TW202239276A - Circuit heat dissipation element and circuit board having the same - Google Patents

Abstract

A circuit heat dissipation element and a circuit board having the element is provided. The circuit board has a board body and a circuit heat dissipation element. The board body of the circuit board is provided with a circuit, and the circuit has a soldering portion. The circuit heat dissipation element includes a ceramic body and a metal layer. The metal layer is coated on a portion of the ceramic body, and the circuit heat dissipation element is soldered with the soldering portion via the metal layer. Thereby, heat could be conducted to the ceramic body from the soldering portion of the circuit through the metal layer, and the other portions of the ceramic body provides heat dissipation surface for heat dissipating. Therefore, waste heat could be directly absorbed into the ceramic body and the waste heat could be efficiently dissipated.

Description

Circuit heat dissipation element and circuit board with the element

The invention relates to heat dissipation of circuit boards, in particular to a circuit heat dissipation element and a circuit board with the element.

Regarding the circuit board, most electronic components are electrically configured, and these electronic components will generate corresponding heat according to the power level. The higher the power, the higher the heat generated, such as CPU (Central Processing Unit) or GPU (Graphics Processing Unit) In order to generate high-heat high-power components or drive components (hereinafter referred to as high-power/drive components), existing circuit boards are specially equipped with radiators for these high-power/drive components.

However, in addition to these high power/drive components, there are many non-high power general power/drive components (hereinafter referred to as power/drive components) on the circuit board. Although the heat generated by these power/drive components is not as high as that of high power/drive Components, but still generate heat, especially the circuit boards will be set in the case or cabinet, causing the ambient temperature inside the case or cabinet to often rise, but the existing circuit boards are not equipped with corresponding heat dissipation, resulting in The operation of these power/drive components is affected.

The object of the present invention is to provide a circuit heat dissipation element and a circuit board with the element.

In order to achieve the above object, the present invention provides a circuit heat dissipation element, which is used for a circuit board provided with a welding part. The circuit heat dissipation element includes: a ceramic body; and a metal layer plated on a part of the ceramic body, the The heat dissipation element of the circuit is welded to the welding part with the metal layer; wherein, the heat transmitted from the welding part is conducted to the ceramic body through the metal layer, and other parts of the ceramic body are heat dissipation surfaces for heat dissipation.

The present invention further provides a circuit board with a circuit heat dissipation element, comprising: a circuit board main body provided with a circuit, the circuit including at least one soldering portion; and at least one circuit heat dissipation element, the circuit heat dissipation element comprising:

A ceramic body; and, a metal layer plated on a part of the ceramic body, and the heat dissipation circuit element is welded to the welding part by the metal layer;

Wherein, the heat from the circuit is conducted from the welding part to the ceramic body through the metal layer, and other parts of the ceramic body are heat dissipation surfaces for heat dissipation.

Compared with the prior art, the present invention has the following effects: the ceramic body can be used to directly absorb waste heat and effectively dissipate the waste heat, so that the operation of the power/drive element is no longer affected by the waste heat.

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

The present invention provides a circuit heat dissipation element and a circuit board with the element, as shown in FIG. Semiconductor elements can be used to collectively refer to power elements and drive elements) to operate without being affected by waste heat. Figures 1 to 2 show the first embodiment of the present invention, and Figures 5 and 6 show the second and third embodiments of the present invention, respectively.

As shown in FIG. 3 to FIG. 4 , the circuit board with circuit heat dissipation element of the present invention includes: at least one circuit heat dissipation element 100 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 in the present invention. The main body 700 of the circuit board is provided with a circuit (the component number is not marked), and the circuit includes a plurality (ie at least two) power/drive elements 7 and a plurality of circuit lines 81 , 82 for connection.

The power/drive element 7 has a plurality of pins 71, 72. These metal pins 71, 72 can be upright pins (not shown) connected upright, or can be connected horizontally as shown in FIG. 3 In this embodiment, the horizontal pin is used as an example for illustration.

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

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

The ceramic body 1a is made by processes such as injection molding and sintering, so the ceramic body 1a can be injected into various shapes, such as: spherical, cylindrical, triangular, trapezoidal or rectangular, etc. Of course, it can also be injected into any shape. Customized shape. As shown in FIG. 1 , it is a rectangular ceramic body 1 a . The rectangular 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 ceramic body 1a in the present invention is a high specific heat, high-density ceramic material, and the ceramic body 1a made by it has: insulation, high temperature resistance, EMI shielding function, heat capacity High heat dissipation, strong rigid structure and chemical stability.

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

The circuit heat dissipation element 100 is soldered to one pin 72 of the plurality of pins 71, 72 (as shown in FIG. 3 and FIG. 4 ) with the metal layer 3 by soldering agent (such as solder, but not limited thereto), Make this pin 72 be regarded as the soldering part of aforementioned circuit; Alternatively, multiple circuit heat dissipation elements 100 can be welded to the pins 72 and the circuit wires 82 respectively; wherein, the pins 72 of the welding part in the present invention can be the pins 72 of general power/drive elements, or can be Pin 72 for the high power/drive element. In other words, the aforesaid pins 72 and circuit wires 82, which are regarded as soldering parts, are existing components that are already installed on the circuit board main body 700. A special welding part for welding the circuit heat dissipation element 100 is additionally provided.

In this way, the heat from the power/drive element 7 will first be conducted to each pin 71, 72 and each circuit wire 81, 82, and then the heat will be directly conducted to the ceramic body 1a through the metal layer 3 to absorb heat (heat storage), so as to utilize the ceramic Each second surface 12 of body 1a has to dissipate heat, and each second surface 12 is equivalent to a heat dissipation surface, so the waste heat generated by the power/drive element 7 can be effectively released through each second surface 12 and then dissipated, so that the power/drive element The operation of the drive element 7 is no longer affected by waste heat. In short, the circuit heat dissipation element 100 of the present invention can directly absorb the waste heat of the power/drive element 7 and dissipate it to the environment, so that the power/drive element 7 can be cooled accordingly.

It should be noted that, the above-mentioned circuit wires 82 used as soldering parts may select the circuit wires 82 located next to the power/drive element 7 to solder the circuit heat dissipation element 100 , but the present invention is not limited thereto.

It should be further noted that, since the present invention can directly absorb the waste heat produced by the power/drive element 7, and can directly dissipate the absorbed waste heat to the environment, the temperature of the power/drive element 7 can be equal to the ambient temperature. Therefore, the temperature of the power/drive element 7 can be effectively reduced, but the ambient temperature of the large environment does not change much, so that the temperature uniformity effect is achieved; in other words, the present invention has a strong temperature uniformity effect, and the power can be increased by uniform temperature / Service life of drive element 7. In simple terms, the present invention can increase the power of the power/drive element 7 at the same operating temperature because of the uniform temperature; conversely, at the same power, the operating temperature is lower, so the power/drive element 7 can be extended. 7 service life.

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

In this way, in the existing limited space, even if the original circuit heat dissipation element 100 cannot be installed due to the interference of other components (not shown in the figure, it can be electronic components or mechanical components), but in this In the second embodiment, however, the escape gap 14 can be used to avoid other components, so the second embodiment of the circuit heat dissipation element 100 of the present invention is particularly suitable for limited space.

It is worth noting that, by forming two avoidance gaps 14 as shown in FIG. 5 on the bottom surface of the ceramic body 1b, the area of the first surface 11 is reduced, so that the metal layer 3 with a correspondingly reduced area can be welded to the ceramic body 1b. The aforesaid welding portion is therefore particularly suitable for use in a limited space so as to prevent the metal layer 3 from contacting and short-circuiting with other metal objects not shown in the figure.

As shown in FIG. 6 , it is the third embodiment of the circuit heat dissipation element 100 of the present invention, the third embodiment is roughly the same as the first embodiment, the only difference is the second surface of the 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 ceramic body 1c is further designed into a wave shape, so that the area of the second surface 16 is larger than that of the second surface 12 of the first embodiment, which is more conducive to heat dissipation. Preferably, as shown in Figure 6, the five second surfaces 16 of the rectangular ceramic body 1c are all formed in a wave shape, and only the first surface 11 is still plane and can have a flat surface after the metal layer 3 is coated. Good for welding.

The following describes the heat dissipation of the circuit heat dissipation element 100 of the present invention:

〔1〕, heat dissipation calculation - heat conduction:

(1-1), heat conduction: the heat from the heat source continues to reach temperature balance:

q=-KA × ΔTΔd

q: heat transfer (W) K: heat transfer coefficient (W/m- ̊K)

T: temperature ( ̊K) d: distance (m)

A: Cross-sectional area perpendicular to the direction of heat transfer (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, the calculation can be omitted. The materials used in the 6 examples cited in the following points (1-3) all have a K value greater than 10.

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

q=ϱCpΔT

ϱ: material density (g/cmˆ3)

Cp: specific heat (jol/g. ̊K) ΔT: temperature difference ( ̊K)

(Note: Jol is the English abbreviation of Joule)

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

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

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

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

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

2. Aluminum oxide Al2O3: 0.875 × 3.9 × 55=188.1jol (44.9 cal 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 cal or 0.0527W)

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

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

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

From the above points 3, 5, and 6, it can be seen that the heat absorption of ATZ ceramics is almost the same as that of iron and is better than that of copper; moreover, 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 in mmˆ3 based on practicality, the heat absorption of ATZ in the sixth point above = 0.0000551W.

〔2〕, heat dissipation calculation - heat convection:

(2-1) Heat convection: The heat released (or absorbed) by the heat source body and the heat sink body to the surrounding environment due to air flow 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 heat on area A

Tw: solid surface temperature (̊K) A: wall area in contact with fluid (mˆ2)

Ta: Fluid temperature ( ̊K) h: Surface convective heat transfer coefficient (W/mˆ2*K)

(2-2), the actual application unit:

1. h (surface convection heat transfer coefficient): Static=0~5; General=8~10; Mandatory: ＞15

2. Area: mmˆ2=0.000001mˆ2

3. 1jol= 0.239 cal; 1 cal=0.00116W (or 1W=860 cal)

(2-3) Examples of heat convection:

The total wall surface of an object in contact with the fluid is 1mˆ2, and the heat convection (thermal conductivity) generated by the heat flow is 8W/mˆ2×K; the temperature of the heat source is constant at 75 ̊C (348 ̊K), while the ambient temperature is 20 ̊C (293 ̊K), Then the heat dissipated is:

Q=h × A × (Tw-Ta)

=8 × 1 × (348-293) = 440W

From the perspective of the actual electronic components and circuit environment, the surface area is mmˆ2, so the heat dissipation by heat convection is 0.00044W/mmˆ2.

3) Heat dissipation calculation - heat radiation:

(3-1) Thermal radiation: The difference between the surface temperature of the source body and the radiator 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: total amount of radiated heat (W)

Є: Radiation emissivity (0 ᷉ 1) A: Material exposed wall area (mˆ2)

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

Tw: object surface temperature ( ̊K) Ta: ambient temperature ( ̊K)

(3-2), surface emissivity of common objects:

General aluminum: 0.1; Anodized 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 heat 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 temperature of the heat source 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

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

Summarize the aforementioned three heat dissipation calculations: under the comparison of the same material and the same conditions, the aforementioned [1], heat conduction (heat absorption): ATZ=0.0000551W, the aforementioned [2], heat convection (heat dissipation): ATZ=0.00044W, the aforementioned [ 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 (the heat dissipation of heat convection of type [2] + the heat dissipation of heat radiation of type [3]) is much higher than the heat absorption capacity of ATZ ceramics (type [1] Specific heat absorption), thus proving that ATZ ceramics can indeed dissipate heat, that is, the circuit heat dissipation element 100 of the present invention does have a heat dissipation effect that can effectively dissipate waste heat.

In summary, the circuit heat dissipation element 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 prior art, and fully meet the requirements of the invention patent application. Please apply in accordance with the Patent Law. Checked and granted the patent of this case in detail to protect the rights of the inventor.

The above is only a preferred embodiment of the present invention, and does 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 the rights, I agree with Chen Ming.

100: circuit heat dissipation element

1a, 1b, 1c: ceramic body

11: First surface

12: Second surface

14: Avoid the gap

16:Second surface

3: metal layer

700: circuit board body

7: Power/drive components

71,72: Pins

81,82: circuit line

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

FIG. 2 is a cross-sectional view of the present invention according to FIG. 1 .

FIG. 3 is a schematic partial top view of the circuit board of the present invention, showing a plurality of circuit heat dissipation components.

FIG. 4 is a schematic partial side view of the present invention according to FIG. 3 .

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

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

100: circuit heat dissipation element

1a: ceramic body

11: First surface

12: Second surface

3: metal layer

700: circuit board body

7: Power/drive components

72: Pin

Claims (13)

A circuit heat dissipation element used for a circuit board provided with a welding part, the circuit heat dissipation element comprising: a ceramic body; and A metal layer is plated on a part of the ceramic body, and the circuit heat dissipation element is welded to the welding part by the metal layer; Wherein, the heat transmitted from the welding part is conducted to the ceramic body through the metal layer, and other parts of the ceramic body are heat dissipation surfaces for heat dissipation. The circuit heat dissipation element as claimed in claim 1, wherein the ceramic body has a first surface and at least one second surface, the metal layer is plated on the first surface, and the at least one second surface is used for heat dissipation noodle. The circuit heat dissipation element as claimed in claim 1, wherein the other part of the ceramic body is further formed into a wave shape. The circuit heat dissipation element as described in claim 3, wherein the part of the ceramic body is a first surface, and the other parts of the ceramic body include a plurality of second surfaces, the metal layer is plated on the first surface, the At least one of the plurality of second surfaces is wavy. The circuit heat dissipation element as described in claim 1, wherein at least one avoidance gap is formed on the part or the other part of the ceramic body, and the at least one avoidance gap is formed on the part or the other part of the ceramic body The area is reduced, and the metal layer has a corresponding area size by being plated on the part or other parts of which the area has been reduced. A circuit board having a circuit heat dissipation element, comprising: a circuit board body provided with a circuit including at least one soldering portion; and at least one circuit heat dissipation element, the circuit heat dissipation element comprising: a ceramic body; and A metal layer is plated on a part of the ceramic body, and the circuit heat dissipation element is welded to the welding part by the metal layer; Wherein, the heat from the circuit is conducted from the welding part to the ceramic body through the metal layer, and other parts of the ceramic body are heat dissipation surfaces for heat dissipation. The circuit board with circuit heat dissipation element as described in claim 6, wherein the ceramic body has a first surface and at least one second surface, the metal layer is plated on the first surface, and the at least one second surface is The cooling surface for heat dissipation. The circuit board with circuit heat dissipation element as claimed in claim 6, wherein the other part of the ceramic body is further formed into a corrugated shape. The circuit board with circuit heat dissipation element as described in claim 8, wherein the part of the ceramic body is a first surface, and the other parts of the ceramic body include a plurality of second surfaces, and the metal layer is plated on the first surface On a surface, at least one of the plurality of second surfaces forms a wave shape. The circuit board with a circuit heat dissipation element as described in claim 6, wherein the circuit includes a power/drive element, the power/drive element has a plurality of pins, at least one of the plurality of pins is set as the soldering part, the heat dissipation element of the circuit is welded to the pin which is set as the welding part with the metal layer. The circuit board with circuit heat dissipation element as described in claim 6, wherein the circuit includes a plurality of circuit lines, at least one of the plurality of circuit lines is set as the welding part, and the circuit heat dissipation element is welded with the metal layer on the circuit line that is set as the soldering portion. The circuit board with circuit heat dissipation element as described in claim 6, wherein at least one avoidance gap is formed on this part or the other part of the ceramic body, and the at least one avoidance gap is formed on the part or the other part of the ceramic body through the formation of the at least one Once the area is reduced by avoiding the gap, the metal layer has a corresponding area size by being plated on the part or other parts whose area has been reduced. The circuit board with circuit heat dissipation element according to claim 6, wherein the main body of the circuit board is a rigid circuit board or a flexible circuit board.

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