CN2408572Y - Laser cooler for large integrated circuit cooling - Google Patents

Abstract

The utility model belongs to the technical field of laser refrigeration, and uses the anti-Stokes fluorescent refrigeration principle to provide a refrigerator for large-scale integrated circuits to dissipate heat. It is mainly composed of a heat-conducting reflective layer, a cooling medium, a laser, a reflective film with high reflectivity, and an optical lens group. In order to dissipate heat for large-scale integrated circuits, the laser cooling medium is made into a waveguide, so that the cooling medium has a trapping effect on the pump laser and increases the absorption of the pump light. The laser refrigerator used for heat dissipation of large-scale integrated circuits has the advantages of small size, light weight, no electromagnetic radiation, no vibration, and no noise.

Description

Laser Cooler for LSI Cooling

The utility model belongs to the technical field of laser refrigeration. According to the principle of anti-Stokes fluorescent refrigeration, a brand-new laser refrigerator for heat dissipation of large-scale integrated circuits is designed.

In order to dissipate heat for large-scale integrated circuits, people have used fans in the past. Due to the large vibration of the fan, it will be covered with dust and make a lot of noise when used for a long time, which determines that it is not an ideal radiator.

The operating temperature is an important indicator of fluorescent cooling devices. At low temperatures, it is difficult to achieve laser cooling because the population number in the high energy level is very small. However, from the characteristics of laser refrigeration, we can infer that the higher the operating temperature, the easier it is to achieve fluorescent refrigeration, and the greater the cooling efficiency that can be obtained.

When people use refrigeration technology, they often do not blindly pursue the lower the temperature, but seek an acceptable equilibrium temperature, as long as the heat generated by the system and the heat absorbed by the refrigerator reach a balance at this temperature. This is the case for the cooling of large-scale integrated circuits. As long as the temperature of the chip does not exceed 85°C, the purpose is achieved. And we know that the higher the temperature, the higher the refrigeration efficiency that fluorescent refrigeration can achieve. Therefore, laser cooling is an ideal choice for constant temperature of devices like integrated circuits. At present, the fans used on microcomputers will generate a lot of vibration and noise. If such a cooling method is used in high-end military technology, it will undoubtedly reduce the concealment level of this military technology. If laser refrigeration technology is introduced, such problems will be solved. Therefore, we can say that the application of fluorescence refrigeration technology at high temperature will have a broader prospect.

The utility model absorbs more pumping light through the trapping effect of the cooling medium on the pumping laser, and aims to provide a laser refrigerator for heat dissipation of large-scale integrated circuits.

Anti-Stokes fluorescent refrigeration technology applies laser technology to refrigeration, which opens up a new way for the cooling of large-scale integrated circuits. This technology is all-optical, and its refrigerator has the characteristics of small size, light weight, no electromagnetic radiation, no vibration, no noise, etc., so it has very attractive application prospects and meets the requirements of military, space, and integrated optics. , microelectronics, medicine and other fields of special requirements, and the attention of foreign researchers. As a basic technology, breakthroughs in laser refrigeration research will inevitably lead to the practical application of many high-tech technologies with special temperature requirements, and promote the development of those fields.

For large-scale and ultra-large-scale integrated circuits, due to the huge number of internal electronic components, the heat is often very serious. Without refrigeration, they typically reach temperatures of several hundred degrees Celsius and either burn out or fail to function properly. After it is refrigerated, it can work normally below 85°C, so the working temperature of refrigeration is relatively high. The higher working temperature means higher cooling efficiency for laser cooling. When the temperature of the cooling medium is higher than the ambient temperature, the thermal radiation of the environment will no longer have a serious impact on the cooling efficiency, because the thermal radiation emitted by the cooling medium is already greater than the thermal radiation absorbed from the environment. It is considered to make the laser cooling medium into a waveguide, so that the cooling medium can trap the pump laser light and increase the absorption of the pump light.

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail.

Fig. 1 is the schematic diagram of the utility model. In the figure, 1-large-scale integrated circuit; 2-heat conduction reflective layer; 3-laser cooling medium, the laser cooling medium can be a substance of different composition and state, as long as it has a laser cooling effect. This embodiment adopts ZBLANP: Yb ³⁺ glass as the laser cooling medium, and its shape structure is a planar waveguide; 4, 5-reflective film with high reflectivity; 6-pumping laser beam entrance; 7-pumping laser, 8 - converging and collimating optical lens group; 9 - pumping laser beam, the wavelength of the laser beam in this embodiment is 1015 nanometers; 10 - outgoing fluorescence.

The specific work of this embodiment is as follows: the 1015nm pump laser 9 sent from the diode pump laser 7 is converged and collimated by the optical lens group 8 and then enters the pump laser beam entrance 6, and the pump laser 9 is on the plane The waveguide-type cooling medium 3 conducts linear and reflection propagation, and reflection occurs when the pumping laser beam 9 is irradiated on the reflective films 4 and 5 with high reflectivity. When the pump laser beam 9 propagates in the laser cooling medium 3, it is absorbed by the Yb ³⁺ ions in the cooling medium 3, and the Yb ³⁺ ions emit anti-Stokes fluorescence, that is, the fluorescence emitted by the outgoing fluorescence 10 is emitted from the cooling medium The upper surface of 3 shoots out, and has taken away energy, has reached the purpose of refrigeration. The upper surface of the large-scale integrated circuit 10 is attached with a layer of heat-conducting medium, that is, the heat-conducting reflective layer 2, which can transfer the heat emitted by 10 to the laser cooling medium 3, and take it out of the system through anti-Stokes fluorescence emission. In addition, the heat conduction layer should have high reflection to the anti-Stokes fluorescence, so as to reduce the reabsorption of the fluorescence. The pump laser is input from the small hole on one side of the cooling medium, and the two sides of the medium are coated with high reflection layers to ensure that the pump light is reflected back and forth in the medium to increase its absorption by the medium. The shape of the cooling medium is made into a thin sheet, so that most of the anti-Stokes fluorescence leaves the cooling medium after traveling a short light path.

According to the principle of anti-Stokes refrigeration, the utility model designs a device for heat dissipation of large-scale integrated circuits. Compared with the existing heat dissipation method, the utility model has the characteristics of small volume, light weight, no vibration, no noise and the like.

Claims (3)

1. A laser refrigerator for cooling large-scale integrated circuits, which is characterized in that a layer of heat-conducting reflective layer (2) is attached to the upper surface of large-scale integrated circuits (1), and a planar waveguide type cooling medium (3) conducts heat On the reflective layer (2), the cooling medium (3) is made into a sheet shape, and the sides are coated with reflective films (4) and (5) with high reflectivity, and a small hole is opened on one side as the laser beam entrance (6); The pump laser beam (9) emitted by the laser (7) is converged and collimated by the optical lens group (8) and then enters the laser beam entrance (6); (3) do straight line and reflection propagation. 2. The laser refrigerator for cooling large-scale integrated circuits according to claim 1, characterized in that the laser (7) used is a diode-pumped laser. 3. The laser refrigerator for cooling large-scale integrated circuits according to claim 2, characterized in that the wavelength of the diode-pumped laser is 1015 nanometers.

Images