TWI828976B - Heat dissipation element for semiconductor power devices and circuit board having the same - Google Patents

Abstract

A heat dissipation element for semiconductor power devices and a circuit board having the heat dissipation element are provided. The circuit board has a board body and the heat dissipation element. A circuit having a soldering portion is arranged on the board body. The heat dissipation element has an ATZ ceramic body and a metal layer coated on a portion of the ATZ ceramic body. The heat dissipation element is soldered with the soldering portion via the metal layer, so that a heat from the circuit could be conducted to the ATZ ceramic body from the soldering portion through the metal layer, and the other portions of the ATZ ceramic body as a heat dissipation surface for heat dissipating. The circuit is therefore via the ATZ ceramic body directly absorbed a waste heat to dissipate.

Description

Heat dissipation component for semiconductor power components and circuit board with the component

The present invention relates to heat dissipation of circuit boards, and in particular, refers to a heat dissipation component for semiconductor power components and a circuit board having the component.

Regarding circuit boards, most electronic components are electrically configured. These electronic components will generate corresponding heat depending on the power level. The higher the power, the higher the heat generated, such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). These are high-power components or drive components that can generate high heat (hereinafter referred to as high-power semiconductor power components), so existing circuit boards are equipped with heat sinks specifically for these high-power semiconductor power components.

However, in addition to these high-power semiconductor power components, there are also many general-power semiconductor power components that are not high-power on the circuit board (general-power semiconductor power components are hereinafter referred to as semiconductor power components). The heat generated by these semiconductor power components Although it is not as good as high-power semiconductor power components, it still generates heat, especially when circuit boards are installed in a casing or cabinet, causing the ambient temperature in the casing or cabinet to often rise. However, existing circuit boards do not do this. Proper heat dissipation is provided, which affects the operation of these semiconductor power components.

The object of the present invention is to provide a heat dissipation component for semiconductor power components and a circuit board having the component.

In order to achieve the above object, the present invention provides a heat dissipation element for semiconductor power components, which is used for circuit boards with soldering parts. The heat dissipation element includes: an ATZ ceramic body; and a metal layer plated on the ATZ ceramic. A part of the body, the heat dissipation element is welded to the welding part with the metal layer; wherein, the heat transferred from the welding part is conducted to the ATZ ceramic body through the metal layer, and other parts of the ATZ ceramic body are A cooling surface for heat dissipation.

The present invention also provides a circuit board with a heat dissipation component, including: a circuit board main body provided with a circuit, the circuit including at least one welding portion; and at least one heat dissipation component, the heat dissipation component including: an ATZ ceramic body ; and, a metal layer is plated on a part of the ATZ ceramic body, and the heat dissipation element is welded to the welding part with the metal layer; wherein the heat from the circuit is conducted from the welding part to the ATZ through the metal layer Ceramic body, other parts of the ATZ ceramic body are heat dissipation surfaces for heat dissipation.

Compared with the prior art, the present invention has the following effects: it can use the ATZ ceramic body to directly absorb waste heat and effectively dissipate the waste heat, so that the operation of the semiconductor power components is no longer affected by the waste heat.

100:Heat leakage element

1a,1b,1c:ATZ ceramic body

11: First surface

12: Second surface

14: Avoid the gap

16: Second surface

3:Metal layer

700:Circuit board body

7: Semiconductor power components

71,72: Pin

81,82:Circuit line

Figure 1 is a perspective view of the first embodiment of the heat dissipation element of the present invention.

Figure 2 is a cross-sectional view of the present invention based on Figure 1.

Figure 3 is a partial top view of the circuit board of the present invention, showing that it is provided with a plurality of heat dissipation components.

Figure 4 is a partial side view of the present invention based on Figure 3.

Figure 5 is a cross-sectional view of the second embodiment of the heat dissipation element of the present invention.

Figure 6 is a side view of the third embodiment of the heat dissipation element of the present invention.

The detailed description and technical content of the present invention are described below with reference to the drawings. However, the attached drawings are only for reference and illustration and are not intended to limit the present invention.

The present invention provides a heat dissipation element for semiconductor power components and a circuit board with the component, as shown in Figure 3, which is used to effectively dissipate waste heat, thereby ensuring that the power components or driving components on the circuit board (hereinafter referred to as semiconductor power The operation of components 7 (generally referred to as power components and drive components) is not affected by waste heat. As shown in FIGS. 1 to 2 , the first embodiment of the present invention is shown, and as shown in FIGS. 5 and 6 , the second and third embodiments of the present invention are respectively shown.

As shown in FIGS. 3 to 4 , the circuit board with a heat dissipation component of the present invention includes: at least one heat dissipation component 100 for semiconductor power components and a circuit board main body 700 .

The circuit board main body 700 can be a flexible circuit board or a rigid circuit board, which is not limited by the present invention. The circuit board body 700 is provided with a circuit (component symbols not shown), which circuit includes a plurality (that is, at least two) of semiconductor power components 7 and a plurality of circuit lines 81 and 82 for connection.

The semiconductor power element 7 has a plurality of pins 71 and 72. These metal pins 71 and 72 can be vertically connected upright pins (not shown in the figure), or can be horizontally connected as shown in Figure 3. The horizontal pins are described in this embodiment by taking the horizontal pins as an example.

The present invention is not limited to how the metal circuit lines 81 and 82 are formed. Taking a rigid circuit board as an example, the circuit lines 81 and 82 are formed by etching, but the invention is not limited thereto. The semiconductor power element 7 is connected to the circuit lines 81 and 82 .

As shown in FIGS. 1 to 4 , the first embodiment of the heat dissipation element 100 of the present invention includes an ATZ ceramic body 1 a and a metal layer 3 .

The ATZ ceramic body 1a is made by processes such as injection molding and sintering. Therefore, the ATZ ceramic body 1a can be injected into various shapes, such as: spherical, cylindrical, triangular, trapezoidal or rectangular. Of course, it can also be injected into any custom shape. As shown in FIG. 1 , it is a rectangular-shaped ATZ ceramic body 1 a. The rectangular-shaped ATZ ceramic body 1 a has six surfaces, and the six surfaces include: one first surface 11 and five second surfaces 12 . It should be noted that the ceramic material used in the ATZ ceramic body 1a in the present invention is a ceramic material with high specific heat and high density, and the ATZ ceramic body 1a made thereof has the following properties: insulation, high temperature resistance, and EMI shielding function , high heat capacity, good heat dissipation, strong rigid structure and chemical stability.

The metal layer 3 is plated (such as electroplating, but not limited to this) on a certain part of the ATZ ceramic body 1a, for example, on a partial outer surface of the spherical ATZ ceramic body, on one end of a cylindrical body, or on a triangular body. In this embodiment, the bottom surface plated on the first surface 11 of the rectangular ATZ ceramic body 1a is taken as an example for description. As for other parts of the ATZ ceramic body 1a, they are the second surfaces 12 of the rectangular ATZ ceramic body 1a. The metal layer 3 may be nickel-tin, for example, but is not limited thereto.

The heat dissipation element 100 uses the metal layer 3 to be welded to one of the plurality of pins 71 and 72 (as shown in FIGS. 3 and 4 ) by soldering agent (such as solder, but not limited to this), so that This pin 72 is regarded as the welding part of the aforementioned circuit; or it is welded to a circuit line 82 among the aforementioned plurality of circuit lines 81 and 82 (as shown in FIG. 3 ), so that this circuit line 82 is regarded as the welding part of the aforementioned circuit; and Or a plurality of heat dissipation elements 100 can be welded to the pins 72 and the circuit lines 82 respectively; among them, the pins 72 regarded as the welding parts in the present invention can be the pins 72 of general-power semiconductor power components, or they can be high-power semiconductor power components. Pin 72 of the power semiconductor power component. In other words, the aforementioned pins 72 and circuit lines 82 which are regarded as welding parts are existing components that are already provided on the circuit board body 700. In other embodiments not shown in the figures, they can also be further included in the circuit board. A special welding section is added specifically for the welding of the heat dissipation element 100 .

In this way, the heat from the semiconductor power element 7 will first be conducted to the pins 71 and 72 and the circuit lines 81 and 82, and then the heat will be directly conducted to the ATZ ceramic body 1a through the metal layer 3 to absorb heat (heat storage), so as to utilize ATZ. The second surfaces 12 of the ceramic body 1a are used to dissipate heat. Each second surface 12 is equivalent to a heat dissipation surface. Therefore, the waste heat generated by the semiconductor power element 7 can be effectively leaked and dissipated through the second surfaces 12, thereby increasing the semiconductor power. The operation of element 7 is no longer affected by waste heat. In short, the heat dissipation element 100 of the present invention can directly absorb the waste heat of the semiconductor power element 7 and dissipate it into the environment, so that the semiconductor power element 7 can cool down.

It should be noted that the circuit line 82 used as the welding part can be selected to be located next to the semiconductor power element 7 to weld the heat dissipation element 100, but it is not limited to this.

It should be noted that since the present invention can directly absorb the waste heat generated by the semiconductor power element 7 and directly dissipate the absorbed waste heat into the environment, the temperature of the semiconductor power element 7 can be equalized with the ambient temperature. Therefore, the temperature of the semiconductor power element 7 can be effectively reduced, but the ambient temperature of the general environment will not change, thus achieving a temperature equalization effect. In other words, the present invention has a strong temperature equalization effect and can improve the semiconductor power element 7 through temperature equalization. service life. Simply put, because of the uniform temperature, the present invention can increase the power of the semiconductor power element 7 at the same operating temperature; conversely, at the same power, the operating temperature is lower, so it can extend the life of the semiconductor power element 7 service life.

As shown in Figure 5, it is the second embodiment of the heat dissipation element 100 of the present invention. The second embodiment is roughly the same as the aforementioned first embodiment. The only difference is that the ATZ ceramic body 1b in the second embodiment is further formed with at least one Avoid Gap 14.

As a result, in the existing limited space, even if the original heat dissipation element 100 cannot be installed due to interference from other components (not shown in the figure, which can be electronic components or mechanical components), in this section In the second embodiment, the avoidance gap 14 can be used to avoid other components. Therefore, the second embodiment of the heat dissipation component 100 of the present invention is particularly suitable for limited spaces.

It is worth noting that by forming two avoidance notches 14 as shown in Figure 5 on the bottom surface of the ATZ ceramic body 1b to reduce the area of the first surface 11, the metal layer 3 with a correspondingly reduced area can be used for welding. In the aforementioned welding portion, it is therefore particularly suitable for use in a limited space to prevent the metal layer 3 from contacting short circuits with other metal objects not shown in the figure.

As shown in Figure 6, it is the third embodiment of the heat dissipation element 100 of the present invention. The third embodiment is roughly the same as the aforementioned first embodiment, and the only difference is the second surface of the ATZ ceramic body 1c in the third embodiment. 16 is different from the second surface 12 of the first embodiment.

In the third embodiment, the second surface 16 of the ATZ ceramic body 1c is further designed in a wavy shape, so that the area of the second surface 16 is larger than the area of the second surface 12 of the first embodiment and is more conducive to heat dissipation. Preferably, as shown in Figure 6, the five second surfaces 16 of the rectangular ATZ ceramic body 1c are all formed into wavy shapes. Only the first surface 11 is still flat and can be obtained after plating the metal layer 3. It has the effect of being beneficial to welding.

The heat dissipation of the heat dissipation element 100 of the present invention is described below:

[1], Heat dissipation calculation-heat conduction:

(1-1) Heat conduction: The heat transferred from the heat source continues to transfer to achieve temperature balance:

q=-KA×△T△d

q: Heat transfer amount (W) K: Heat transfer coefficient (W/m-°K)

T: Temperature (°K) d: Distance (m)

A: Cross-sectional area perpendicular to the heat transfer direction (mˆ2)

Among them, the heat transfer coefficient (thermal conductivity) K does not need to be specially calculated. As long as the K value is greater than 10 for materials, there is no need to calculate it. The materials used in the six examples listed in points (1-3) below all have K values greater than 10.

(1-2), another representation: the endothermic material absorbs heat and reaches temperature equilibrium:

：材料密度(g/cmˆ3)

：Material density (g/cmˆ3)

Cp: Specific heat (jol/g.°K) △T: Temperature difference (°K)

(Note: Jol is the English abbreviation of Joule)

(1-3), examples (including unit conversion):

Pure aluminum (Al) after anode has a specific heat C of 0.9 and a specific gravity of 2.7g/cmˆ3

Aluminum oxide (Al2O3), specific heat C is 0.875, specific gravity is 3.9g/cmˆ3

After being heated, the temperature of both of them rises from 20℃ to 75℃, then the heat absorption per unit volume cmˆ3 of the two is:

1. Aluminum Al: 0.9×2.7×55=133.65jol (31.9 calories or 0.0371W)

2. Alumina Al2O3: 0.875×3.9×55=188.1jol (44.9 calories or 0.0523W)

Under the same conditions, the heat absorbed by general heat dissipation or high thermal conductivity materials is as follows:

3. Copper Cu: Q=0.385×8.96×55=189.7jol (43.4 calories or 0.0527W)

4. Silver Ag: Q=0.234×10.49×55=134.9jol (32.3 cards or 0.0341W)

5. Iron Fe: Q=0.461×7.87×55=199.5jol (47.7 calories or 0.0554W)

6.ATZ (alumina-zirconia composite material, ATZ ceramic): Q=0.89×4.05×55=198.2jol (47.4 calories or 0.0551W)

From points 3, 5, and 6 above, it can be seen that the heat absorption of ATZ ceramics is almost the same as that of iron and better than that of copper. Furthermore, ATZ ceramics are insulators, while iron and copper are both conductors. ATZ ceramics have the dual advantages of high heat absorption and being an insulator.

It should be noted that if the volume is calculated based on practicality to mmˆ3, then the heat absorption of ATZ in point 6 above = 0.0000551W.

[2], Heat dissipation calculation-thermal convection:

(2-1) Thermal convection: The heat source body and heat sink body release (or absorb) heat to the surrounding environment due to air flow, which is proportional to the surface area of the object.

q ^' =h×(Tw-Ta); Q=h×A×(Tw-Ta)

q ^' : Heat flux density (W/mˆ2) Q: Heat transfer amount on area A

Tw: Solid surface temperature (°K) A: Wall surface area in contact with fluid (mˆ2)

Ta: fluid temperature (°K) h: surface convection heat transfer coefficient (W/mˆ2 ^* K)

(2-2), Practical application units:

1.h (surface convection heat transfer coefficient): static=0~5; general=8~10; mandatory: >15

2. Area: mmˆ2=0.000001mˆ2

3.1jol=0.239 cards; 1 card=0.00116W (or 1W=860 cards)

(2-3) Examples of thermal convection:

The total wall surface of an object in contact with fluid is 1mˆ2, and the heat convection (thermal conductivity) generated by its heat flow is 8W/mˆ2×K; the heat source temperature is constant at 75°C (348°K), and the ambient temperature is 20°C (293°K ), then the heat dissipated is: Q=h×A×(Tw-Ta)=8×1×(348-293)=440W

Judging from the actual electronic components and circuit environment, the surface area is mmˆ2, so the heat dissipation by thermal convection is 0.00044W/mmˆ2.

3〕, heat dissipation calculation-thermal radiation:

(3-1) Thermal radiation: The difference between the surface temperature of the source body and the heat sink and the surrounding environment produces thermal radiation, which is related to the fourth power of the absolute temperature difference (°K); it is also related to the surface area (A) of the object .

q ^" =єσ(Tsˆ4) Q=єσA(Twˆ4-Taˆ4)

q ^" : Thermal radiation flux Q: The total amount of radiant heat (W)

є: Radiation emissivity (0 ^~ 1) A: Material exposed wall area (mˆ2)

σ：Stph-Bog Const.(5.67x10ˆ-8W-mˆ2×°Kˆ4)

Tw: Object surface temperature (°K) Ta: Ambient temperature (°K)

(3-2). Surface emissivity of common objects:

General aluminum: 0.1; anode aluminum: 0.9; polished copper: 0.04

Copper oxide: 0.8; red brick: 0.85; cement: 0.9

Paint: 0.9; ATZ: 0.9

(3-3) Examples of thermal radiation:

The total wall surface of an object in contact with the air is 1mˆ2, and the surface emissivity of the material is 0.9; the heat source temperature is constant at 75°C (348°K), and the ambient temperature is 20°C (293°K), then the heat dissipated is : Q=єσA(Twˆ4-Taˆ4)=0.9×5.67×10ˆ-8×1×(348ˆ4-293ˆ4)=0.9×5.67×10ˆ-8×1×73×10ˆ8=372.5W

Judging from the actual electronic components and circuit environment, the surface area is mmˆ2, and the material emissivity is 0.9, so the heat dissipation of thermal radiation is 0.000373W/mmˆ2.

To summarize the above three heat dissipation calculations: under the comparison of the same material and the same conditions, the above [1], heat conduction (heat absorption): ATZ = 0.0000551W, the above [2], thermal convection (heat dissipation): ATZ = 0.00044W, the above [ 3], Thermal radiation (heat dissipation): ATZ=0.000373W. Therefore, comparing these three heat dissipation calculations, it can be seen that the heat dissipation capacity of ATZ ceramics (heat dissipation of type [2] thermal convection + heat dissipation of type [3] thermal radiation) is much higher than the heat absorption capacity of ATZ ceramics (type [1] kind of heat absorption), thereby proving that ATZ ceramics can indeed dissipate heat, that is, the heat dissipation element 100 of the present invention does have a heat dissipation effect that can effectively dissipate waste heat.

To sum up, the heat dissipation element for semiconductor power components of the present invention and the circuit board with the element can indeed achieve the expected purpose of use and solve the deficiencies of the existing technology. It fully meets the requirements for invention patent application and complies with the patent law. If you submit an application, please review it carefully and grant the patent in this case to protect the rights of the inventor.

The above are only the best possible embodiments of the present invention, which do not limit the patent scope of the present invention. All equivalent structural changes made by using the description and drawings of the present invention are also included in the present invention. Within the scope of rights, it shall be stated clearly.

100:Heat leakage element

1a:ATZ ceramic body

11: First surface

12: Second surface

3:Metal layer

700:Circuit board body

7: Semiconductor power components

72: Pin

Claims (7)

A heat dissipation element for semiconductor power components, used for circuit boards with soldering parts. The heat dissipation element includes: an ATZ ceramic body with a first surface and a plurality of second surfaces, at least one of the plurality of second surfaces. One of them is formed into a wavy shape; and a metal layer is plated on the first surface of the ATZ ceramic body and covers the entire first surface, and the heat dissipation element is welded to the welding portion with the metal layer; wherein, from The heat from the welding part is conducted to the ATZ ceramic body through the metal layer, and the plurality of second surfaces of the ATZ ceramic body are heat dissipation surfaces. The heat dissipation element for semiconductor power components as described in claim 1, wherein the plurality of second surfaces of the ATZ ceramic body are formed with at least one escape notch, and the second surface of the ATZ ceramic body is formed with at least one escape gap. An area is reduced by avoiding the notch, and the metal layer is plated on the second surface with a reduced area to have a corresponding area size. A circuit board with a heat dissipation component, including: a circuit board main body provided with a circuit, the circuit including at least one welding portion; and at least one heat dissipation component for semiconductor power components, the heat dissipation component including: an ATZ ceramic The body has a first surface and a plurality of second surfaces, at least one of the plurality of second surfaces is formed into a wave shape; and a metal layer is plated on the first surface of the ATZ ceramic body and covers the entire first surface. surface, the heat dissipation element is welded to the welding part with the metal layer; wherein, the heat from the circuit is conducted from the welding part to the ATZ ceramic body through the metal layer, and the plurality of second surfaces of the ATZ ceramic body are A cooling surface for heat dissipation. The circuit board with a heat dissipation component as claimed in claim 3, wherein the circuit includes a semiconductor power component, the semiconductor power component has a plurality of pins, at least one of the plurality of pins is configured as the welding portion, and the The heat dissipation element is welded to the pin set as the welding part with the metal layer. The circuit board with a heat dissipation element as claimed in claim 3, wherein the circuit includes a plurality of circuit lines, at least one of the plurality of circuit lines is set as the welding portion, and the heat dissipation element is welded to the metal layer with the metal layer. Set on the circuit line of the welding part. The circuit board with a heat dissipation element as described in claim 3, wherein the main body of the circuit board is a rigid circuit board or a flexible circuit board. A heat dissipation element for semiconductor power components, used for circuit boards with soldering parts. The heat dissipation element includes: an ATZ ceramic body; and a metal layer plated on a part of the ATZ ceramic body. The heat dissipation element The component is welded to the welding part with the metal layer, and at least one escape notch is formed in this part or the other part of the ATZ ceramic body. The at least one avoidance notch is formed in this part or the other part of the ATZ ceramic body. To reduce the area, the metal layer has a corresponding area size by being plated on the part or the other part where the area has been reduced; wherein, the heat transferred from the welding part is conducted to the ATZ ceramic body through the metal layer, Other parts of the ATZ ceramic body are heat dissipation surfaces for heat dissipation.

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