CN107896422A - A fast heat dissipation PCB - Google Patents

Abstract

The invention relates to the technical field of circuit boards, and discloses a PCB capable of quickly dissipating heat, which comprises a stepped groove and a heat dissipation substrate; the stepped groove comprises a through groove and a groove, and the through groove is used for accommodating a high-power component; the heat dissipation substrate is arranged in the groove and used for supporting the bottom of the high-power component, the inner wall of the through groove and the heat dissipation substrate support the surface of the high-power component are provided with an integrated metallization layer, and the high-power component is welded with the metallization layer through solder paste. The invention solves the problem that the PCB is difficult to quickly dissipate heat.

Description

A fast heat dissipation PCB

technical field

The invention relates to the technical field of circuit boards, in particular to a PCB with rapid heat dissipation.

Background technique

With the development of electronic product technology, the trend of surface-mounting and miniaturization of components is becoming more and more obvious. The density of products is increasing, the main frequency of components is increasing, and the power consumption of individual components is gradually increasing, resulting in heat flow. A sharp increase in density. Therefore, in order to ensure the service life of electronic equipment, it is necessary to solve the problem of heat dissipation of high-power components. Using a common heat dissipation structure to assist the heat dissipation of the device can no longer meet the heat dissipation requirements of high-power components. Therefore, it is necessary to provide a fast heat dissipation structure to solve the problem that the PCB is difficult to quickly dissipate heat.

Contents of the invention

The object of the present invention is to provide a PCB with rapid heat dissipation, which is used to solve the problem that the PCB is difficult to quickly dissipate heat.

For reaching this purpose, the present invention adopts following technical scheme:

Provide a PCB with rapid heat dissipation, including stepped grooves, which include through grooves and grooves, and the through grooves are used to accommodate high-power components;

The heat dissipation substrate is arranged in the groove and is used to support the bottom of the high-power components. The inner wall of the through groove and the surface of the heat dissipation substrate supporting the high-power components have an integral metallization layer, so The high-power components and the metallization layer are soldered together with solder paste.

The metallization layer on the surface of the through groove and the heat dissipation substrate is uniform and has good thermal conductivity. Setting the metallization layer can make the heat generated by high-power components quickly transfer to the heat dissipation substrate and metal layer through the solder paste and metallization layer, so that the heat Can dissipate quickly.

Solder paste is selected because the melting point of solder paste is about 150°C-220°C, it is easy to melt, and it is convenient to fix high-power components. At the same time, the heat generated by high-power components will not reach the melting point of solder paste. It will not melt, and the solder paste has good electrical and thermal conductivity and low cost.

Further, the upper surface of the heat dissipation substrate has a recess, and the recess accommodates the bottom of the high-power components. On the one hand, the purpose of setting the concave part is to make the side wall of the high-power components contact with the heat-dissipating substrate, increase the contact area between the high-power components and the heat-dissipating substrate, and enable most of the heat generated by the high-power components to be dissipated quickly. The substrate spreads out, improving the heat dissipation efficiency. On the other hand, because the high-power components are arranged in the concave part and the through groove, compared with the products in the prior art that mount or place high-power components on the surface of the PCB, the occupied space of the PCB surface components is reduced. The overall volume of the PCB is reduced, thereby improving the integration of components on the PCB.

Preferably, the heat dissipation substrate is made of copper. The main body of the heat dissipation substrate is made of copper, mainly because copper has good thermal conductivity and electrical conductivity, and can quickly conduct heat to the heat sink for dissipation.

Further, the heat dissipation substrate is buried in the groove. The heat-dissipating substrate is fixed in the groove through the thermalized prepreg during the pressing process, which saves the need to use other processes or materials to fix the heat-dissipating substrate, saving production costs; and the core board and the prepreg are pressed together. During the process, the fixing of the heat dissipation substrate is completed at the same time, and the work efficiency is improved.

Preferably, the bottom surface of the heat dissipation substrate is flush with one side of the PCB. On the one hand, this structural setting can ensure that the heat dissipation substrate is fixed inside the PCB in the form of embedding, which reduces the overall structural size of the PCB and makes the structure of the PCB more compact, thereby ensuring the integrity of the PCB and facilitating the processing and installation of the PCB. It is convenient to cover the copper layer on the outside of the PCB, and it is also more beautiful; on the other hand, it can quickly dissipate heat from the bottom surface of the heat dissipation substrate. In addition, compared with products in the prior art that mount or place heat dissipation substrates on the surface of the PCB, the overall thickness of the PCB of the present invention is greatly reduced, and the structure is more compact.

Preferably, the bottom surface of the heat dissipation substrate and the one side of the PCB are covered with a copper layer. The purpose of covering the copper layer is to increase the heat dissipation area, so that the heat in the heat dissipation substrate can be quickly dissipated at the bottom metal layer of the PCB, and at the same time enhance the overall structural strength of the PCB.

Preferably, a heat sink is provided on the bottom surface of the copper layer. Setting the heat sink can increase the contact area between the heat and the air, and achieve better temperature difference transfer, so that the heat can be dissipated faster.

Preferably, via holes are also included. The via hole is a kind of plated through hole, and one of its functions is to dissipate heat. In order to transfer the heat generated by the high-power components from the metal layer to the via hole, and dissipate it into the air through the via hole, it plays an auxiliary role. The function of heat dissipation; the other function is to electrically conduct the metal layer, which is used to connect the copper foil line between two or more layers of the PCB.

Preferably, the heat sink covers the via hole. In order to dissipate the heat of the via hole and the metal layer around the via hole to the air as soon as possible, so as to prevent the PCB from overheating and causing damage to the PCB.

Beneficial effects of the present invention:

1. Embed the heat dissipation substrate in the groove opened on the PCB, so that the high-power components are in contact with the heat dissipation substrate through the solder paste and the metallization layer, so that the main heat generated by the high-power components can be quickly dissipated into the air through the heat dissipation substrate , Solve the problem of PCB rapid heat dissipation.

2. Embed the heat dissipation substrate in the groove on one side of the PCB, set a through groove on the other side of the PCB, and set a recess on the heat dissipation substrate, and set high-power components in the through groove and the recess of the heat dissipation substrate. Compared with products that mount or place high-power components on the surface of the PCB in the prior art, the space occupied by the components on the surface of the PCB is reduced, and the overall structure size of the PCB is reduced, thereby improving the integration of components on the PCB .

Description of drawings

Fig. 1 is a kind of structural schematic diagram (three core boards) of the fast heat dissipation PCB (not including high-power components) of embodiment one;

Fig. 2 is a kind of structure schematic diagram (three core boards) of the fast heat dissipation PCB of embodiment one;

Fig. 3 is another structural schematic diagram (three core boards) of the rapid heat dissipation PCB (not including high-power components) of the second embodiment;

Fig. 4 is a schematic diagram of a heat dissipation path (three core boards) of the rapid heat dissipation PCB of embodiment two;

Fig. 5 is the structural enlarged view of the I place of Fig. 4 among the embodiment two;

Fig. 6 is a schematic diagram of another heat dissipation path of the rapid heat dissipation PCB of the second embodiment (three core boards);

FIG. 7 is a structural schematic diagram of a rapid heat dissipation PCB (four core boards) in Embodiment 3. FIG.

In the picture:

1. Step groove; 11. Through groove; 12. Groove; 2. High-power components; 3. High thermal conductivity metal block; 4. Metallization layer; 5. Solder paste; 6. Copper layer; 7. Heat sink; 8. Via hole.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation methods.

The orientation words used in the embodiments of the present invention such as "upper", "lower", "top" and "bottom" are defined in the case of the structure of the rapid heat dissipation PCB provided in this embodiment, as shown in the accompanying drawings, " "Up", "Down", "Top", and "Bottom" refer to the upper, lower, top and bottom of the PCB itself. These orientation words are adopted for ease of understanding, and thus do not constitute a limitation of the protection scope of the present invention.

Embodiment one

As shown in Figure 1-2, this embodiment provides a PCB with rapid heat dissipation, which is composed of three core boards pressed together (not limited to three core boards, two or more core boards can also be pressed together Into), the above-mentioned PCB includes a stepped groove 1, which includes a through-groove 11 and a groove 12, the above-mentioned through-groove 11 runs through the first core board on the upper layer and the adjacent prepreg, and the through-groove 11 is used to accommodate high-power components 2. The heat dissipation substrate is disposed in the groove 12 , and the heat dissipation substrate in this embodiment may be a metal block 3 with high thermal conductivity. The inner wall of the through groove 11 and the surface of the high thermal conductivity metal block 3 supporting the high power components 2 have an integrated metallization layer 4 . The high thermal conductivity metal block 3 is buried in the groove 12, and the high thermal conductivity metal block 3 is fixed in the groove 12 through the thermalized prepreg, so that the high thermal conductivity metal block 3 can be saved and other process methods can be used or material, which saves the production cost, and in the thermal lamination process of the core board and the prepreg, the fixing of the high thermal conductivity metal block 3 is also completed, which improves the work efficiency and avoids misalignment caused by multiple positioning. or an increase in alignment error.

The high-power components 2 and the metallization layer 4 are soldered together with solder paste 5 . Solder paste 5 is selected because the melting point of solder paste 5 is about 150-220°C, it is easy to melt, and it is convenient to fix high-power components 2. At the same time, the heat generated by high-power components 2 will not reach the melting point of solder paste 5, so the solder paste 5 will not melt during use, and the solder paste 5 has good electrical and thermal conductivity and low cost.

The metallization layer 4 on the surface of the through groove 11 and the high thermal conductivity metal block 3 is uniform and has good thermal conductivity. The purpose of setting the metallization layer 4 is to enable the heat generated by the high-power components 2 to quickly pass through the metallization layer 4 and the metallization layer 4. The solder paste 5 is transferred to the high thermal conductivity metal block 3 and the outer metal layer, and finally the heat is dissipated quickly, wherein the outer metal layer includes a top metal layer and a bottom metal layer.

The metallization layer 4 can be made of silver, gold, nickel or copper, preferably copper.

Further, the high thermal conductivity metal block 3 is made of copper, and may also be gold, silver, aluminum, nickel or tungsten. Preferably, the high thermal conductivity metal block 3 is made of copper; the main body of the high thermal conductivity metal block 3 is made of copper, mainly because copper has good thermal conductivity and electrical conductivity, and can quickly conduct heat to the heat sink 7 for dissipation. And compared with other metals, the cost of copper is low, and the processing technology is less difficult.

Further, the bottom surface of the high thermal conductivity metal block 3 is flush with the bottom surface of the PCB. On the one hand, this structural setting can ensure that the high thermal conductivity metal block 3 is fixed inside the PCB in the form of embedding, which reduces the overall structural size of the PCB and makes the structure of the PCB more compact, thereby ensuring the integrity of the PCB and facilitating PCB assembly. It is easy to process and install and cover the copper layer on the outside of the PCB, and it is also more beautiful; on the other hand, it can quickly dissipate heat from the bottom surface of the high thermal conductivity metal block 3 . In addition, compared with the products in the prior art that mount or place the high thermal conductivity metal block 3 on the lower surface of the PCB, the overall size of the PCB in this embodiment is greatly reduced, and the structure is more compact.

The bottom surface of the above-mentioned high thermal conductivity metal block 3 and the lower surface of the PCB are covered with a copper layer 6 . After the copper layer 6 is covered, the metal layer on the lower surface of the PCB and the copper layer 6 form the bottom metal layer of the PCB. The purpose of covering the copper layer 6 is to increase the heat dissipation area, so that the heat in the high thermal conductivity metal block 3 can be dissipated The bottom metal layer dissipates quickly, and also enhances the overall structural strength of the PCB.

Preferably, a heat sink 7 is provided on the bottom surface of the copper layer 6 . By arranging the heat sink 7 on the bottom surface of the copper layer 6, compared with the direct contact with the air of the copper layer 6, it is equivalent to increasing the heat dissipation area and realizing better temperature difference transfer, so that the heat can be dissipated faster.

As shown in Figure 2, the heat generated by the high-power component 2 is mainly transferred to the high-thermal-conductivity metal block 3 through the bottom of the high-power component 2 through the solder paste 5 and the metallization layer 4, and the heat in the high-thermal-conduction metal block 3 is transferred through heat conduction. The form is transferred to the heat sink 7, so that the heat is transferred and dissipated through the heat sink 7.

The rapid heat dissipation PCB in this embodiment further includes a via hole 8 , and the heat sink 7 covers the via hole 8 . As shown in Figure 2, a small part of the heat generated by the high-power components 2 is transferred to the inner metal layer of the PCB through the solder paste 5 and the metallization layer 4, and the heat conducts in the inner metal layer, and the heat on the inner metal layer The heat is transferred to the inner wall of the via hole 8, part of it exchanges heat with the air in the via hole 8, and part of the heat is transferred to the top metal layer and the bottom metal layer of the PCB, and the heat of the top metal layer can be directly dissipated into the air. The heat of the bottom metal layer dissipates into the air through the heat sink 7 .

Embodiment two

As shown in Figures 3-6, on the basis of the first embodiment above, this embodiment differs from the PCB structure of the first embodiment in that a recess is provided on the upper surface of the high thermal conductivity metal block 3, and the recess Bottom for accommodating high power components 2. An integral metallization layer 4 is plated on the inside of the recess and the through groove 11 , and the high-power components 2 and the metallization layer 4 are welded together by solder paste 5 .

The heat transfer path in this embodiment is different from that in Embodiment 1 in that, as shown in FIG. After the paste 5, it is transferred to the groove bottom of the concave part of the high thermal conductivity metal block 3, and then the heat is transferred through the high thermal conductivity metal block 3, and then the heat is dissipated through the heat sink 7;

Part of the sidewall of the high-power component 2 is in contact with the solder paste 5, and part of the heat generated by it is transferred to the sidewall of the concave part of the high thermal conductivity metal block 3 through the metallization layer 4 and the solder paste 5, and the heat is inside the high thermal conductivity metal block 3 Conduct heat conduction, and finally also dissipate the heat through the heat sink 7 . The technical solution in this embodiment improves the heat dissipation effect by increasing the contact area between the high thermal conductivity metal block 3 and the high power component 2 .

Embodiment Three

As shown in Figure 7, on the basis of Embodiment 2, this embodiment is different from the above-mentioned Embodiment 2 in that this embodiment provides a PCB with rapid heat dissipation, which is composed of four core boards pressed together. But it is not limited to being formed by laminating four core boards.

The above-mentioned through groove 11 runs through the upper two core boards and the prepreg between the upper two core boards, and the above-mentioned groove 12 runs through the lower two core boards and the prepreg adjacent to the lower two core boards.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. All modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (9)

1. A kind of 1. PCB of quick heat radiating, it is characterised in that including：

   Step trough (1), it includes groove (11) and groove (12), and the groove (11) is used to accommodate high power component (2)；

   Heat-radiating substrate, it is arranged in the groove (12), for supporting the bottom of the high power component (2), the groove (11) inwall and the heat-radiating substrate support the surface of the high power component (2) to have the metal layer (4) of one, described Welded together between high power component (2) and the metal layer (4) with tin cream (5).
2. 2. the PCB of quick heat radiating according to claim 1, it is characterised in that the upper surface of the heat-radiating substrate has recessed Portion, the recess accommodate the bottom of the high power component (2).
3. 3. the PCB of quick heat radiating according to claim 1, it is characterised in that the heat-radiating substrate material is copper.
4. 4. the PCB of quick heat radiating according to claim 1, it is characterised in that the heat-radiating substrate is embedded to the groove (12) in.
5. 5. the PCB of quick heat radiating according to claim 1, it is characterised in that the bottom surface of the heat-radiating substrate and the PCB One side it is concordant.
6. 6. the PCB of quick heat radiating according to claim 5, it is characterised in that the bottom surface of the heat-radiating substrate and the PCB The one side be covered with layers of copper (6).
7. 7. the PCB of quick heat radiating according to claim 6, it is characterised in that the bottom surface of the layers of copper (6) is provided with radiating Piece (7).
8. 8. the PCB of quick heat radiating according to claim 7, it is characterised in that also including via hole (8).
9. 9. the PCB of quick heat radiating according to claim 8, it is characterised in that the fin (7) covers the via hole (8)。