Encapsulated built-in flow-equalizing and soaking device

Abstract

The invention provides a packaged built-in flow equalizing and soaking device. The packaged built-in flow equalizing and soaking device comprises a substrate, a chip, a flow guide assembly and a soaking assembly, the chips are connected with the substrate, the chips are vertically interconnected to form a plurality of groups of stacked chips, and the heights of different groups of stacked chips are different; the flow guide assembly comprises a flow guide inclined plate and a connecting plate, the flow guide inclined plate is obliquely arranged relative to the substrate and the chips, the connecting plate is parallel to the substrate and the chips, the soaking assembly comprises a bridging plate and a heat transfer plate, the bridging plate is parallel to the substrate and the chips, and the heat transfer plate is arranged on the side face of each group of stacked chips. According to the invention, the internal flow resistance difference can be balanced, so that the pressure difference is reduced, and the generation of plastic package air holes and holes is reduced; a heat dissipation plane with a large area can be formed above the stacked chips, heat of a lower layer can be rapidly taken away, and the packaging performance of the three-dimensional stacked chips is improved.

Description

Technical Field

[0001] The invention relates to the technical field of microelectronic packaging, and in particular to a packaged built-in current and heat equalization device. Background Art

[0002] With the development of integrated circuit technology, integrated circuit packaging technology is also constantly improving, and the requirements for integration are getting higher and higher. For example, it is required to integrate more chip devices in a given space, and in order to shorten the interconnection distance between chips and improve signal integrity, a multi-chip stacking packaging form has been produced. This type of package has multiple chips stacked inside, and the internal chips are protected by filling the outside with epoxy resin molding compound.

[0003] There are two main problems with multi-chip stacking packaging. First, during the plastic encapsulation process, inconsistent flow resistance is generated due to the existence of height differences, and there will be obvious pressure differences in the downstream flow, which will lead to cavitation and voids. Second, when multiple chips are stacked, heat will accumulate at the lower end and cannot be dissipated in time, causing a significant temperature difference in the plastic encapsulation cavity, which will not only affect the flow and curing process of the plastic encapsulation material, but may also cause the chip, substrate, etc. to deform and warp, ultimately affecting the packaging quality.

[0004] Therefore, a method is needed to ensure that the internal plastic packaging flow field has uniform flow and heat as much as possible when packaging multiple chips in a stacked manner. Summary of the invention

[0005] The purpose of the present invention is to provide a solution that can improve the internal plastic sealing flow field to make the flow of plastic sealing material and heat more uniform in view of the shortcomings of the above-mentioned background technology.

[0006] In order to achieve the above-mentioned object, the present invention provides a packaged built-in current and heat balancing device, comprising a substrate, a chip, a flow guide component and a heat balancing component;

[0007] The chip is connected to the substrate, and the chips are vertically interconnected to form a plurality of groups of stacked chips, and different groups of stacked chips have different heights;

[0008] The guide assembly includes a guide inclined plate arranged obliquely relative to the substrate and the chip, and a connecting plate arranged parallel to the substrate and the chip, the connecting plate being connected to the guide inclined plate, the guide inclined plate being used to make the plastic encapsulation material flow upward along the inclined surface, the guide inclined plate being provided with a plurality of through holes, the through holes being used for the plastic encapsulation material to pass through, so that when the plastic encapsulation material flows toward the area where the stacked chips are located, it can smoothly enter the back side of the guide inclined plate from the through holes and fill the area above the first group of stacked chips;

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

[0010] Furthermore, the guide inclined plate is connected to the chip by welding, and the connecting plate is integrally arranged with the guide inclined plate or connected by welding.

[0011] Furthermore, the inclination angle of the guide inclined 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 arranged at the same height.

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

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

[0016] Furthermore, the heat transfer plate is a thermoelectric temperature averaging plate, which has multiple pairs of P-type and N-type semiconductors built in. The thermoelectric temperature averaging plate is connected to the substrate through solder balls, and the part of the thermoelectric temperature averaging plate close to the substrate is the cold end, and the part close to the bridge plate or the connecting plate is the hot end.

[0017] Furthermore, when the chip workload exceeds the preset ratio of the maximum load, the thermoelectric temperature plate is turned on, electron-hole pairs are generated inside the cold end, the internal energy is reduced, the temperature is lowered, and the heat of the lower layer is taken away. Due to the recombination of the electron-hole pairs, the internal energy of the hot end increases, the temperature rises, and the heat is transferred to the bridge plate and the connecting plate for heat dissipation;

[0018] When the chip workload is lower than a preset ratio of the maximum load, the thermoelectric vapor chamber is turned off.

[0019] The above scheme of the present invention has the following beneficial effects:

[0020] The package built-in flow and heat equalization device provided by the present invention has the following two advantages: by setting the flow guide inclined plate, connecting plate and the like in the flow guide component, the flow of the plastic sealing material under the flow guide action of the flow guide inclined plate is more uniform during the plastic sealing process, and the internal flow resistance difference can be balanced, thereby reducing the pressure difference, and further reducing the generation of plastic sealing cavitations and holes; by setting the bridge plate and the thermoelectric temperature equalization plate of the heat equalization component, while ensuring the reliable support of the overall structure, a heat dissipation plane with a larger area can be formed above the stacked chips, which can directly contact the system heat dissipation structure, thereby accelerating the removal of heat generated by the chips, etc., and improving the packaging performance; in addition, the thermoelectric temperature equalization plate can accelerate the removal of heat from the lower layer when the chip is running at high load, and can be shut down to save energy when running at low load, further improving the packaging performance of the three-dimensional stacked chips;

[0021] Other beneficial effects of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0023] Figure 2 Another schematic diagram of the overall structure of the present invention;

[0024] Figure 3 Schematic diagram of the flow direction of the plastic packaging material.

[0025] [Description of Reference Numerals]

[0026] 1-substrate; 2-chip; 2a-first group of stacked chips; 2b-second group of stacked chips; 3-guide ramp; 4-connecting plate; 5-through hole; 6-bridge plate; 7-thermoelectric temperature plate. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a locking connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] like Figure 1-Figure 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 flow guide component and a heat equalization component. Among them, the chip 2 is connected to the substrate 1 by means of solder balls or leads, and at the same time, for each group of stacked chips 2, the vertical interconnection between the chips 2 and the chips 2 adopts through silicon vias (TSV) or solder balls, etc., which improves the signal transmission rate compared to a large number of long-distance connections. After the chip 2 and the substrate 1, and the chip 2 and the chip 2 are connected, the welding positions and gap positions between the chip 2 and the substrate 1, and the chip 2 and the chip 2 need to be filled with plastic packaging materials, and at the same time, each group of stacked chips 2 is surrounded to fully protect the stacked chips 2.

[0031] In the actual packaging process, the heights of different groups of stacked chips 2 may be inconsistent. For example, the number of the first group of stacked chips 2a shown in the figure is two, and the number of the second group of stacked chips 2b is three, thus forming a height difference. During the plastic encapsulation process, the plastic encapsulation material flows from one direction toward the area where the stacked chips 2 are located. When it passes through the stacked chips 2, the plastic encapsulation material will be subject to inconsistent flow resistance in the areas of the two groups of stacked chips 2 due to the different blocking conditions of the stacked chips 2 at different heights. As a result, there is a significant pressure difference in the downstream flow, especially on the back flow side of the two groups of stacked chips 2, resulting in cavitation and voids. Based on this, in this embodiment, the plastic encapsulation material is guided by a guide component to improve this situation.

[0032] Specifically, the flow guide assembly includes a flow guide inclined plate 3 that is tilted relative to the substrate 1 and the chip 2, and a connecting plate 4 that is parallel to the substrate 1 and the chip 2. Among them, the connecting plate 4 and the flow guide inclined plate 3 can be arranged in an integral manner or connected by welding. A plurality of through holes 5 are provided on the flow guide inclined plate 3, and the through holes 5 are used for the passage of the plastic encapsulation material, so that when the plastic encapsulation material flows toward the area where the stacked chip 2 is located, it can smoothly enter the back of the flow guide inclined plate 3 from the through holes 5, thereby filling the upper area of ​​the stacked chip 2. At the same time, the inclined flow guide inclined plate 3 can guide the plastic encapsulation material so that the plastic encapsulation material flows upward along the inclined surface. Therefore, when the flow guide inclined plate 3 is arranged on the first group of stacked chips 2a with a lower height, the overall flow field of the plastic encapsulation material can be improved, so that the flow of the plastic encapsulation material on the frontal side of the first group of stacked chips 2a and the second group of stacked chips 2b is more uniform, so that the flow downstream will also be more uniform, and the pressure difference will be smaller, thereby achieving the purpose of improving the quality of the plastic encapsulation.

[0033] It should be noted that the setting method of the guide bevel 3 can be: the lowest side of the guide bevel 3 contacts the upper edge of the first group of stacked chips 2a, and the highest side of the guide bevel 3 is connected to the connecting plate 4, and the height of the connecting plate 4 is consistent with that of the second group of stacked chips 2b. In this way, the flow consistency of the plastic encapsulation material in the area of ​​the first group of stacked chips 2a and the plastic encapsulation material in the area of ​​the second group of stacked chips 2b can be better ensured, thereby achieving the effect of equal flow.

[0034] The purpose of setting the guide plate 3 in an inclined manner rather than a vertical manner is that the height of the guide plate 3 is not large, that is, the thickness of the chip 2 package is not large, so when the guide plate 3 is set vertically, it is relatively difficult to arrange the through holes 5, thereby making it difficult to fill the area above the first group of stacked chips 2a. The inclined manner of this embodiment can be more conducive to the arrangement of the through holes 5. In addition, when packaging stacked chips 2 with different height differences, the inclination angle can be adjusted to achieve the purpose of flexible adaptation.

[0035] As a preferred embodiment, the inclination angle of the guide ramp 3 in this embodiment is set to 30-60°, and it is inclined upward along the downstream of the flow. The shape of the through hole 5 can be set to circular, rectangular or other shapes, and there is no specific limitation here. Those skilled in the art can choose after testing based on the actual effect. By adjusting the flow resistance of the guide ramp 3, the flow resistance difference of the stacked chips 2 with different height differences can be effectively reduced, and the flow direction of the fluid can be guided at the same time, thereby effectively reducing the cavitation and void problems caused by excessive flow resistance differences during the filling process of the plastic packaging material.

[0036] In this embodiment, the heat-saturating assembly includes a bridge plate 6. The bridge plate 6 is also arranged in parallel, the first end of the bridge plate 6 is connected to the connecting plate 4 (it can also be arranged in an integrated manner), and the lower surface of the second end of the bridge plate 6 is in contact with the upper surface of the second group of stacked chips 2b (i.e., the upper surface of the uppermost chip 2). It can be understood that in this arrangement, the bridge plate 6 is arranged higher than the height of the second group of stacked chips 2b as a whole. In order to improve the overall continuity of the bridge plate 6 and the connecting plate 4, it is necessary to set the connecting plate 4 to be equal in height to the bridge plate 6, and preferably equal in thickness, so that there will be no height difference in the area where the first group of stacked chips 2a and the second group of stacked chips 2b are located.

[0037] As described above, the bridge plate 6 can also be regarded as an extension of the connecting plate 4, connected to the upper surface of the second group of stacked chips 2b. The bridge plate 6 and the connecting plate 4 as a whole can be regarded as a large heat dissipation plane, and its material can be a high thermal conductivity metal material such as copper. After the plastic packaging is completed, the plastic packaging layer is trimmed so that the upper surface of the bridge plate 6 and the connecting plate 4 is flush with the upper surface of the plastic packaging material, that is, the upper surface of the bridge plate 6 and the connecting plate 4 is exposed, so as to contact with the system radiator or other heat dissipation structure, and quickly take away the heat generated by the chip 2.

[0038] At the same time, the heat spreader assembly also includes a thermoelectric heat spreader 7, which is arranged below the bridge plate 6 and the connecting plate 4. The bottom of the thermoelectric heat spreader 7 is in contact with the substrate 1, and the top is in contact with the bridge plate 6 or the connecting plate 4. On the one hand, it can further support the bridge plate 6 and the connecting plate 4 to prevent the stacked chip 2 from being subjected to excessive pressure, thereby 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, and the part close to the substrate 1 is the cold end, and the part close to the heat dissipation plane is the hot end.

[0039] The working principle of the thermoelectric temperature plate 7 is as follows: when the workload of the chip 2 exceeds 50% (or other preset ratio), the thermoelectric temperature plate 7 is turned on, and electron-hole pairs are generated inside the cold end, the internal energy is reduced, and the temperature is lowered, thereby taking away the heat of the lower layer. At the same time, the hot end increases the internal energy and temperature due to the recombination of electron-hole pairs. When the hot end is in direct contact with the heat dissipation plane, the heat is transferred to the heat dissipation plane and taken away by the system heat dissipation;

[0040] When the chip 2 workload is lower than 50% (or other preset ratio), the internal heat accumulation density is relatively small, the thermoelectric temperature plate 7 is closed, and no additional assistance is provided for vertical heat transfer, thereby reducing the power loss of the system.

[0041] It should be noted that the thermoelectric temperature plate 7 is also in contact with the side edge of the stacked chip 2, so it can quickly dissipate heat in the lateral area of ​​the stacked chip 2, thereby achieving the purpose of overall rapid heat dissipation. Of course, in order to reduce costs, the thermoelectric temperature plate 7 can also be set as an ordinary heat transfer plate, which is made of a material with a high heat transfer coefficient, so that the heat can be fully transferred to the heat dissipation plane and then taken away by the system heat dissipation.

[0042] It can be understood that, in this embodiment, the first group of stacked chips 2a and the second group of stacked chips 2b are used as examples for explanation. In actual application, more groups of stacked chips 2 may be packaged on the substrate 1. Therefore, multiple built-in flow and heat equalization devices provided in this embodiment can be used to improve the flow field during the overall plastic packaging and the temperature field during operation, so that the reliability can still be guaranteed while significantly improving the packaging density of the chip 2.

[0043] By using the packaged built-in current and heat balancing device provided in this embodiment, the packaging of the first group of stacked chips 2a and the second group of stacked chips 2b is first completed according to the current advanced packaging process, and then the thermoelectric temperature balancing plate 7 is placed in a suitable position and connected to the substrate 1 through solder balls. Finally, the guide ramp 3, the connecting plate 4, and the bridge plate 6 are placed in the preset position and stabilized, and then each welding point is welded and packaged, and finally the plastic sealing process is carried out.

[0044] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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 only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A package with built-in current and heat equalization device, characterized in that: It includes a substrate, a chip, a flow guide component and a heat spreader component; The chip is connected to the substrate, and the chips are vertically interconnected to form a plurality of groups of stacked chips, and different groups of stacked chips have different heights; The guide assembly includes a guide inclined plate arranged obliquely relative to the substrate and the chip, and a connecting plate arranged parallel to the substrate and the chip, the connecting plate being connected to the guide inclined plate, the guide inclined plate being used to make the plastic encapsulation material flow upward along the inclined surface, the guide inclined plate being provided with a plurality of through holes, the through holes being used for the plastic encapsulation material to pass through, so that when the plastic encapsulation material flows toward the area where the stacked chips are located, it can smoothly enter the back side of the guide inclined plate from the through holes and fill the area above the first group of stacked chips; The heat spreader assembly includes a bridge plate and a heat transfer plate. The bridge plate is arranged in parallel with the substrate and the chip. The first end of the bridge plate is connected to the connecting plate. The lower surface of the second end of the bridge plate contacts the upper surface of the second group of stacked chips. The heat transfer plate is arranged on the side of each group of stacked chips. The bottom of the heat transfer plate is connected to the substrate, and the top of the heat transfer plate is connected to the bridge plate and / or the connecting plate.

2. A packaged built-in current and heat equalization device according to claim 1, characterized in that: The guide inclined plate is connected to the chip by welding, and the connecting plate is integrally arranged with the guide inclined plate or connected by welding.

3. A packaged built-in current and heat equalization device according to claim 1, characterized in that: The inclination angle of the guide inclined plate is set to 30-60°.

4. The packaged built-in current 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 packaged built-in current and heat equalization device according to claim 1, characterized in that: The bridging plate and the connecting plate are arranged at the same height.

6. A packaged built-in current and heat equalization device according to claim 5, characterized in that: The bridging plate and the connecting plate are arranged to have the same thickness.

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

8. The packaged built-in current and heat equalization device according to claim 1, characterized in that: The heat transfer plate is a thermoelectric temperature averaging plate, which has multiple pairs of P-type and N-type semiconductors built in it. The thermoelectric temperature averaging plate is connected to the substrate through solder balls, and the part of the thermoelectric temperature averaging plate close to the substrate is the cold end, and the part close to the bridge plate or the connecting plate is the hot end.

9. A packaged built-in current and heat equalization device according to claim 8, characterized in that: When the chip workload exceeds the preset ratio of the maximum load, the thermoelectric temperature plate is turned on, electron-hole pairs are generated inside the cold end, the internal energy is reduced, the temperature is lowered, and the heat of the lower layer is taken away. The hot end increases the internal energy and temperature due to the recombination of electron-hole pairs, and the heat is transferred to the bridge plate and the connecting plate for heat dissipation; When the chip workload is lower than a preset ratio of the maximum load, the thermoelectric vapor chamber is turned off.

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