PCB (Printed Circuit Board) aluminum substrate convenient for passing electromagnetic compatibility EMC (Electro Magnetic Compatibility) test

Abstract

The utility model discloses a printed circuit board (PCB) aluminum substrate convenient for passing electromagnetic compatibility (EMC) test, which comprises a PCB aluminum substrate circuit layer and a metal substrate which is arranged below the PCB aluminum substrate circuit layer and is used as a full-plane horizon layer, the PCB aluminum substrate circuit layer is provided with a ground wire copper foil circuit, and the ground wire copper foil circuit is connected to the metal substrate of the PCB aluminum substrate through a metal piece; a copper foil GND circuit bonding pad is arranged on the PCB aluminum substrate circuit board; a coupling capacitor Y is arranged between a ground wire copper foil circuit of the PCB aluminum substrate circuit layer and a copper foil GND circuit bonding pad of the aluminum substrate; and two ends of the coupling capacitor are respectively connected to the ground wire copper foil circuit and the copper foil GND circuit bonding pad. According to the utility model, the structure arrangement is reasonable, the grounding performance is good, the metal substrate is used as a horizon layer to provide a common reference point for all unit circuits in a circuit system, the stability of the whole circuit system is improved, and the EMC test can be passed.

Description

Technical Field

[0001] The utility model belongs to the technical field of PCB aluminum substrates, and in particular relates to a PCB aluminum substrate which is convenient for passing an electromagnetic compatibility (EMC) test. Background Art

[0002] PCB is a common circuit structure. PCB aluminum substrate is an electronic device with excellent thermal conductivity and strong dielectric thermal conductivity, suitable for efficient heat dissipation. Single-sided aluminum substrate is inexpensive and is widely used in LED lighting driver power supplies, power adapters and AC-DC converters. However, due to its single-sided characteristics, it is difficult to design EMC circuits for single-sided PCB aluminum substrates, and it is difficult to pass the electromagnetic compatibility EMC test because it cannot be connected to the ground layer at the shortest distance like a double-sided board. Without a common ground layer connection, the top ground wire part can only be connected together in a discontinuous or segmented form, which will lead to an increase in the signal loop area and an increase in the impedance of the high-frequency signal line, thereby increasing radiation and conduction interference. The signal integrity problem of the single-sided aluminum substrate will also affect the signal transmission performance, especially in high-frequency applications. The signal integrity will lead to a significant reduction in EMC performance, so it is difficult to pass the EMC electromagnetic compatibility test, and the conductivity and magnetic permeability characteristics of the aluminum substrate are also not conducive to EMC design in some frequency ranges, so the applicability and practicality are limited. Summary of the invention

[0003] The utility model aims to provide a PCB aluminum substrate which has a reasonable structure and is conducive to satisfying EMC design and is easy to pass the electromagnetic compatibility (EMC) test.

[0004] The technical solution to achieve the purpose of the utility model is a PCB aluminum substrate that is easy to pass the electromagnetic compatibility (EMC) test, including a PCB aluminum substrate circuit layer and a metal substrate that is located below the PCB aluminum substrate circuit layer and serves as a full-plane ground layer, wherein the PCB aluminum substrate circuit layer is provided with a ground copper foil circuit, and the ground copper foil circuit is connected to the metal substrate of the PCB aluminum substrate through a metal piece;

[0005] The PCB aluminum substrate circuit board is provided with a copper foil GND circuit pad;

[0006] A coupling capacitor is provided between the ground copper foil circuit of the PCB aluminum substrate circuit layer and the copper foil GND circuit pad of the aluminum substrate;

[0007] The two ends of the coupling capacitor are respectively connected to the ground copper foil line and the copper foil GND line pad.

[0008] More preferably, the coupling capacitor is a small-capacitance capacitor.

[0009] More preferably, the aluminum substrate is a single-sided aluminum substrate.

[0010] The utility model has positive effects: the structure of the utility model is reasonable, and the aluminum substrate is used as a full-plane ground layer, and the ground copper foil line, copper foil GND line pad and coupling capacitor are matched, so it has good grounding performance, and optimizes the line layout, provides a common reference point for all unit lines, can reduce the impedance of the power supply and signal loop, reduce the signal reflection and electromagnetic interference caused by impedance mismatch, and can effectively suppress common mode interference, and provide a loop for common mode interference, reduce the radiation of common mode current to the outside world, and can also reduce the electromagnetic interference inside and outside the circuit, which is conducive to meeting the EMC test. The aluminum substrate has good heat dissipation performance and shielding function, can reduce thermal noise, and can also reduce the electromagnetic field coupling between different parts in the circuit, reduce mutual interference, and reduce the sensitivity of the circuit to external radiation interference. It has strong applicability and practicality. At the same time, it can be processed through a simple metal stamping process without making line vias, improves processing efficiency, reduces processing costs, and solves the technical deficiencies of traditional single-sided PCB aluminum substrates that cannot pass EMC tests, especially in the use of switching power supplies, LED DOB solutions and AC-DC converters to save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to make the content of the utility model easier to understand, the utility model is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein:

[0012] Figure 1 It is a structural schematic diagram of the utility model;

[0013] Figure 2 This is another perspective structural diagram of the utility model;

[0014] Figure 3 It is a specific circuit diagram of the utility model;

[0015] Figure 4 It is the structural layer of the PCB aluminum substrate of the utility model.

[0016] Reference numerals: dielectric layer 1 , metal substrate 2 , ground copper foil line 3 , copper foil GND line pad 4 , coupling capacitor 5 , copper foil 6 . DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0018] Example

[0019] See Figures 1 to 4 As shown, a PCB aluminum substrate that is easy to pass the electromagnetic compatibility (EMC) test, a metal substrate 2 is located below the PCB aluminum substrate circuit layer and serves as a full-plane ground layer, the PCB aluminum substrate circuit layer is provided with a ground copper foil circuit, and the ground copper foil circuit is connected to the metal substrate 2 of the PCB aluminum substrate through a metal part; a copper foil GND circuit pad 4 is provided on the PCB aluminum substrate circuit board; and a coupling capacitor 5 is provided between the ground copper foil circuit of the PCB aluminum substrate circuit layer and the copper foil GND circuit pad of the aluminum substrate; as shown Figure 3 Y capacitor. The two ends of the coupling capacitor are connected to the ground copper foil line and the copper foil GND line pad respectively. In actual application, the coupling capacitor is a small capacitance capacitor, the capacitance of which is very small and the leakage current is extremely low, belonging to the hair level leakage current, and it has strong high voltage resistance performance, and plays the role of electrical isolation in the circuit. In actual application, there is a dielectric layer 1 between the aluminum substrate and the ground copper foil line.

[0020] The aluminum substrate is a single-sided aluminum substrate. Using the metal substrate of the PCB aluminum substrate as a ground layer provides a common reference point for all unit circuits in the circuit system, which is conducive to optimizing the circuit layout, which is crucial to the stability of the entire circuit system. Providing a low-impedance loop for high-frequency currents, reducing signal reflections and electromagnetic interference caused by line impedance mismatch problems, can effectively suppress common-mode interference, and also reduce the circuit's sensitivity to external radiation interference, reduce mutual interference, and can also reduce electromagnetic interference inside and outside the circuit. The aluminum substrate has good heat dissipation performance, reduces thermal noise, and can reduce electromagnetic field coupling between different parts in the circuit, so that sensitive signal lines are away from power lines or switch nodes that may cause interference, which is conducive to meeting EMC test passing.

[0021] At the same time, it can be made through a simple metal stamping process, without the need to make double-sided aluminum substrate vias, thereby improving processing efficiency and reducing processing costs. In particular, through the improvement of this utility model, the high cost of making a single-sided aluminum substrate into a double-sided aluminum substrate in order to pass the EMC test is eliminated, so this solution can also greatly save production costs and material costs. Therefore, this solution solves the technical deficiency that the traditional PCB single-sided aluminum substrate cannot pass the EMC test, especially when used in switching power supplies, LED DOBs, and AC-DC converter solutions to save costs.

[0022] The utility model has positive effects: the structure of the utility model is reasonably arranged, and the aluminum substrate is used as a full-plane ground layer, and is matched with copper foil ground wire pins and pads, ground wire copper foil lines and coupling capacitors, so it has good grounding performance. The aluminum substrate metal substrate is used as a ground layer to provide a common reference point for all unit circuits in the circuit system, which is very important for the stability of the entire circuit system. It provides a low-impedance loop for high-frequency current, reduces signal reflection and electromagnetic interference caused by line impedance mismatch problems, can effectively suppress common-mode interference, and also reduces the circuit's sensitivity to external radiation interference, reduces mutual interference, and can also reduce electromagnetic interference inside and outside the circuit. The aluminum substrate has good heat dissipation performance and shielding function, can reduce thermal noise, can reduce the electromagnetic field coupling between different parts in the circuit, and keep sensitive signal lines away from power lines or switch nodes that may cause interference, which is conducive to meeting EMC test passing.

[0023] It has strong applicability and practicality. At the same time, it can be processed through a simple metal stamping process without the need for a double-sided aluminum substrate through-hole process, thereby improving processing efficiency and reducing processing costs and material costs. Through the improvement of this utility model, the high cost of making a single-sided aluminum substrate into a double-sided aluminum substrate in order to pass the EMC test is eliminated, so this solution can also greatly save production costs and material costs. Therefore, this solution solves the technical deficiency that the traditional PCB single-sided aluminum substrate cannot pass the EMC test, especially when used in switching power supplies, LED DOBs, and AC-DC converter solutions to save costs.

[0024] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural components recorded in the specification can also be directly processed according to existing technical common sense. At the same time, the connection method of each component adopts the mature conventional means in the prior art, and the machinery, parts and equipment all adopt the conventional models in the prior art, so no specific description will be given here.

[0025] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still belong to the protection scope of the present invention.

Claims

1. A PCB aluminum substrate that is easy to pass the electromagnetic compatibility (EMC) test, comprising a PCB aluminum substrate circuit layer and a metal substrate located below the PCB aluminum substrate circuit layer and serving as a full-plane ground layer, characterized in that: The PCB aluminum substrate circuit layer is provided with a ground copper foil circuit, and the ground copper foil circuit is connected to the metal substrate of the PCB aluminum substrate through a metal part; The PCB aluminum substrate circuit board is provided with a copper foil GND circuit pad; A coupling capacitor is provided between the ground copper foil circuit of the PCB aluminum substrate circuit layer and the copper foil GND circuit pad of the aluminum substrate; The two ends of the coupling capacitor are respectively connected to the ground copper foil line and the copper foil GND line pad, and the copper foil pad is connected to the metal substrate through a metal piece.

2. The PCB aluminum substrate that is easy to pass the electromagnetic compatibility (EMC) test according to claim 1, characterized in that: The coupling capacitor is a small-capacitance capacitor.

3. The PCB aluminum substrate that is easy to pass the electromagnetic compatibility (EMC) test according to claim 2, characterized in that: The aluminum substrate is a single-sided aluminum substrate.

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