CN104703387A - PCB of power circuit for automobile instrument and design method of PCB - Google Patents

Abstract

The invention relates to a PCB board for a power supply circuit of an automobile meter and a design method thereof, belonging to the design field of a PCB board for a power supply circuit of an automobile meter. The invention aims to solve the problem that the voltage output is unstable due to the heating of the power supply circuit for the automobile instrument, and the working efficiency is low due to the use of cooling fins, screws and nuts for fixing, which is not conducive to the production of the production line. On the PCB board of the power supply circuit for automotive instrumentation, the pads of each heating element are covered with a large-area top-layer copper clad layer. In the design method of the PCB board of the power supply circuit for the automotive instrument, a large-area top-layer copper clad layer is designed at the pad of each heating element. The top copper clad layer dissipates heat quickly and ensures stable voltage output. It is suitable for the production of PCB boards for power circuits for automotive instrumentation.

Description

PCB board and design method of power supply circuit for automobile instrument

technical field

The invention belongs to the design field of the PCB board of the power supply circuit of the automobile instrument, in particular to the design of the heat dissipation PCB board of the high-power power supply circuit.

Background technique

The power supply circuit of a 12V automotive instrument generally only uses a SMD power chip to supply power to the entire instrument. With the development of automobile technology, more and more signals need to be indicated by the automotive instrument, and the current carried by the power chip of the automotive instrument is constantly increasing. As the current increases, the heat generated by the heating elements in the power circuit also increases. As shown in Figure 1, it is the main heat dissipation device in the 12V automotive instrument power circuit. The heating of the components in the power circuit will cause the voltage output to be unstable. , in order to ensure that the circuit can work stably under high heat generation, it is necessary to carry out heat dissipation treatment on the power supply circuit of the automobile instrument.

In this case, the heat dissipation is usually fixed with a special heat sink and the heat dissipation surface of the high-power electrical components in the power circuit, usually with screws and nuts. However, since each high-power electrical component must be fixed with heat sinks, screws, and nuts, the work efficiency is very low, which is not conducive to large-scale production of the production line.

Contents of the invention

The present invention aims to solve the problem that the power supply circuit for automobile instrumentation will cause unstable voltage output due to heating, and the use of heat sinks, screws, and nuts to fix the work efficiency is low, which is not conducive to the production of the production line. Now it provides a PCB board for the power supply circuit for automobile instrumentation. and its design method.

On the PCB board of the power supply circuit for automotive instrumentation, the pads of each heating element are covered with a large-area top layer of copper clad layer, and the area of the top layer of copper clad layer is greater than 10 times the area of the pads of the heating element.

The top copper clad layer on the PCB board is provided with a plurality of via holes, and the bottom layer of the PCB board corresponding to the plurality of via holes is covered with the bottom copper clad layer.

The area of the bottom copper clad layer on the bottom layer of the PCB is close to that of the corresponding top layer copper clad layer, and the bottom clad copper layer partially overlaps with the corresponding top layer copper clad layer.

One-half to two-thirds of the surface area of the bottom copper clad layer is plated with a tin layer, and the area where the tin layer is located is a non-overlapping area between the bottom copper clad layer and the top copper clad layer.

The design method of the PCB board of the power supply circuit for the automotive instrument, the method is: design a large-area top layer copper clad layer at the pad of each heating element, and the area of the copper layer is 10 times larger than the area of the pad of the heating element.

Design multiple vias on the top copper clad layer of the PCB, and design the bottom copper clad layer on the bottom layer of the PCB corresponding to the multiple vias.

The area of the bottom copper clad layer on the bottom layer of the PCB is close to that of the corresponding top layer copper clad layer, and the bottom clad copper layer partially overlaps with the corresponding top layer copper clad layer.

One-half to two-thirds of the surface area of the bottom copper clad layer is plated with a tin layer, and the area where the tin layer is located is a non-overlapping area between the bottom copper clad layer and the top copper clad layer.

In the PCB board of the power supply circuit for automobile instrument according to the present invention, the pads of each heating element are covered with a large-area top layer of copper clad layer. Because the thermal conductivity of copper is good, the copper layer connected to the pads of the heating elements is increased. The area can make the heat on the element dissipate quickly to the connected copper layer, so that the heat does not accumulate on the element, effectively prevents the damage of the heating element due to the long working time and temperature rise, and prolongs the service life of the element ; At the same time, due to the rapid dissipation of heat, the stable output of voltage is guaranteed. The invention does not need a heat sink, simplifies the circuit structure, is more conducive to the production of the production line, and further improves the work efficiency.

In the present invention, a copper clad layer for heat dissipation is added to the bottom layer of the PCB board, so that the heat is distributed on the top layer and the bottom layer of the PCB board, and the heat dissipation can be effectively accelerated.

In the present invention, the areas of the bottom copper-clad layer and the top-layer copper-clad layer are close to each other, so that the heat dissipation of the top layer and the bottom layer of the PCB board is similar. The copper clad layer of the bottom layer overlaps with the corresponding copper clad layer of the top layer, that is, overlaps only in the part of the via hole, and the via hole transfers the heat of the copper clad layer of the top layer to the copper clad layer of the bottom layer.

The above technical features ensure that the bottom copper clad layer does not overlap with the top copper clad layer of the same network in a large area. This is because the large area overlap of the heat dissipation copper layers of the top layer and the bottom layer is not conducive to heat dissipation, so the overlap is reduced. The area can also ensure the heat dissipation speed of the PCB board of the circuit.

The invention adds a tin layer in the non-overlapping area of the bottom copper clad layer and the top copper clad layer, which can increase the heat dissipation rate of the bottom copper clad layer, and then dissipate the heat on the bottom copper clad layer to the air more quickly, thereby ensuring the power supply The heat dissipation efficiency of the heating element in the circuit.

In the design method of the PCB board of the power supply circuit of the automobile instrument according to the present invention, a large-area top layer copper clad layer is designed at the pad of each heating element. The PCB board can quickly dissipate the heat on the component to the connected copper layer, so that the heat does not accumulate on the component, effectively preventing the damage of the heating component due to the long working time and temperature rise, and prolonging the service life of the component ; At the same time, due to the rapid dissipation of heat, the stable output of voltage is guaranteed. In this embodiment, no heat sink is needed, which simplifies the circuit structure, is more conducive to the production of the production line, and further improves the work efficiency.

The power of the power device inside the automobile instrument is generally 1w-3w. For this kind of power device, the heat dissipation method adopted in this field is realized by heat sink. The present invention completely abandons the heat sink, but adopts the copper clad layer of the PCB board to realize the heat generation of this kind of power device using the copper clad layer on the PCB board to realize ^{heat dissipation.} It can be realized, and the area of the PCB board of the automobile instrument and the layout of the components can fully meet the above-mentioned requirements of the area of the copper clad layer, so the method of the present invention can fully achieve the effect of heat dissipation.

Description of drawings

Figure 1 is a circuit schematic diagram of the main heat dissipation devices in the power supply circuit for 12V automotive instrumentation;

Fig. 2 is the layout diagram of the top layer copper clad layer of the PCB board of the power supply circuit for automobile instrument described in the first embodiment;

Fig. 3 is a layout diagram of the bottom copper clad layer of the PCB board of the power circuit for automotive instrument according to the third specific embodiment.

Detailed ways

Specific embodiment one: this embodiment is described in detail with reference to Fig. 2, the PCB board of the power supply circuit for automobile instrument described in this embodiment, the welding pad of each heating element is all covered with the top layer copper clad layer 1 of large area, and The area of the top copper clad layer 1 is greater than 10 times the area of the pad of the heating element.

In the PCB board of the power supply circuit for automobile instrument described in this embodiment, the pads of each heating element are all covered with a large-area top layer copper clad layer 1. Since copper has good thermal conductivity, the number of pads connected to the heating element is increased. The area of the copper layer can quickly dissipate the heat on the component to the connected copper layer, so that the heat will not accumulate on the component, effectively prevent the damage of the heating component due to the long working time and temperature rise, and prolong the life of the component Long service life; at the same time, due to the rapid dissipation of heat, the stable output of voltage is guaranteed. In this embodiment, no heat sink is needed, which simplifies the circuit structure, is more conducive to the production of the production line, and further improves the work efficiency.

Specific Embodiment 2: Refer to FIG. 3 to illustrate this embodiment. This embodiment is a further description of the PCB board of the power supply circuit for automobile instrument described in Embodiment 1. In this embodiment, a plurality of via holes 2 are opened on the top copper clad layer 1 on the PCB, and there The bottom layer of the PCB board corresponding to each via hole 2 is covered with a bottom copper clad layer 3 .

In this embodiment, a copper clad layer 3 for heat dissipation is added to the bottom layer of the PCB, so that the heat is distributed on the top and bottom layers of the PCB, and the heat dissipation can be effectively accelerated.

Specific embodiment three: this embodiment is described in detail with reference to Fig. 3, and this embodiment is to further illustrate the PCB board of the power supply circuit for automobile instrument described in specific embodiment two, and in this embodiment, the bottom layer of the PCB bottom layer is covered with copper The area of layer 3 is close to that of the corresponding top copper clad layer 1 , and the bottom cladding copper layer 3 partially overlaps with the corresponding top copper clad layer 1 .

In this embodiment, the areas of the bottom copper clad layer 3 and the top copper clad layer 1 are similar, so that the heat dissipation of the top layer and the bottom layer of the PCB board is similar. The bottom cladding copper layer 3 partially overlaps with the corresponding top copper clad layer 1 , that is, it only overlaps the part of the via hole 2 , and the via hole 2 transfers the heat of the top copper clad layer to the bottom copper clad layer 3 . This technical feature ensures that the bottom copper clad layer 3 does not overlap with the top copper clad layer 1 of the same network in a large area. The small overlapping area can also ensure the heat dissipation speed of the PCB board of the circuit.

Embodiment 4: This embodiment is to further illustrate the PCB board of the power supply circuit for automobile instrument described in Embodiment 3. In this embodiment, one-half to two-thirds of the bottom copper clad layer 3 The surface area is plated with a tin layer 4 , and the area where the tin layer 4 is located is a non-overlapping area between the bottom copper clad layer 3 and the top copper clad layer 1 .

In this embodiment, the tin layer 4 is added in the non-overlapping area between the bottom copper clad layer 3 and the top copper clad layer 1, which can increase the heat dissipation rate of the bottom copper clad layer, and then dissipate the heat on the bottom copper clad layer 3 more quickly. To the air, thereby ensuring the heat dissipation efficiency of the heating element in the power circuit.

Embodiment five: this embodiment is the design method of the PCB board of the power supply circuit for automobile instrument described in embodiment one, the method is: design a large-area top layer copper clad layer at the pad of each heating element, And the area of the copper layer is 10 times larger than the area of the pad of the heating element.

In the design method of the PCB board of the power supply circuit for automobile instrument described in this embodiment, a large-area top layer copper clad layer is designed at the pad of each heating element. Since copper has good thermal conductivity, it is designed by this method. The PCB board can quickly dissipate the heat on the component to the connected copper layer, so that the heat will not accumulate on the component, effectively prevent the damage of the heating component due to the long working time and temperature rise, and prolong the use of the component Life; at the same time, due to the rapid dissipation of heat, the stable output of voltage is guaranteed. In this embodiment, no heat sink is needed, which simplifies the circuit structure, is more conducive to the production of the production line, and further improves the working efficiency.

Specific embodiment six: this embodiment is to further illustrate the design method of the PCB board of the power supply circuit of the automobile instrument described in the specific embodiment five. holes, and design the underlying copper clad layer on the bottom layer of the PCB board corresponding to the multiple vias.

In this embodiment, a copper clad layer for heat dissipation is added to the bottom layer of the PCB board, so that heat is distributed on the top layer and the bottom layer of the PCB board, and the heat dissipation can be effectively accelerated.

Embodiment 7: This embodiment is to further explain the design method of the PCB board of the power supply circuit for automobile instrument described in Embodiment 6. In this embodiment, the bottom copper clad layer of the PCB bottom layer and the corresponding top layer clad The areas of the copper layers are close to each other, and the copper layer of the bottom cladding layer partially overlaps with the corresponding copper cladding layer of the top layer.

In this embodiment, the areas of the bottom copper clad layer and the top copper clad layer are similar, so that the heat dissipation of the top layer and the bottom layer of the PCB board is similar. The copper clad layer of the bottom layer overlaps with the corresponding copper clad layer of the top layer, that is, overlaps only in the part of the via hole, and the via hole transfers the heat of the copper clad layer of the top layer to the copper clad layer of the bottom layer. This technical feature ensures that the bottom copper clad layer does not overlap with the top copper clad layer of the same network in a large area. This is because the large area overlap of the heat dissipation copper layers on the top layer and the bottom layer will not be conducive to heat dissipation, so the overlap is reduced. The area can also ensure the heat dissipation speed of the PCB board of the circuit.

Embodiment 8: This embodiment is to further explain the design method of the PCB board of the power circuit for automobile instrument described in Embodiment 7. In this embodiment, one-half to one-third of the bottom copper clad layer The second surface area is plated with a tin layer, and the area where the tin layer is located is a non-overlapping area between the bottom copper clad layer and the top copper clad layer.

In this embodiment, adding a tin layer in the non-overlapping area of the bottom copper clad layer and the top copper clad layer can increase the heat dissipation rate of the bottom copper clad layer, and then dissipate the heat on the bottom copper clad layer to the air more quickly. Further, the heat dissipation efficiency of the heating element in the power supply circuit is ensured.

Claims (8)

1. the pcb board of automobile instrument power circuit, is characterized in that, the pad place of each heater element is all coated with large-area top layer copper clad layers (1), and the area of this top layer copper clad layers (1) is greater than 10 times of heater element bonding pad area.

2. the pcb board of automobile instrument power circuit according to claim 1, it is characterized in that, top layer copper clad layers (1) on pcb board has multiple via hole (2), and is coated with bottom copper clad layers (3) at the pcb board bottom that multiple via hole (2) is corresponding.

3. the pcb board of automobile instrument power circuit according to claim 2, it is characterized in that, the bottom copper clad layers (3) of pcb board bottom is close with the area of corresponding top layer copper clad layers (1), and described bottom coating layers of copper (3) is heavy with corresponding top layer copper clad layers (1) part.

4. the pcb board of automobile instrument power circuit according to claim 3, it is characterized in that, bottom copper clad layers (3) 2/1 to three/2nds surface area be coated with tin layers (4), and this tin layers (4) region is bottom copper clad layers (3) and the non-coincidence region of top layer copper clad layers (1).

5. the method for designing of the pcb board of automobile instrument power circuit according to claim 1, it is characterized in that, the method is: design large-area top layer copper clad layers at the pad place of each heater element, and the area of this layers of copper is greater than 10 times of heater element bonding pad area.

6. the method for designing of the pcb board of automobile instrument power circuit according to claim 5, is characterized in that, the top layer copper clad layers of pcb board designs multiple via hole, and in pcb board bottom-layer design bottom copper clad layers corresponding to multiple via hole.

7. the method for designing of the pcb board of automobile instrument power circuit according to claim 6, it is characterized in that, the bottom copper clad layers of pcb board bottom is close with the area of corresponding top layer copper clad layers, and described bottom coating layers of copper partially overlaps with corresponding top layer copper clad layers.

8. the method for designing of the pcb board of automobile instrument power circuit according to claim 7, it is characterized in that, bottom copper clad layers 2/1 to three/2nds surface area be coated with tin layers, and this tin layers region is the non-coincidence region of bottom copper clad layers and top layer copper clad layers.