Device and method for selecting specification of micro-gap heat conduction material based on three-dimensional point cloud

Abstract

The invention provides a micro-gap heat conduction material specification selection device and method based on three-dimensional point cloud.The device comprises a placing tool, a transmission mechanism, an acquisition device and a control unit, the control unit receives three-dimensional point cloud data, analyzes and calculates the numerical value of a heat conduction gap between a circuit board and a shell according to the three-dimensional point cloud data, and sends the numerical value to the circuit board; measuring the manufacturing error of the thickness of the heat-conducting insulating pad; and the control unit is also used for performing matching judgment according to the actual thickness value of the heat-conducting insulating pad, the specification parameter of the current heat-conducting insulating pad and the heat-conducting gap corresponding to the heat-conducting insulating pad. According to the method, the influence of errors of the heat-conducting insulation pad material on model selection can be accurately evaluated, meanwhile, selection differences caused by different experiences of operators or different product cognizations are reduced or avoided, high-precision automatic selection of the specifications of the heat-conducting insulation pad is achieved, and mistaken selection of the thickness specifications of the heat-conducting insulation pad is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic equipment manufacturing, and in particular to a device and method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds. Background Art

[0002] According to the development trend of national defense electronic information technology, the complexity of equipment systems is increasing, electronic products are developing towards high density and high integration, heat dissipation design often tends to the limit, and heat dissipation problems are gradually prominent. Therefore, temperature control has become a crucial link in design, manufacturing and assembly. Failure of the temperature control link will cause overheating and damage of components, becoming one of the main causes of quality problems in electronic equipment. Thermally conductive insulation pads are used to reduce the contact thermal resistance of heating devices in the heat dissipation channel to reduce the temperature of heating devices. They are a kind of thermal interface material. Its function is to conduct the heat of the device to the radiator or metal casing, reduce the temperature of the heating device, and improve the efficiency and service life of the heating electronic components.

[0003] Most of the industry uses manual or machine measurement of the assembly gap and then selects the specifications of the thermal conductive material according to the process standards. The current operation method is: according to the thermal conductive gap value, refer to the relevant standards and manually select the model of the thermal conductive insulation pad. In order to further improve efficiency, the relevant standards and rules can be written into the program to realize the automatic selection of the thermal conductive insulation pad; in addition, both the current manual operation method and the automatic operation method ignore the manufacturing error of the thermal conductive insulation pad itself, and regard the nominal value of the thickness of the selected thermal conductive insulation pad as the real thickness value, and do not measure the real thickness value of the thermal conductive insulation pad. This may lead to the consequence that due to the manufacturing error of the thermal conductive insulation pad itself, there is a large difference between its nominal value and the real thickness value, which causes the thermal conductive insulation pad to have poor contact or excessive compression in the thermal conductive gap, affecting the heat dissipation effect or causing stress on the circuit board. For example, in patent CN 111964594 A, a system and method for intelligent selection of thermal conductive insulation pads for heat sinks on board-level devices are proposed, but in the specification recommendation stage, it is simply carried out through database rule matching, ignoring the impact of the manufacturing error of the thermal conductive insulation pad itself on the selection. For example, in a Chinese invention patent with publication number CN 111964594A, a system and method for intelligent selection of thermal insulation pads for heat sinks on board-level devices are proposed. However, in the specification recommendation stage, it is simply carried out through database rule matching, ignoring the impact of the manufacturing error of the thermal insulation pad itself on the selection. Summary of the invention

[0004] The present invention aims to at least solve the technical problems in the prior art that the influence of the manufacturing error of the thermally conductive insulating pad on the selection is ignored during the selection process of the thermally conductive insulating pad, and poor contact or excessive compression is easily present in the thermal conductive gap.

[0005] To this end, a first aspect of the present invention provides a device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds.

[0006] A second aspect of the present invention provides a method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds.

[0007] The present invention provides a device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds, comprising:

[0008] A placement tool is used to place a piece to be tested, wherein the piece to be tested includes a circuit board, a housing and a thermally conductive insulating pad;

[0009] A transport mechanism, which carries the placement tool and moves the placement tool between designated workstations;

[0010] A collection device, comprising at least a three-dimensional laser scanner, for collecting three-dimensional point cloud data of the object to be tested;

[0011] A control unit receives the three-dimensional point cloud data, calculates the value of the thermal gap between the circuit board and the shell according to the three-dimensional point cloud data analysis, and measures the manufacturing error of the thickness of the thermal insulation pad; the control unit is provided with a selection database, and the specification parameters of the thermal insulation pad are recorded in the selection database; the control unit is also used to match and judge the thermal gap corresponding to the thermal insulation pad according to the actual thickness value of the thermal insulation pad and the specification parameters of the current thermal insulation pad, and the judgment rules at least include: the compression limit of the thermal insulation pad is less than the minimum value of the thermal gap and the size of the thermal insulation pad before compression is greater than the maximum value of the thermal gap.

[0012] The device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to the above technical solution of the present invention may also have the following additional technical features:

[0013] In the above technical solution, the transmission mechanism includes:

[0014] A conveying component, wherein the placing tool is arranged on the conveying component and is displaced under the driving of the conveying component;

[0015] A limit sensor, used for acquiring the position of the tooling and transmitting the acquired position information to the control unit;

[0016] The control unit controls the movement of the conveying component according to the position information of the placed tooling.

[0017] In the above technical solution, the collection device also includes:

[0018] Industrial cameras are used to position tooling;

[0019] A three-axis motion platform, the industrial camera and the three-dimensional laser scanner are arranged on the three-axis motion platform, and the three-axis motion platform can at least carry the three-dimensional laser scanner to move according to the positioning information collected by the industrial camera, so that the scanning direction of the three-dimensional laser scanner is aligned with the workpiece to be tested placed in the tooling.

[0020] In the above technical solution, the specification parameters of the thermally conductive insulating pad include: thermal conductivity parameters, standard thickness dimensions, compressible range and optimal compression range.

[0021] In the above technical solution, the control unit is also used to determine whether the value of the thermal conductive gap between the circuit board and the housing meets the selection criteria, and the determination method includes:

[0022] Identify the location of the heat dissipation boss according to the three-dimensional point cloud data of the shell;

[0023] Identifying, based on the three-dimensional point cloud data of the circuit board, the interval between the circuit element at the corresponding position of the heat dissipation boss and the heat dissipation boss when the circuit board is assembled on the mounting plane in the housing, and defining the interval as a thermal conductive gap;

[0024] Calculate the average value of all thermal gaps in the heat dissipation boss area;

[0025] It is determined whether the average value of the thermal conductive gap meets the threshold requirement, and the housing that does not meet the threshold requirement is reworked and repaired, and the position of the heat dissipation boss is redesigned.

[0026] The present invention provides a method for selecting the specifications of a micro-gap thermal conductive material based on a three-dimensional point cloud, which uses a device as described in any one of the above technical solutions to select the specifications of a micro-gap thermal conductive material. The method includes:

[0027] Establish a selection database and input the specification parameters of each type of thermal insulation pad;

[0028] Calculate the thermal gap value between the circuit board and the shell based on the three-dimensional point cloud data of the circuit board and the shell;

[0029] According to the values ​​of thermal conductive gaps at various locations on the circuit board, a preliminary selection plan for thermal conductive insulation pads is drawn up:

[0030] According to the preliminary selection scheme, select the corresponding thermal insulation pad and obtain the three-dimensional point cloud data of the thermal insulation pad;

[0031] Checking the manufacturing accuracy of the thickness of the thermally conductive insulating pad; wherein, the maximum value, minimum value and average value of the thickness of the thermally conductive insulating pad are calculated based on the three-dimensional point cloud data of the thermally conductive insulating pad, and judging whether the manufacturing accuracy of the thermally conductive insulating pad is within the allowable error range, wherein the manufacturing accuracy includes the difference between the actual thickness value and the standard thickness size and the fluctuation of the actual thickness value;

[0032] Determine whether the compression performance of the selected thermally conductive insulating pad in the corresponding thermally conductive gap meets the requirements based on the specification parameters of the thermally conductive insulating pad; among which, the actual compression limit thickness value of the thermally conductive insulating pad should be less than the minimum value of the thermally conductive gap, the actual size of the thermally conductive insulating pad before compression should be greater than the maximum value of the thermally conductive gap, and the thermally conductive gap value should be within the actual optimal compression range of the thermally conductive insulating pad.

[0033] In the above technical solution, the method for preliminarily formulating a selection scheme for the thermally conductive insulating pad includes:

[0034] The compression limit of the thermal insulation pad should be less than the minimum value of the thermal gap;

[0035] The size of the thermal insulation pad before compression should be larger than the maximum value of the gap;

[0036] The thermal gap value should be within the optimal compression range of the thermal insulation pad.

[0037] The above technical solution also includes:

[0038] According to the thermal gap values ​​at various locations, the actual thickness of the thermal insulation pad before compression, and the actual thickness of the thermal insulation pad under the compression limit, a simulation diagram of the indentation distribution of the thermal insulation pad is obtained, and the poor contact area, normal indentation area, and overpressure area are marked;

[0039] Wherein, in the poor contact area, the value of the thermal gap is greater than the actual thickness of the thermal insulation pad before compression; in the normal indentation area, the value of the thermal gap is greater than the actual thickness of the thermal insulation pad under the compression limit and less than the actual thickness of the thermal insulation pad before compression; in the overpressure area, the value of the thermal gap is less than the actual thickness of the thermal insulation pad under the compression limit;

[0040] The area percentages of the three types of indentation areas were calculated, and the assembly performance of the thermally conductive insulation pad was evaluated based on the proportions of the three types of indentation areas.

[0041] In the above technical solution, the evaluation of the assembly performance of the thermally conductive insulating pad according to the proportion of the three types of indentation areas includes:

[0042] When the proportion of poor contact areas exceeds the first set threshold, a heat dissipation effect alarm is issued; when the proportion of normal indentation areas is lower than the second set threshold, a heat dissipation effect alarm is issued; when the proportion of overpressure areas exceeds the third set threshold, an excessive stress alarm is issued.

[0043] The above technical solution also includes:

[0044] The assembly tightness of each thermal conductive gap on the circuit board is quantitatively evaluated, and an alarm message is issued when the difference in tightness of the thermal conductive insulation pads in adjacent thermal conductive gaps exceeds the limit.

[0045] In summary, due to the adoption of the above technical features, the beneficial effects of the present invention are:

[0046] The present invention can accurately evaluate the impact of the error of the thermal insulation pad material itself on the selection, while reducing or avoiding the selection differences caused by different operator experience or product awareness, and realizing high-precision automatic selection of thermal insulation pad specifications. It can solve the current problem of thermal insulation pads relying on manual selection and low efficiency, realize the automatic selection of thermal insulation pads, and effectively avoid the misselection of thermal insulation pad thickness specifications. Specifically, the present invention carries out precise measurement of thermal gaps and thermal insulation pads based on three-dimensional laser line scanning, which helps to realize the digitization and transparency of the entire assembly process, accurately grasp the key parameter information of the entire assembly process, eliminate the "blind spots" in the assembly process, and eliminate the hidden dangers that lead to assembly quality problems.

[0047] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0049] Figure 1 It is a structural schematic diagram of a device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to an embodiment of the present invention;

[0050] Figure 2 It is a partially enlarged schematic diagram of a collection device in a device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds according to an embodiment of the present invention;

[0051] Figure 3 This is an operation flow chart of a device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds according to an embodiment of the present invention;

[0052] Figure 4 It is a flow chart of a method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds according to an embodiment of the present invention.

[0053] in, Figures 1 to 4 The corresponding relationship between the reference numerals and the component names is as follows:

[0054] 1. Placement of tooling; 2. Transmission mechanism; 3. Collection device; 4. Control unit;

[0055] 21. Conveying components; 22. Limit sensor; 23. Servo motor;

[0056] 31. 3D laser scanner; 32. Industrial camera; 33. Three-axis motion platform. DETAILED DESCRIPTION

[0057] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0058] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0059] Refer to the following Figures 1 to 4 The following describes a device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds according to some embodiments of the present invention.

[0060] Some embodiments of the present application provide a device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds.

[0061] like Figure 1 and Figure 2 As shown, the first embodiment of the present invention proposes a device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds, including a placement tool 1, a transmission mechanism 2, a collection device 3 and a control unit 4.

[0062] The placement tool 1 is used to place the DUT, which includes a circuit board, a housing, and a thermally conductive insulating pad. Specifically, the placement tool 1 can have a specific shape, such as a tray structure, or can be specifically a station for placing the DUT. The number of placement tools 1 can be multiple, such as Figure 1 As shown, three placement fixtures 1 are used to place the circuit board, the housing and the thermal insulation pad respectively; in other embodiments, only one placement fixture 1 may be provided to place the test pieces in sequence as needed.

[0063] The transmission mechanism 2 carries the placement tool 1 and moves the placement tool 1 between designated workstations; the transmission mechanism 2 is mainly used to move the placement tool 1 to a designated workstation, such as an initial workstation, a testing workstation, etc., according to a control command. The transmission mechanism 2 can be in various forms, such as a conveyor belt, a guide rail screw, a conveyor chain, etc.

[0064] In a specific embodiment, the transmission mechanism 2 includes: a transmission component 21 and a limit sensor 22. Figure 1 , wherein the conveying component 21 adopts a guide rail screw, and the two guide rail screws are driven by a servo motor 23 respectively to carry the placement tool 1 on the guide rail screw to move. Among them, the limit sensor 22 is used to obtain the position of the placement tool 1 and transmit the collected position information to the control unit 4; Figure 1 In the illustrated embodiment, the limit sensor 22 adopts a limit photoelectric switch, and four limit photoelectric switches are used to identify the position of the placement tool 1, two of which are used to sense whether the placement tool 1 has reached the initial position, and the other two limit photoelectric switches are used to sense whether the placement tool 1 has reached the detection position. The control unit 4 controls the opening and closing of the servo motor 23 according to the position information of the placement tool 1 detected by the limit photoelectric switch, so that the placement tool 1 reaches the specified position.

[0065] The acquisition device 3 at least includes a 3D laser scanner 31 to acquire the 3D point cloud data of the object to be tested. The acquisition device 3 can be set in a variety of ways. In the present disclosure, the acquisition device 3 only needs to be able to accurately acquire the 3D point cloud data of the target object to be tested.

[0066] In a specific embodiment, see Figure 1 and Figure 2 , the acquisition device 3 includes an industrial camera 32, a three-dimensional laser scanner 31 and a three-axis motion platform 33; the industrial camera 32 and the three-dimensional laser scanner 31 are both arranged on the three-axis motion platform 33, the industrial camera 32 is used to position the tooling 1; the three-axis motion platform 33 can at least carry the three-dimensional laser scanner 31 to move according to the positioning information collected by the industrial camera 32, so that the scanning direction of the three-dimensional laser scanner 31 is aligned with the workpiece to be tested in the tooling 1. Specifically, the three-axis motion platform 33 can carry the three-dimensional laser scanner 31 to move in three mutually perpendicular directions respectively, so as to ensure that the three-dimensional laser scanner 31 can reach any point in the three-dimensional space to adapt to the orientation of the workpiece to be tested.

[0067] The control unit 4 receives the three-dimensional point cloud data, calculates the value of the thermal gap between the circuit board and the shell according to the three-dimensional point cloud data analysis, and measures the manufacturing error of the thickness of the thermal insulation pad; the control unit 4 is provided with a selection database, and the specification parameters of the thermal insulation pad are recorded in the selection database, wherein the specification parameters of the thermal insulation pad include: thermal conductivity performance parameters, standard thickness size, compressible range and optimal compression range, etc.; the control unit 4 is also used to match and judge the thermal gap corresponding to the thermal insulation pad according to the actual thickness value of the thermal insulation pad and the specification parameters of the current thermal insulation pad, and the judgment rules include at least: the compression limit of the thermal insulation pad is less than the minimum value of the thermal gap and the size of the thermal insulation pad before compression is greater than the maximum value of the thermal gap.

[0068] In a specific embodiment, the execution process of the device selected in the present disclosure is: the hardware of the motion mechanism is initialized when the machine is turned on: all guide rails and lead screws find the initial position through the limit photoelectric switch, and send instructions to all guide rails and lead screws to move in a certain direction, so that they move until the limit photoelectric switch is triggered to stop. This is the initial position. The shell and the circuit board are placed in the placement tool 1 respectively. After pressing the start button, the three-axis motion platform 33 moves the three-dimensional laser scanner 31 to the appropriate position, wherein the placement tool 1 is positioned by the industrial camera 32, and the three-dimensional laser scanner 31 starts working at the same time, scanning and obtaining the three-dimensional point cloud data of the test piece, and outputting the average value of the heat dissipation gap between each heat dissipation boss of the shell and the corresponding circuit board component in the control unit 4, that is, the host computer. And according to the above operation, the three-dimensional point cloud data of the thermal conductive insulation pad is also obtained for further analysis.

[0069] In a specific embodiment, the judgment process of the selection device is as follows: Figure 3 shown.

[0070] The control unit 4 first determines whether the thermal conductive gap value between the circuit board and the housing meets the selection criteria, and the determination method includes:

[0071] The position of the heat dissipation boss is identified based on the three-dimensional point cloud data of the shell and the circuit board; technicians in this field can understand that the heat dissipation boss refers to a structure for heat dissipation arranged on the shell and protruding relative to the shell body, which corresponds to the components on the circuit board. One heat dissipation boss can correspond to one or more circuit board components. Similarly, one circuit board component can also correspond to one heat dissipation boss or multiple heat dissipation bosses.

[0072] According to the three-dimensional point cloud data of the circuit board, when the circuit board is assembled on the mounting plane in the housing, the interval between the circuit element at the corresponding position of the heat dissipation boss and the heat dissipation boss is identified, and the interval is defined as the thermal conductive gap; the average value of all thermal conductive gaps in the heat dissipation boss area is calculated. It should be noted that the thermal conductive gap may not be completely equal in width, and it may be an irregularly shaped gap.

[0073] It is determined whether the average value of the thermal conductive gap meets the threshold requirement, and the housing that does not meet the threshold requirement is reworked and repaired, and the position of the heat dissipation boss is redesigned.

[0074] When the average value of the thermal conductive gap meets the threshold requirement, it indicates that the current shell meets the selection specifications of the circuit board. The selected thermal conductive insulation pad can then be subjected to three-dimensional laser line scanning to obtain three-dimensional point cloud data. The manufacturing error of the thermal conductive insulation pad can be identified based on the three-dimensional point cloud data, thereby obtaining the true parameters of the thermal conductive insulation pad, and then determining whether the current selection of the thermal conductive insulation pad matches the thermal conductive gap, that is, determining whether the current assembly condition is within the material usage range. If not, other thermal conductive insulation pads with the same nominal size are replaced; if compliant, a thermal conductive insulation pad of this specification is selected and the assembly condition is archived.

[0075] The second embodiment of the present invention provides a method for selecting the specifications of a small gap thermal conductive material based on a three-dimensional point cloud, and adopts a device as described in any of the above embodiments to select the specifications of a small gap thermal conductive material. Figure 4 As shown, the method includes steps S1-S6.

[0076] S1. Establish a selection database and input the specification parameters of each type of thermally conductive insulating pad; input the thermal conductivity parameters (thermal conductivity), standard thickness, compressible range, optimal compression range and other information of each type of thermally conductive insulating pad into the selection database. The selection database can be called in the software later to provide a suitable thermally conductive insulating pad selection plan for the thermally conductive insulating pad model selected by the operator.

[0077] S2. Calculate the value of the thermal gap between the circuit board and the shell based on the three-dimensional point cloud data of the circuit board and the shell; it can be understood that after clarifying the meaning of the thermal gap, calculating the value of the thermal gap based on the three-dimensional point cloud data is content known to those skilled in the art and will not be repeated here.

[0078] S3. According to the values ​​of the thermal gaps at various locations on the circuit board, a preliminary selection plan for the thermal insulation pads is formulated. After the thermal gaps at various locations on the circuit board have been obtained, a preliminary selection plan for the thermal insulation pads is formulated in accordance with relevant standards and specifications. While the plan is formulated in accordance with standards and specifications, it should also meet the following requirements: the compression limit of the thermal insulation pad should be less than the minimum value of the thermal gap to prevent stress and strain on the circuit board, which will affect its lifespan; the size of the thermal insulation pad before compression should be greater than the maximum value of the gap to prevent poor contact of the thermal insulation pad in the gap and heat dissipation failure; and the thermal gap value should be within the optimal compression range of the thermal insulation pad to achieve both low circuit board stress and high heat dissipation efficiency.

[0079] S4. According to the preliminary selection scheme, a corresponding thermally conductive insulating pad is selected, and three-dimensional point cloud data of the thermally conductive insulating pad is obtained.

[0080] S5. Check the manufacturing accuracy of the thickness of the thermally conductive insulating pad; wherein, the maximum, minimum and average thickness of the thermally conductive insulating pad are calculated based on the three-dimensional point cloud data of the thermally conductive insulating pad to determine whether the manufacturing accuracy of the thermally conductive insulating pad is within the allowable error range, and the manufacturing accuracy includes the difference between the actual thickness value and the standard thickness size and the fluctuation of the actual thickness value.

[0081] Specifically, the manufacturing error of the thermal insulation pad itself may greatly affect the heat dissipation effect. For example, the thickness tolerance given by the manufacturer of the TGP5000 series thermal insulation pad is ±10%. According to the existing thermal insulation pad thickness selection principle, there is a situation where the thermal insulation pad has poor contact. If the measured thermal conductivity spacing is 0.90mm, according to the design requirements, a thermal insulation pad with a thickness of 1mm should be selected. If the thickness value of the thermal insulation pad is a negative tolerance (0.90mm), there is no contact pressure between the thermal insulation pad and the device after installation, and the contact is poor. Among them, whether the manufacturing accuracy is within the allowable error range should be understood as whether the actual value of the selected thermal insulation pad is within the range specified by the standard specification.

[0082] S6. Determine whether the compression performance of the selected thermally conductive insulating pad in the corresponding thermally conductive gap meets the requirements based on the specification parameters of the thermally conductive insulating pad; wherein, the actual compression limit thickness value of the thermally conductive insulating pad should be less than the minimum value of the thermally conductive gap, the actual size of the thermally conductive insulating pad before compression should be greater than the maximum value of the thermally conductive gap, and the thermally conductive gap value should be within the actual optimal compression range of the thermally conductive insulating pad.

[0083] In some embodiments, the method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds further includes step S7, in which the thermal conductive insulating pad selection scheme is locally checked.

[0084] S7. Based on the values ​​of the thermal gaps at various locations, the actual values ​​of the thickness of the thermal insulation pad before compression and the actual thickness of the thermal insulation pad under the compression limit, a simulation diagram of the indentation distribution of the thermal insulation pad is obtained, and the poor contact area, normal indentation area and overpressure area are marked; it can be understood that the values ​​of the thermal gaps and the actual values ​​of the thickness of the thermal insulation pad before compression are both measured values, and the actual thickness of the thermal insulation pad under the compression limit is an estimated value; the actual thickness of the thermal insulation pad under the compression limit can be obtained by proportionally converting the lower limit of the compressible range of the thermal insulation pad in the selection database and the difference between the standard thickness and the actual thickness.

[0085] Specifically, the indentation distribution simulation diagram can be established by the three-dimensional point cloud data of the thermal insulation pad and the thermal gap; the principle of regional division is as follows: in the poor contact area, the thermal gap value is greater than the actual thickness of the thermal insulation pad before compression; in the normal indentation area, the thermal gap value is greater than the actual thickness of the thermal insulation pad under the compression limit and less than the actual thickness of the thermal insulation pad before compression; in the overpressure area, the thermal gap value is less than the actual thickness of the thermal insulation pad under the compression limit;

[0086] The area percentages of the three types of indentation areas were calculated, and the assembly performance of the thermally conductive insulation pad was evaluated based on the proportions of the three types of indentation areas.

[0087] The evaluation of the assembly performance of the thermally conductive insulating pad according to the proportion of the three types of indentation areas includes:

[0088] When the proportion of poor contact areas exceeds the first set threshold, a heat dissipation effect alarm is issued; when the proportion of normal indentation areas is lower than the second set threshold (for example, 70%), a heat dissipation effect alarm is issued; when the proportion of overvoltage areas exceeds the third set threshold, an excessive stress alarm is issued.

[0089] The values ​​of the first set threshold and the third set threshold can be selected within the range of 10%-30% according to process requirements.

[0090] In some embodiments, the method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point clouds further includes step S8, in which a global check is performed on the thermal conductive insulating pad selection scheme.

[0091] S8. Quantitatively evaluate the assembly tightness of each thermal conductive gap on the circuit board, and issue an alarm message when the difference in tightness of the thermal conductive insulation pads in adjacent thermal conductive gaps exceeds the limit.

[0092] Specifically, if there are two components close to each other on a circuit board, and one of them has a tightly assembled thermal insulation pad, while the other has a loosely assembled thermal insulation pad, the former will easily "lift up" the circuit board, thereby increasing the thermal conductive gap of the latter, causing the latter to have poor contact and poor thermal conductivity. To avoid the above situation, a quantitative assessment is conducted on the assembly tightness of each thermal conductive gap on the circuit board, and it is checked whether the distance is close and the difference in tightness is too large. If so, an alarm message is output to prompt the operator to conduct further inspection, testing, disassembly and debugging of the thermal conductive insulation pad assembly effect, so as to effectively eliminate the quality risks in the thermal conductive insulation pad assembly process and achieve the global optimal heat dissipation effect within the entire circuit board.

[0093] In a specific implementation, the criterion can be defined as if the compression rate of a certain thermal insulation pad is less than 50% of the compression rate of the surrounding thermal insulation pads, then the device is too loose. Conversely, if the compression rate of a certain thermal insulation pad is greater than 50% of the compression rate of the surrounding thermal insulation pads, then the device is too tight. For example: assuming that the compression rate of the thermal insulation pad matching the thermal gap A is 10%, and the compression rates of the corresponding thermal insulation pads of the adjacent devices around it are all above 15%, then the thermal insulation pad corresponding to the thermal gap A is too loose, triggering an alarm.

[0094] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0095] Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud, characterized in that: include: A placement tool is used to place a piece to be tested, wherein the piece to be tested includes a circuit board, a housing and a thermally conductive insulating pad; A transport mechanism, which carries the placement tool and moves the placement tool between designated workstations; A collection device, comprising at least a three-dimensional laser scanner, for collecting three-dimensional point cloud data of the object to be tested; A control unit receives the three-dimensional point cloud data, calculates the value of the thermal gap between the circuit board and the shell according to the three-dimensional point cloud data analysis, and measures the manufacturing error of the thickness of the thermal insulation pad; the control unit is provided with a selection database, and the specification parameters of the thermal insulation pad are recorded in the selection database; the control unit is also used to match and judge the thermal gap corresponding to the thermal insulation pad according to the actual thickness value of the thermal insulation pad and the specification parameters of the current thermal insulation pad, and the judgment rules at least include: the compression limit of the thermal insulation pad is less than the minimum value of the thermal gap and the size of the thermal insulation pad before compression is greater than the maximum value of the thermal gap.

2. The device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to claim 1, characterized in that: The transmission mechanism comprises: A conveying component, wherein the placing tool is arranged on the conveying component and is displaced under the driving of the conveying component; A limit sensor, used for acquiring the position of the tooling and transmitting the acquired position information to the control unit; The control unit controls the movement of the conveying component according to the position information of the placed tooling.

3. The device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to claim 1, characterized in that: The collection device also includes: Industrial cameras are used to position tooling; A three-axis motion platform, the industrial camera and the three-dimensional laser scanner are arranged on the three-axis motion platform, and the three-axis motion platform can at least carry the three-dimensional laser scanner to move according to the positioning information collected by the industrial camera, so that the scanning direction of the three-dimensional laser scanner is aligned with the workpiece to be tested placed in the tooling.

4. The device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to claim 1, characterized in that: The specification parameters of the thermally conductive insulating pad include: thermal conductivity parameters, standard thickness dimensions, compressible range and optimal compression range.

5. The device for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to claim 1, characterized in that: The control unit is also used to determine whether the thermal conductive gap value between the circuit board and the housing meets the selection criteria, and the determination method includes: Identify the location of the heat dissipation boss according to the three-dimensional point cloud data of the shell; Identifying, based on the three-dimensional point cloud data of the circuit board, the interval between the circuit element at the corresponding position of the heat dissipation boss and the heat dissipation boss when the circuit board is assembled on the mounting plane in the housing, and defining the interval as a thermal conductive gap; Calculate the average value of all thermal gaps in the heat dissipation boss area; It is determined whether the average value of the thermal conductive gap meets the threshold requirement, and the housing that does not meet the threshold requirement is reworked and repaired, and the position of the heat dissipation boss is redesigned.

6. A method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud, characterized in that: The device according to any one of claims 1 to 5 is used to select the specification of the micro-gap thermal conductive material, and the method comprises: Establish a selection database and input the specification parameters of each type of thermal insulation pad; Calculate the thermal gap value between the circuit board and the shell based on the three-dimensional point cloud data of the circuit board and the shell; According to the values ​​of thermal conductive gaps at various locations on the circuit board, a preliminary selection plan for thermal conductive insulation pads is drawn up: According to the preliminary selection scheme, select the corresponding thermal insulation pad and obtain the three-dimensional point cloud data of the thermal insulation pad; Checking the manufacturing accuracy of the thickness of the thermally conductive insulating pad; wherein, the maximum value, minimum value and average value of the thickness of the thermally conductive insulating pad are calculated based on the three-dimensional point cloud data of the thermally conductive insulating pad, and judging whether the manufacturing accuracy of the thermally conductive insulating pad is within the allowable error range, wherein the manufacturing accuracy includes the difference between the actual thickness value and the standard thickness size and the fluctuation of the actual thickness value; Determine whether the compression performance of the selected thermally conductive insulating pad in the corresponding thermally conductive gap meets the requirements based on the specification parameters of the thermally conductive insulating pad; among which, the actual compression limit thickness value of the thermally conductive insulating pad should be less than the minimum value of the thermally conductive gap, the actual size of the thermally conductive insulating pad before compression should be greater than the maximum value of the thermally conductive gap, and the thermally conductive gap value should be within the actual optimal compression range of the thermally conductive insulating pad.

7. The method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to claim 6, characterized in that: The method for preliminarily formulating a selection scheme for thermally conductive insulating pads comprises: The compression limit of the thermal insulation pad should be less than the minimum value of the thermal gap; The size of the thermal insulation pad before compression should be larger than the maximum value of the gap; The thermal gap value should be within the optimal compression range of the thermal insulation pad.

8. The method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to claim 6, characterized in that: Also includes: According to the thermal gap values ​​at various locations, the actual thickness of the thermal insulation pad before compression, and the actual thickness of the thermal insulation pad under the compression limit, a simulation diagram of the indentation distribution of the thermal insulation pad is obtained, and the poor contact area, normal indentation area, and overpressure area are marked; Wherein, in the poor contact area, the value of the thermal gap is greater than the actual thickness of the thermal insulation pad before compression; in the normal indentation area, the value of the thermal gap is greater than the actual thickness of the thermal insulation pad under the compression limit and less than the actual thickness of the thermal insulation pad before compression; in the overpressure area, the value of the thermal gap is less than the actual thickness of the thermal insulation pad under the compression limit; The area percentages of the three types of indentation areas were calculated, and the assembly performance of the thermally conductive insulation pad was evaluated based on the proportions of the three types of indentation areas.

9. The method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to claim 8, characterized in that: The evaluation of the assembly performance of the thermally conductive insulation pad according to the proportion of the three types of indentation areas includes: When the proportion of poor contact areas exceeds the first set threshold, a heat dissipation effect alarm is issued; when the proportion of normal indentation areas is lower than the second set threshold, a heat dissipation effect alarm is issued; when the proportion of overpressure areas exceeds the third set threshold, an excessive stress alarm is issued.

10. The method for selecting specifications of micro-gap thermal conductive materials based on three-dimensional point cloud according to claim 6, characterized in that: Also includes: The assembly tightness of each thermal conductive gap on the circuit board is quantitatively evaluated, and an alarm message is issued when the difference in tightness of the thermal conductive insulation pads in adjacent thermal conductive gaps exceeds the limit.

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