PCB board structure and fixture and method for testing sensing distance threshold thereof

Abstract

The invention discloses a PCB board structure and a jig and method for testing a threshold of a sensing distance thereof, which can improve the versatility of a sensing switch PCB board and reduce production input costs. The PCB board structure comprises a touch spring, one end of which is fixed to the PCB board, and the other end of which is fixed to a touch button. The PCB board is provided with a positioning hole, a welding PAD, and a calibration PAD, and the calibration PAD is electrically connected to a controller. The test jig comprises a shell, a reflector, a probe, and a controller. A calibration trigger pad is electrically connected to a trigger pin of the controller, the reflector corresponds to an infrared sensing lamp bead, the calibration trigger pad is short-circuited with a negative electrode pad of a power supply through a probe, and the reflector corresponds to an infrared sensing lamp bead on the PCB board. A method for testing the sensing distance of a PCB board by using the test jig is disclosed, and a preset threshold value of the sensing distance of the PCB board is calibrated by the method.

Description

Technical Field

[0001] The present invention relates to the technical field of induction switches, and in particular to an induction switch PCB board structure, a test fixture for testing an induction distance threshold of an induction switch on a PCB board, and a testing and calibration method. Background Art

[0002] The induction switch is an automatic control product based on infrared technology. It can be automatically activated when a person passes through the infrared sensing detection area of ​​the induction switch. It can be widely used in automatic lighting and automatic ventilation in corridors, stairways, warehouses, garages, basements and other places. It can also be used for automatic sensing of the switch of hand washing machines or soap dispensers in the bathroom. The induction switch mainly includes a PCB board, infrared induction lamp beads, an infrared induction lamp bead connection circuit arranged on the PCB board, and a shell encapsulated outside the induction switch. The infrared induction lamp bead connection circuit includes a touch spring, and the circuit is started by touching the spring. However, the sensing distance of the existing infrared induction lamp beads and infrared induction lamp bead connection circuits is overly dependent on the consistency of electronic components. When selecting electronic components, they need to be customized according to the magnification and sensitivity. General electronic components cannot be used, resulting in poor versatility and high investment costs of the induction switch. Summary of the invention

[0003] In view of the problems of poor versatility and high investment cost of the induction switch in the prior art, the present invention provides a test fixture and a test method for testing the induction distance of an induction switch PCB board, which can improve the versatility of the induction switch PCB board and reduce the production investment cost.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme:

[0005] A PCB structure of an induction switch comprises a touch spring, one end of the touch spring is fixed to the PCB, the other end of the touch spring is fixed to the touch button, an infrared sensing lamp bead and an infrared sensing lamp bead connection circuit are arranged on the PCB, the infrared sensing lamp bead connection circuit comprises a controller, and the structure is characterized in that at least three through holes are opened on the PCB, the through holes comprise a positioning hole, a welding PAD, and a calibration PAD, one end of the touch spring is provided with a positioning column and a connecting rod respectively corresponding to the positioning hole and the welding PAD, the positioning of the touch spring and the PCB is achieved through the positioning column and the positioning hole, the connecting rod is connected to the welding PAD, the welding PAD and the calibration PAD are both electrically connected to the infrared sensing lamp bead connection circuit; the calibration PAD is used for testing the PCB, the outer peripheries of the welding PAD and the calibration PAD are respectively provided with pads, the pads on the outer periphery of the calibration PAD are calibration trigger pads, the calibration trigger pads are electrically connected to the controller, and the structure also comprises a negative power supply pad, the negative power supply pad is electrically connected to the negative power supply.

[0006] It is further characterized in that the model of the controller is E85F3204TF:

[0007] The calibration PAD includes at least one;

[0008] The pads are all annular;

[0009] The solder pad is solder paste, and the solder paste is soldered to the periphery of the soldering PAD and the calibration PAD through a patch line reflow furnace.

[0010] A test fixture for the above-mentioned PCB board sensing test and sensing distance calibration, comprising a shell, a reflector, and a probe, characterized in that a first mounting plate is arranged on the top of the shell, a through hole corresponding to the infrared sensing lamp bead is opened in the middle of the first mounting plate, a second mounting plate is arranged on the bottom of the shell, the PCB board is fixed to the first mounting plate, the reflector is fixed to the second mounting plate, the reflector corresponds to the infrared sensing lamp bead, during the test, the calibration trigger pad and the negative electrode pad of the power supply are short-circuited by the probe, the calibration trigger pad is electrically connected to the trigger pin of the controller, and the reflector is used to calibrate the sensing distance of the infrared sensing lamp bead.

[0011] It is further characterized in that the adjustment distance between the reflector and the infrared sensing lamp beads is 70 mm to 110 mm.

[0012] A method for testing and calibrating the sensing distance threshold including the PCB board using the above-mentioned test fixture, setting the initial value of the sensing distance threshold to a preset sensing threshold value A, characterized in that the sensing distance threshold is calibrated by adjusting the preset sensing threshold value A, and the test steps are as follows:

[0013] S1. Fix the distance between the reflector and the infrared sensing lamp bead, and the fixed distance is L;

[0014] S2, starting the test fixture;

[0015] S3, judging whether the preset sensing threshold value meets the standard requirements, that is, judging whether there is a calibration requirement, the judging method is: detecting whether the calibration PAD and the negative pole of the power supply are conductive,

[0016] S31, if the red calibration PAD and the negative electrode of the power supply are connected, it means that there is a calibration requirement, and step S4 is executed to calibrate the sensing distance threshold of the sensing switch;

[0017] S32, if the red calibration PAD and the negative electrode of the power supply are not connected, it means that there is no calibration requirement, and step S33 is executed;

[0018] S33, if the red calibration PAD and the negative electrode of the power supply are not conducting, and the fixed distance L is greater than the preset sensing threshold value A, it indicates that the preset threshold value meets the standard and can be put into use;

[0019] S4, calibrating the sensing distance threshold: adjusting the preset sensing threshold value A, and detecting the conduction results of the receiving end and the transmitting end of the infrared sensing lamp bead:

[0020] Under the condition that the fixed distance L is greater than the preset sensing threshold value A, the preset sensing threshold value A is increased and adjusted to A1, A<A1<L. At this time, it is judged whether the receiving end and the transmitting end of the infrared sensing lamp bead are turned on, S41. If not, it indicates that the adjusted preset sensing threshold value A1 meets the standard, and the adjusted preset sensing threshold value A1 is stored; S42. If it is turned on, it indicates that the adjusted preset sensing threshold value A1 still does not meet the standard, and the preset sensing threshold value A is continued to be increased, and the preset sensing threshold value A is adjusted to A2, A<A1<L. At this time, it is judged whether the receiving end and the transmitting end of the infrared sensing lamp bead are turned on. If not, execute step S41 and store A2. If it is turned on, execute step S42, continue to adjust the preset sensing threshold value A, and repeat this cycle to finally obtain a preset sensing threshold value set that meets the standard.

[0021] It is further characterized in that the fixed distance L is 70 mm to 110 mm.

[0022] The above structure and method of the present invention can achieve the following beneficial effects: (1) Positioning holes are set on the PCB board, and the touch spring is positioned through the positioning holes, thereby facilitating the installation of the touch spring and improving the processing consistency.

[0023] (2) A calibration PAD is reserved on the PCB board. Before the PCB board is put into use, the sensing distance of the PCB board is tested and calibrated using the test fixture and the test and calibration method of the present application, so that the sensing threshold value of the PCB board can be adjusted. Therefore, when producing the PCB board, general electronic components can be used without relying on the consistency of the electronic components, nor customizing or screening the electronic components, thereby greatly reducing the investment cost.

[0024] (3) Before the product leaves the factory, the product is tested first. During the product testing, the sensing distance of the PCB board is tested using the test fixture of this application. According to actual usage requirements, the sensing distance of the PCB board is tested and gradually adjusted using the test and calibration method of this application so that the sensing distance just meets the target distance and is stored, thereby completing the calibration of the sensing target distance and achieving consistency in the sensing distance of the product leaving the factory. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the top view of the PCB board of the present invention;

[0026] Figure 2 This is a schematic diagram of the main structure of the touch spring of the present invention;

[0027] Figure 3 This is a schematic diagram of the main structure of the test fixture of the present invention;

[0028] Figure 4 The figure is a flow chart of the testing and calibration method of the present invention. DETAILED DESCRIPTION

[0029] See Figure 1 , Figure 2A PCB structure of an induction switch includes a touch spring 1, one end of the touch spring 1 is fixed to a PCB board 2, and the other end of the touch spring 1 is fixed to a touch button. An infrared sensing lamp bead connection circuit is provided on the PCB board 2 (not shown in the figure, the infrared sensing lamp bead connection circuit can adopt an existing commonly used circuit for driving infrared sensing lamp beads), and the infrared sensing lamp bead connection circuit is connected to an infrared sensing lamp bead 3 (the infrared sensing lamp bead includes an existing infrared receiving tube and an infrared light emitting diode). In this example, the through hole on the PCB board 2 includes a positioning hole 4, a welding PAD 5, and a calibration PAD 6. The welding PAD 5 and the calibration PAD 6 both include copper foil and a hole, and the copper foil is exposed to facilitate electrical connection with other electronic components. A positioning column 11 and a connecting rod 12 corresponding to the positioning hole 4 and the welding PAD 5 are provided at one end of the touch spring 1. The positioning of the touch spring 1 and the PCB board 2 is achieved through the positioning column 11 and the positioning hole 4. The connecting rod 12 is correspondingly connected to the welding PAD 5; the calibration PAD 6 is used for testing the PCB board 2, and the welding PAD 5 and the calibration PAD 6 Solder pads are respectively provided on the outer periphery.

[0030] The pad on the periphery of the calibration PAD 6 is the calibration trigger pad 61, which is electrically connected to the controller. A negative power pad 62 is also provided on the PCB board, which is connected to the negative power supply. The calibration trigger pad 61 and the negative power pad 62 are both annular and are filled with solder paste. The solder paste is soldered to the periphery of the welding PAD 6 and the calibration PAD 6 by means of a SMD wire reflow furnace.

[0031] See Figure 3 A test fixture for the induction test and induction distance calibration of the above-mentioned PCB board 2 includes a shell 7, a reflector 8, a probe 9, and a controller. A first mounting plate 71 is arranged on the top of the shell 7. A through hole 73 corresponding to the infrared sensing lamp bead 3 is opened in the middle of the first mounting plate 71. A second mounting plate 72 with adjustable position is arranged at the bottom of the shell 7 (in this embodiment, guide rails can be arranged on both sides of the shell 7, and sliders corresponding to the guide rails are arranged at both ends of the second mounting plate 72. The slide is pushed and moved on the guide rail. The sliding connection and fixation of the guide rail and the slider can adopt the existing technology. When the second mounting plate is adjusted to a fixed position, The slider and the guide rail are fixed by bolts (not shown in the figure), and the distance between the reflector 8 and the infrared sensing lamp bead 3 is adjusted by adjusting the second mounting plate 72. The PCB board 2 is fixed to the first mounting plate 71, and the reflector 8 is fixed to the second mounting plate 72. The reflector 8 corresponds to the infrared sensing lamp bead 3. During the test, the calibration trigger pad 61 and the negative power pad 62 are short-circuited by the probe 9. The adjustment distance between the reflector 8 and the infrared sensing lamp bead 3 is 70mm~110mm, and the reflector 8 is used to calibrate the sensing distance of the infrared sensing lamp bead 3.

[0032] See Figure 4 A method for testing and calibrating a sensing distance threshold including a PCB board 2 using the test fixture of the present application, wherein the calibration trigger pad 61 is triggered by a controller, and the model of the controller in the present application is selected according to actual needs (the controller can select the E85F3204TF series), and the initial value of the sensing distance threshold is set to a preset sensing threshold value A. In this example, the preset sensing threshold value A=60mm, and the calibration of the sensing distance threshold is achieved by adjusting the preset sensing threshold value A. The test steps are as follows:

[0033] S1. Fix the distance between the reflector 8 and the infrared sensing lamp bead 3 to be L. In this example, the fixed distance L is 110 mm.

[0034] S2, start the test fixture;

[0035] S3. Determine whether the calibration PAD and the negative pole of the power supply are conductive, that is, determine whether there is a calibration requirement. The determination method is: detect whether the calibration PAD and the negative pole of the power supply are conductive:

[0036] S31, if the calibration PAD and the negative electrode of the power supply are turned on, it means that there is a calibration requirement, and step S4 is executed to calibrate the sensing distance threshold of the sensing switch;

[0037] S32, if the calibration PAD and the negative electrode of the power supply are not connected, it means that there is no calibration requirement, and step S33 is executed;

[0038] S33, if the transmitting end and the receiving end of the infrared sensing lamp bead 3 are not turned on, and the fixed distance L is greater than the preset sensing threshold value A, it indicates that the preset threshold value meets the standard requirements or actual use requirements, the detection is completed, and it can be put into use;

[0039] S4. Calibrate the sensing distance threshold: adjust the preset sensing threshold value A, and detect whether the receiving end and the transmitting end of the infrared sensing lamp bead are turned on (when the receiving end and the transmitting end of the infrared sensing lamp bead are turned on, it means that the calibration PAD and the negative pole of the power supply are turned on, otherwise it means that the calibration PAD and the negative pole of the power supply are not turned on): Under the condition that the fixed distance L is greater than the preset sensing threshold value A, increase the preset sensing threshold value A, and adjust the preset sensing threshold value A to A1, A1=70, A<A1<L. At this time, judge whether the receiving end and the transmitting end of the infrared sensing lamp bead 3 are turned on.

[0040] S41, if it is not connected, it indicates that the adjusted preset sensing threshold value A1 meets the standard, and the adjusted preset sensing threshold value A1 is stored;

[0041] S42, if it is conductive, it indicates that the adjusted preset sensing threshold value A1 still does not meet the standard, and the preset sensing threshold value A is continued to be increased, and the preset sensing threshold value A is adjusted to A2, A1<A2<L, A2=80, at this time, it is determined whether the receiving end and the transmitting end of the infrared sensing lamp bead 3 are conductive, if conductive, step S41 is executed, and A2 is stored, if conductive, the preset sensing threshold value A is continued to be adjusted, and this cycle is repeated, and finally a set of preset sensing threshold values ​​that meet the standard is obtained, and step S5 can be entered for use;

[0042] This embodiment includes step S5, putting into use.

[0043] When the PCB board is processed, the sensing threshold value of the PCB board is calibrated using the above-mentioned calibration fixture and calibration method to obtain a set of sensing threshold values ​​that meet the standards, and the set is put into use as the sensing threshold value of the PCB board. The sensing switch made of the PCB board calibrated by the above-mentioned calibration fixture and calibration method can effectively avoid the problem of false triggering when the sensing distance is far (for example, when the sensing distance is greater than 110mm).

[0044] In the prior art, the processing and production of the induction switch circuit board requires the use of two processing production lines, the patch line and the plug-in line, which require a lot of investment in the production line and occupy a large space. In addition, the waste gas and solid waste generated during the production process of the plug-in line are discharged more, which seriously affects the environment. In this application, all electronic components and cable plug-in wires on the PCB board are selected from existing models that can be processed by patch processing. Therefore, the production and processing of related products only use patch production lines, which reduces the investment in production lines and the occupied space area. In this application, before the PCB is put into use, the distance test of the PCB board 2 is first carried out, and the calibration PAD 6 is reserved on the PCB board 2 through the test fixture. The calibration PAD 6 is connected to the trigger pin of the controller in the test fixture. The sensing distance of the PCB board is tested by the controller and the test method, and the sensing distance threshold is calibrated by the calibration method, which improves the accuracy of the product sensing distance and avoids the problem of false triggering. At the same time, the consistency setting of the product sensing distance is achieved, which reduces the excessive dependence on the consistency of electronic components and reduces the product material cost.

[0045] The above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A test fixture for sensing distance test and sensing distance calibration of a sensing switch PCB structure, wherein the sensing switch PCB structure comprises a touch spring, one end of the touch spring is fixed to the PCB, and the other end of the touch spring is fixed to the touch button, and an infrared sensing lamp bead and an infrared sensing lamp bead connection circuit are arranged on the PCB, and the infrared sensing lamp bead connection circuit comprises a controller, characterized in that: At least three through holes are provided on the PCB board, and the through holes include a positioning hole, a welding PAD, and a calibration PAD. A positioning column and a connecting rod corresponding to the positioning hole and the welding PAD are provided at one end of the touch spring, and the touch spring and the PCB board are positioned by the positioning column and the positioning hole, and the connecting rod is connected to the welding PAD accordingly; the calibration PAD is used for testing the PCB board, and the peripheries of the welding PAD and the calibration PAD are respectively provided with pads, and the pads on the periphery of the calibration PAD are calibration trigger pads, and the calibration trigger pads are electrically connected to the controller, and it also includes a negative power supply pad, and the negative power supply pad is electrically connected to the negative power supply; The solder pad is solder paste, and the solder paste is soldered to the periphery of the soldering PAD and the calibration PAD through a patch line reflow furnace; The test fixture includes a shell, a reflector, and a probe, and also includes a controller. The calibration trigger pad is electrically connected to the trigger pin of the controller. A first mounting plate is provided on the top of the shell, and a through hole corresponding to the infrared sensing lamp bead is opened in the middle of the first mounting plate. A second mounting plate is provided on the bottom of the shell, the PCB board is fixed to the first mounting plate, and the reflector is fixed to the second mounting plate. The reflector corresponds to the infrared sensing lamp bead. During the test, the calibration trigger pad is short-circuited with the negative electrode pad of the power supply through the probe, and the reflector is used to calibrate the sensing distance of the infrared sensing lamp bead. The adjustment distance between the reflector and the infrared sensing lamp beads is 70 mm to 110 mm.

2. A method for testing and calibrating the sensing distance threshold of the PCB board structure using the test fixture described in claim 1, wherein the initial value of the sensing distance threshold is set to a preset sensing threshold value, characterized in that: By adjusting the preset sensing threshold value, the sensing distance threshold is calibrated. The test steps are as follows: Fixing the distance between the reflector and the infrared sensing lamp beads; Starting the test fixture; Determine whether the preset sensing threshold value meets the standard requirements, that is, whether there is a need for calibration. The judgment method is: Check whether the calibration PAD and the negative pole of the power supply are conductive: If the calibration PAD and the negative pole of the power supply are connected, it means that there is a calibration requirement, and the sensing distance threshold of the sensing switch is calibrated; If the calibration PAD and the negative pole of the power supply are not connected, it means that there is no calibration requirement; if the calibration PAD and the negative pole of the power supply are not connected, and the fixed distance is greater than the preset sensing threshold value, it means that the preset sensing threshold value meets the standard and is put into use; Calibrate the sensing distance threshold: adjust the preset sensing threshold value, and detect whether the receiving end and the transmitting end of the infrared sensing lamp bead are turned on; The fixed distance is 70 mm to 110 mm.

3. The method according to claim 2, characterized in that When there is a calibration requirement, under the condition that the fixed distance is greater than the preset sensing threshold value, the preset sensing threshold value is increased and the preset sensing threshold value is adjusted to A1. At this time, it is determined whether the receiving end and the transmitting end of the infrared sensing lamp bead are turned on: if not, it indicates that the adjusted preset sensing threshold value A1 meets the standard, and the adjusted preset sensing threshold value A1 is stored; If it is turned on, it indicates that the adjusted preset sensing threshold value A1 still does not meet the standard, and the preset sensing threshold value is continued to be increased, and the preset sensing threshold value is adjusted to A2, and it is judged again whether the receiving end and the transmitting end of the infrared sensing lamp bead are turned on, and this cycle is repeated to finally obtain a preset sensing threshold value set that meets the standard.

Images