WO2024179385A1 - Chip module and preparation method therefor, optical module, communication system, and electronic device - Google Patents

Abstract

Disclosed in embodiments of the present application are a chip module and a preparation method therefor, an optical module, a communication system, and an electronic device. The chip module comprises a circuit board and a chip provided on the circuit board; a heat dissipation structure is provided on the side of chip away from the circuit board; a thermal interface material is provided between the chip and the heat dissipation structure; and a heat spreader is provided between the chip and the thermal interface material and/or between the thermal interface material and the heat dissipation structure. The thermal expansion coefficient of the heat spreader matches the thermal expansion coefficient of the chip, and the thermal conductivity coefficient of the heat spreader is greater than the thermal conductivity coefficient of the thermal interface material. Therefore, by providing the heat spreader having a high thermal conductivity coefficient on the surface of the chip, the heat spreading performance is better, so that heat can be better spread and the power density of the chip is reduced, thereby reducing the temperature difference between the chip and the thermal interface material and improving the heat dissipation performance of the chip. In addition, the thermal expansion coefficient of the heat spreader is close to the thermal expansion coefficient of the chip, thereby reducing the thermal stress and preventing the separation and cracking of soldering surfaces.

Description

Chip module and preparation method thereof, optical module, communication system and electronic device

This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on February 28, 2023, with application number 202310230206.2 and application name “Chip module and preparation method thereof, optical module, communication system and electronic device”, all contents of which are incorporated by reference in this application.

Technical Field

The embodiments of the present application relate to the field of electronic technology, and in particular to a chip module and a method for preparing the same, an optical module, a communication system, and an electronic device.

Background Art

At present, with the increase in power consumption of electronic devices, a large amount of heat will be generated when the chip is running. If the heat is not effectively dissipated to ensure that the chip runs at a safe temperature, the chip life will be sharply reduced, and in severe cases it will even burn out. Therefore, heat dissipation technology has become a key technology to support the further development of electronic technology.

The current chip heat dissipation method is to set a thermal interface material on the chip surface and then directly contact the conductor to dissipate heat.

As shown in FIG1 , the optical module includes: an upper shell 200, a bottom plate 300, a substrate 100, and a chip 101 arranged on the substrate 100, wherein the upper shell 200 and the bottom plate 300 enclose a space for accommodating the substrate 100 and the chip 101, wherein the lower surface of the upper shell 200 is provided with at least one second bump 2012 for contacting the upper surface of the chip 101, and when working, the heat generated on the chip 101 can be transferred to the upper shell 200 through the second bump 2012 for heat dissipation.

The chip module 2 in FIG13 can be used in electronic devices such as routers and servers. As shown in FIG13 , the chip module 2 includes: a chip 101, a heat sink 600, a circuit board 400 and a substrate 100, wherein the chip 101 is arranged on the circuit board 400, the heat sink 600 is fixed on the chip 101, and the chip 101 is in contact with the heat sink 600 through the thermal interface material 103 for heat dissipation.

However, the greater the chip power density, the greater the temperature difference caused by the thermal resistance of the thermal interface material, and the worse the heat dissipation effect.

Summary of the invention

The embodiments of the present application provide a chip module and a preparation method thereof, an optical module, a communication system and an electronic device to improve the heat dissipation performance of a chip.

In order to achieve the above-mentioned purpose, the embodiment of the present application adopts the following technical solution:

The first aspect of the embodiment of the present application provides a chip module, including: a circuit board, and a chip arranged on the circuit board; a heat dissipation structure is arranged on the side of the chip away from the circuit board; a thermal interface material is arranged between the chip and the heat dissipation structure; a temperature balancing plate is arranged between the chip and the thermal interface material, and/or between the thermal interface material and the heat dissipation structure; wherein the thermal expansion coefficient of the temperature balancing plate matches the thermal expansion coefficient of the chip, and the thermal conductivity of the temperature balancing plate is greater than the thermal conductivity of the thermal interface material. Therefore, a temperature balancing plate with a high thermal conductivity is arranged on the surface of the chip, and the temperature balancing performance is better, and the heat can be better dispersed, thereby reducing the chip power density, so as to reduce the temperature difference between the chip and the thermal interface material, thereby reducing the chip operating temperature, that is, the chip junction temperature, and improving the chip heat dissipation performance. In addition, the thermal expansion coefficients of the temperature balancing plate and the chip are close, which can reduce the thermal stress between the chip and the temperature balancing plate and avoid separation and cracking of the welding surface.

In an optional implementation, the size of the temperature spreader is greater than or equal to the size of the chip. As a result, the surface of the temperature spreader and the chip can be completely fitted together, increasing the contact area between the temperature spreader and the chip. At the same time, the size of the temperature spreader is larger, which improves the thermal conductivity of the temperature spreader to ensure that the heat of the chip can be fully transferred through the temperature spreader.

In an optional implementation, the temperature spreader includes: a first temperature spreader, the first temperature spreader is arranged between the chip and the thermal interface material, the first temperature spreader is connected to the chip by welding, and the welding surface of the chip and the welding surface of the first temperature spreader are plated with a metal film. Thus, by arranging the metal film on the welding surface, the welding performance of the chip and the first temperature spreader can be improved, so that the chip and the first temperature spreader can be better connected by solder welding.

In an optional implementation, the first temperature spreader includes a first part and a second part, the first part is arranged close to the chip, the second part is arranged close to the thermal interface material, the size of the first part is the same as the size of the chip, and the size of the second part is larger than the size of the first part. Thus, the connection stability between the first temperature spreader and the chip is improved, and the heat dissipation area is increased.

In an optional implementation, the temperature balancing plate includes: a second temperature balancing plate, the second temperature balancing plate is arranged between the thermal interface material and the heat dissipation structure, the heat dissipation structure and the second temperature balancing plate are welded and connected, and the welding surface of the heat sink and the welding surface of the second temperature balancing plate are welded. Thus, by providing the metal film on the welding surface of the heat sink and the welding surface of the second temperature balancing plate, the welding performance of the heat dissipation structure and the second temperature balancing plate can be improved, so that the heat dissipation structure and the second temperature balancing plate can be better connected by soldering.

In an optional implementation, the temperature-regulating plate is made of diamond or an alloy material containing diamond. Therefore, the material of the temperature-regulating plate includes diamond, whose thermal expansion coefficient is close to that of the chip, so as to avoid chip warping during welding or use, and diamond has a high thermal conductivity, which can better dissipate heat.

In an optional implementation, the thermal interface material includes: thermally conductive gel, thermally conductive silicone grease or thermally conductive sheet. Thus, the thermal interface material uses a flexible thermally conductive material such as thermally conductive gel, and the fluidity of the flexible thermal interface material can be used to fully fill the gap between adjacent structures, so that two adjacent structures connected by the thermal interface material are in full contact, so that the heat generated by the chip can be timely transferred to the heat dissipation structure through the flexible thermal interface material and dissipated, thereby enhancing the heat dissipation performance of the optical module and improving the reliability of the optical module.

In an optional implementation, a stopper is provided on the circuit board, and the height of the stopper from the circuit board is higher than the height of the chip from the circuit board. Thus, the stopper can support the device above the chip to prevent the solder above the chip from being squeezed out during welding, thereby better controlling the thickness of the solder after welding.

In an optional implementation, the heat dissipation structure includes: a cold plate, a temperature equalizing plate, and an evaporative heat sink, thereby further improving the heat dissipation performance of the chip module.

The second aspect of the embodiment of the present application provides an optical module, comprising: a housing, and the chip module as described above, wherein the heat dissipation structure is a part of the housing, or the heat dissipation structure is arranged outside the housing. Thus, the optical module adopts the chip module as described above, and has better heat dissipation performance.

In an optional implementation, the optical module further includes: a substrate and an optical device, and the optical device and the chip module are arranged on the substrate, thereby facilitating the control of the optical module.

In an optional implementation, the housing includes: an upper shell and a bottom plate, the upper shell includes: a top plate and a bracket, the bracket is connected to the bottom plate, and the base plate is connected to the bottom plate. Thus, after the base plate is connected to the bottom plate and the chip module is assembled, the upper shell can be buckled onto the bottom plate, which facilitates the assembly of the chip module.

In an optional implementation, the top plate is provided with a first bump and a second bump, the first bump is connected to the optical device through a thermal interface material, and the second bump is connected to the chip module. Thus, by providing the first bump and the second bump, the housing can be fully in contact with the optical device through the first bump, and the housing can be fully in contact with the chip module through the second bump, thereby improving the heat dissipation performance of the optical module.

In a third aspect of the embodiments of the present application, a communication system is provided, comprising: a data source, an optical channel, and the optical module as described above, wherein the data source is used to send a data signal to the optical module, and the optical module is used to convert the data signal into an optical signal and transmit it through the optical channel. Thus, the communication system adopts the optical module, and has better heat dissipation performance.

According to a fourth aspect of the embodiments of the present application, an electronic device is provided, the electronic device comprising: a substrate, and the chip module as described above, the chip module being arranged on the substrate. Thus, the electronic device adopts the chip module as described above, and has better heat dissipation performance.

In an optional implementation, the electronic device is a router or a server. Thus, the chip module has a wider application range.

In a fifth aspect of an embodiment of the present application, a method for preparing a chip module is provided, comprising: soldering a chip on a circuit board; stacking a temperature spreader and a thermal interface material on a side of the chip away from the circuit board; the thermal expansion coefficient of the temperature spreader matches the thermal expansion coefficient of the chip, and the thermal conductivity of the temperature spreader is greater than the thermal conductivity of the thermal interface material; and arranging a heat dissipation structure on a side of the stacked temperature spreader and the thermal interface material away from the chip, wherein the temperature spreader is provided between the chip and the thermal interface material, and/or between the thermal interface material and the heat dissipation structure.

In an optional implementation, before soldering the chip to the circuit board, the method further includes: coating a metal film on the soldering surface of the temperature spreader, the soldering surface of the chip and/or the soldering surface of the heat dissipation structure.

In an optional implementation, before setting the temperature equalizer and thermal interface material on the side of the chip away from the circuit board, the method also includes: setting a limiter on the surface of the circuit board or the chip, wherein the height of the limiter from the circuit board is higher than the height of the chip from the circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of an optical module provided by the prior art;

FIG2 is a schematic diagram of the structure of an optical module provided in an embodiment of the present application;

FIG3 is a schematic diagram of the structure of another optical module provided in an embodiment of the present application;

FIG4 is a schematic diagram of the structure of another optical module provided in an embodiment of the present application;

FIG5 is a flow chart of a method for preparing a chip module provided in an embodiment of the present application;

Figures 6, 7, 8 and 9 are schematic diagrams of product structures obtained after executing the steps in Figure 5;

FIG10 is a flow chart of another method for preparing a chip module provided in an embodiment of the present application;

FIG11 is a flow chart of another method for preparing a chip module provided in an embodiment of the present application;

FIG12 is a three-dimensional diagram of a chip module provided in an embodiment of the present application;

FIG13 is a schematic diagram of the structure of a chip module provided by the prior art;

FIG14 is a schematic diagram of the structure of a chip module provided in an embodiment of the present application;

FIG15 is a schematic diagram of the structure of another chip module provided in an embodiment of the present application;

FIG16 is a schematic diagram of the structure of another chip module provided in an embodiment of the present application;

FIG. 17 is a schematic diagram of the structure of a chip module provided in an embodiment of the present application.

DETAILED DESCRIPTION

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

In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, unless otherwise specified, "plurality" means two or more.

In addition, in the present application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to the changes in the orientation of the components in the drawings.

An embodiment of the present application provides a communication system, including: a data source, an optical channel, and an optical module, wherein the data source is used to send a data signal to the optical module, and the optical module is used to convert the data signal into an optical signal and transmit it through the optical channel.

The optical module provided in the embodiment of the present application is described below in conjunction with the accompanying drawings. Figure 2 is a schematic diagram of the structure of the first optical module provided in the embodiment of the present application. As shown in Figure 2, the optical module 1 includes: a housing, a substrate 100, wherein one or more chips 101 and an optical device 102 are provided on the substrate 100, and the substrate 100, the chip 101 and the optical device 102 are all located in the housing.

The embodiment of the present application does not limit the structure and material of the housing. In one implementation of the present application, the housing includes: an upper housing 200 and a bottom plate 300, the upper housing 200 and the bottom plate 300 are buckled together, and the substrate 100 is located in the area enclosed by the upper housing 200 and the bottom plate 300.

In some embodiments of the present application, the upper shell 200 is composed of, for example, a top plate 201 and a bracket 202 . The bracket 202 is supported on the bottom plate 300 , and the bracket 202 is disposed around the chip 101 .

The embodiment of the present application does not limit the molding method of the bracket 202 and the top plate 201. In one implementation of the present application, the bracket 202 can be made of the same material as the top plate 201. During processing, the bracket 202 can be die-cast as a whole with the top plate 201, and the end of the bracket 202 away from the top plate 201 can be fixedly connected to the bottom plate 300 by a thermally conductive adhesive.

In other implementations of the present application, the bracket 202 and the top plate 201 can be die-cast separately, and the bracket 202, for example, includes a first end and a second end relative to each other. The first end of the bracket 202 can be fixedly connected to the top plate 201 by, for example, a thermally conductive adhesive, and the second end of the bracket 202 can be fixedly connected to the bottom plate 300 by, for example, a thermally conductive adhesive.

The embodiment of the present application does not limit the specific structure of the bracket 202. In one implementation of the present application, the bracket 202 can adopt an annular structure, and the bracket 202 is evenly supported at the edge of the circuit board, for example.

Thus, the bracket 202 can support the top plate 201 on the bottom plate 300 and evenly distribute the gravity of the top plate 201 on the bottom plate 300 .

The embodiment of the present application does not limit the connection method between the upper shell 200 and the bottom plate 300. In some embodiments of the present application, the upper shell 200 and the bottom plate 300 are fixedly connected by bolts.

The substrate 100 includes a first surface and a second surface opposite to each other, the first surface of the substrate 100 is connected to the bottom plate 300, and the second surface of the substrate 100 is away from the bottom plate 300. In some embodiments of the present application, the first surface of the substrate 100 is connected to the bottom plate 300 via a connector.

One or more chips 101 and optical devices 102 are disposed on the second surface of the substrate 100 .

The optical device 102 includes a first surface and a second surface opposite to each other. The first surface of the optical device 102 is connected to the second surface of the substrate 100 , and the second surface of the optical device 102 is connected to the top plate 201 via the thermal interface material 103 .

In some embodiments of the present application, a first bump 2011 is provided on one side of the top plate 201 close to the optical device, the first bump 2011 is opposite to the optical device 102, and the shape of the first bump 2011 matches the shape of the optical device 102, and the optical device 102 is connected to the first bump 2011 through a thermal interface material (TIM) 103. Therefore, by providing the first bump 2011, the housing can be fully in contact with the optical device 102 through the first bump 2011, thereby improving the heat dissipation performance of the optical module.

The thermal interface material 103 may be a flexible thermally conductive material. The thermal interface material 103 includes: thermally conductive gel, thermally conductive silicone grease or thermally conductive sheet.

In some embodiments of the present application, the chip 101 is disposed on the circuit board 400 and is electrically connected to the substrate 100 through the circuit board 400. In some embodiments of the present application, the circuit board 400 is electrically connected to the substrate 100 through the first electrical connector 401. In some embodiments of the present application, the chip 101 is electrically connected to the circuit board 400 through the second electrical connector 402.

The embodiment of the present application does not limit the structures of the first electrical connector 401 and the second electrical connector 402. For example, the first electrical connector 401 and the second electrical connector 402 may include a plurality of uniformly arranged solder balls.

In some embodiments of the present application, a second bump 2012 is provided on one side of the top plate 201 close to the chip 101, the second bump 2012 is, for example, opposite to the chip 101, and the shape of the second bump 2012 matches the shape of the chip 101, and the chip 101 can be connected through the thermal interface material 103 and the second bump 2012. Thus, by providing the second bump 2012, the housing can be fully in contact with the chip module 101 through the second bump 2012, thereby improving the heat dissipation performance of the optical module.

In some embodiments of the present application, the thermal interface material 103 may be a flexible thermally conductive material. The thermal interface material 103 includes: thermally conductive gel, thermally conductive silicone grease or a thermally conductive sheet.

However, as the chip power density increases, the temperature difference caused by the thermal resistance of the thermal interface material becomes larger and the heat dissipation effect becomes worse.

To this end, an embodiment of the present application provides an improved optical module 1.

2 , the optical module 1 further includes a temperature-distributing plate 500 . The temperature-distributing plate 500 and the thermal interface material 103 may be disposed between the chip 101 and the second bump 2012 to evenly disperse the heat generated by the chip 101 and reduce the power density of the chip 101 .

In some embodiments of the present application, the thermal expansion coefficient of the temperature-regulating plate matches the thermal expansion coefficient of the chip. The thermal expansion coefficient of the temperature-regulating plate matches the thermal expansion coefficient of the chip, which means that the thermal expansion coefficient of the temperature-regulating plate is close to the thermal expansion coefficient of the chip. In some embodiments, the thermal expansion coefficient of the temperature-regulating plate and the thermal expansion coefficient of the chip may differ by 3m/K-7m/K. Therefore, the thermal expansion coefficients of the temperature-regulating plate and the chip are close, which can reduce the thermal stress between the chip and the temperature-regulating plate and avoid separation and cracking of the welding surface.

The thermal conductivity of the temperature plate 500 is greater than the thermal conductivity of the material of the thermal interface 103. Thermal conductivity, also known as "thermal conductivity", is a measure of the thermal conductivity of a material, and refers to the amount of heat transferred through a unit horizontal cross-sectional area per unit time when the vertical downward temperature gradient is 1°C/m.

As a result, the thermal conductivity of the temperature spreader is higher and the temperature uniformity performance is better, which can better disperse the heat to reduce the temperature difference between the chip and the thermal interface material and improve the chip's heat dissipation performance.

In some embodiments of the present application, the material of the temperature spreader 500 includes diamond or diamond copper alloy, diamond silver alloy, diamond aluminum alloy, etc. Therefore, the material of the temperature spreader includes diamond, whose thermal expansion coefficient is close to that of the chip, so as to avoid chip warping during welding or use, and the thermal conductivity of diamond is high, so as to better dissipate heat.

The embodiment of the present application does not limit the scope of the temperature balancing plate 500. In one implementation of the present application, as shown in FIG3 , the temperature balancing plate 500 can be only arranged at a position where the upper shell 200 is opposite to the chip 101, so as to connect the chip 101 and the upper shell 200, and transfer the heat generated by the substrate 100 or the chip 101 to the upper shell 200, and then the upper shell 200 transfers the heat to the external environment.

The number and location of the temperature balancing plate 500 can be adjusted as needed. In some embodiments of the present application, as shown in FIG2 , the optical module 1 includes a temperature balancing plate 500 , which is disposed on the surface of the top plate 201 close to the chip 101 , and the thermal interface material 103 is located between the temperature balancing plate 500 and the chip 101 .

In some embodiments of the present application, as shown in FIG. 3 , the optical module 1 includes a temperature spreader 500 , which is disposed on a surface of the chip 101 close to the top plate 201 , and the thermal interface material 103 is located between the temperature spreader 500 and the second bump 2012 .

In some examples of this embodiment, the temperature balance plate 500 may include a first part and a second part, the first part is arranged close to the chip 101, the second part is arranged close to the thermal interface material 103, the size of the first part is the same as the size of the chip 101, and the size of the second part is larger than the size of the first part.

In some embodiments of the present application, as shown in FIG4 , the optical module 1 includes two temperature spreaders 500: a first temperature spreader 500 and a second temperature spreader 700. The first temperature spreader 500 is disposed on a surface of the top plate 201 close to the chip 101, and the second temperature spreader 700 is disposed on a surface of the chip 101 close to the top plate 201. The thermal interface material 103 is located between the first temperature spreader 500 and the second temperature spreader 700.

The temperature-regulating plate 500 can be processed into a shape that is the same as or similar to that of the chip 101 .

In some examples of this embodiment, the second temperature stabilizer 700 may include a first part and a second part, the first part is arranged close to the chip 101, the second part is arranged close to the thermal interface material 103, the size of the first part is the same as the size of the chip 101, and the size of the second part is larger than the size of the first part.

In some embodiments of the present application, the size of the temperature equalizer 500 is greater than or equal to the size of the chip 101, so that the temperature equalizer 500 and the upper surface of the chip 101 can be completely fitted together, thereby increasing the contact area between the temperature equalizer 500 and the chip 101 and improving the thermal conductivity of the temperature equalizer 500 to ensure that the heat of the chip 101 can be fully transferred through the temperature equalizer 500.

Therefore, a high thermal conductivity temperature spreader 500 is welded on the chip surface to reduce the chip power density. When the power density is low, the temperature difference generated by the thermal interface material will be reduced, thereby reducing the chip operating temperature, that is, the chip junction temperature.

In addition, compared with installing a heat sink such as a temperature-averaging plate, installing a temperature-averaging sheet can reduce overheating and facilitate heat transfer.

The superheat is the temperature difference between the outer shell surface and the working fluid inside the heat dissipation structure when the heat of the phase change or liquid cooling heat dissipation structure such as the temperature equalizer is transferred from the heat source to the surface of the heat dissipation structure.

The embodiment of the present application also provides a method for preparing an optical module 1. As shown in FIG5 , the method for preparing a chip module comprises the following steps:

S101. As shown in FIG6 , solder the chip onto the substrate.

When processing the optical module 1 , the substrate 100 may be first fixed on the bottom plate 300 , and then the chip 101 may be fixed on the substrate 100 .

In some embodiments of the present application, the substrate 100 may be fixed on the bottom plate 300 by welding. In some embodiments of the present application, the chip 101 may be fixed on the substrate 100 by welding. For example, the chip 101 may be welded to the substrate 100 by a reflow process.

In some embodiments of the present application, the chip 101 is disposed on the circuit board 400 and is electrically connected to the substrate 100 through the circuit board 400. In some embodiments of the present application, the circuit board 400 is electrically connected to the substrate 100 through the first electrical connector 401. In some embodiments of the present application, the chip 101 is electrically connected to the circuit board 400 through the second electrical connector 402.

The embodiment of the present application does not limit the structures of the first electrical connector 401 and the second electrical connector 402. For example, the first electrical connector 401 and the second electrical connector 402 may include a plurality of uniformly arranged solder balls.

In some embodiments of the present application, the optical module 1 further includes an optical device 102. In some embodiments of the present application, the optical device 102 may be fixed on the substrate 100 by welding.

S102. As shown in FIG. 7 , FIG. 8 , and FIG. 9 , a temperature balancing sheet and a thermal interface material are stacked on a side of the chip away from the circuit board.

The shell is thermally connected to the chip through the temperature balancing plate 500 .

In some implementations of the present application, the top plate 201 and the chip 101, for example, respectively include a first surface and a second surface opposite to each other, wherein the first surface of the chip 101 is close to the substrate 100, the second surface of the chip 101 is away from the substrate 100, the first surface of the top plate 201 faces the second surface of the chip 101, and the second surface of the top plate 201 is away from the chip 101. The temperature spreader 500 is, for example, disposed between the top plate 201 and the chip 101.

The temperature balancing plate is disposed between the chip 101 and the thermal interface material 103 , and/or between the thermal interface material 103 and the top plate 201 .

The thermal expansion coefficient of the temperature spreader 500 matches the thermal expansion coefficient of the chip 101 , and the thermal conductivity of the temperature spreader 500 is greater than the thermal conductivity of the thermal interface material 103 .

In some embodiments of the present application, as shown in FIG. 2 , the optical module 1 includes a temperature spreader 500 , which is disposed on a surface of the top plate 201 close to the chip 101 , and the thermal interface material 103 is located between the temperature spreader 500 and the chip 101 .

In some embodiments of the present application, as shown in FIG. 3 , the optical module 1 includes a temperature spreader 500 , which is disposed on a surface of the chip 101 close to the top plate 201 , and the thermal interface material 103 is located between the temperature spreader 500 and the second bump 2012 .

In some embodiments of the present application, as shown in FIG4 , the optical module 1 includes two temperature spreaders 500: a first temperature spreader 500 and a second temperature spreader 700. The first temperature spreader 500 is disposed on a surface of the top plate 201 close to the chip 101, and the second temperature spreader 700 is disposed on a surface of the chip 101 close to the top plate 201. The thermal interface material 103 is located between the first temperature spreader 500 and the second temperature spreader 700.

In some embodiments of the present application, the thermal interface material 103 may be a flexible thermally conductive material. The thermal interface material 103 includes: thermally conductive gel, thermally conductive silicone grease or thermally conductive sheet.

Therefore, the fluidity of the flexible thermal interface material 103 can be used to fully fill the gaps between adjacent structures, and the air between adjacent structures can be squeezed so that the adjacent structures are in full contact, so that the heat generated by the chip 101 can be timely transferred to the shell through the temperature equalizer 500 and the flexible thermal interface material 103 and dissipated, thereby enhancing the heat dissipation performance of the optical module 1 and improving the reliability of the optical module 1.

S103 . As shown in FIG. 2 , FIG. 3 , and FIG. 4 , a heat dissipation structure is provided on a side of the stacked temperature-balancing plate and the thermal interface material away from the chip 101 .

Finally, the upper shell 200 can be covered on the bottom plate 300 , so that the second bumps 2012 on the upper shell 200 are pressed onto the thermal interface material 103 .

In some embodiments of the present application, the upper shell 200 can serve as a heat dissipation structure to transfer the heat generated by the chip 101 to the air.

In other embodiments of the present application, after the upper shell 200 of the housing is covered on the bottom plate 300, a heat sink may be provided on the side of the upper shell 200 corresponding to the chip 101. For example, the heat sink includes: a copper or aluminum heat sink, a vapor chamber (VC), an evaporator, and a liquid cooling heat sink (including a cold plate).

The radiator shell material is copper or aluminum, and the inside is liquid working medium.

Among them, the cold plate is a liquid cooling component. When the cold plate shell contacts the heat source, the liquid working medium in the cold plate can take away the heat.

The evaporator is a phase-change heat dissipation structural component. When the evaporator shell comes into contact with the heat source, the internal liquid working fluid undergoes phase change and absorbs heat, taking away the heat.

In some embodiments of the present application, the heat sink includes: a sealed vacuum cavity, wherein the cavity is filled with a coolant, and a capillary structure is provided on the inner wall of the cavity. The coolant may be a refrigerant such as Freon or water. The capillary structure is, for example, a copper mesh micro-evaporator.

When the radiator is used, the bottom of the radiator contacts with the chip 101 and is heated. The heat source heats the copper mesh micro-evaporator. The coolant at the bottom of the vacuum chamber is heated and quickly evaporates into hot air in the vacuum ultra-low pressure environment. The interior of the radiator adopts a vacuum design, which allows the hot air to circulate more quickly in the copper mesh micro-environment. The hot air then rises due to the heat, dissipates heat after encountering the cold source on the upper part of the radiator, and condenses into liquid again. The condensed coolant flows back to the evaporation source at the bottom of the radiator through the copper micro-structure capillary channel. The refluxed coolant is heated by the evaporator and vaporizes again after passing through the copper mesh micro-tube, and the action is repeated in this way.

Among them, the evaporation and condensation process of the radiator is carried out in the vacuum chamber, which is similar to the heat conduction principle of the heat pipe 203, but the heat in the vacuum chamber is conducted on a two-dimensional surface, and the heat dissipation of the heat pipe 203 belongs to one-dimensional linear heat conduction. Compared with the heat pipe 203, the radiator has a higher thermal conductivity efficiency.

In some embodiments of the present application, the temperature-regulating plate 500 is connected to the chip 101 by welding. In some embodiments of the present application, the welding process of the chip 101 and the temperature-regulating plate 500 includes: placing a prefabricated solder sheet on the surface of the chip 101, and then covering the temperature-regulating plate 500 on the surface of the solder sheet, applying pressure on the top of the temperature-regulating plate 500 through a pressing block or an elastic structure, and then welding in a vacuum environment, and using a reducing atmosphere to surround the sample during the welding process. In some embodiments of the present application, the melting point of the solder sheet is 120 to 180°C, and the welding temperature is about 120 to 180°C.

In order to improve the welding performance of the welding surface between the temperature-balancing plate 500 and the chip 101 , the welding surface between the temperature-balancing plate 500 and the chip 101 may be metallized.

In some embodiments of the present application, as shown in FIG10 , before step S101, the method further includes:

S104. Coating a metal film on the welding surface of the temperature equalizer, the welding surface of the chip 101 and/or the welding surface of the heat dissipation structure.

In some embodiments of the present application, as shown in FIG2 , the temperature-regulating plate 500 is connected to the top plate 201 by welding with the solder 104. In order to improve the welding performance of the temperature-regulating plate 500 and the top plate 201, a metal film may be plated on the surface where the second bump 2012 contacts the solder 104, that is, the welding surface of the second bump 2012, and on the surface where the temperature-regulating plate 500 contacts the solder 104, that is, the welding surface of the temperature-regulating plate 500. For example, the material of the metal film includes: titanium Ti, nickel Ni, and gold Au.

In some embodiments of the present application, as shown in FIG3 , the temperature-distributing plate 500 and the chip 101 are connected by soldering 104. In order to improve the soldering performance between the temperature-distributing plate 500 and the chip 101, the surface of the chip 101 in contact with the solder 104, i.e., the surface of the chip 101 A metal film is plated on the welding surface of the temperature spreader 500 and the surface in contact with the solder 104, that is, the welding surface of the temperature spreader 500. For example, the material of the metal film includes: titanium Ti, nickel Ni, and gold Au.

In some embodiments of the present application, as shown in FIG. 4 , the first temperature spreader 500 is welded to the top plate 201 via a first layer of solder 104 , and the second temperature spreader 700 is welded to the chip 101 via a second layer of solder 106 . In order to improve the welding performance of the chip 101, the first temperature balancing plate 500, the second temperature balancing plate 700 and the top plate 201, a first metal film 1071 can be plated on the surface where the second temperature balancing plate 700 is connected to the second layer of solder 106, that is, the welding surface of the second temperature balancing plate 700, a second metal film 1072 can be plated on the surface where the chip 101 is connected to the second layer of solder 106, that is, the welding surface of the chip 101, a third metal film 1051 can be plated on the surface where the second bump 2012 of the top plate 201 is connected to the first layer of solder 104, that is, the welding surface of the second bump 2012 of the top plate 201, and a fourth metal film 1052 can be plated on the surface where the first temperature balancing plate 500 is connected to the first layer of solder 104, that is, the welding surface of the first temperature balancing plate 500. For example, the material of the metal film includes: titanium Ti, nickel Ni, and gold Au.

In some embodiments of the present application, after the metal film is plated on the welding surface of the temperature plate, the welding surface of the chip 101 and/or the welding surface of the heat dissipation structure, the method further includes: cleaning the welding surface of the temperature plate and the welding surface of the chip 101.

In some embodiments of the present application, the coated surface of the chip 101 and the surface of the temperature spreader 500 may be cleaned. In some embodiments of the present application, the cleaning process includes organic cleaning, plasma cleaning, and the like.

In some embodiments of the present application, a protective member 1010 may be further disposed around the chip 101 to protect the chip 101 .

In addition, in the above-mentioned welding process of welding chip 101 and temperature equalizer 500, it is necessary to apply pressure on the top of temperature equalizer 500 through a pressure block or elastic structure, and then perform welding in a vacuum environment, and use a reducing atmosphere to surround the sample during the welding process. In order to avoid the pressure applied to the temperature equalizer to squeeze out the molten solder, leave space for the solder. To this end, in some embodiments of the present application, as shown in Figure 11, before setting the temperature equalizer and thermal interface material 103 on the side of the chip 101 away from the circuit board in step S102, the method also includes:

S105. Set a stopper (not shown in the figure) on the surface of the chip or circuit board.

The stopper is higher than the chip 101. In some embodiments of the present application, the height of the stopper from the circuit board is higher than the height of the chip from the circuit board. For example, the stopper is about 100 to 250 um higher than the surface of the chip 101, which is used to control the thickness of the solder after welding.

The embodiments of the present application do not limit the structure of the limiter. In some embodiments of the present application, the limiter is a ring structure. In other embodiments of the present application, the limiter can be a columnar structure, and the limiter can be one or more, arranged on the surface of the circuit board or chip.

Therefore, the heat generated by the chip 101 can be transferred to the temperature equalizer 500, and the heat is dispersed under the action of the temperature equalizer 500, thereby reducing the power density of the chip 101 and the temperature difference between the chip 101 and the thermal interface material 103, so that the heat can be better transferred to the shell through the thermal interface material 103, thereby improving the heat dissipation efficiency of the optical module 1.

In some embodiments of the present application, in order to conduct the heat transferred to the shell to the external environment to achieve a better heat dissipation effect, the optical module 1, for example, also includes a heat dissipation fin connected to the shell, and the heat dissipation fin is arranged on a side of the shell away from the chip 101.

The heat emitted by chip 101 can be transferred to the shell through the heat-conducting components, and then transferred to the heat sink fins by the shell. Since the heat sink fins have a large heat dissipation area, they can use the external cooling airflow to dissipate the accumulated heat, further improving the heat dissipation efficiency of the chip module.

In the communication system of the embodiment of the present application, the implementation principle and technical effect of the optical module 1 are the same as those of the optical module 1 in the above embodiments, and will not be repeated here.

Therefore, the communication system adopts the optical module 1 as described above, which has better heat dissipation performance, improves the reliability of the optical module 1, and also improves the reliability of the optical communication system.

The present application also provides a chip module 2, which can be used in electronic devices such as routers and servers. Figure 12 is a three-dimensional diagram of a chip module 2 provided in an embodiment of the present application. As shown in Figure 12, the chip module 2 at least includes: a circuit board 400, a chip 101 and a heat sink 600.

FIG14 is a schematic diagram of the structure of a chip module provided in an embodiment of the present application. As shown in FIG14, in some embodiments of the present application, the chip 101 is disposed on a circuit board 400 and is electrically connected to the substrate 100 through the circuit board 400. In some embodiments of the present application, the circuit board 400 is electrically connected to the substrate 100 through a first electrical connector 401. In some embodiments of the present application, the chip 101 is electrically connected to the circuit board 400 through a second electrical connector 402.

The embodiment of the present application does not limit the structure of the first electrical connector 401 and the second electrical connector 402. For example, the first electrical connector 401 and the second electrical connector 402 may include a plurality of uniformly arranged solder balls. The heat sink 600 is disposed on the side of the chip 101 away from the circuit board 400. In some embodiments of the present application, a thermal interface material 103 is disposed between the chip 101 and the circuit board 400.

In some embodiments of the present application, the thermal interface material 103 may be a flexible thermally conductive material. The thermal interface material 103 includes: thermally conductive gel, thermally conductive silicone grease or a thermally conductive sheet.

However, as the power density of the chip 101 increases, the temperature difference caused by the thermal resistance of the thermal interface material 103 becomes larger, and the heat dissipation effect becomes worse.

To this end, an embodiment of the present application provides an improved chip module 2.

The chip module 2 further includes a temperature balancing plate 500. The temperature balancing plate 500 can be disposed between the chip 101 and the heat sink 600 to evenly disperse the heat generated by the chip 101 and reduce the power density of the chip 101. The heat is then transferred to the heat sink 600 through the temperature balancing plate 500 and dissipated through the heat sink 600.

In some embodiments of the present application, the material of the temperature spreader 500 may be diamond or diamond copper alloy, diamond silver alloy, diamond aluminum alloy, etc. Therefore, the material of the temperature spreader includes diamond, whose thermal expansion coefficient is close to that of the chip, so as to avoid chip warping during welding or use, and the thermal conductivity of diamond is high, so as to better dissipate heat.

The embodiment of the present application does not limit the scope of the temperature balancing plate 500. In one implementation of the present application, as shown in FIG3 , the temperature balancing plate 500 can be only arranged at a position opposite to the heat sink and the chip 101 to connect the chip 101 and the heat sink, and transfer the heat generated by the substrate 100 or the chip 101 to the heat sink, and then the heat sink transfers the heat to the external environment.

The temperature-regulating plate 500 can be processed into a shape that is the same as or similar to that of the chip 101 .

In some embodiments of the present application, the lower surface area of the temperature equalizer 500 can be greater than or equal to the upper surface area of the chip 101, so that the temperature equalizer 500 and the upper surface of the chip 101 can be completely fitted together, thereby increasing the contact area between the temperature equalizer 500 and the chip 101 and improving the thermal conductivity of the temperature equalizer 500 to ensure that the heat of the chip 101 can be fully transferred through the temperature equalizer 500.

Therefore, a high thermal conductivity temperature balancing sheet 500 is welded on the surface of the chip 101 to reduce the power density of the chip 101 . When the power density is low, the temperature difference generated by the thermal interface material 103 is reduced, thereby reducing the junction temperature of the chip 101 .

In some embodiments of the present application, as shown in FIG. 14 , the chip module 2 includes a temperature spreader 500 , which is disposed on a surface of the heat sink 600 close to the chip 101 , and the thermal interface material 103 is located between the temperature spreader 500 and the chip 101 .

In some embodiments of the present application, as shown in FIG. 15 , the optical module 1 includes a temperature-balancer 500 , which is disposed on the surface of the chip 101 close to the heat sink 600 , and the thermal interface material 103 is located between the temperature-balancer 500 and the heat sink 600 .

In some embodiments of the present application, as shown in FIG16 , the chip module 2 includes two temperature spreaders 500: a first temperature spreader 500 and a second temperature spreader 700. The first temperature spreader 500 is disposed on a surface of the heat sink 600 close to the chip 101, and the second temperature spreader 700 is disposed on a surface of the chip 101 close to the heat sink 600. The thermal interface material 103 is located between the first temperature spreader 500 and the second temperature spreader 700.

In some embodiments of the present application, as shown in FIG14 , the temperature-regulating plate 500 is connected to the heat sink 600 by welding with the solder 104. In order to improve the welding performance of the temperature-regulating plate 500 and the heat sink 600, a metal film may be plated on the surface of the heat sink 600 in contact with the solder 104, that is, the welding surface of the heat sink 600, and on the surface of the temperature-regulating plate 500 in contact with the solder 104, that is, the welding surface of the heat sink 600. For example, the material of the metal film includes: titanium Ti, nickel Ni, and gold Au.

In some embodiments of the present application, as shown in FIG15 , the temperature spreader 500 is connected to the chip 101 by welding with the solder 104. In order to improve the welding performance of the temperature spreader 500 and the chip 101, a metal film may be plated on the surface of the chip 101 in contact with the solder 104, that is, the welding surface of the chip 101, and on the surface of the temperature spreader 500 in contact with the solder 104, that is, the welding surface of the temperature spreader 500. For example, the material of the metal film includes: titanium Ti, nickel Ni, and gold Au.

In some embodiments of the present application, as shown in FIG16 , the first temperature spreader 500 is connected to the heat sink 600 by welding through the first layer of solder 104, and the second temperature spreader 700 is connected to the chip 101 by welding through the second layer of solder 106. In order to improve the welding performance of the chip 101, the first temperature spreader 500, the second temperature spreader 700 and the heat sink 600, a first metal film 1071 may be plated on the surface where the second temperature spreader 700 is connected to the second layer of solder 106, that is, the welding surface of the second temperature spreader 700, a second metal film 1072 may be plated on the surface where the chip 101 is connected to the second layer of solder 106, that is, the welding surface of the chip 101, a third metal film 1051 may be plated on the surface where the heat sink 600 is connected to the first layer of solder 104, that is, the welding surface of the heat sink 600, and a fourth metal film 1052 may be plated on the surface where the first temperature spreader 500 is connected to the first layer of solder 104, that is, the welding surface of the first temperature spreader 500. Example, metal film The materials include: titanium Ti, nickel Ni, and gold Au.

The embodiment of the present application does not limit the structure of the radiator 600. In some embodiments of the present application, the radiator 600 includes: a copper or aluminum radiator, a vapor chamber (VC), an evaporator, and a liquid cooling radiator (including a cold plate). In other embodiments of the present application, as shown in Figures 14, 15, and 16, the radiator 600 also includes heat dissipation teeth. Therefore, the radiator 600 uses heat dissipation teeth to increase the heat dissipation surface of the radiator 600 and improve the heat dissipation performance.

In some embodiments of the present application, the outer shell material of the heat sink 600 is copper or aluminum, and the interior is filled with liquid working fluid.

Among them, the cold plate is a liquid cooling component. When the cold plate shell contacts the heat source, the liquid working medium in the cold plate can take away the heat.

The evaporator is a phase-change heat dissipation structural component. When the evaporator shell comes into contact with the heat source, the internal liquid working fluid undergoes phase change and absorbs heat, taking away the heat.

Among them, Figure 17 is a schematic diagram of the structure of a radiator provided by an embodiment of the present application. In some embodiments of the present application, as shown in Figure 17, in some embodiments of the present application, the radiator 600 includes: a shell 601, the shell 601 is surrounded by a sealed vacuum cavity, wherein the cavity is filled with a working medium 602, the working medium 602 includes: a coolant, and a capillary structure is provided on the inner wall of the cavity. Among them, the coolant can be a refrigerant such as Freon or water. The capillary structure is, for example, a copper mesh micro-evaporator.

When the radiator is used, the bottom of the radiator contacts with the heat source 1001 for heating, and the heat source 1001 may include the chip module 2 as described above. The heat source heats the copper mesh micro-evaporator, and the coolant at the bottom of the vacuum chamber is heated and quickly evaporates into hot air in the vacuum ultra-low pressure environment. The inside of the radiator adopts a vacuum design, so that the hot air circulates more quickly in the copper mesh micro-environment. Then the hot air rises due to the heat, dissipates heat after encountering the cold source on the upper part of the radiator, and condenses into liquid again. The condensed coolant flows back to the evaporation source at the bottom of the radiator through the copper micro-structure capillary channel. The refluxed coolant is heated by the evaporator and vaporizes again and passes through the copper mesh micro-tube, and the action is repeated.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (20)

A chip module, characterized in that it comprises: a circuit board, and a chip arranged on the circuit board; A heat dissipation structure is provided on a side of the chip away from the circuit board; A thermal interface material and a temperature-dissipating sheet are stacked between the chip and the heat dissipation structure; The thermal expansion coefficient of the temperature-regulating plate matches the thermal expansion coefficient of the chip, and the thermal conductivity of the temperature-regulating plate is greater than the thermal conductivity of the thermal interface material. The chip module according to claim 1 is characterized in that the size of the temperature spreader is greater than or equal to the size of the chip. The chip module according to claim 1 or 2 is characterized in that the temperature spreader comprises: a first temperature spreader, and the first temperature spreader is arranged between the chip and the thermal interface material. The chip module according to claim 3 is characterized in that the first temperature spreader is welded to the chip, and a metal film is plated on the welding surface of the chip and the welding surface of the first temperature spreader. The chip module according to claim 3 or 4 is characterized in that the first temperature spreader includes a first part and a second part, the first part is arranged close to the chip, the second part is arranged close to the thermal interface material, the size of the first part is the same as the size of the chip, and the size of the second part is larger than the size of the first part. The chip module according to any one of claims 1 to 5 is characterized in that the temperature spreader comprises: a second temperature spreader, and the second temperature spreader is arranged between the thermal interface material and the heat dissipation structure. The chip module according to any one of claims 1 to 6 is characterized in that the temperature spreader is made of diamond or an alloy material containing diamond. The chip module according to any one of claims 1 to 7, characterized in that the thermal interface material comprises: thermally conductive gel, thermally conductive silicone grease or a thermally conductive sheet. The chip module according to any one of claims 1 to 8 is characterized in that a limiting member is provided on the circuit board, the limiting member is arranged around the chip, and the limiting member is higher than the chip. The chip module according to any one of claims 1 to 9 is characterized in that the heat dissipation structure comprises: a cold plate, a temperature homogenizing plate, and an evaporative heat sink. An optical module, characterized in that it comprises: a shell, and a chip module according to any one of claims 1 to 10, wherein the heat dissipation structure is a part of the shell, or the heat dissipation structure is arranged outside the shell. The optical module according to claim 11 is characterized in that the optical module further comprises: a substrate and an optical device, and the optical device and the chip module are arranged on the substrate. The optical module according to claim 12 is characterized in that the shell comprises: an upper shell and a bottom plate, the upper shell comprises: a top plate and a bracket, the bracket is connected to the bottom plate, and the base plate is connected to the bottom plate. The optical module according to claim 13 is characterized in that a first bump and a second bump are provided on the top plate, the first bump is connected to the optical device through a thermal interface material, and the second bump is connected to the chip module. A communication system, characterized in that it comprises: a data source, an optical channel, and an optical module as described in any one of claims 11 to 14, wherein the data source is used to send a data signal to the optical module, and the optical module is used to convert the data signal into an optical signal and transmit it through the optical channel. An electronic device, characterized in that the electronic device comprises: a substrate, and a chip module according to any one of claims 1 to 10, wherein the chip module is arranged on the substrate. The electronic device according to claim 16 is characterized in that the electronic device is a router or a server. A method for preparing a chip module, characterized by comprising: Solder the chip on the circuit board; A temperature spreader and a thermal interface material are stacked on a side of the chip away from the circuit board; the thermal expansion coefficient of the temperature spreader matches the thermal expansion coefficient of the chip, and the thermal conductivity of the temperature spreader is greater than the thermal conductivity of the thermal interface material; A heat dissipation structure is arranged on the side of the stacked temperature equalizer and the thermal interface material away from the chip, wherein the temperature equalizer is arranged between the chip and the thermal interface material, and/or between the thermal interface material and the heat dissipation structure. The method for preparing a chip module according to claim 18, characterized in that before soldering the chip on the circuit board, the method further comprises: A metal film is plated on the welding surface of the temperature equalizer, the welding surface of the chip and/or the welding surface of the heat dissipation structure. The method for preparing a chip module according to claim 18 or 19, characterized in that before providing a temperature spreader and a thermal interface material on a side of the chip away from the circuit board, the method further comprises: A limiting member is disposed on a surface of the circuit board or the chip; wherein a height of the limiting member from the circuit board is higher than a height of the chip from the circuit board.