights of different stacked chip groups 2 may be inconsistent. For example, the first stacked chip group 2a has two chips, while the second stacked chip group 2b has three chips, creating a height difference. During molding, the molding compound flows from one direction towards the area where the stacked chips 2 are located. When it passes through the stacked chips 2, the molding compound experiences inconsistent flow resistance in the areas of the two stacked chip groups 2 due to the varying degrees of obstruction from the stacked chips 2 at different heights. This results in a significant pressure difference downstream, especially on the back flow side of the two stacked chip groups 2, leading to cavitation and voids. Therefore, in this embodiment, a flow guiding component is used to guide the flow of the molding compound to improve this situation.

[0032] Specifically, the flow guiding assembly includes a flow guiding ramp 3 inclined relative to the substrate 1 and the chip 2, and a connecting plate 4 parallel to the substrate 1 and the chip 2. The connecting plate 4 and the flow guiding ramp 3 can be integrally formed or welded together. The flow guiding ramp 3 has multiple through holes 5 for the molding compound to pass through, allowing it to flow smoothly into the back of the flow guiding ramp 3 towards the area where the stacked chips 2 are located, thus filling the upper area of ​​the stacked chips 2. Simultaneously, the inclined flow guiding ramp 3 guides the molding compound, allowing it to flow upwards along the ramp. Therefore, when the flow guiding ramp 3 is placed on the first set of stacked chips 2a, which has a lower height, it improves the overall flow field of the molding compound, making the flow of the molding compound on the upstream side of the first set of stacked chips 2a and the second set of stacked chips 2b more uniform, resulting in more uniform downstream flow, smaller pressure differences, and improved molding quality.

[0033] It should be noted that the flow guide plate 3 can be configured such that the lowest edge of the flow guide plate 3 contacts the upper edge of the first stacked chip 2a, the highest edge of the flow guide plate 3 is connected to the connecting plate 4, and the height of the connecting plate 4 is consistent with that of the second stacked chip 2b. This can better ensure the consistency of the flow of the molding compound in the area of ​​the first stacked chip 2a and the area of ​​the second stacked chip 2b, and achieve the effect of uniform flow.

[0034] The purpose of setting the flow guide sloping plate 3 in an inclined rather than vertical manner is that the height dimension of the flow guide sloping plate 3 is not large, that is, the thickness of the chip 2 package is not large. Therefore, when the flow guide sloping plate 3 is set vertically, the arrangement of its through holes 5 is relatively difficult, making it difficult to fill the area above the first group of stacked chips 2a. The inclined method adopted in this embodiment is more conducive to the arrangement of through holes 5. In addition, the tilt angle can be adjusted for stacked chips 2 packages with different height differences, achieving the purpose of flexible adaptation.

[0035] In a preferred embodiment, the inclination angle of the flow guide sloping plate 3 is set to 30~60°, and it slopes upward along the downstream flow. The shape of the through hole 5 can be circular, rectangular, or other shapes, and there is no specific limitation here. Those skilled in the art can select the shape after testing based on actual effects. By adjusting the flow resistance of the flow guide sloping plate 3, the flow resistance difference of stacked chips 2 with different height differences can be effectively reduced, and the flow direction of the fluid can be guided, thereby effectively reducing the cavitation and void problems caused by excessive flow resistance differences during the molding compound filling process.

[0036] In this embodiment, the heat dissipation assembly includes a bridging plate 6. The bridging plate 6 is also arranged in parallel. The first end of the bridging plate 6 is connected to the connecting plate 4 (or can be integrally formed), and the lower surface of the second end of the bridging plate 6 contacts the upper surface of the second group of stacked chips 2b (i.e., the upper surface of the uppermost chip 2). It is understood that in this arrangement, the bridging plate 6 is generally higher than the second group of stacked chips 2b. To improve the overall continuity between the bridging plate 6 and the connecting plate 4, the connecting plate 4 needs to be set to have the same height as the bridging plate 6, and preferably the same thickness, so that there is no height difference between the areas containing the first group of stacked chips 2a and the second group of stacked chips 2b.

[0037] As described above, the bridging board 6 can also be considered as an extension of the connecting board 4, connecting to the upper surface of the second stacked chip 2b. The bridging board 6 and the connecting board 4 as a whole can be considered as a large heat dissipation plane, which can be made of a high thermal conductivity metal material such as copper. After molding, the molding layer is trimmed so that the upper surface of the bridging board 6 and the connecting board 4 is flush with the upper surface of the molding material, that is, the upper surface of the bridging board 6 and the connecting board 4 is exposed so as to contact the system heat sink or other heat dissipation structure and quickly remove the heat generated by the chip 2.

[0038] Meanwhile, the heat dissipation assembly also includes a thermoelectric heat spreader 7, which is positioned below the bridging plate 6 and the connecting plate 4. The bottom of the thermoelectric heat spreader 7 contacts the substrate 1, and the top contacts the bridging plate 6 or the connecting plate 4. On the one hand, it can further support the bridging plate 6 and the connecting plate 4, preventing the stacked chips 2 from bearing excessive pressure and improving the stability and consistency of the entire device during packaging. On the other hand, the thermoelectric heat spreader 7 has multiple pairs of P-type and N-type semiconductors built in, which are also connected to the substrate 1 through solder balls, with the cold end near the substrate 1 and the hot end near the heat dissipation plane.

[0039] The working principle of the thermoelectric vapor chamber 7 is as follows: When the working load of the chip 2 exceeds 50% (or other preset ratio), the thermoelectric vapor chamber 7 is turned on. Electron-hole pairs are generated inside the cold end, the internal energy decreases, and the temperature drops, thereby carrying away the heat from the lower layer. At the same time, due to the recombination of electron-hole pairs, the internal energy of the hot end increases and the temperature rises. When the hot end is in direct contact with the heat dissipation plane, the heat is transferred to the heat dissipation plane and carried away by the system heat dissipation.

[0040] When the workload of chip 2 is below 50% (or other preset ratio), the internal heat accumulation density is relatively small, the thermoelectric heat spreader 7 is turned off, and no additional assistance is provided for vertical heat transfer, thus reducing the power loss of the system.

[0041] It should be noted that the thermoelectric vapor chamber 7 also contacts the side edge of the stacked chip 2, thus enabling rapid heat dissipation in the lateral area of ​​the stacked chip 2, thereby achieving rapid overall heat dissipation. Of course, to reduce costs, the thermoelectric vapor chamber 7 can also be set as a regular heat transfer plate, which is made of a material with a high thermal conductivity, thereby fully transferring heat to the heat dissipation plane and then carrying it away through system heat dissipation.

[0042] It is understood that this embodiment uses the first group of stacked chips 2a and the second group of stacked chips 2b as examples for illustration. In actual applications, more stacked chips 2 may be packaged on the substrate 1. Therefore, multiple package-integrated flow and heat equalization devices provided in this embodiment can be used to improve the flow field during overall molding and the temperature field during operation, so as to significantly improve the chip 2 packaging density while ensuring reliability.

[0043] Using the built-in current and heat equalization device provided in this embodiment, the first set of stacked chips 2a and the second set of stacked chips 2b are packaged according to the current advanced packaging process. Then, the thermoelectric heat equalization plate 7 is placed in a suitable position and connected to the substrate 1 by solder balls. Finally, the flow guide plate 3, the connecting plate 4, and the bridging plate 6 are placed in the preset position and stabilized. Then, each solder point is soldered and packaged. Finally, the molding process is performed.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A packaged, built-in flow and heat equalization device, characterized in that, This includes the substrate, chip, current guiding components, and heat dissipation components; The chip is connected to the substrate, and the chips are vertically interconnected to form multiple stacked chip groups with different heights. The flow guiding assembly includes a flow guiding ramp that is inclined relative to the substrate and the chip, and a connecting plate that is parallel to the substrate and the chip. The connecting plate is connected to the flow guiding ramp. The flow guiding ramp is used to allow the molding compound to flow upward along the ramp. The flow guiding ramp has multiple through holes for the molding compound to pass through, so that when the molding compound flows toward the area where the stacked chips are located, it can smoothly enter the back side of the flow guiding ramp through the through holes and fill the area above the first set of stacked chips. The heat dissipation assembly includes a bridging plate and a heat transfer plate. The bridging plate is arranged parallel to the substrate and the chip. A first end of the bridging plate is connected to the connecting plate. The lower surface of the second end of the bridging plate contacts the upper surface of the second group of stacked chips. The heat transfer plate is disposed on the side of each group of stacked chips. The bottom of the heat transfer plate is connected to the substrate. The top of the heat transfer plate is connected to the bridging plate and / or the connecting plate. The first group of stacked chips and the second group of stacked chips form a height difference, and the bridge board and the connecting board are set at the same height; The lowest edge of the flow guide plate contacts the upper edge of the first group of stacked chips, and the highest edge of the flow guide plate is connected to the connecting plate. The connecting plate is at the same height as the second group of stacked chips.

2. The encapsulated built-in flow and heat equalization device according to claim 1, characterized in that, The flow guide plate is welded to the chip, and the connecting plate is integrally formed with or welded to the flow guide plate.

3. The encapsulated built-in flow and heat equalization device according to claim 1, characterized in that, The tilt angle of the guide plate is set to 30~60°.

4. The encapsulated built-in flow and heat equalization device according to claim 1, characterized in that, The shape of the through hole is set to be circular or rectangular.

5. The encapsulated built-in flow and heat equalization device according to claim 1, characterized in that, The bridging plate and the connecting plate are of equal thickness.

6. A packaged built-in flow and heat equalization device according to claim 1 or 5, characterized in that, The upper surface of the bridging plate and the connecting plate is a heat dissipation plane, and the bridging plate and the connecting plate are made of a high thermal conductivity metal material.

7. The encapsulated built-in flow and heat equalization device according to claim 1, characterized in that, The heat transfer plate is a thermoelectric vapor chamber, which has multiple pairs of P-type and N-type semiconductors built in it. The thermoelectric vapor chamber is connected to the substrate by solder balls, and the part of the thermoelectric vapor chamber closer to the substrate is the cold end, while the part closer to the bridging plate or the connecting plate is the hot end.

8. The encapsulated built-in flow and heat equalization device according to claim 7, characterized in that, When the chip's workload exceeds the maximum load preset ratio, the thermoelectric vapor chamber is turned on. Electron-hole pairs are generated inside the cold end, reducing the internal energy and lowering the temperature, thus carrying away the heat from the lower layer. At the hot end, due to the recombination of electron-hole pairs, the internal energy increases and the temperature rises, transferring the heat to the bridge board and the connecting board for heat dissipation. When the chip's workload falls below a preset percentage of the maximum load, the thermoelectric vapor chamber is shut off.

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