CN206042656U - A piston type heat transfer radiator - Google Patents

Abstract

The utility model discloses a piston heat transfer radiator, it relates to the remote heat transfer of high -power water -tight equipment chip in the communications field. It is including thermally conductive housing, heat conduction piston, base, heat pipe, heat conduction filler, sealing screw, joint strip, sealed cushion and the spring of taking cooling fin. It when realizing that the crate is sealed, the effective control to the contact force of chip, prevent that the chip from damaging because of pressure is too big, it has also realized the large -span heat transfer of the chip far away apart from chassis wall to still have simple structure, low cost, the commonality is good and the reliability is high characteristics. The specially adapted heat -generating chip high -power sealed electronic equipment far away apart from chassis wall.

Description

A piston type heat transfer radiator

technical field

The utility model relates to a radiator suitable for high-power sealing and electronic equipment in the field of communication measurement and control. It is especially suitable for electronic equipment that requires long-distance and large-span heat transfer.

Background technique

At present, the heat dissipation form of sealing equipment is mainly to attach the heating device to the inner wall of the chassis, the heat flow is conducted to the outer wall of the chassis through heat conduction, and then dissipates heat to the external space through the ribs on the outer wall of the chassis by natural convection and radiation. This method has many disadvantages, especially for single-board chassis with many interfaces, the heating chip is far away from the chassis wall, and the traditional heat conduction method of metal parts and thermal pads is difficult to control the pressure on the chip. Especially for BGA-packaged surface-mount devices, excessive pressure can easily damage the spherical pads of the device, resulting in the failure of the chip to work or reducing the life of the device. On the other hand, since the heat-generating chip is far away from the chassis wall, the heat conduction resistance increases sharply, which greatly affects the heat dissipation effect.

Utility model content

The technical problem to be solved by the utility model is to propose a "piston" type radiator suitable for sealing the chassis. While controlling the pressure on the chip and reducing the thermal resistance of the heat conduction, it also takes into account the sealing performance of the chassis, making it suitable for sealing Heat dissipation of the device.

The technical problem to be solved by the utility model is realized by the following technical solutions:

A piston type heat transfer radiator, comprising a heat conduction shell 1 with heat dissipation ribs, a heat conduction piston 2 and a spring 3; inside the heat conduction shell 1 there is an accommodation space for accommodating the heat conduction piston 2 and the spring 3; the spring 3 is arranged in the accommodation In the space, one end of the spring 3 is connected to the upper surface of the accommodating space, and the other end is connected to the top of the heat conducting piston 2; The bottom end is used for contacting with the heating element.

Among them, it also includes a base 4 with openings, the heat conduction shell 1 is fixedly connected with the base 4 , the heat conduction piston 2 is stepped, the area of the bottom end is smaller than the area of the top end, and the bottom of the heat conduction piston 2 passes through the opening of the base 4 .

Wherein, the preset gap between the heat conduction shell 1 and the heat conduction piston 2 is filled with a heat conduction medium aviation silicone grease.

Wherein, the top of the heat conduction piston 2 is provided with a groove matching with the spring 3 .

Wherein, at least one exhaust hole is opened on the outer wall of the heat conduction shell 1 .

Wherein, a heat pipe 5 is also included, and the heat pipe 5 is fixed on the outer wall of the heat conduction shell 1 .

Wherein, the base 4 is provided with a limiting column.

Among them, the top of the heat conduction shell 1 is provided with a round hole for installing the sealing screw 6 and the sealant pad 7, and a small hole for installing the fixing screw is opened on the base 4 corresponding to the round hole; the top edge of the heat conduction shell 1 is provided with a useful The groove for installing the sealant strip.

Compared with the background technology, the utility model has the following advantages:

The utility model effectively controls the contact pressure on the chip while realizing the sealing of the case, prevents the chip from being damaged due to excessive pressure, and also realizes the large-span heat transfer of the chip far away from the case wall. Generally speaking, the heat dissipation fins are exposed outside the chassis, and directly conduct convective heat exchange with the air, which can effectively reduce the thermal resistance of long-distance heat transfer and increase heat transfer efficiency. And it also has the advantages of simple structure, low cost, good versatility and high reliability.

Description of drawings:

Fig. 1 is a structural sectional view and a thermal circuit diagram of a radiator;

Figure 2 is a schematic diagram of radiator sealing screw installation;

Figure 3 is a schematic diagram of the appearance of the radiator;

Figure 4 is a cross-sectional view of the installation of the radiator in the chassis;

Figure 5 is an appearance view of the radiator installed in the chassis.

detailed description:

In order to make the purpose, technical solutions and advantages of the utility model more clear, the implementation of the utility model will be further described in detail with reference to the accompanying drawings, Fig. 1 to Fig. 5 .

As shown in Figures 1 and 2, a piston-type heat transfer radiator includes a heat-conducting shell 1 with cooling ribs, a heat-conducting piston 2, a spring 3, a base 4 with holes, a heat pipe 5, sealing screws 6 and sealing rubber pads 7. The heat-conducting shell 1 is fixedly connected with the base 4, and an accommodating space for accommodating the heat-conducting piston 2 and the spring 3 is formed inside; the top of the heat-conducting piston 2 is provided with a groove matching the spring 3; One end of the spring 3 is connected to the upper surface of the accommodation space, and the other end is connected to the top of the heat conduction piston 2; the outer wall of the heat conduction piston 2 is fitted with the inner wall of the accommodation space, and the heat conduction shell 1 The preset gap between the heat conduction piston 2 is filled with heat conduction medium aviation silicone grease, and its thermal conductivity is 0.0966W/m.K; the bottom end of the heat conduction piston 2 is used to contact the heating body; The end area is smaller than the top area, and the bottom of the heat transfer piston 2 passes through the opening of the base 4; the base 4 is provided with a limiting post.

The top of the heat conduction housing 1 is provided with a round hole for installing the sealing screw 6 and the sealing rubber pad 7, and the base 4 is provided with a small hole for installing the fixing screw at a position corresponding to the round hole; the top edge of the heat conduction housing 1 is provided with a hole for installing The groove of the sealing rubber strip, and at least one exhaust hole is opened on the outer wall of the heat conduction shell 1; the heat pipe 5 is fixed on the outer wall of the heat conduction shell 1. The specific implementation steps include:

1) The heat generated by the chip 11 on the printed board is transferred to the heat conduction piston 2, and then passes through the heat conduction piston 2 through the heat conduction filling medium between the shell and the piston, the heat conduction shell 1 and the heat pipe 5, and finally passes through the heat dissipation ribs on the heat conduction shell Convective heat exchange with ambient air;

2) The contact pressure between the piston and the chip can be adjusted by the spring 3;

3) The force on the radiator can be transmitted to the bottom plate of the chassis 8 through the limiting pillar of the base 4 so as to protect the chip from being damaged;

4) As shown in Figure 5, the utility model is suitable for large-span heat transfer where the chip 11 is far away from the wall of the chassis 8, and can be opened on the chassis cover 9 to expose the heat dissipation ribs to the chassis 8, through the rubber strip 10 on the heat conduction shell 1 Contact with the case cover plate 9 to realize sealing.

The installation process is as follows:

1) welding the heat pipe 5 to the periphery of the heat conduction shell 1;

2) Evenly apply aviation silicone grease to the outer surface of the heat conduction piston 2;

3) Install the spring 3, the heat conduction piston 2 and the base 4 on the heat conduction shell 1 in sequence;

4) When installing, first remove the sealing screw 6, install the radiator on the bottom plate of the chassis, then install the base screw through the hole where the sealing screw 6 is installed, and tighten the sealing screw 6 with the sealing rubber pad 7.

Assembled into a whole radiator, the appearance diagram is shown in Figure 3.

The structural features are as follows:

1) The contact pressure between the heat conduction piston 2 and the chip 11 is adjusted and controlled by the spring, and the influence of the chip height tolerance can be completely offset by reasonable design of the compression amount of the spring and the height of the limit pillar, and the contact pressure can be controlled at 5.5lb within;

2) The gap between the heat conduction piston 2 and the heat conduction shell 1 is matched with a maximum gap of 0.03mm, so that the piston 2 can move up and down to adjust the contact pressure of the chip, and at the same time, the gap between the "piston" and the shell will be filled with air, increasing the heat conduction resistance. Although the gap is small, the air in the gap must be removed to reduce thermal resistance. Aviation grease is used to fill the gap. Aviation grease has a high viscosity and is not easy to flow. It does not require high sealing performance of the radiator, and the grease contained in it can also play a lubricating role;

3) The radiator base 4 has four limiting posts connected to the bottom plate of the chassis through screws, so that the force on the radiator is transmitted to the chassis by the limiting posts, which protects the chip from other external forces;

4) The heat dissipation process is as follows: the heat of the chip is first transmitted to the heat conduction piston 2, through the heat conduction filling medium, the heat pipe 5 and the heat conduction shell 1, and finally conducts convective heat exchange with the air through the heat dissipation fins on the heat conduction shell 1. The heat transfer path of the whole structure is shown in Figure 1, and its total thermal resistance is:

R _total = R _c +R _cp +R _t +R _ph +R _h +R _hk

The meanings of each thermal resistance in the formula are as follows:

a) R _c is the internal thermal resistance of the chip. Assuming that the heat flow on the surface of the chip is uniform, the back of the chip is in point contact with the piston, and most of the heat can only be transferred to the piston through the center area of the chip, which is equivalent to a shrinkage thermal resistance. R _c is determined by the ratio of the effective heat transfer radius to the heat transfer radius of the chip itself. The chip-to-piston thermal resistance R _cp is the thermal resistance of the metal contact point. It is required to minimize this thermal resistance by filling thermal grease or The method of flexible thermal pad reduces this contact thermal resistance generally R _cp ;

b) The thermal resistance R _t of the piston itself, the heat is diffused from the end of the piston to the piston, forming a diffusion thermal resistance.

c) The thermal resistance R _ph from the piston to the heat conduction shell can be calculated according to the thermal resistance of a multi-layer cylinder by using this article;

d) The thermal resistance R _h of the heat conduction shell itself is composed of the thermal resistance R ₁ of the side wall of the heat conduction shell and the thermal resistance R ₂ of the bottom substrate of the heat dissipation rib in series, as shown in Figure 1, L ₁ is the length of the heat conduction path of the shell wall, L ₂ is the thickness of the substrate at the bottom of the heat dissipation rib, the diameter of the inner wall of the housing d _h , the width of the outer wall of the housing is d _c , d _p is the diameter of the piston, and k is the thermal conductivity of the material of the heat-conducting housing, then the thermal resistance R _h is:

e) The thermal resistance R _hk between the heat dissipation rib and the air can be calculated according to the heat conduction method of the straight rib with equal cross-section, and its value is; δ is the thickness of the heat dissipation rib substrate, A ₁ is the surface area of the side without ribs, and A ₂ is the surface area of the side with ribs;

f) The radiator of this example is suitable for sealing the chassis. The upper cover of the chassis can be opened to expose the ribs of the radiator, and the seal can be realized through the conductive sealing rubber strip between the chassis cover and the radiator, as shown in Figure 4 and Figure 5.

Claims (8)

1. A piston-type heat transfer radiator, comprising a heat-conducting housing (1) with cooling ribs, characterized in that: it also includes a heat-conducting piston (2) and a spring (3); the inside of the heat-conducting housing (1) has a The accommodation space of the piston (2) and the spring (3); the spring (3) is arranged in the accommodation space, one end of the spring (3) is connected with the upper surface of the accommodation space, and the other end is connected with the The top ends are connected; the outer wall of the heat conducting piston (2) is in clearance fit with the inner wall of the accommodating space, and the bottom end of the heat conducting piston (2) is used to contact the heating body. 2. A piston type heat transfer radiator according to claim 1, characterized in that: it also includes a base (4) with openings, the heat conduction shell (1) is fixedly connected with the base (4), and the heat conduction piston (2) It is stepped, the area of the bottom end is smaller than the area of the top end, and the bottom of the heat conduction piston (2) passes through the opening of the base (4). 3. A piston type heat transfer radiator according to claim 1, characterized in that: the preset gap between the heat conduction shell (1) and the heat conduction piston (2) is filled with heat conduction medium aviation silicone grease. 4. A piston type heat transfer radiator according to claim 1, characterized in that: the top of the heat conduction piston (2) is provided with a groove matching the spring (3). 5. A piston type heat transfer radiator according to claim 1, characterized in that: at least one exhaust hole is opened on the outer wall of the heat conduction shell (1). 6. A piston type heat transfer radiator according to claim 1, characterized in that it further comprises a heat pipe (5), and the heat pipe (5) is fixed on the outer wall of the heat conduction shell (1). 7. A piston type heat transfer radiator according to claim 2, characterized in that: the base (4) is provided with a limiting post. 8. A piston type heat transfer radiator according to claim 2, characterized in that: the top of the heat conduction shell (1) is provided with round holes for installing sealing screws (6) and sealing rubber pads (7) and the base (4) A small hole for installing a fixing screw is provided at a position corresponding to the round hole; a groove for installing a sealing rubber strip is provided on the top edge of the heat conduction shell (1).