IGCT power supply control circuit board and heat dissipation design method thereof

Abstract

The invention relates to a heat dissipation design method and a heat dissipation structure of an I GCT power supply control circuit board. According to the technical scheme, the heat dissipation design method is characterized by comprising the following steps: acquiring heat values of all positions in the circuit board; dividing the circuit board into a low heating area, a high heating area and an IGCT area according to the heating value; calculating temperature rise rates of the low heating area, the high heating area and the IGCT area; calculating a current equivalent heat conductivity coefficient according to the temperature rise rate; calculating an equivalent heat conduction difference value according to the expected temperature rise rate and the current equivalent heat conduction coefficient; a corresponding heat dissipation structure is matched according to the equivalent heat conduction difference value; corresponding heat dissipation structures are arranged in the low heating area, the high heating area and the IGCT area of the circuit board respectively; different heat dissipation structures can be adopted in different areas, so that the cost is controlled while the heat dissipation requirement of a product is met, and the heat dissipation structure is additionally arranged in the PCB structure on the premise that the circuit layout is not affected, so that the heat dissipation capacity of the whole board is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of PCB design, and more particularly to an IGCT power supply control circuit board and a heat dissipation design method thereof. Background Art

[0002] IGCT (integrated gate commutated thyristors) is a fully controlled power semiconductor device with high efficiency and high reliability. It has the advantages of fast switching speed, low loss, high blocking voltage and large output current.

[0003] IGCTs have numerous power devices, generating significant heat. The driver circuitry of the IGCT's universal power control board includes numerous transistors, along with the massive IGCT semiconductor package. Conventional measures to improve heat dissipation in IGCT power control boards involve increasing the thickness of the conductive copper layer and the number of vias.

[0004] Increasing copper thickness can achieve limited cooling. This is because the temperature rise accommodated by adding 1oz of copper is very minimal, making the PCB unsuitable as a heat sink. Using the PCB as a heat dissipation channel and covering the entire board with copper is a better approach to improve heat dissipation and reduce localized high temperatures. However, this approach is limited by the circuit layout, limiting the copper area. Adding vias from the top to the bottom of the PCB to dissipate heat is also affected by the circuit layout and cannot be added arbitrarily in densely populated areas, where localized high temperatures are more likely to occur.

[0005] Therefore, the existing heat dissipation design of the IGCT power control board is difficult to meet the heat dissipation requirements of the IGCT power control board. How to add a heat dissipation structure within the PCB structure without affecting the circuit layout to effectively improve the heat dissipation capacity of the entire board has become a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention aims to provide an IGCT power supply control circuit board and a heat dissipation design method thereof to solve the above technical problems.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions: A heat dissipation design method for an IGCT power supply control circuit board, comprising:

[0008] Get the heat value of each location in the circuit board;

[0009] The circuit board is divided into low heat generation area, high heat generation area and IGCT area according to the heat generation;

[0010] Calculate the temperature rise rate of low heat generation area, high heat generation area and IGCT area;

[0011] Calculating a current equivalent thermal conductivity according to the temperature rise rate;

[0012] Calculate the equivalent thermal conductivity difference based on the expected temperature rise rate and the current equivalent thermal conductivity;

[0013] Match the corresponding heat dissipation structure according to the equivalent thermal conductivity difference;

[0014] Corresponding heat dissipation structures are respectively provided in the low-heating area, high-heating area and IGCT area of the circuit board.

[0015] Specifically, after completing the circuit design of the IGCT power supply control circuit board, the heat generation of each position in the circuit board is first obtained according to the heat generation power of each position in the circuit design. The IGCT power supply control circuit board produced according to the circuit design can also be monitored to obtain the heat generation of each part of the IGCT power supply control circuit board; then, according to the heat generation of each part in the IGCT power supply control circuit board, the circuit board is divided into low heat generation area, high heat generation area and IGCT area; among them, the low heat generation area is the area where conventional components are placed, and the heat generation is small; the high heat generation area mainly contains high-power, high-current components, and the components have high heat generation and high heat dissipation requirements; the IGCT area is the main chip area; dividing the circuit board into low heat generation area, high heat generation area and IGCT area facilitates the heat dissipation design of each area separately. Then, the temperature rise rates of the low-heating area, the high-heating area and the IGCT area are calculated respectively, and the current equivalent thermal conductivity coefficients of the low-heating area, the high-heating area and the IGCT area are calculated; then, the equivalent thermal conductivity differences of the low-heating area, the high-heating area and the IGCT area are calculated in combination with the expected temperature rise rates, and the increased equivalent thermal conductivity coefficients required for the low-heating area, the high-heating area and the IGCT area are determined; and the equivalent thermal conductivity differences are matched according to the equivalent thermal conductivity coefficients of each predetermined heat dissipation structure, and corresponding heat dissipation structures are set in the low-heating area, the high-heating area and the IGCT area, thereby completing the heat dissipation design of the IGCT power supply control circuit board.

[0016] By determining the required heat dissipation structure based on the heat generated by various parts of the IGCT power control circuit board, different heat dissipation structures can be used in different areas, thereby meeting the heat dissipation requirements of the product while controlling costs. Heat dissipation structures can be added to the PCB structure without affecting the circuit layout, effectively improving the heat dissipation capacity of the entire board.

[0017] Optionally, the temperature rise rates of the low-heating area, the high-heating area, and the IGCT area are calculated by the following formula:

[0018]

[0019] Where ΔT is the temperature rise rate; Q is the calorific value; c is the specific heat capacity of the circuit board area; m is the mass of the circuit board area; ρ is the density of the circuit board material; and V is the volume of the circuit board.

[0020] Specifically, the formula shows that the temperature rise rate is positively correlated with the heat generation under the premise that the internal structure of the circuit board remains unchanged. The temperature rise rates of the low heat generation area, high heat generation area and IGCT area can be directly obtained through the heat generation of the low heat generation area, high heat generation area and IGCT area.

[0021] Optionally, the current equivalent thermal conductivity is calculated according to the temperature rise rate, specifically by the following formula:

[0022] ΔTλ e =PL / A;

[0023] Where ΔT is the temperature rise rate; P is the heat generation power in the circuit board; L is the thickness of the circuit board; A is the area of the circuit board; λ e is the equivalent thermal conductivity of the circuit board.

[0024] Specifically, when the heat source and heat dissipation channel dimensions are constant, the equivalent thermal conductivity is inversely proportional to the temperature rise rate, so increasing the equivalent thermal conductivity can reduce the temperature rise rate. The thermal conductivity difference is obtained by calculating the current equivalent thermal conductivity, combining it with the expected temperature rise rate, and performing the difference calculation.

[0025] Optionally, the heat dissipation structure includes: paved surface copper, metallized vias and metallized blind holes.

[0026] Specifically, when laying copper with a thickness of 1oz and bonding with high-thermal-conductivity prepreg, the equivalent thermal conductivity is 2W / mK. Metallized vias (PVs) are created within the PCB with a diameter of 0.2mm and a copper thickness of 20μm. When filled with resin, the equivalent thermal conductivity is 18W / mK. Metallized blind vias are typically laser-drilled with a diameter of 0.15mm and filled with copper vias ...

[0027] Optionally, matching the corresponding heat dissipation structure according to the equivalent thermal conductivity difference includes:

[0028] Obtain the equivalent thermal conductivity of each heat dissipation structure;

[0029] One or more heat dissipation structures are selected according to the thermal conductivity and equivalent thermal conductivity difference of each heat dissipation structure, and the total equivalent thermal conductivity of the one or more heat dissipation structures is greater than or equal to the equivalent thermal conductivity difference.

[0030] Specifically, the required thermal conductivity structures for the low-heat, high-heat, and IGCT regions can be determined based on the equivalent thermal conductivity coefficients of each heat dissipation structure and the difference in equivalent thermal conductivity between these regions. Surface copper is the most fundamental thermal conductivity structure, and both plated vias and plated blind vias are designed based on this surface copper.

[0031] Optionally, the step of providing corresponding heat dissipation structures in the low-heating area, high-heating area, and IGCT area of the circuit board includes:

[0032] When laying the surface copper, after completing the circuit design of the IGCT power supply control circuit board, copper heat dissipation layers are set in the areas near the top and bottom layers inside the circuit board based on the circuit design; anti-pads are set on the copper heat dissipation layers to avoid the conductive holes in the circuit design, so that the copper heat dissipation layers are not conductive to the circuit design;

[0033] When setting up metallized blind vias, after completing the design of the copper heat dissipation layer, copper foil is laid in the areas without pads on the top and / or bottom layers of the PCB, and a blind via array is set between the copper foil and the copper heat dissipation layer, the blind via array connecting the copper heat dissipation layer and the copper foil;

[0034] When setting the metallized via, after completing the design of the metallized blind hole, a buried hole structure is set between the two copper-plated heat dissipation layers, and an anti-solder pad is set on the inner circuit board to avoid the buried hole structure; both ends of the buried hole are connected to the copper-plated heat dissipation layer.

[0035] Specifically, for low-heat-generating areas, it is usually sufficient to simply lay copper to meet the equivalent thermal conductivity difference. For high-heat-generating areas and IGCT areas, if the equivalent thermal conductivity difference is less than 30W / mK, a heat dissipation design can be implemented by combining copper laying and metalized blind vias. If the equivalent thermal conductivity difference is between 30 and 48W / mK, a heat dissipation design can be implemented by combining copper laying, metalized blind vias, and metalized vias. For circuit boards with particularly high heat generation, simply designing an internal heat dissipation structure is no longer sufficient to meet the heat dissipation requirements. In this case, a metal substrate or buried copper block can be used to dissipate heat from the circuit board using a larger area of heat conductor.

[0036] The present application also proposes an IGCT power supply control circuit board, comprising: a circuit board; the circuit board is composed of N circuit layers stacked in sequence; the circuit board includes a low-heating area, a high-heating area and an IGCT area; a first heat dissipation structure is provided in the low-heating area; a first heat dissipation structure and a second heat dissipation structure are provided in both the high-heating area and the IGCT area.

[0037] Specifically, by dividing the circuit board into low-heating area, high-heating area and IGCT area, and setting different heat dissipation structures in the low-heating area, high-heating area and IGCT area, the heat dissipation requirements of the circuit board can be met while controlling costs. In addition, the heat dissipation structure can be added to the PCB structure without affecting the circuit layout, so as to effectively improve the heat dissipation capacity of the entire board.

[0038] Optionally, the first heat dissipation structure includes: two layers of copper-plated heat dissipation layers; the two layers of copper-plated heat dissipation layers are respectively arranged between the first circuit layer and the second circuit layer, and between the N-1th circuit layer and the Nth circuit layer; the copper-plated heat dissipation layer is provided with a first anti-soldering pad for avoiding the conductive hole of the circuit board.

[0039] Specifically, by placing a copper heat sink between the first and second circuit layers, and between the N-1 and N layers, the PCB heat can be effectively balanced, preventing localized overheating and product reliability issues. Furthermore, a first anti-pad is placed on the copper heat sink to achieve thermal and electrical separation, improving the heat dissipation capacity of the IGCT power control PCB while maintaining the electrical performance of the original design.

[0040] Optionally, the second heat dissipation structure includes a copper sheet; the copper sheet is arranged on the first circuit layer and / or the Nth circuit layer; a clearance hole for avoiding the solder pad is opened on the copper sheet; a blind hole array is arranged between the copper sheet and the copper-plated heat dissipation layer, and the blind hole array connects the copper-plated heat dissipation layer and the copper sheet.

[0041] Specifically, by placing copper foil on the first and / or Nth circuit layers, creating a large copper-clad structure with gaps in the outer circuit layers, and then designing buried blind vias to conduct heat throughout the board, the thermal conductivity between the outer layers is increased, improving the thermal efficiency of the entire board and facilitating rapid heat release. The blind via array specifically includes several blind vias with a diameter of 0.1-0.15mm, arranged between the copper foil and the copper-clad heat dissipation layer; several of the blind vias are filled with copper.

[0042] Optionally, the second heat dissipation structure also includes: a buried hole structure; the buried hole structure is arranged between two copper-clad heat dissipation layers; a second anti-pad is opened on the circuit layer for avoiding the buried hole structure; the two ends of the buried hole structure are respectively connected to the two copper-clad heat dissipation layers.

[0043] Specifically, in addition to copper foil and blind vias, buried vias can be installed between two copper-clad heat dissipation layers. Due to the complex internal circuitry of the IGCT circuit control circuit board, the use of built-in high-thermal-conductivity metal is not suitable. Therefore, a buried via design that allows for flexible layout of thermal paths is adopted. When installing buried vias, avoid the routing areas of inner-layer circuits, and, if necessary, provide anti-pads on the inner-layer circuits to prevent conductive contact between the buried vias and the inner layers. The minimum buried via diameter is 0.2mm, the minimum copper wall thickness is 20μm, and the minimum spacing between the via edges is 0.3mm. The center of the via is filled with resin to dissipate heat from the inner-layer circuits.

[0044] In summary, the present invention has the following beneficial effects: by determining the heat dissipation structure to be added according to the heat generated by various parts of the IGCT power supply control circuit board, different heat dissipation structures can be adopted in different areas, thereby meeting the heat dissipation requirements of the product while controlling costs, and adding a heat dissipation structure within the PCB structure without affecting the circuit layout, thereby effectively improving the heat dissipation capacity of the entire board. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a flow chart of the method of the present invention;

[0046] Figure 2 It is a structural schematic diagram of the IGCT power supply control circuit board of the present invention;

[0047] Figure 3 It is a schematic cross-sectional view of the IGCT power supply control circuit board in the present invention;

[0048] Figure 4 This is a schematic cross-sectional view of a first heat dissipation structure added to the IGCT power supply control circuit board of the present invention;

[0049] Figure 5 This is a schematic cross-sectional view of a second heat dissipation structure added to the IGCT power supply control circuit board of the present invention;

[0050] Figure 6 It is a schematic cross-sectional view of a structure in which another second heat dissipation structure is added to the IGCT power supply control circuit board of the present invention.

[0051] In the figure: 1. Circuit layer; 2. Low heat generation area; 3. High heat generation area; 4. IGCT area; 5. First heat dissipation structure; 6. Second heat dissipation structure; 61. Copper foil; 62. Buried hole structure; 7. First anti-pad; 8. Blind hole array; 9. Second anti-pad; 10. Via hole. DETAILED DESCRIPTION

[0052] To make the objectives, features, and advantages of the present invention more readily apparent, the following detailed description of the present invention is provided with reference to the accompanying drawings. The accompanying drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

[0053] In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0054] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0055] Example 1

[0056] This embodiment provides a heat dissipation design method for an IGCT power supply control circuit board. Figure 1-3 As shown, it includes: obtaining the heat value of each position in the circuit board;

[0057] The circuit board is divided into low heat generation area 2, high heat generation area 3 and IGCT area 4 according to the heat generation;

[0058] Calculate the temperature rise rate of low heat generation area 2, high heat generation area 3 and IGCT area 4;

[0059] Calculating a current equivalent thermal conductivity according to the temperature rise rate;

[0060] Calculate the equivalent thermal conductivity difference based on the expected temperature rise rate and the current equivalent thermal conductivity;

[0061] Match the corresponding heat dissipation structure according to the equivalent thermal conductivity difference;

[0062] Corresponding heat dissipation structures are respectively provided in the low-heating area 2 , the high-heating area 3 and the IGCT area 4 of the circuit board.

[0063] Specifically, after completing the circuit design of the IGCT power supply control circuit board, the heat generation of each position in the circuit board is first obtained according to the heat generation power of each position in the circuit design. The IGCT power supply control circuit board produced according to the circuit design can also be monitored to obtain the heat generation of each part of the IGCT power supply control circuit board; then, according to the heat generation of each part in the IGCT power supply control circuit board, the circuit board is divided into low heat generation area 2, high heat generation area 3 and IGCT area 4; among them, the low heat generation area 2 is the conventional component placement area with low heat generation; the high heat generation area 3 mainly contains high-power, high-current components, and the components have high heat generation and high heat dissipation requirements; the IGCT area 4 is the main chip area; dividing the circuit board into low heat generation area 2, high heat generation area 3 and IGCT area 4 facilitates the heat dissipation design of each area separately. Then, the temperature rise rates of the low-heating area 2, the high-heating area 3 and the IGCT area 4 are calculated respectively, and the current equivalent thermal conductivity coefficients of the low-heating area 2, the high-heating area 3 and the IGCT area 4 are calculated; then, the equivalent thermal conductivity difference of the low-heating area 2, the high-heating area 3 and the IGCT area 4 is calculated in combination with the expected temperature rise rate, and the increased equivalent thermal conductivity coefficient required for the low-heating area 2, the high-heating area 3 and the IGCT area 4 has been determined; and the equivalent thermal conductivity difference is matched according to the equivalent thermal conductivity coefficients of each predetermined heat dissipation structure, and corresponding heat dissipation structures are respectively set in the low-heating area 2, the high-heating area 3 and the IGCT area 4 to complete the heat dissipation design of the IGCT power supply control circuit board.

[0064] By determining the required heat dissipation structure based on the heat generated by various parts of the IGCT power control circuit board, different heat dissipation structures can be used in different areas, thereby meeting the heat dissipation requirements of the product while controlling costs. Heat dissipation structures can be added to the PCB structure without affecting the circuit layout, effectively improving the heat dissipation capacity of the entire board.

[0065] Optionally, the temperature rise rates of the low-heating area 2, the high-heating area 3, and the IGCT area 4 are calculated by the following formula:

[0066]

[0067] Where ΔT is the temperature rise rate; Q is the calorific value; c is the specific heat capacity of the circuit board area; m is the mass of the circuit board area; ρ is the density of the circuit board material; and V is the volume of the circuit board.

[0068] Specifically, the formula shows that the temperature rise rate is positively correlated with the heat generation under the premise that the internal structure of the circuit board remains unchanged. The temperature rise rates of the low heat generation area 2, the high heat generation area 3 and the IGCT area 4 can be directly obtained through the heat generation of the low heat generation area 2, the high heat generation area 3 and the IGCT area 4.

[0069] Optionally, the current equivalent thermal conductivity is calculated according to the temperature rise rate, specifically by the following formula:

[0070] ΔTλ e =PL / A;

[0071] Where ΔT is the temperature rise rate; P is the heat generation power in the circuit board; L is the thickness of the circuit board; A is the area of the circuit board; λ e is the equivalent thermal conductivity of the circuit board.

[0072] Specifically, when the heat source and heat dissipation channel dimensions are constant, the equivalent thermal conductivity is inversely proportional to the temperature rise rate, so increasing the equivalent thermal conductivity can reduce the temperature rise rate. The thermal conductivity difference is obtained by calculating the current equivalent thermal conductivity, combining it with the expected temperature rise rate, and performing the difference calculation.

[0073] Optionally, the heat dissipation structure includes: paved surface copper, metallized vias and metallized blind holes.

[0074] Specifically, when laying copper with a thickness of 1oz and bonding with high-thermal-conductivity prepreg, the equivalent thermal conductivity is 2W / mK. Metallized vias (PVs) are created within the PCB with a diameter of 0.2mm and a copper thickness of 20μm. When filled with resin, the equivalent thermal conductivity is 18W / mK. Metallized blind vias are typically laser-drilled with a diameter of 0.15mm and filled with copper vias ...

[0075] Optionally, matching the corresponding heat dissipation structure according to the equivalent thermal conductivity difference includes:

[0076] Obtain the equivalent thermal conductivity of each heat dissipation structure;

[0077] One or more heat dissipation structures are selected according to the thermal conductivity and equivalent thermal conductivity difference of each heat dissipation structure, and the total equivalent thermal conductivity of the one or more heat dissipation structures is greater than or equal to the equivalent thermal conductivity difference.

[0078] Specifically, the required thermal conductivity structures for low-heat-generating area 2, high-heat-generating area 3, and IGCT area 4 can be determined based on the equivalent thermal conductivity of each heat dissipation structure and the difference in equivalent thermal conductivity between low-heat-generating area 2, high-heat-generating area 3, and IGCT area 4. Surface copper is the most fundamental thermal conductivity structure, and both plated vias and plated blind vias are designed based on this surface copper.

[0079] Optionally, the corresponding heat dissipation structures are provided in the low-heating area 2, the high-heating area 3 and the IGCT area 4 of the circuit board, including:

[0080] When laying the surface copper, after completing the circuit design of the IGCT power supply control circuit board, copper heat dissipation layers are respectively set in the areas near the top and bottom layers inside the circuit board based on the circuit design; anti-pads are set on the copper heat dissipation layers to avoid the conductive holes 10 in the circuit design, so that the copper heat dissipation layers are not conductive to the circuit design;

[0081] When setting the metalized blind vias, after completing the design of the copper heat dissipation layer, copper foil 61 is laid in the areas without pads on the top and / or bottom layers of the PCB, and a blind via array 8 is set between the copper foil 61 and the copper heat dissipation layer, the blind via array 8 connecting the copper heat dissipation layer and the copper foil 61;

[0082] When setting the metallized via, after completing the design of the metallized blind hole, a buried hole structure 62 is set between the two copper-clad heat dissipation layers, and an anti-solder pad is set on the inner circuit board to avoid the buried hole structure 62; both ends of the buried hole are connected to the copper-clad heat dissipation layer.

[0083] Specifically, for low-heat-generating area 2, simply laying copper surface is usually sufficient to meet the equivalent thermal conductivity differential. For high-heat-generating area 3 and IGCT area 4, if the equivalent thermal conductivity differential is less than 30W / mK, a heat dissipation design combining copper surface laying and metalized blind vias can be used. If the equivalent thermal conductivity differential is between 30 and 48W / mK, a heat dissipation design combining copper surface laying, metalized blind vias, and metalized vias can be used. For PCBs with particularly high heat generation, simply designing an internal heat dissipation structure is insufficient. In these cases, a metal substrate or buried copper block can be used to dissipate heat from the PCB using a larger thermal conductor area.

[0084] Example 2

[0085] This embodiment provides an IGCT power supply control circuit board, such as Figure 2-5 As shown, it includes: a circuit board; the circuit board is composed of N circuit layers 1 stacked in sequence; the circuit board includes a low-heating area 2, a high-heating area 3 and an IGCT area 4; a first heat dissipation structure 5 is provided in the low-heating area 2; and the first heat dissipation structure 5 and the second heat dissipation structure 6 are provided in both the high-heating area 3 and the IGCT area 4.

[0086] Specifically, by dividing the circuit board into low-heating area 2, high-heating area 3 and IGCT area 4, and setting different heat dissipation structures in low-heating area 2, high-heating area 3 and IGCT area 4, the heat dissipation requirements of the circuit board are met while controlling costs. In addition, the heat dissipation structure is added to the PCB structure without affecting the circuit layout, so as to effectively improve the heat dissipation capacity of the entire board.

[0087] Optionally, the first heat dissipation structure 5 includes: two layers of copper-plated heat dissipation layers; the two layers of copper-plated heat dissipation layers are respectively arranged between the first circuit layer 1 and the second circuit layer 1, and between the N-1th layer and the Nth circuit layer 1; the copper-plated heat dissipation layer is provided with a first anti-soldering pad 7 for avoiding the conductive hole 10 of the circuit board.

[0088] Specifically, by providing a copper heat dissipation layer between the first and second circuit layers 1, and between the N-1 and N circuit layers 1, the PCB heat can be effectively balanced, preventing localized overheating and product reliability issues. Furthermore, a first anti-pad 7 is provided on the copper heat dissipation layer to achieve thermal and electrical separation, improving the heat dissipation capacity of the IGCT power control PCB while maintaining the electrical performance of the original design.

[0089] Optionally, the second heat dissipation structure 6 includes a copper sheet 61; the copper sheet 61 is arranged on the first circuit layer 1 and / or the Nth circuit layer 1; a clearance hole for avoiding the solder pad is opened on the copper sheet 61; a blind hole array 8 is arranged between the copper sheet 61 and the copper-plated heat dissipation layer, and the blind hole array 8 connects the copper-plated heat dissipation layer and the copper sheet 61.

[0090] Specifically, by providing copper foil 61 on the first circuit layer 1 and / or the Nth circuit layer 1, a larger copper-clad structure is designed to create gaps between the outer circuit layers. Buried blind vias are then designed to conduct heat throughout the board. This increases the thermal conductivity between the outer layers, improving the overall board's thermal efficiency and facilitating rapid heat release. The blind via array 8 specifically includes several blind vias, each with a diameter of 0.1-0.15 mm, disposed between the copper foil 61 and the copper-clad heat dissipation layer. Several of these blind vias are filled with copper.

[0091] Example 3

[0092] This embodiment provides an IGCT power supply control circuit board, such as Figure 2-6 As shown, it includes: a circuit board; the circuit board is composed of N circuit layers 1 stacked in sequence; the circuit board includes a low-heating area 2, a high-heating area 3 and an IGCT area 4; a first heat dissipation structure 5 is provided in the low-heating area 2; and the first heat dissipation structure 5 and the second heat dissipation structure 6 are provided in both the high-heating area 3 and the IGCT area 4.

[0093] Specifically, by dividing the circuit board into low-heating area 2, high-heating area 3 and IGCT area 4, and setting different heat dissipation structures in low-heating area 2, high-heating area 3 and IGCT area 4, the heat dissipation requirements of the circuit board are met while controlling costs. In addition, the heat dissipation structure is added to the PCB structure without affecting the circuit layout, so as to effectively improve the heat dissipation capacity of the entire board.

[0094] Optionally, the first heat dissipation structure 5 includes: two layers of copper-plated heat dissipation layers; the two layers of copper-plated heat dissipation layers are respectively arranged between the first circuit layer 1 and the second circuit layer 1, and between the N-1th layer and the Nth circuit layer 1; the copper-plated heat dissipation layer is provided with a first anti-soldering pad 7 for avoiding the conductive hole 10 of the circuit board.

[0095] Specifically, by providing a copper heat dissipation layer between the first and second circuit layers 1, and between the N-1 and N circuit layers 1, the PCB heat can be effectively balanced, preventing localized overheating and product reliability issues. Furthermore, a first anti-pad 7 is provided on the copper heat dissipation layer to achieve thermal and electrical separation, improving the heat dissipation capacity of the IGCT power control PCB while maintaining the electrical performance of the original design.

[0096] Optionally, the second heat dissipation structure 6 includes a copper sheet 61; the copper sheet 61 is arranged on the first circuit layer 1 and / or the Nth circuit layer 1; a clearance hole for avoiding the solder pad is opened on the copper sheet 61; a blind hole array 8 is arranged between the copper sheet 61 and the copper-plated heat dissipation layer, and the blind hole array 8 connects the copper-plated heat dissipation layer and the copper sheet 61.

[0097] Specifically, by providing copper foil 61 on the first circuit layer 1 and / or the Nth circuit layer 1, a larger copper-clad structure is designed to create gaps between the outer circuit layers. Buried blind vias are then designed to conduct heat throughout the board. This increases the thermal conductivity between the outer layers, improving the overall board's thermal efficiency and facilitating rapid heat release. The blind via array 8 specifically includes several blind vias, each with a diameter of 0.1-0.15 mm, disposed between the copper foil 61 and the copper-clad heat dissipation layer. Several of these blind vias are filled with copper.

[0098] Optionally, the second heat dissipation structure 6 also includes: a buried hole structure 62; the buried hole structure 62 is arranged between two layers of copper-clad heat dissipation layers; a second anti-pad 9 is opened on the circuit layer 1 for avoiding the buried hole structure 62; the two ends of the buried hole structure 62 are respectively connected to the two layers of copper-clad heat dissipation layers.

[0099] Specifically, in addition to the copper foil 61 and blind vias, a buried via structure 62 can be provided between the two copper-clad heat dissipation layers. Because the internal circuitry of the IGCT circuit control circuit board is complex, a solution with built-in high-thermal-conductivity metal is not suitable. Therefore, a buried via design that allows for flexible layout of thermal paths is adopted. When setting up buried vias, avoid the routing areas of the inner-layer circuits, and, if necessary, provide anti-pads on the inner-layer circuits to prevent the buried vias from conducting with the inner layers. The minimum buried via diameter is 0.2mm, the minimum copper wall thickness is 20μm, the minimum spacing between the via edges is 0.3mm, and the center of the via is filled with resin to dissipate heat from the inner-layer circuits.

[0100] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A heat dissipation design method for an IGCT power supply control circuit board, characterized in that: include: Get the heat value of each location in the circuit board; The circuit board is divided into low heat generation area, high heat generation area and IGCT area according to the heat generation; Calculate the temperature rise rate of low heat generation area, high heat generation area and IGCT area; Calculating a current equivalent thermal conductivity according to the temperature rise rate; Calculate the equivalent thermal conductivity difference based on the expected temperature rise rate and the current equivalent thermal conductivity; Match the corresponding heat dissipation structure according to the equivalent thermal conductivity difference; Corresponding heat dissipation structures are respectively provided in the low-heating area, high-heating area and IGCT area of the circuit board.

2. The heat dissipation design method of an IGCT power supply control circuit board according to claim 1, characterized in that: The temperature rise rates of the low-heating area, high-heating area, and IGCT area are calculated using the following formula: Where ΔT is the temperature rise rate; Q is the calorific value; c is the specific heat capacity of the circuit board area; m is the mass of the circuit board area; ρ is the density of the circuit board material; and V is the volume of the circuit board.

3. The heat dissipation design method of an IGCT power supply control circuit board according to claim 2, characterized in that: The current equivalent thermal conductivity is calculated according to the temperature rise rate, specifically by the following formula: ΔTλ e =PL / A; Where ΔT is the temperature rise rate; P is the heat generation power in the circuit board; L is the thickness of the circuit board; A is the area of the circuit board; λ e is the equivalent thermal conductivity of the circuit board.

4. The heat dissipation design method for an IGCT power supply control circuit board according to claim 3, characterized in that: The heat dissipation structure includes: paved surface copper, metallized vias and metallized blind holes.

5. The heat dissipation design method of an IGCT power supply control circuit board according to claim 4, characterized in that: The matching of the corresponding heat dissipation structure according to the equivalent thermal conductivity difference includes: Obtain the equivalent thermal conductivity of each heat dissipation structure; One or more heat dissipation structures are selected according to the thermal conductivity and equivalent thermal conductivity difference of each heat dissipation structure, and the total equivalent thermal conductivity of the one or more heat dissipation structures is greater than or equal to the equivalent thermal conductivity difference.

6. The heat dissipation design method for an IGCT power supply control circuit board according to claim 5, characterized in that: The corresponding heat dissipation structures are provided in the low-heating area, high-heating area and IGCT area of the circuit board, including: When laying the surface copper, after completing the circuit design of the IGCT power supply control circuit board, copper heat dissipation layers are set in the areas near the top and bottom layers inside the circuit board based on the circuit design; anti-pads are set on the copper heat dissipation layers to avoid the conductive holes in the circuit design, so that the copper heat dissipation layers are not conductive to the circuit design; When setting up metallized blind vias, after completing the design of the copper heat dissipation layer, copper foil is laid in the areas without pads on the top and / or bottom layers of the PCB, and a blind via array is set between the copper foil and the copper heat dissipation layer, the blind via array connecting the copper heat dissipation layer and the copper foil; When setting the metallized via, after completing the design of the metallized blind hole, a buried hole structure is set between the two copper-plated heat dissipation layers, and an anti-solder pad is set on the inner circuit board to avoid the buried hole structure; both ends of the buried hole are connected to the copper-plated heat dissipation layer.

7. An IGCT power supply control circuit board, characterized in that: include: circuit boards; The circuit board is composed of N circuit layers stacked in sequence; the circuit board includes a low-heating area, a high-heating area and an IGCT area; a first heat dissipation structure is provided in the low-heating area; and a first heat dissipation structure and a second heat dissipation structure are provided in both the high-heating area and the IGCT area.

8. The IGCT power supply control circuit board according to claim 7, characterized in that: The first heat dissipation structure includes: two layers of copper-plated heat dissipation layers; the two layers of copper-plated heat dissipation layers are respectively arranged between the first circuit layer and the second circuit layer, and between the N-1th circuit layer and the Nth circuit layer; a first anti-soldering pad is provided on the copper-plated heat dissipation layer for avoiding the conductive hole of the circuit board.

9. The IGCT power supply control circuit board according to claim 8, characterized in that: The second heat dissipation structure includes a copper sheet; the copper sheet is arranged on the first circuit layer and / or the Nth circuit layer; a clearance hole for avoiding the soldering pad is opened on the copper sheet; a blind hole array is arranged between the copper sheet and the copper-plated heat dissipation layer, and the blind hole array connects the copper-plated heat dissipation layer and the copper sheet.

10. The IGCT power supply control circuit board according to claim 9, characterized in that: The second heat dissipation structure also includes: a buried via structure; the buried via structure is arranged between two copper-clad heat dissipation layers; a second anti-pad is opened on the circuit layer for avoiding the buried via structure; and both ends of the buried via structure are respectively connected to the two copper-clad heat dissipation layers.

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