A circuit board testing device

Abstract

The application aims at the problem that a certain type of weapon system television guide equipment circuit board lacks test method, and proposes a kind of circuit board special test equipment, the equipment includes host computer, test component, circuit board placing component and cable, power supply; and the finite element joint simulation thermal solid coupling optimization design method is used to optimize the design of the circuit board placing component structure part.The circuit board special test equipment can test the function and performance of the circuit board component of a certain type of weapon system television guide equipment under the conditions of normal temperature, high and low temperature (-40 DEG C to + 50 DEG C), impact vibration, etc., and can test 10 sets of circuit board components at one time.

Description

Technical Field

[0001] This invention belongs to the field of electronic testing technology, and specifically relates to a circuit board testing device. Background Technology

[0002] Circuit boards are key components of electronic products, and their functions and performance directly affect the overall quality and cost of the product. Therefore, quality testing of circuit board functions and performance is particularly important.

[0003] A certain type of weapon system's television guidance equipment can operate normally under conditions including normal temperature, high and low temperatures (-40℃ to +50℃), and vibration frequencies of 45Hz to 60Hz. Its circuit board assemblies, including electronic components, connectors, and mechanical supports, should also undergo functional and performance testing under the same conditions. However, currently available testers, such as finger testers and parallel testers, are insufficient to meet the testing requirements of the circuit board assemblies for this type of weapon system's television guidance equipment. Therefore, a dedicated circuit board testing device is needed to perform functional and performance testing on the circuit board assemblies of this weapon system's television guidance equipment under conditions including normal temperature, high and low temperatures (-40℃ to +50℃), and shock and vibration. Furthermore, to improve the testing efficiency of the circuit board assemblies, the dedicated testing device should also have the capability to perform batch testing of 10 sets of circuit board assemblies simultaneously.

[0004] To meet the testing requirements of the circuit board assembly of a certain type of weapon system's television guidance equipment, the dedicated circuit board testing equipment still faces many problems and difficulties, as follows:

[0005] 1) The television guidance equipment of a certain type of weapon system is a special military device. Simulation testing of this circuit component is a technical challenge in this design.

[0006] 2) In order to improve efficiency and reduce costs, and to test 10 sets of circuit components at the same time, how to achieve electrical isolation to prevent various forms of interference became another technical challenge of the present invention.

[0007] 3) This equipment operates in environments with normal temperature, high and low temperatures (-40℃~50℃) and vibration frequencies of 45Hz~60Hz. How to prevent the product from resonating and damaging the circuit components in this complex environment is another technical challenge of this invention.

[0008] 4) Ensuring the reliability of the elastic pin contact of the circuit components under vibration and shock environments is another technical challenge of this invention. Summary of the Invention

[0009] To address the lack of testing methods for the circuit boards of a certain type of weapon system's television guidance equipment, a dedicated circuit board testing device is proposed. The specific technical solution is as follows:

[0010] A circuit board testing device includes a host computer, a testing component 6, a circuit board mounting component 5, cables, and a power supply. The testing device secures the host computer, testing component 6, and circuit board mounting component 5 to a standard cabinet 1 using fixing screws 7. The host computer includes a 19-inch monitor 2, an industrial computer 3, and a standard keyboard 4, and is installed at the top of the cabinet 1. The circuit board mounting component 5 is installed in the middle of the standard cabinet 1. The testing component 6 is installed at the bottom of the standard cabinet 1, and the host computer is connected to the testing component 6 via a USB interface cable #2 8.

[0011] The test assembly 6 includes a front panel assembly 11, an upper cover 12, a side panel 13, a lower cover 18, a mechanism assembly 23, eight large power supplies 20, eight small power supplies 22, and a handle 10. A small fan 17 is installed on the inner side of the side panel 13 for heat dissipation, and two connectors Y11P-1007 14 are installed on the outer side; one is used to connect to a 220V power supply, and the other connects to a host computer to transmit data. The lower cover 18 is equipped with ten connectors Y11P-225516 for connecting to the circuit board assembly 49 under test to transmit data and power. The front panel assembly 11 integrates a rocker switch 25 and LED indicator lights 27; each power supply corresponds to an independent LED indicator light, and the illuminated light indicates that the power supply is in operation. The mechanism assembly 23 includes a guide rail groove 2 31, a rear plate 32, a guide rail 2 34, a connecting plate 35, a guide rail 1 38, a cable motherboard 39, a guide rail groove 1 40, and a guide rail 3. 44 is used to install the data acquisition and storage circuit; the data acquisition and storage circuit includes four circuit boards: small printed circuit board assembly 1 33, small printed circuit board assembly 2 36, large printed circuit board assembly 2 41, and large printed circuit board assembly 1 42, which are respectively connected to two connectors Y11P-1007 14 and ten connectors Y11P-2255 16 to realize the connection between the interface and control circuit, analog output and isolation circuit, switch output isolation circuit, and switch acquisition circuit;

[0012] The circuit board mounting assembly 5 includes a reinforcing base 46, an upper connecting plate 47, left and right side plates 48, 10 sets of circuit board assemblies under test 49, a lower connecting plate 50, and a handle 52. Each circuit board assembly under test 49 includes a test carrier 53, a hinge 54, a handle 55, a flip cover 57, a socket plate 61, a dedicated test printed circuit board 62, and a spring pin assembly 65, used to mount the circuit board under test #2 56 and the circuit board under test #1 58 for testing. A connector socket Y11P-2255ZJ is fixedly connected to the socket plate 61. 59 can be connected to the test component 6 via cable #1 9 for data transmission and power supply; the circuit board assembly under test 49 is connected to the test component 6 via cable #1 9. The circuit board mounting component 5 has two working conditions: fixed and mobile. In the fixed condition, the circuit board mounting component 5 is installed in the middle of the standard cabinet 1, in a natural workshop environment; in the mobile condition, the circuit board mounting component 5 is removed from the cabinet 1 and moved into a high temperature, low temperature, vibration, and shock environment test chamber. Cable #1 9 includes both long and short cables. The short cable is used in the fixed mode, and its length is comparable to the final usage length of the product, which more realistically simulates the actual usage state of the product; the long cable is used in the mobile mode, which flexibly arranges the relative positions of the test component and the circuit board mounting component. The host computer and the test component 6 are suitable for uncontrolled natural workshop environments.

[0013] The #2 test circuit board 56 and the #1 test circuit board 58 are mounted on the upper part of the test carrier 53, and the dedicated test printed circuit board 62 is mounted on the lower part of the test carrier 53. The #2 test circuit board 56 and the #1 test circuit board 58 are connected to the dedicated test printed circuit board 62 by an elastic pin assembly 65. The elastic pin assembly 65 includes a probe sleeve 68, a probe holder 69, and a probe 70. The probe holder 69 is fixed on the dedicated test printed circuit board 62. One end of the probe 70 is connected to the dedicated test printed circuit board 62 through a wire, and the other end contacts the #2 test circuit board 56 and the #1 test circuit board 58. Spring compensation is introduced into the elastic pin structure. A spring 67 is added to absorb the energy of the elastic displacement change under temperature load and vibration impact conditions, which plays a buffering role, reduces the frequency and amount of displacement change of the elastic pin, and makes the elastic pin contact reliable.

[0014] The circuit board testing employs interference isolation technology: the 10 circuit components are isolated from each other, each with its own independent power supply and no common ground; each power supply, each set of switch excitation signals, each set of analog excitation signals, and each set of test signals are independently shielded; the entire path is designed with equal length to ensure the consistency of the signals received by the 10 circuit components.

[0015] Under mobile operating conditions, the circuit board mounting assembly 5 was placed in a high and low temperature chamber and a vibration table for environmental testing. Using the finite element co-simulation method, a thermo-structure coupling optimization design technology was proposed, and the specific steps are as follows:

[0016] 1) Create the initial geometric model of the circuit mounting components in Solidworks;

[0017] 2) Import the geometric model into Hypermesh, mesh it with hexahedral elements (C3D8R), and divide it into design and non-design regions.

[0018] 3) Constraints: Condition 1 is fixed with constraints at the holes in the fixed plate; Condition 2 is loaded with gravity load;

[0019] 4) Mechanical boundary conditions: Vibration analysis was performed using a vibration load applied at the center of gravity, and the result is boundary condition 1; analysis and calculation were performed using a temperature load applied, and the result is boundary condition 2.

[0020] 5) Design objectives and variables: According to formula (1), the stiffness k is maximized, and the volume v is taken as the variable.

[0021]

[0022] Among them, f n where k is the natural frequency, k is the stiffness, and m is the mass;

[0023] 6) Topology optimization:

[0024] Topology optimization is essentially a problem of material distribution in the structural design space, providing support for subsequent structural optimization design. In structural topology, we use the density method as the material interpolation model, which introduces a material model with relative density varying between 0 and 1. We assume a nonlinear relationship between material density and elastic modulus. A commonly used application is the orthogonal material density method (SIMP). The relative density assigned to the mesh is used as a variable. The relative density ranges from 0 to 1; when it is 1, the material is retained; when it is 0, the material is removed. The optimization model based on minimizing structural flexibility (SIMP) is as follows:

[0025]

[0026]

[0027] KU=F (5)

[0028] k i =(x i ) p k0 (6)

[0029] 0 <x min ≤x i ≤x max (7)

[0030] Where C is the strain energy of structural flexibility, U is the displacement vector, F is the force vector, K is the structural stiffness matrix, and N is the total number of elements.i The displacement vectors of the nodes, k0 and k i V is the initial and optimized stiffness matrix of the element, V is the topologically optimized structural volume, and V0 is the unoptimized structural volume. 0 v represents the volume that needs to be removed during the optimization process. i It is the calculated unit volume, x min The lower limit of element density is used to prevent distortion of the stiffness matrix, x. max This is the upper limit of the cell density. The parameter P is a penalty factor used to reduce the number of cells with intermediate cell densities, making the result as close as possible to a 0, 1 distribution. In optimization, the value of P is usually 3.

[0031] For topology optimization numerical algorithms, we employ the Moving Asymptotic Method (MMA). The MMA constructs explicit convex functions to replace the objective and constraint functions based on the objective function, constraint functions, and the derivatives of the left and right asymptotic points, and then solves the problem. When the two asymptotic points approach infinity, the MMA becomes equivalent to an approximation using sequential linear programming.

[0032] 7) Result Extraction:

[0033] The topology optimization result is the topological density distribution of the designed region structure. The density distribution of elements between 0 and 1 is shown in red and blue, where red represents the non-removable material and blue represents the removable material. Guided by the topology optimization result, we remodeled the structure using 3D software to obtain a smooth and aesthetically pleasing shape.

[0034] 8) Iterative optimization design: Re-mesh the reconstructed model, set boundary conditions, apply forces, and perform modal analysis. If the results meet the requirements, output the results; otherwise, return to step 3).

[0035] 9) Experimental verification: Vibration analysis was performed on a Soviet-style vibration table to verify the design results. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall system design of the present invention;

[0037] Figure 2 For finite element co-simulation design model;

[0038] Figure 3 Main view of the assembly of circuit board testing equipment;

[0039] Figure 4 Side view of the assembly of circuit board testing equipment;

[0040] Figure 5 This is the main view of the test component;

[0041] Figure 6Top view of the test component;

[0042] Figure 7 This is the main view of the front panel component;

[0043] Figure 8 This is the rear view of the front panel components;

[0044] Figure 9 This is the main view of the movement assembly;

[0045] Figure 10 To mount components on the circuit board;

[0046] Figure 11 This is the main view of the circuit board assembly;

[0047] Figure 12 Rear view of the circuit board assembly;

[0048] Figure 13 This is the main view of the elastic needle component.

[0049] The components are as follows: 1-Standard cabinet, 2-19-inch monitor, 3-Industrial computer, 4-Standard keyboard, 5-Circuit board mounting assembly, 6-Test assembly, 7-Fixing screws, 8-No. 2 cable, 9-No. 1 cable, 10-Handle, 11-Front panel assembly, 12-Top cover, 13-Side panel, 14-Connector Y11P-1007, 15-Rear cover, 16-Connector Y11P-2255, 17-Fan, 18-Bottom cover, 19-Counterhead screws. 20 - Main power supply; 21 - Power supply mounting bracket; 22 - Small power supply; 23 - Mechanism assembly; 24 - Front panel; 25 - Rocker switch; 26 - Light-transmitting plate; 27 - LED indicator light; 28 - Lamp board pressure plate; 29 - LED lamp board; 30 - Screw; 31 - Guide rail groove 2; 32 - Rear plate; 33 - Small printed circuit board assembly 1; 34 - Guide rail 2; 35 - Connecting plate; 36 - Small printed circuit board assembly 2; 37 - Rectangular connector (J18BW48) T), 38-Guide rail 1, 39-Cable motherboard, 40-Guide rail groove 1, 41-Large printed circuit board assembly 2, 42-Rectangular connector (J18BW96T), 43-Large printed circuit board assembly 1, 44-Guide rail 3, 45-Pull puller, 46-Reinforcing seat, 47-Upper connecting plate, 48-Left and right side plates, 49-Test circuit board assembly, 50-Lower connecting plate, 51-Non-removable screw, 52-Handle, 53-Screw, 53-Test carrier plate holder, 54 - Hinge, 55- Handle, 56- 2# Test Circuit Board, 57- Flip Cover, 58- 1# Test Circuit Board, 59- Connector Socket Y11P-2255ZJ, 60- Countersunk Screw, 61- Socket Board, 62- Test PCB, 63- Pressure Plate, 64- Screw, 65- Flexible Pin Assembly, 66- Rectangular Connector J18BW96T, 67- Spring, 68- Probe Sleeve, 69- Probe Holder, 70- Probe, 58- 1# Test Circuit Board. Detailed Implementation

[0050] The detailed technical solution of the present invention is described below with reference to the accompanying drawings:

[0051] A circuit board testing device includes a host computer, a testing component 6, a circuit board mounting component 5, cables, and a power supply. The testing device secures the host computer, testing component 6, and circuit board mounting component 5 to a standard cabinet 1 using fixing screws 7. The host computer includes a 19-inch monitor 2, an industrial computer 3, and a standard keyboard 4, and is installed at the top of the cabinet 1. The circuit board mounting component 5 is installed in the middle of the standard cabinet 1. The testing component 6 is installed at the bottom of the standard cabinet 1, and the host computer is connected to the testing component 6 via a USB interface cable #2 8.

[0052] The test assembly 6 includes a front panel assembly 11, an upper cover 12, a side panel 13, a lower cover 18, a mechanism assembly 23, eight large power supplies 20, eight small power supplies 22, and a handle 10. A small fan 17 is installed on the inner side of the side panel 13 for heat dissipation, and two connectors Y11P-1007 14 are installed on the outer side; one is used to connect to a 220V power supply, and the other connects to a host computer to transmit data. The lower cover 18 is equipped with ten connectors Y11P-225516 for connecting to the circuit board assembly 49 under test to transmit data and power. The front panel assembly 11 integrates a rocker switch 25 and LED indicator lights 27; each power supply corresponds to an independent LED indicator light, and the illuminated light indicates that the power supply is in operation. The mechanism assembly 23 includes a guide rail groove 2 31, a rear plate 32, a guide rail 2 34, a connecting plate 35, a guide rail 1 38, a cable motherboard 39, a guide rail groove 1 40, and a guide rail 3. 44 is used to install the data acquisition and storage circuit; the data acquisition and storage circuit includes four circuit boards: small printed circuit board assembly 1 33, small printed circuit board assembly 2 36, large printed circuit board assembly 2 41, and large printed circuit board assembly 1 42, which are respectively connected to two connectors Y11P-1007 14 and ten connectors Y11P-2255 16 to realize the connection between the interface and control circuit, analog output and isolation circuit, switch output isolation circuit, and switch acquisition circuit;

[0053] The circuit board mounting assembly 5 includes a reinforcing base 46, an upper connecting plate 47, left and right side plates 48, 10 sets of circuit board assemblies under test 49, a lower connecting plate 50, and a handle 52. Each circuit board assembly under test 49 includes a test carrier 53, a hinge 54, a handle 55, a flip cover 57, a socket plate 61, a dedicated test printed circuit board 62, and a spring pin assembly 65, used to mount the circuit board under test #2 56 and the circuit board under test #1 58 for testing. A connector socket Y11P-2255ZJ is fixedly connected to the socket plate 61. 59 can be connected to the test component 6 via cable #1 9 for data transmission and power supply; the circuit board assembly under test 49 is connected to the test component 6 via cable #1 9. The circuit board mounting component 5 has two working conditions: fixed and mobile. In the fixed condition, the circuit board mounting component 5 is installed in the middle of the standard cabinet 1, in a natural workshop environment; in the mobile condition, the circuit board mounting component 5 is removed from the cabinet 1 and moved into a high temperature, low temperature, vibration, and shock environment test chamber. Cable #1 9 includes both long and short cables. The short cable is used in the fixed mode, and its length is comparable to the final usage length of the product, which more realistically simulates the actual usage state of the product; the long cable is used in the mobile mode, which flexibly arranges the relative positions of the test component and the circuit board mounting component. The host computer and the test component 6 are suitable for uncontrolled natural workshop environments.

[0054] The #2 test circuit board 56 and the #1 test circuit board 58 are mounted on the upper part of the test carrier 53, and the dedicated test printed circuit board 62 is mounted on the lower part of the test carrier 53. The #2 test circuit board 56 and the #1 test circuit board 58 are connected to the dedicated test printed circuit board 62 by an elastic pin assembly 65. The elastic pin assembly 65 includes a probe sleeve 68, a probe holder 69, and a probe 70. The probe holder 69 is fixed on the dedicated test printed circuit board 62. One end of the probe 70 is connected to the dedicated test printed circuit board 62 through a wire, and the other end contacts the #2 test circuit board 56 and the #1 test circuit board 58. Spring compensation is introduced into the elastic pin structure. A spring 67 is added to absorb the energy of the elastic displacement change under temperature load and vibration impact conditions, which plays a buffering role, reduces the frequency and amount of displacement change of the elastic pin, and makes the elastic pin contact reliable.

[0055] The circuit board testing employs interference isolation technology: the 10 circuit components are isolated from each other, each with its own independent power supply and no common ground; each power supply, each set of switch excitation signals, each set of analog excitation signals, and each set of test signals are independently shielded; the entire path is designed with equal length to ensure the consistency of the signals received by the 10 circuit components.

[0056] Under mobile operating conditions, the circuit board mounting assembly 5 was placed in a high and low temperature chamber and a vibration table for environmental testing. Using the finite element co-simulation method, a thermo-structure coupling optimization design technology was proposed, and the specific steps are as follows:

[0057] 2) Create the initial geometric model of the circuit mounting components in Solidworks;

[0058] 2) Import the geometric model into Hypermesh, mesh it with hexahedral elements (C3D8R), and divide it into design and non-design regions.

[0059] 3) Constraints: Condition 1 is fixed with constraints at the holes in the fixed plate; Condition 2 is loaded with gravity load;

[0060] 4) Mechanical boundary conditions: Vibration analysis was performed using a vibration load applied at the center of gravity, and the result is boundary condition 1; analysis and calculation were performed using a temperature load applied, and the result is boundary condition 2.

[0061] 5) Design objectives and variables: According to formula (1), the stiffness k is maximized, and the volume v is taken as the variable.

[0062]

[0063] Among them, f n where k is the natural frequency, k is the stiffness, and m is the mass;

[0064] 6) Topology optimization:

[0065] Topology optimization is essentially a problem of material distribution in the structural design space, providing support for subsequent structural optimization design. In structural topology, we use the density method as the material interpolation model, which introduces a material model with relative density varying between 0 and 1. We assume a nonlinear relationship between material density and elastic modulus. A commonly used application is the orthogonal material density method (SIMP). The relative density assigned to the mesh is used as a variable. The relative density ranges from 0 to 1; when it is 1, the material is retained; when it is 0, the material is removed. The optimization model based on minimizing structural flexibility (SIMP) is as follows:

[0066]

[0067]

[0068] KU=F (5)

[0069] k i =(x i ) p k0 (6)

[0070] 0 <x min ≤x i ≤x max (7)

[0071] Where C is the strain energy of structural flexibility, U is the displacement vector, F is the force vector, K is the structural stiffness matrix, and N is the total number of elements.i The displacement vectors of the nodes, k0 and k i V is the initial and optimized stiffness matrix of the element, V is the topologically optimized structural volume, and V0 is the unoptimized structural volume. 0 v represents the volume that needs to be removed during the optimization process. i It is the calculated unit volume, x min The lower limit of element density is used to prevent distortion of the stiffness matrix, x. max This is the upper limit of the cell density. The parameter P is a penalty factor used to reduce the number of cells with intermediate cell densities, making the result as close as possible to a 0, 1 distribution. In optimization, the value of P is usually 3.

[0072] For topology optimization numerical algorithms, we employ the Moving Asymptotic Method (MMA). The MMA constructs explicit convex functions to replace the objective and constraint functions based on the objective function, constraint functions, and the derivatives of the left and right asymptotic points, and then solves the problem. When the two asymptotic points approach infinity, the MMA becomes equivalent to an approximation using sequential linear programming.

[0073] 7) Result Extraction:

[0074] The topology optimization result is the topological density distribution of the designed region structure. The density distribution of elements between 0 and 1 is shown in red and blue, where red represents the non-removable material and blue represents the removable material. Guided by the topology optimization result, we remodeled the structure using 3D software to obtain a smooth and aesthetically pleasing shape.

[0075] 8) Iterative optimization design: Re-mesh the reconstructed model, set boundary conditions, apply forces, and perform modal analysis. If the results meet the requirements, output the results; otherwise, return to step 3).

[0076] 9) Experimental verification: Vibration analysis was performed on a Soviet-style vibration table to verify the design results.

[0077] Example 1

[0078] A circuit board testing device, such as Figure 1As shown, the dedicated circuit board testing equipment mainly consists of a host computer, testing component 6, circuit board mounting component 5, cables, power supply, etc. The circuit board mounting component 5 can simultaneously perform performance tests on ten sets of circuit board assemblies 49 under various environments, including natural workshop conditions, high and low temperatures, vibration, and shock. Electromagnetically, the dedicated circuit board testing equipment integrates ten sets of circuit board assemblies 49 under test, plus the host computer, testing component 6, etc., resulting in a relatively large number and high bandwidth for both excitation and output signals. To prevent mutual interference, we have developed an interference isolation technology for the dedicated circuit board testing equipment, ensuring its performance meets technical requirements. Structurally, to prevent irreversible damage to the circuit boards under test caused by vibration and shock, we have developed a resonance avoidance technology for the circuit board mounting component and optimized its design to reduce irreversible damage to the circuit boards under test. The specific implementation scheme is as follows:

[0079] like Figure 3-4 As shown, the test assembly 6 includes a front panel assembly 11, an upper cover 12, a side panel 13, a lower cover 18, a mechanism assembly 23, eight large power supplies 20, eight small power supplies 22, and a handle 10. A small fan 17 is installed on the inner side of the side panel 13 for heat dissipation, and two connectors Y11P-1007 14 are installed on the outer side; one is used to connect to a 220V power supply, and the other connects to a host computer to transmit data. The lower cover 18 is equipped with ten connectors Y11P-2255 16 for connecting to the circuit board assembly 49 under test to transmit data and power. The front panel assembly 11 integrates a rocker switch 25 and LED indicator lights 27; each power supply corresponds to an independent LED indicator light, and the illuminated light indicates that the power supply is in operation. The mechanism assembly 23 includes a guide rail groove 2 31, a rear plate 32, a guide rail 234, a connecting plate 35, a guide rail 1 38, a cable motherboard 39, a guide rail groove 1 40, and a guide rail 3. 44 is used to install the data acquisition and storage circuit; the data acquisition and storage circuit includes four circuit boards: small printed circuit board assembly 1 33, small printed circuit board assembly 2 36, large printed circuit board assembly 2 41, and large printed circuit board assembly 1 42, which are respectively connected to two connectors Y11P-1007 14 and ten connectors Y11P-2255 16 to realize the connection between the interface and control circuit, analog output and isolation circuit, digital output isolation circuit, and digital acquisition circuit.

[0080] Test assembly 6 consists of a front panel assembly 11, an upper cover 12, a side panel 13, a lower cover 18, a mechanism assembly 23, eight large power supplies 20, and eight small power supplies 22, and is equipped with a dedicated handle 10 for easy carrying. A small fan 17 is installed on the inner side of the side panel 13 for heat dissipation, and two connectors Y11P-1007 14 are installed on the outer side; one is used to connect to a 220V power supply, and the other connects to a host computer for data transmission. The lower cover 18 is equipped with ten connectors Y11P-2255 16 for connecting to the circuit board assembly under test 49 for data transmission and power supply. The front panel assembly 11 integrates a rocker switch 25 and LED indicator lights 27; each power supply corresponds to an independent LED indicator light, and an illuminated light indicates that the power supply is in operation. The mechanism assembly 23 consists of guide rail slot 231, back plate 32, guide rail 234, connecting plate 35, guide rail 138, cable motherboard 39, guide rail slot 140, and guide rail 344, and is mainly used to install the data acquisition and storage circuit. The data acquisition and storage circuit is divided into four circuit boards: small printed circuit board assembly 133, small printed circuit board assembly 236, large printed circuit board assembly 241, and large printed circuit board assembly 142. These circuit boards are respectively connected to two connectors Y11P-1007 14 and ten connectors Y11P-2255 16 to realize interface and control circuits, analog output and isolation circuits, digital output isolation circuits, and digital acquisition circuits.

[0081] The circuit board mounting assembly 5 consists of a reinforcing base 46, an upper connecting plate 47, left and right side plates 48, 10 sets of circuit board assemblies under test 49, a lower connecting plate 50, and a handle 52. The circuit board assembly under test 49 consists of a test carrier 53, a hinge 54, a handle 55, a flip cover 57, a socket board 61, a dedicated test printed circuit board 62, and a spring pin assembly 65. It is used to mount the circuit boards under test 2# 56 and 1# 58 and to perform testing. A connector socket Y11P-2255ZJ 59 is fixedly connected to the socket board 61, which can be connected to the test assembly 6 via cable 1# 9 for data transmission and power supply.

[0082] Circuit boards under test 2#56 and 1#58 are mounted on the upper part of the test carrier 53, and a dedicated test PCB 62 is mounted on the lower part of the test carrier 53. To facilitate the placement and removal of circuit boards under test 2#56 and 1#58, they are connected to the dedicated test PCB 62 using an elastic pin assembly 65. The elastic pin assembly 65 consists of a probe sleeve 68, a probe holder 69, and a probe 70. The probe holder 69 is fixed to the dedicated test PCB 62. One end of the probe 70 is connected to the dedicated test PCB 62 via a wire, and the other end contacts circuit boards under test 2#56 and 1#58. Traditionally, the probe sleeve 68 and probe 70 use an interference fit to ensure reliable contact. However, considering the environmental conditions faced by this invention, under test conditions such as temperature load and vibration shock, poor contact between probe 70 and circuit boards under test 2#56 and 1#58 is highly likely, affecting the test. Therefore, during the design process, a spring compensation system is introduced into the elastic needle structure. Spring 67 is added to absorb the energy of displacement changes caused by temperature load and vibration impact conditions, which plays a buffering role, reduces the frequency and amount of displacement changes of the elastic needle, and makes the contact of the elastic needle reliable.

[0083] To meet the testing requirements of the television guidance equipment circuit board for a certain weapon system, interference isolation technology was adopted: From an electrical design perspective, the 10 circuit components were isolated from each other, each using an independent power supply and not sharing a common ground. Due to the separate power supply, cable lengths could potentially cause variations in product test parameters. Therefore, in the design, each power supply path, each set of digital excitation signals, each set of analog excitation signals, and each set of test signals were independently shielded. This minimizes electromagnetic interference. From an overall design perspective, the entire path was designed to be as equal in length as possible, which can basically ensure the consistency of the signals received by the 10 circuit components.

[0084] The host computer's data processing software employs object-oriented programming techniques, is developed using VC++ 6.0, and operates primarily through mouse clicks. After powering on, the host computer runs the human-machine interface software, allowing users to select the required circuit board assembly 49 number, set the excitation signal parameters and test time (1-5 minutes), and then select "Connect Test Assembly." Upon receiving the command, test assembly 6 selects any combination of power supply options for the circuit board assemblies 49 integrated in circuit board placement assembly 5, connects to the excitation signal emitted by the FPGA, and connects to the FPGA's signal acquisition circuit. If a circuit board assembly is not selected, its power supply and the corresponding FPGA signal acquisition circuit are grounded. After the test time is met, the host computer automatically sends a data read command. Upon receiving the command, test assembly 6 uploads all data from the Flash memory via the USB interface. After receiving the data, the host computer can view it graphically, in tables, or as a file, and can also choose to print it out.

[0085] Under mobile operating conditions, the circuit board mounting assembly 5 is placed in high and low temperature chambers and vibration tables for environmental testing. Vibration, particularly the resonance and shock generated on the tested circuit boards 2#56 and 1#58, can cause irreversible damage to the circuit boards, affecting their performance. Therefore, the housing of the circuit board mounting assembly 5 needs to be optimized to improve its inherent flatness, avoid resonance, and reduce vibration shock. Traditional structural optimization methods involve structural design—prototyping—testing—structural optimization—prototyping—testing—qualification, which is costly and has a long development cycle. Therefore, this invention introduces… Figure 2 The finite element co-simulation design model shown employs a combination of finite element method and experimental verification to develop a thermo-mechanical coupling optimization design technique.

[0086] 1. Using SolidWorks, establish the initial geometric model of the circuit mounting components;

[0087] 2. Import the geometric model into Hypermesh, mesh it with hexahedral elements (C3D8R), and divide it into design and non-design regions.

[0088] 3. Constraints: Working condition 1—Fixed plate hole position fixing constraint;

[0089] Working condition 2—Applying gravity load;

[0090] 4. Mechanical boundary conditions: 1) Vibration analysis is performed with a vibration load applied to the center of gravity, and the result is boundary condition 1; 2) Analysis and calculation are performed with a temperature load applied, and the result is boundary condition 2.

[0091] 5. Design Objectives and Variations:

[0092] To avoid resonance, the system's natural frequency needs to be increased. Three factors influence the natural frequency: damping, stiffness, and mass. The relationship between these three factors is as follows:

[0093]

[0094]

[0095] Note: f n denoted as natural frequency, k as stiffness, m as mass, and § as damping ratio.

[0096] Since most structural components in this system are connected by screws, which is a rigid connection, the damping ratio § is much less than 10%, 1-§ 2 Since the value is close to 1, this system can be treated as an undamped system and analyzed using the above formula (1).

[0097] In an undamped system, two factors affect the natural frequency: stiffness and mass. As shown in formula (1), increasing the stiffness k or decreasing the mass m can both increase the natural frequency. Considering that the system model needs to be iteratively designed based on the calculation results, we take maximizing the stiffness k (minimizing the flexibility) as the design objective and the volume v as the variable.

[0098] 6. Topology optimization:

[0099] Topology optimization is essentially a problem of material distribution in the structural design space, providing support for subsequent structural optimization design. In structural topology, we use the density method as the material interpolation model, which introduces a material model with relative density varying between 0 and 1. We assume a nonlinear relationship between material density and elastic modulus. A commonly used application is the orthogonal material density method (SIMP). The relative density assigned to the mesh is used as a variable. The relative density ranges from 0 to 1; when it is 1, the material is retained; when it is 0, the material is removed. The optimization model based on minimizing structural flexibility (SIMP) is as follows:

[0100]

[0101]

[0102] KU=F (5)

[0103] k i =(x i ) p k0 (6)

[0104] 0 <x min ≤x i ≤x max (7)

[0105] Where C is the strain energy of structural flexibility, U is the displacement vector, F is the force vector, K is the structural stiffness matrix, and N is the total number of elements. i The displacement vectors of the nodes, k0 and k i V is the initial and optimized stiffness matrix of the element, V is the topologically optimized structural volume, and V0 is the unoptimized structural volume. 0 v represents the volume that needs to be removed during the optimization process. i It is the calculated unit volume, x min The lower limit of element density is used to prevent distortion of the stiffness matrix, x. max This is the upper limit of the cell density. The parameter P is a penalty factor used to reduce the number of cells with intermediate cell densities, making the result as close as possible to a 0, 1 distribution. In optimization, the value of P is usually 3.

[0106] For topology optimization numerical algorithms, we employ the Moving Asymptotic Method (MMA). The MMA constructs explicit convex functions to replace the objective and constraint functions based on the objective function, constraint functions, and the derivatives of the left and right asymptotic points, and then solves the problem. When the two asymptotic points approach infinity, the MMA becomes equivalent to an approximation using sequential linear programming.

[0107] 7. Result Extraction:

[0108] The topology optimization result is the topological density distribution of the designed region structure, with the density distribution of elements between 0 and 1, displayed in red and blue. Red represents non-removable material portions, and blue represents removable material portions. Guided by the topology optimization results, we remodeled the structure using 3D software to obtain a smooth and aesthetically pleasing shape.

[0109] 8. Iterative optimization design:

[0110] For the reconstructed model, re-mesh, set boundary conditions, apply forces, and perform modal analysis. If the results meet the requirements, output the results; otherwise, remodel and go through the process again.

[0111] 9. Experimental verification: Vibration analysis was performed on a Soviet-style vibration table to verify the design.

Claims

1. A circuit board testing device, characterized in that: The system includes a host computer, a testing component, a circuit board mounting component, cables, and a power supply. The circuit board testing equipment secures the host computer, testing component, and circuit board mounting component to a standard cabinet 1 using fixing screws. The host computer includes a 1-inch display, an industrial computer, and a standard keyboard, and is installed at the top of the cabinet. The circuit board mounting component is installed in the middle of the standard cabinet. The testing component is installed at the bottom of the standard cabinet, and the host computer is connected to the testing component via USB interface cable #2. The testing component and the circuit board mounting component are connected via cable #1. The test assembly includes a front panel assembly, upper cover, side panels, lower cover, mechanism assembly, 8 large power supplies, 8 small power supplies, and a handle. A small fan is installed on the inner side of the side panel for heat dissipation, and two Y11P-1007 connectors are installed on the outer side: one for connecting to a 220V power supply and the other for connecting to a host computer to transmit data. The lower cover is equipped with 10 Y11P-2255 connectors for connecting to the circuit board assembly under test to transmit data and power. The front panel assembly integrates a rocker switch and LED indicator lights; each power supply corresponds to an independent LED indicator light. A lit indicator light signifies that the power supply is in operation. The core assembly includes a guide rail slot 2, a rear plate, a guide rail 2, a connecting plate, a guide rail 1, a cable motherboard, a guide rail slot 1, and a guide rail 3, used to install the data acquisition and storage circuit. The data acquisition and storage circuit includes four circuit boards: a small printed circuit board assembly 1, a small printed circuit board assembly 2, a large printed circuit board assembly 2, and a large printed circuit board assembly 1. These are connected to two connectors Y11P-1007 and ten connectors Y11P-2255, respectively, to connect the interface to the control circuit, the analog output and isolation circuit, the digital output isolation circuit, and the digital acquisition circuit. The circuit board mounting assembly includes a reinforcing base, an upper connecting plate, left and right side plates, 10 sets of circuit board assemblies under test, a lower connecting plate, and a handle. Each circuit board assembly under test includes a test carrier, a hinge, a handle, a flip cover, a socket board, a dedicated test PCB, and a spring-loaded pin assembly. These are used to mount the #2 and #1 circuit boards under test and to perform testing. A connector Y11P-2255ZJ is fixedly connected to the socket board, allowing connection to the test assembly via cable #1 for data transmission and power supply. The circuit board assemblies under test are connected to the test assembly via cable #1. The circuit board mounting assembly has both fixed and movable configurations. There are two operating modes: In the fixed mode, the circuit board mounting assembly is installed in the middle of a standard cabinet in a natural laboratory environment; in the mobile mode, the circuit board mounting assembly is removed from the cabinet and moved into a high-temperature, low-temperature, vibration, and shock environment testing chamber. Cable #1 includes both long and short cables. The short cable is used in the fixed mode, with a length comparable to the product's final usage state, realistically simulating its actual use. The long cable is used in the mobile mode, allowing for flexible arrangement of the relative positions of the test components and the circuit board mounting assembly. The host computer and test components are suitable for uncontrolled natural laboratory environments. The circuit boards under test (PCBs #2 and #1) are mounted on the upper part of the test carrier, while the dedicated test PCB is mounted on the lower part. The PCBs under test (PCBs #2 and #1) are connected to the dedicated test PCB using an elastic pin assembly. The elastic pin assembly includes a probe sleeve, a probe holder, and a probe. The probe holder is fixed to the dedicated test PCB. One end of the probe is connected to the dedicated test PCB via a wire, and the other end contacts the PCBs under test (PCBs #2 and #1). Spring compensation is introduced into the elastic pin structure to absorb the energy of displacement changes under temperature loads and vibration impacts, thus buffering the movement and reducing the frequency and amount of displacement changes, ensuring reliable contact. The circuit board testing employs interference isolation technology: the 10 circuit components are isolated from each other, each with its own independent power supply and no common ground; each power supply, each set of switch excitation signals, each set of analog excitation signals, and each set of test signals are independently shielded; the entire path is designed with equal length to ensure the consistency of the signals received by the 10 circuit components. Under mobile operating conditions, the circuit board mounting assembly was placed in a high and low temperature chamber and a vibration table for environmental testing. The thermo-structure coupling optimization design method of finite element co-simulation was used to optimize the structural design of the circuit board mounting assembly. The specific steps are as follows: 1) Create the initial geometric model of the circuit mounting components in Solidworks; 2) Import the geometric model into Hypermesh, mesh it with hexahedral elements (C3D8R), and divide it into design and non-design regions. 3) Constraints: Condition 1 is fixed with constraints at the holes in the fixed plate; Condition 2 is loaded with gravity load; 4) Mechanical boundary conditions: Vibration analysis was performed using a vibration load applied at the center of gravity, and the result is boundary condition 1; analysis and calculation were performed using a temperature load applied, and the result is boundary condition 2. 5) Design objectives and variations: According to formulas (0) and (1), the stiffness k is maximized. m=ρv (0) Among them, f n Where is the natural frequency, k is the stiffness, m is the mass, ρ is the density, and v is the spatial distribution volume of the designed structural component; 6) Topology optimization: The material interpolation model adopted is the density method, introducing a material model with relative density varying between 0 and 1. It is assumed that the material density and elastic modulus have a nonlinear relationship, and the most commonly used method is the anisotropic orthogonal penalized material density method. The relative density assigned to the mesh is used as a variable, with the relative density ranging from 0 to 1. When the relative density is 1, the material is retained; when it is 0, the material is removed. The optimization model based on minimizing structural flexibility is as follows: KU=F (5) k i =(x i ) p k0 (6) 0<x min ≤x i ≤x max (7) Where C is the strain energy of structural flexibility, U is the displacement vector, F is the force vector, K is the structural stiffness matrix, and N is the total number of elements. i The displacement vectors of the nodes, k0 and k i V represents the initial and optimized stiffness matrices of the elements, V is the topologically optimized structural volume, and V0 is the unoptimized structural volume. 0 v represents the volume that needs to be removed during the optimization process. i It is the calculated unit volume, x min The lower limit of element density is used to prevent distortion of the stiffness matrix, x. max It is the upper limit of the cell density. The parameter P is a penalty factor used to reduce the number of cells with intermediate cell density, so that the result is as close as possible to the 0, 1 distribution. In optimization, the value of P is usually 3.

02. For topology optimization numerical algorithms, we adopt the moving asymptotic method. The moving asymptotic method constructs an explicit convex function to replace the objective and constraint functions based on the objective function, constraint function, and the derivatives of the left and right asymptotic points, and then solves the problem. When the asymptotic points at both ends approach infinity, the moving asymptotic method is equivalent to the sequential linear programming method. 7) Result Extraction: The topology optimization result is the topological density distribution of the design region structure. The density distribution of elements between 0 and 1 is shown in red and blue, where red represents the non-removable material portion and blue represents the removable material portion. We use the topology optimization result as a design guide to derive a 3D model. 8) Model Reconstruction Import the 3D model obtained in step 7) into SolidWorks and display it in red and blue areas. The material in the blue area can be added or removed, while the red area affects the structural stiffness. Use the blue area as the design area and retain or fine-tune the red area to carry out the shape design and finally obtain the desired design structure. 9) Iterative optimization design: Re-mesh the reconstructed model, set boundary conditions, apply forces, and perform modal analysis. If the results meet the requirements, output the results; otherwise, return to step 3). 10) Experimental verification: Perform vibration analysis on a Soviet-style vibration table to verify the design results.

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