A heat sink, a processing method of the heat sink and a three-dimensional packaging structure

Abstract

The application relates to the field of three-dimensional packaging, and discloses a heat dissipation fin, a processing method of the heat dissipation fin and a three-dimensional packaging structure. The heat dissipation fin comprises a main plate, the main plate comprises a heat conduction part and a heat dissipation part which are connected with each other, the surface of the heat conduction part is composed of a plurality of discontinuous planes, and the planes are provided with through holes. The surface of the heat conduction part is divided into a plurality of discontinuous planes, and the through holes are arranged in the planes, so that the accumulated distance of thermal expansion of the main plate and resin in a single direction is reduced, and the resin and the gold main plate cannot be separated and combined loosely due to the excessive thermal expansion difference.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of three-dimensional packaging, in particular to a heat sink, a processing method of the heat sink and a three-dimensional packaging structure. BACKGROUND

[0002] SIP three-dimensional packaging is a new integrated circuit packaging technology in recent years, which breaks through the concept of traditional planar packaging; it is a packaging technology that realizes stacking multiple chips (packaged chips or bare chips) in a single package in three-dimensional space. SIP three-dimensional packaging chips will be more and more widely used in the future of aviation, aerospace electronics due to their high integration, vibration resistance, radiation resistance, low power consumption and other characteristics.

[0003] The current IC device size is continuously reduced and the computer operation speed is continuously improved, which results in large heat and small volume, and the heat is not easy to dissipate, especially in the SIP three-dimensional packaging process of large-scale components stacking. Solving the heat dissipation problem can place the high heat chip more closely in the package to improve the performance of the package and reduce the overall design volume. In the prior art, a large number of chips are packaged in a small SIP structure, and the packaging process is wrapped with a large amount of resin inside the chip. The thermal conductivity of the resin is low, and the inner-enclosed chip mainly relies on the soldered substrate or the exposed pin of the chip for heat dissipation. The small contact area of the heat dissipation point has poor effect and cannot meet the heat dissipation requirements of the chip with large heat. The general metal heat sink cannot be applied in the SIP packaging technology, because the thermal expansion characteristics of the resin and the metal are very different in the current SIP technology. The resin cannot be attached to the surface of the metal with a large area, which is easy to cause the formation of gaps between the metal and the resin. The gap formed in the SIP packaging is easy to cause corrosion gas and conductive substances to enter the inside of the package, which is unacceptable for SIP packaging. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a heat sink, a processing method of the heat sink and a three-dimensional packaging structure, which can be closely combined with the resin to increase the heat dissipation performance of the SIP three-dimensional packaging.

[0005] According to a heat sink provided by a first aspect of an embodiment of the present application, the heat sink comprises a main plate, the main plate comprises a heat-conducting part and a heat-dissipating part connected to each other, the surface of the heat-conducting part is composed of a plurality of discontinuous planes, and a through hole is arranged on the plane.

[0006] The fin according to the first aspect of the embodiment of the present application has at least the following beneficial effects: the fin of the present application reduces the accumulated distance of thermal expansion of the main plate and the resin in a single direction by dividing the surface of the heat-conducting part into several discontinuous planes and arranging through holes in the planes, and the combination of the resin and the gold main plate will not be detached due to the excessive thermal expansion difference.

[0007] The fin according to the first aspect of the embodiment of the present application has at least the following beneficial effects: the fin of the present application reduces the accumulated distance of thermal expansion of the main plate and the resin in a single direction by dividing the surface of the heat-conducting part into several discontinuous planes and arranging through holes in the planes, and the combination of the resin and the gold main plate will not be detached due to the excessive thermal expansion difference.

[0008] The fin according to the first aspect of the embodiment of the present application has at least the following beneficial effects: the fin of the present application reduces the accumulated distance of thermal expansion of the main plate and the resin in a single direction by dividing the surface of the heat-conducting part into several discontinuous planes and arranging through holes in the planes, and the combination of the resin and the gold main plate will not be detached due to the excessive thermal expansion difference.

[0009] The fin according to the first aspect of the embodiment of the present application has at least the following beneficial effects: the fin of the present application reduces the accumulated distance of thermal expansion of the main plate and the resin in a single direction by dividing the surface of the heat-conducting part into several discontinuous planes and arranging through holes in the planes, and the combination of the resin and the gold main plate will not be detached due to the excessive thermal expansion difference.

[0010] The fin according to the first aspect of the embodiment of the present application has at least the following beneficial effects: the fin of the present application reduces the accumulated distance of thermal expansion of the main plate and the resin in a single direction by dividing the surface of the heat-conducting part into several discontinuous planes and arranging through holes in the planes, and the combination of the resin and the gold main plate will not be detached due to the excessive thermal expansion difference.

[0011] The fin according to the first aspect of the embodiment of the present application has at least the following beneficial effects: the fin of the present application reduces the accumulated distance of thermal expansion of the main plate and the resin in a single direction by dividing the surface of the heat-conducting part into several discontinuous planes and arranging through holes in the planes, and the combination of the resin and the gold main plate will not be detached due to the excessive thermal expansion difference.

[0012] The fin according to the first aspect of the embodiment of the present application has at least the following beneficial effects: the fin of the present application reduces the accumulated distance of thermal expansion of the main plate and the resin in a single direction by dividing the surface of the heat-conducting part into several discontinuous planes and arranging through holes in the planes, and the combination of the resin and the gold main plate will not be detached due to the excessive thermal expansion difference.

[0013] The fin according to the first aspect of the embodiment of the present application has at least the following beneficial effects: the fin of the present application reduces the accumulated distance of thermal expansion of the main plate and the resin in a single direction by dividing the surface of the heat-conducting part into several discontinuous planes and arranging through holes in the planes, and the combination of the resin and the gold main plate will not be detached due to the excessive thermal expansion difference.

[0014] The three-dimensional packaging structure according to the second aspect of the embodiment of the present application has at least the following beneficial effects: the three-dimensional packaging structure of the present application uses the fin according to the first aspect of the embodiment of the present application, and the fin is placed between adjacent chips, and the heat of the chips is conducted away through the fin, so that the heat dissipation of the packaging is greatly improved, and the design of the SIP three-dimensional packaging is no longer restricted by the heat of the chips, and the design and production can be more flexible.

[0015] The three-dimensional packaging structure according to the second aspect of the embodiment of the present application has at least the following beneficial effects: the three-dimensional packaging structure of the present application uses the fin according to the first aspect of the embodiment of the present application, and the fin is placed between adjacent chips, and the heat of the chips is conducted away through the fin, so that the heat dissipation of the packaging is greatly improved, and the design of the SIP three-dimensional packaging is no longer restricted by the heat of the chips, and the design and production can be more flexible.

[0016] According to the fin processing method of the third aspect of the embodiment of the present application, the following steps are included: embossing, the rolling machine forms the staggered indentation on the surface of the main plate, and the surface of the main plate is staggered from a single surface to multiple discontinuous planes; drilling, the drilling machine is used to punch on each discontinuous plane of the main plate to form a staggered net structure; surface treatment, the sandblasting or polishing method is used to form the frosted effect on the main plate.

[0017] According to the fin processing method of the third aspect of the embodiment of the present application, at least the following beneficial effects are obtained: through embossing, drilling and surface treatment, the main plate with multiple discontinuous planes is formed, the cumulative distance of thermal expansion of the main plate and the resin in a single direction is reduced, the combination of the resin and the gold main plate will not be separated due to the large difference in thermal expansion and the loose combination, and the frosted effect can increase the adhesion between the main plate and the resin, so that the combination is more compact.

[0018] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0020] Figure 1 It is a structure schematic view of the front surface of the fin in the embodiment of the present application;

[0021] Figure 2 It is a structure schematic view of the back surface of the fin in the embodiment of the present application; Figure 1 It is a partial enlarged view of A part in the embodiment of the present application;

[0022] Figure 3 It is a structure schematic view of the back surface of the fin in the embodiment of the present application;

[0023] Figure 4 It is a structure schematic view of the back surface of the fin in the embodiment of the present application; Figure 2 It is a partial enlarged view of B part in the embodiment of the present application;

[0024] Figure 5 It is a structure schematic view of the back surface of the fin in the embodiment of the present application;

[0025] Figure 6 It is a structure schematic view of the back surface of the fin in the embodiment of the present application; Figure 5 It is a structure schematic view of the back surface of the fin in the embodiment of the present application; DETAILED DESCRIPTION

[0026] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below are exemplary and are intended to explain the present application, but are not to be understood as limiting the present application.

[0027] In the description of the present application, if the orientation description such as the positive, negative, upper, lower, and the like is indicated, the orientation or position relationship based on the orientation or position relationship shown in the drawings is for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0028] In the description of the present application, the meaning of several is one or more, and the meaning of multiple is two or more. Greater than, less than, more than, and the like are understood as not including the number itself. Above, below, and the like are understood as including the number itself. If the first and second are described, they are only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of technical features indicated.

[0029] In the description of the present application, unless otherwise explicitly limited, the words such as arrangement, installation, connection, and the like should be broadly understood, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0030] The following description of the embodiments of the present application is made with reference to the accompanying drawings. Figures 1 to 4 A heat sink is described.

[0031] As shown in Figures 1 to 4 A heat sink includes a main plate 1, the main plate 1 includes a heat-conducting part 11 and a heat-dissipating part 12 connected to each other, the surface of the heat-conducting part 11 is composed of a plurality of discontinuous planes 111, and a through hole 112 is arranged on the plane 111. By dividing the surface of the heat-conducting part 11 into a plurality of discontinuous planes 111 and arranging the through hole 112 in the plane 111, the accumulated distance of thermal expansion of the main plate 1 and the resin in a single direction is reduced, and the combination of the resin and the gold main plate 1 will not be detached or combined loosely due to the large difference in thermal expansion. The heat-conducting part 11 is the part in contact with the heat source, and the heat source can be a three-dimensional packaged heat-generating chip. The heat-dissipating part 12 does not need to be in contact with the chip, and the heat is transferred from the heat-conducting part 11 to the heat-dissipating part 12, and dissipated through the heat-dissipating part 12.

[0032] In some embodiments of the present application, the heights of the adjacent planes 111 are different or the contact positions of the adjacent planes 111 are provided with grooves 113, which are divided by the planes 111 with different height differences or the grooves 113 between the different planes 111.

[0033] In some embodiments of the present application, the cross sections of the through holes 112 are polygons, such as hexagons, pentagons, quadrilaterals, etc., which are gradually reduced from one side of the opening to the other side, and are reduced to a circle at the outlet. Moreover, the shapes of the through holes 112 provided on the planes 111 with different heights are the same and are opposite in direction.

[0034] Specifically, the front and back surfaces of the heat dissipation part 12 are divided into a plurality of planes 111, and the shapes of the planes 111 can be changed arbitrarily. In the present embodiment, each plane 111 is a regular hexagon, and each seven planes 111 is a unit. Each unit includes six planes 111 surrounding a regular hexagon at the center and one plane 111 at the center. The plane 111 at the center is different in height from the other six planes 111, and the other six planes 111 are provided with wedge-shaped grooves 113 on the adjacent sides. The shapes of the grooves 113 are not limited, such as rectangles, circles, etc. See Figure 2 and Figure 4 The heights of the six planes 111 at the edges of each unit on the front surface of the heat dissipation part 12 are higher than that of the plane 111 at the center, and the height of the plane 111 at the center on the back surface is higher than that of the planes 111 at the edges. Each discontinuous hexagonal plane 111 is provided with a through hole 112, and the cross section of the through hole 112 is a hexagon which is gradually reduced from one side of the opening to the other side, and is reduced to a circle at the outlet. Moreover, the shapes of the through holes 112 provided on the planes 111 with different heights are the same and are opposite in direction. For example, the shapes of the through holes 112 on the plane 111 at the center and the through holes 112 on the planes 111 at the edges in each unit are the same and are opposite in direction.

[0035] In some embodiments of the present application, the heat dissipation part 12 is provided with heat dissipation strips 121. The heat dissipation strips 121 can be one or more, and the heat dissipation area is increased by increasing the heat dissipation strips 121, thereby improving the heat dissipation performance.

[0036] In some embodiments of the present application, the heat dissipation strips 121 are wave-shaped, which can form a larger contact surface in a smaller space, thereby improving the heat dissipation performance.

[0037] In some embodiments of the present application, the main board 1 is a metal plate with good heat dissipation performance. For example, it is a copper plate, a tin plate, an aluminum plate, a titanium plate or a silver plate, etc. The metal plate, especially the copper plate, the tin plate, the aluminum plate, the titanium plate or the silver plate, etc. has good heat dissipation performance and good ductility, and is easy to process.

[0038] See Figure 5A three-dimensional packaging structure comprises at least two mutually stacked chip layers 3, each of which comprises at least one chip, and at least one set of adjacent chip layers 3 is provided with the heat sink as described above. The three-dimensional packaging structure of the embodiment of the present application uses the heat sink of the first aspect of the present application, and the heat sink is placed between the adjacent chip layers 3. The heat of the chip is conducted out through the heat sink, so that the heat dissipation of the package is greatly improved. The design of the SIP three-dimensional package is no longer subject to the heat generated by the chip, and the design and production can be more flexible. The three-dimensional packaging structure in the embodiment is subjected to resin pouring treatment to form a product as shown in Figure 6 The heat sink is sealed inside the resin, and the heat of the chip is dissipated through the heat sink and the poured resin in turn.

[0039] The embodiment of the present application also provides a processing method of the heat sink, which comprises the following steps: embossing, forming staggered indentations on the surface of the main plate 1 by using a rolling machine to stagger the surface of the main plate 1 from a single surface into a plurality of discontinuous planes 111; drilling, performing punching on each discontinuous plane 111 of the main plate 1 by using a drilling machine to form a staggered mesh structure; surface treatment, forming a frosted effect on the main plate 1 by using sandblasting or polishing. The material of the main plate 1 is selected from metal plates with good heat dissipation, such as copper plates, tin plates, aluminum plates, titanium plates or silver plates. The metal plates, especially copper plates, tin plates, aluminum plates, titanium plates or silver plates, have good heat dissipation performance and good ductility, are convenient to process, and can be polished to remove burrs generated in the processing process during surface roughening treatment. Through embossing, drilling and surface treatment, the main plate 1 with a plurality of discontinuous planes 111 is formed, the cumulative distance of thermal expansion of the main plate 1 and the resin in a single direction is reduced, and the resin and the gold main plate 1 will not be detached or combined loosely due to the large difference in thermal expansion. The frosted effect can increase the adhesion between the main plate 1 and the resin, so that they are combined more tightly.

Claims

1. A heat sink for a SIP (System in Package), characterized by: The heat sink for SIP three-dimensional packaging comprises a main plate (1), the main plate (1) comprises a heat-conducting part (11) and a heat-dissipating part (12) connected with each other, the surface of the heat-conducting part (11) is composed of several discontinuous planes (111), and the planes (111) are provided with through holes (112); The heights of the adjacent planes (111) are different, and the contact positions of the adjacent planes (111) are provided with grooves (113); The cross section of the through hole (112) is a polygon gradually reduced from one side to the other side, and is reduced into a circle at the outlet; The shapes of the through holes (112) provided on the planes (111) with different heights are the same, and the directions are opposite, the discontinuous planes and the through holes can reduce the accumulated distance of thermal expansion and contraction of the main plate and the packaging resin in a single direction.

2. The heat sink for a SIP package of claim 1, wherein: The heat-dissipating part (12) is provided with heat-dissipating strips (121).

3. A heat sink for a SIP package according to claim 2, wherein: The heat-dissipating strips (121) are in a wave shape.

4. The heat sink for a SIP package of claim 1, wherein: The main plate (1) is a metal plate.

5. A heat sink for a SIP package according to claim 4, wherein: The main plate (1) is a copper plate, a tin plate, an aluminum plate, a titanium plate or a silver plate.

6. A three-dimensional packaging structure, characterized by comprising: The heat sink for SIP three-dimensional packaging comprises at least two chip layers (3) stacked with each other, each chip layer (3) comprises at least one chip, and at least one group of adjacent chip layers (3) are provided with the heat sink for SIP three-dimensional packaging according to any one of claims 1 to 5.

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