Multi-chip plastic package structure and method for improving heat dissipation and uniform temperature

Abstract

The invention relates to a multi-chip plastic package structure and method for improving heat dissipation and uniform temperature, and relates to the technical field of chip packaging, the multi-chip plastic package structure for improving heat dissipation and uniform temperature comprises a plurality of chips, a substrate and cooling fins; the plurality of chips are all arranged on the substrate; at least one chip is provided with a heat conducting pad, so that the heights of all the chips are consistent; the radiating fins are arranged on all the chips; and the plurality of chips, the substrate, the radiating fin and the heat conducting pad are packaged together by plastic package. Visibly, according to the multi-chip plastic package structure, the heat conduction pads are arranged on the chips, so that the heights above all the chips are consistent, and then the cooling fins are arranged on the chips for temperature equalization, so that the temperature uniformity of the multi-chip plastic package structure can be effectively improved, and the heat dissipation effect is improved.

Description

Technical Field

[0001] The present invention relates to the field of packaging technology, and in particular to a multi-chip plastic packaging structure and method for improving heat dissipation and temperature uniformity. Background Art

[0002] Multi-chip plastic packaging is a common situation in the chip packaging field.

[0003] The inventors of the present application have discovered that, for multi-chip plastic encapsulation, there is an uneven distribution of power consumption among different chips. For example, some chips have high power consumption and high temperatures, while some chips have low power consumption and low temperatures. This results in an obvious temperature gradient in the package and a prominent local maximum temperature in the package. Summary of the invention

[0004] The present invention provides a multi-chip plastic packaging structure and method for improving heat dissipation uniformity, so as to solve the problem of uneven temperature distribution and difficulty in effective heat dissipation in the existing multi-chip packaging structure.

[0005] In the first aspect, the present invention provides a multi-chip plastic package structure for improving heat dissipation and temperature uniformity, comprising a plurality of chips, a substrate and a heat sink; the plurality of chips are arranged on the substrate; at least one of the chips is provided with a thermal pad so that the heights of all chips are consistent; the heat sink is arranged on all the chips; the plurality of chips, the substrate, the heat sink and the thermal pad are packaged together by plastic packaging.

[0006] A further technical solution is that the type of the chip includes at least one of FC die and WB die.

[0007] A further technical solution is that the thermal pad is made of thermally conductive material.

[0008] A further technical solution is that the heat sink is made of metal material.

[0009] A further technical solution is that the upper surface of the heat sink is exposed.

[0010] In a second aspect, the present invention provides a multi-chip plastic packaging method for improving heat dissipation and temperature uniformity, comprising:

[0011] Grinding and mounting multiple chips onto a substrate respectively;

[0012] By arranging a spacer on at least one chip, the heights of all the chips are made consistent;

[0013] Disposing heat sinks on all of the chips;

[0014] The plurality of chips, the substrate, the heat sink and the thermal pad are packaged by plastic encapsulation.

[0015] A further technical solution is that after the plurality of chips, the substrate, the heat sink and the thermal pad are packaged by plastic packaging, the method further comprises:

[0016] The resin on the heat sink is thinned to a preset thickness.

[0017] A further technical solution is that after the plurality of chips, the substrate, the heat sink and the thermal pad are packaged by plastic packaging, the method further comprises:

[0018] The resin on the heat sink is thinned until the heat sink is exposed.

[0019] A further technical solution is that the type of the chip includes at least one of FC die and WB die.

[0020] A further technical solution is that the thermal pad is made of a thermally conductive material; and the heat sink is made of a metal material.

[0021] The above technical solution provided by the embodiment of the present invention has the following advantages compared with the prior art:

[0022] The technical solution of the embodiment of the present invention is that the multi-chip plastic package structure for improving heat dissipation and temperature uniformity includes multiple chips, a substrate and a heat sink; multiple chips are arranged on the substrate; at least one chip is provided with a thermal pad so that the heights of all chips are consistent; the heat sink is arranged on all the chips; multiple chips, the substrate, the heat sink and the thermal pad are packaged together by plastic packaging. It can be seen that the present invention can effectively improve the temperature uniformity of the multi-chip plastic package structure and improve the heat dissipation effect by placing thermal pads on the chips to make the heights above all chips consistent, and then placing heat sinks to even out the temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0026] Figure 1 A schematic structural diagram of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention;

[0027] Figure 2 A schematic structural diagram of a multi-chip plastic packaging structure for improving heat dissipation and temperature uniformity provided by another embodiment of the present invention;

[0028] Figure 3 A schematic structural diagram of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity provided by another embodiment of the present invention;

[0029] Figure 4 A schematic diagram of step S1 of a multi-chip plastic packaging method for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of step S2 of a multi-chip plastic packaging method for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention;

[0031] Figure 6 A schematic diagram of step S3 of a multi-chip plastic packaging method for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention;

[0032] Figure 7 A schematic diagram of step S4 of a multi-chip plastic packaging method for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention;

[0033] Figure 8 A schematic diagram of step S5 of a multi-chip plastic packaging method for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention;

[0034] Fig. 9 A schematic diagram of a simulation structure of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention;

[0035] Fig.10 Another schematic diagram of a multi-chip plastic package structure simulation structure for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention;

[0036] Fig.11 A diagram of parameters of a simulation structure of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention;

[0037] Fig.12A schematic diagram of simulating a multi-chip plastic package structure for improving heat dissipation and temperature uniformity in a Still Air environment provided by an embodiment of the present invention;

[0038] Fig.13 A test result diagram of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention, which is simulated in a Still Air environment;

[0039] Fig.14 Another test result diagram of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention is simulated in a Still air environment;

[0040] Fig.15 Another test result diagram of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity provided by an embodiment of the present invention, which is simulated in a Still air environment;

[0041] Fig.16 A schematic diagram of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity under a forced air environment according to an embodiment of the present invention;

[0042] Fig.17 A result diagram of a thermal simulation test of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity under a forced air environment provided by an embodiment of the present invention;

[0043] Fig.18 Another result diagram of a thermal simulation test of a multi-chip plastic package structure for improving heat dissipation and temperature uniformity in a forced air environment provided by an embodiment of the present invention.

[0044] Reference numerals

[0045] Substrate 10 , heat sink 20 , thermal pad 30 , FC die 40 , WB die 50 , resin 60 . DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0048] For ease of description, spatial relative terms may be used herein to describe the relative positional relationship or movement of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", "front", "back", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure undergoes a position flip or a posture change or a motion state change, then these directional indications also change accordingly, for example: an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative descriptors used herein are interpreted accordingly.

[0049] In order to solve the problem of uneven temperature distribution and difficulty in effective heat dissipation in multi-chip packaging structures in the prior art, the present invention provides a multi-chip plastic packaging structure and method for improving heat dissipation uniformity, which can achieve temperature uniformity of the multi-chip plastic packaging structure, thereby achieving good heat dissipation performance.

[0050] See also Figure 1-Figure 3 The embodiment of the present invention provides a multi-chip plastic packaging structure for improving heat dissipation and temperature uniformity. The multi-chip plastic packaging structure for improving heat dissipation and temperature uniformity includes: a plurality of chips, a substrate 10 and a heat sink 20. The specific structure is described as follows:

[0051] The die is disposed on the substrate 10. Specifically, a plurality of the chips are mounted on the substrate 10 at intervals. The type of the chip includes at least one of FC die 40 and WB die 50. For example, the plurality of chips include both FC die 40 and WB die 50.

[0052] Furthermore, there are differences in the heights of the plurality of chips. In the embodiment of the present invention, at least one of the chips is provided with a thermal pad 30 so that the heights of all the chips are consistent. Specifically, the thermal pad 30 may be provided on some or all of the chips so that the heights of all the chips are consistent, which is not specifically limited in the present invention.

[0053] Furthermore, the heat sink 20 is disposed on all the chips, and the heat sink 20 can cover all the chips. The multiple chips, the substrate 10 , the heat sink 20 and the thermal pad 30 are packaged together by plastic packaging, that is, packaged by resin 60 .

[0054] The technical solution of the embodiment of the present invention is that the multi-chip plastic package structure for improving heat dissipation and uniform temperature includes multiple chips, a substrate 10 and a heat sink 20; multiple chips are arranged on the substrate 10; at least one chip is provided with a thermal pad 30, so that the height of all chips is consistent; the heat sink 20 is arranged on all the chips; multiple chips, the substrate 10, the heat sink 20 and the thermal pad 30 are packaged together by plastic packaging. It can be seen that the present invention can effectively improve the temperature uniformity of the multi-chip plastic package structure and improve the heat dissipation effect by padding the thermal pad 30 on the chip to make the height above all chips consistent, and then padding the heat sink 20 for uniform temperature.

[0055] In some embodiments, such as the present embodiment, the material of the thermal pad 30 is a thermal conductive material. For example, the material of the thermal pad 30 is thermal conductive silica gel, which is not specifically limited in the present invention. The material of the thermal pad 30 is a thermal conductive material, so that the heat generated by the chip can be quickly transferred, greatly improving the heat dissipation effect.

[0056] In some embodiments, such as the present embodiment, the heat sink 20 is made of a metal material. For example, the heat sink 20 is made of copper, aluminum, etc., which is not specifically limited in the present invention. The heat sink 20 is made of a metal material, which has good heat dissipation performance, thereby greatly improving the heat dissipation effect.

[0057] In some embodiments, such as the present embodiment, the upper surface of the heat sink 20 is exposed, that is, the resin 60 on the upper surface of the heat sink 20 is completely removed, thereby greatly improving the heat dissipation efficiency.

[0058] Accordingly, see Figure 4-Figure 8 The embodiment of the present invention provides a multi-chip plastic packaging method for improving heat dissipation and temperature uniformity, and the multi-chip plastic packaging method for improving heat dissipation and temperature uniformity includes the following steps:

[0059] S1, grinding and mounting multiple chips onto a substrate respectively.

[0060] In a specific implementation, the chip (die) is arranged on the substrate, and specifically, a plurality of the chips are mounted on the substrate at intervals. The type of the chip includes at least one of FC die and WB die. For example, in this embodiment, the plurality of the chips include both FC die and WB die.

[0061] S2, setting a gasket on at least one chip so that the heights of all the chips are consistent.

[0062] In a specific implementation, the heights of the plurality of chips are different. In an embodiment of the present invention, at least one of the chips is provided with a thermal pad so that the heights of all the chips are consistent. Specifically, a thermal pad may be provided on some or all of the chips so that the heights of all the chips are consistent, which is not specifically limited in the present invention.

[0063] S3, setting a heat sink on all the chips.

[0064] In a specific implementation, the heat sink is disposed on all the chips, and the heat sink can cover all the chips.

[0065] S4, encapsulating the plurality of chips, the substrate, the heat sink and the thermal pad by plastic packaging.

[0066] It can be seen that the present invention can effectively improve the temperature uniformity of the multi-chip plastic packaging structure and enhance the heat dissipation effect by placing a thermal pad on the chip to make the height above all chips consistent, and then placing a heat sink to even out the temperature.

[0067] In some embodiments, such as the present embodiment, after the plurality of chips, the substrate, the heat sink and the thermal pad are packaged by plastic encapsulation, the method further includes step S5: thinning the resin on the heat sink until the heat sink is exposed.

[0068] In a specific implementation, the upper surface of the heat sink is exposed, that is, the resin on the upper surface of the heat sink is completely removed, thereby greatly improving the heat dissipation efficiency.

[0069] In some embodiments, such as the present embodiment, after the plurality of chips, the substrate, the heat sink and the thermal pad are packaged by plastic encapsulation, the method further comprises: thinning the resin on the heat sink to a preset thickness.

[0070] In a specific implementation, the preset thickness can be set by those skilled in the art according to heat dissipation requirements, and the present invention does not specifically limit it. By thinning the resin on the heat sink to a preset thickness, the heat dissipation efficiency can be effectively improved.

[0071] In some embodiments, such as the present embodiment, the material of the thermal pad is a thermally conductive material. For example, the material of the thermal pad is thermally conductive silica gel, which is not specifically limited in the present invention. The material of the thermal pad is a thermally conductive material, so that the heat generated by the chip can be quickly transferred, greatly improving the heat dissipation effect.

[0072] In some embodiments, such as the present embodiment, the heat sink is made of a metal material. For example, the heat sink is made of copper, aluminum, etc., which is not specifically limited in the present invention. The heat sink is made of a metal material, which has good heat dissipation performance, thereby greatly improving the heat dissipation effect.

[0073] In order to verify the technical effect of the present invention, the following simulation verification test is carried out:

[0074] Simulation model: 15*15*1.5mm, FCCSP package, heat sink is made of copper, thickness is 0.1mm. Its structure is as follows Figure 9-10 As shown. It includes two WB dies (U1, U2) and one FC die (U3).

[0075] Simulation input power consumption: two 0.1W low-power WB dies (U1, U2), one 3W high-power FC die (U3), the parameters are as follows Fig.11 shown.

[0076] A. Perform simulation in a Still Air environment (based on the JEDEC environment), see Fig.12 .

[0077] The simulation results can be found in Figure 13-Figure 15 .

[0078] It can be seen that after the improvement: the maximum temperature of the package is reduced from 86.3℃ to 76.8℃, a decrease of 9.5℃, the temperature gain is 11%, and the temperature gradient of the die inside the package is within 5℃.

[0079] B. Thermal simulation in forced air environment (based on JEDEC environment), see Fig.16 .

[0080] For simulation results, see Figure 17-Figure 18 It can be seen that the maximum temperature inside the package is reduced after improvement, and the package has a uniform temperature within 5°C.

[0081] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0082] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0083] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0084] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0085] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0086] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0087] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0088] The above is a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A multi-chip plastic packaging structure for improving heat dissipation and temperature uniformity, characterized in that: It includes multiple chips, a substrate and a heat sink; the multiple chips are arranged on the substrate; at least one chip is provided with a thermal pad so that the heights of all chips are consistent; the heat sink is arranged on all the chips; the multiple chips, the substrate, the heat sink and the thermal pad are packaged together by plastic packaging.

2. The multi-chip plastic package structure for improving heat dissipation and temperature uniformity according to claim 1, characterized in that: The chip type includes at least one of FC die and WB die.

3. The multi-chip plastic package structure for improving heat dissipation and temperature uniformity according to claim 1, characterized in that: The thermal pad is made of thermally conductive material.

4. The multi-chip plastic package structure for improving heat dissipation and temperature uniformity according to claim 1, characterized in that: The heat sink is made of metal.

5. The multi-chip plastic package structure for improving heat dissipation and temperature uniformity according to claim 1, characterized in that: The upper surface of the heat sink is exposed.

6. A multi-chip plastic packaging method for improving heat dissipation and temperature uniformity, characterized in that: include: Grinding and mounting multiple chips onto a substrate respectively; By arranging a spacer on at least one chip, the heights of all the chips are made consistent; Disposing heat sinks on all of the chips; The plurality of chips, the substrate, the heat sink and the thermal pad are packaged by plastic encapsulation.

7. The multi-chip plastic packaging method for improving heat dissipation and temperature uniformity according to claim 6, characterized in that: After the plurality of chips, the substrate, the heat sink and the thermal pad are packaged by plastic packaging, the method further comprises: The resin on the heat sink is thinned to a preset thickness.

8. The multi-chip plastic packaging method for improving heat dissipation and temperature uniformity according to claim 6, characterized in that: After the plurality of chips, the substrate, the heat sink and the thermal pad are packaged by plastic packaging, the method further comprises: The resin on the heat sink is thinned until the heat sink is exposed.

9. The multi-chip plastic packaging method for improving heat dissipation and temperature uniformity according to claim 6, characterized in that: The chip type includes at least one of FC die and WB die.

10. The multi-chip plastic packaging method for improving heat dissipation and temperature uniformity according to claim 6, characterized in that: The material of the thermal pad is a thermal conductive material; the material of the heat sink is a metal material.

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