CN107195603A - A kind of preparation method of the encapsulating structure based on high heat conduction phase-change material phase-change heat technology - Google Patents

Abstract

The invention belongs to integrated antenna package technical field, it is related to a kind of active heat removal technical field of wafer-level packaging chips.In the embodiment of the present invention, the preparation method of the encapsulating structure based on high heat conduction phase-change material phase-change heat technology, it is characterised in that including：Groove or blind hole are made at the wafer stage chip back side using standard etch technique；The high heat conduction phase-change material as heat catalysis is put into wafer stage chip back side groove or blind hole；Wafer stage chip back side welding upper cover plate carries out sealing cap, ensures that high heat conduction phase-change material does not spill over package body structure in phase transition process；Single-chip with phase change radiator structure is obtained by conventional scribing process.

Description

Preparation of a packaging structure based on high thermal conductivity phase change material phase change heat dissipation technology method

technical field

The invention belongs to the technical field of integrated circuit packaging, and relates to an active heat dissipation technology for chips in wafer-level packaging, in particular to a technology that uses high thermal conductivity phase change materials in the cavity on the back of the chip to easily undergo phase transition due to temperature changes Features, technology to realize active cooling of chips.

Background technique

In a distributed database system, the master node divides multiple data records stored in the data table into multiple data tables and distributes them to multiple slave nodes. When it is necessary to query some data records, it is necessary to connect the associated data records stored in the data tables on each slave node. In the specific implementation process, every two data tables are connected. Therefore, this data The record query method is called the two-table join method, and an example is given below.

With the increase of integration, power consumption and size reduction of modern electronic chips, the rapidly increasing heat generation of chip systems has become a major challenge in the development and application of advanced electronic chip systems. Generally, the failure rate of components increases exponentially with the increase of device temperature, and the reliability of the device decreases by 5% for every 1 ℃ increase in the level of 70-80 ℃.

Therefore, traditional cooling methods can no longer meet the heat dissipation requirements of future advanced electronic components (such as high-power microwave, millimeter-wave devices, and airborne and spaceborne electronic equipment, etc.). Solving the heat dissipation problem of high heat flux electronic components requires a new breakthrough, which makes thermal management a key technology in the development and application of electronic chip systems, and objectively puts forward very urgent requirements for the heat dissipation technology of microelectronic devices .

Phase change heat dissipation technology is a technology that utilizes the phase change of matter to release the latent heat of phase change. Experimental data shows that the ability of phase change to dissipate heat is several times or even dozens of times higher than that of simple temperature difference. Phase change materials can store or release a large amount of heat during the phase change process, and the phase change process is approximately isothermal, which can effectively protect the chip from overheating. At the same time, it has the advantages of small size, light weight, reliable performance, economy and no energy consumption, which makes phase change heat dissipation become a research hotspot in the field of thermal science recently.

Contents of the invention

The invention provides a method for preparing a packaging structure based on a high-thermal-conductivity phase-change material phase-change heat dissipation technology, and a heat dissipation structure for a wafer-level package chip, which can rapidly dissipate heat for an integrated circuit chip.

An embodiment of the present invention provides a method for preparing a packaging structure based on phase change heat dissipation technology of high thermal conductivity phase change materials, including: using a standard etching process to make grooves or blind holes on the back of the wafer-level chip; Put a high thermal conductivity phase change material as a heat transfer medium in the groove or blind hole; weld the upper cover plate on the back of the wafer level chip to seal the cap, so as to ensure that the high thermal conductivity phase change material does not overflow the package structure during the phase transition process; A single chip with a phase-change heat dissipation structure is obtained through a conventional planning wafer process.

Optionally, the size of the groove or the blind hole depends on the specific product, and the etching depth should not exceed the thickness of the chip body.

Optionally, the amount of phase change material put into the groove or blind hole depends on the size of the groove or blind hole. Optionally, the bonding method of the cover plate and the chip depends on the material of the cover plate.

Optionally, the bonding method of the cover plate and the chip is silicon-silicon direct bonding, or alloy eutectic bonding.

The embodiment of the present invention also provides a heat dissipation structure for a wafer-level packaged chip. The heat dissipation structure includes a wafer-level packaged chip 3 and a heat-conducting cover plate 1. The chip 3 and the cover plate 1 are welded together by solder 2; its features The reason is that the heat dissipation structure also includes grooves or blind holes etched on the back of the wafer-level package chip 3, and the high thermal conductivity phase change material 4 is installed in the grooves or blind holes; the entire heat dissipation structure manufacturing process is completed on the wafer.

Optionally, the size of the groove or the blind hole depends on the specific product, and the etching depth should not exceed the thickness of the chip body.

Optionally, the bonding method of the cover plate and the chip depends on the material of the cover plate.

Optionally, the bonding method of the cover plate and the chip is silicon-silicon direct bonding, or alloy eutectic bonding.

With such a technical solution, most of the heat generated by the chip can be quickly exported through the back of the chip. The specific heat dissipation principle of the chip is: the chip generates heat during operation, and the phase change material in the cavity on the back of the chip near the heating end of the chip changes from solid to liquid Or change from liquid to vapor to absorb heat; the phase change material near the cold end of the cover plate changes from liquid to solid or from vapor to liquid to release heat, forming a heat conduction cycle. In this way, the active heat dissipation process of the chip is completed, and the high thermal conductivity phase change material acts as a heat transfer medium, thereby realizing the purpose of quickly dissipating heat from the integrated circuit chip, effectively improving the operating speed and efficiency, improving operating reliability, and extending service life.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Figure 1 is a schematic diagram of the back of the wafer-level chip; 1-1 wafer; 1-2 the back of the chip;

Figure 2 is a schematic diagram of the back of the chip after etching the groove;

Figure 3 is a phase change material with high thermal conductivity placed in the groove;

Fig. 4 is a cross-sectional view of a single chip structure obtained after welding the cover plate and dicing.

Among them, 1 metal/silicon cover plate; 2 solder; 3 chip; 4 high thermal conductivity phase change material.

detailed description

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only the present invention.

Some of the embodiments are described, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

FIG. 1 to FIG. 4 show specific embodiments of the heat dissipation structure of the cavity on the back side of the wafer-level packaged chip. It includes a metal/silicon cover plate 1 , solder 2 for welding the cover plate and the chip, a chip 3 with grooves or blind holes etched on the backside, and a phase-change material 4 with high thermal conductivity.

The above-mentioned preparation method of the packaging structure based on the high thermal conductivity phase change material phase change heat dissipation technology includes the following steps:

Step 1: Use a standard etching process to make grooves or blind holes on the back of the wafer-level chip. The size of the groove or blind hole depends on the specific product, and the etching depth should not exceed the thickness of the chip body.

Step 2: Put a high thermal conductivity phase change material as a heat transfer medium into the groove or blind hole on the back of the wafer-level chip, and the amount depends on the size of the groove or blind hole;

Step 3: Weld the upper cover plate on the back of the wafer-level chip to seal the cap to ensure that the high thermal conductivity phase change material does not overflow the package structure during the phase transition process. The thickness of the cover plate depends on the specific product. The bonding method between the cover plate and the chip depends on the material of the cover plate, including but not limited to silicon-silicon direct bonding, alloy eutectic and other methods.

Step 4: Obtain a single chip with a phase-change heat dissipation structure through the conventional planning chip process, realize the purpose of quickly dissipating heat from the integrated circuit chip, effectively improve the operating speed and efficiency, improve the operating reliability, and prolong the service life.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

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 equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (9)

1. A method for preparing a packaging structure based on high thermal conductivity phase change material phase change heat dissipation technology, characterized in that it includes: Make grooves or blind holes on the backside of wafer-level chips using standard etching processes; Put a high thermal conductivity phase change material as a heat transfer medium in the groove or blind hole on the back of the wafer-level chip; The upper cover plate is welded on the back of the wafer-level chip to seal the cap, so as to ensure that the high thermal conductivity phase change material does not overflow the package structure during the phase transition process; A single chip with a phase-change heat dissipation structure is obtained through a conventional planning wafer process. 2. The preparation method according to claim 1, wherein the size of the groove or the blind hole depends on the specific product, and the etching depth should not exceed the thickness of the chip body. 3. The preparation method according to claim 1, characterized in that the amount of phase change material put into the groove or blind hole depends on the size of the groove or blind hole. 4. The manufacturing method according to claim 1, wherein the bonding method of the cover plate and the chip depends on the material of the cover plate. 5. The manufacturing method according to claim 1, wherein the bonding method of the cover plate and the chip is silicon-silicon direct bonding, or alloy eutectic bonding. 6. A heat dissipation structure for a wafer-level packaged chip, said heat dissipation structure comprising: a wafer-level packaged chip 3, a heat-conducting cover plate 1, and the chip 3 and the cover plate 1 are welded together by solder 2; it is characterized in that: heat dissipation The structure also includes grooves or blind holes etched on the back of the wafer-level package chip 3, and a high thermal conductivity phase change material 4 is installed in the grooves or blind holes; the entire heat dissipation structure manufacturing process is completed on the wafer. 7. The heat dissipation structure according to claim 6, wherein the size of the groove or the blind hole depends on the specific product, and the etching depth should not exceed the thickness of the chip body. 8. The heat dissipation structure according to claim 6, wherein the bonding method of the cover plate and the chip depends on the material of the cover plate. 9. The heat dissipation structure according to claim 6, wherein the bonding method of the cover plate and the chip is silicon-silicon direct bonding, or alloy eutectic bonding.