CN116381451A - Testing device and method for welding open-circuit single-ended planting needle based on thermosensitive piece - Google Patents
Testing device and method for welding open-circuit single-ended planting needle based on thermosensitive piece Download PDFInfo
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Abstract
The invention provides a testing device and a method based on a thermal-sensitive sheet welding open-short circuit single-ended planting needle, wherein the method comprises the steps that a testing circuit board provides an excitation source signal which is contacted with one end of an FPC/FFC golden finger welded with the thermal-sensitive sheet through a testing probe, the excitation source signal flows through a loop formed by an internal circuit of the thermal-sensitive sheet through an FPC/FFC circuit, the resistance value and the voltage drop between a PIN foot and a GND protection circuit of related signals in the thermal-sensitive sheet IC are detected, and whether the welding quality of the corresponding circuit is abnormal is judged by switching the measurement of each PIN foot according to a set normal threshold value; and after the test is finished, outputting the test result through a test result output circuit. The invention can solve the problems of high cost, incapability of carrying out open circuit test, high misjudgment rate, excessive waste of manpower and time, and the like in the prior art, thereby achieving the purposes of low cost, carrying out open circuit test, high accuracy, manpower and material resource saving, and the like.
Description
Technical Field
The invention relates to the technical field of electronic element testing, in particular to a testing device based on a thermal-sensitive sheet welding open-short circuit single-ended planting needle and a testing method using the device.
Background
At present, a flexible circuit board (particularly, two types of FPC and FFC) is welded on a key component of a thermal printer, and due to the technical reasons of welding technology, a test probe can only be planted at the gold finger end of the flexible circuit board, but can not be planted at the other end, and the thermal printer belongs to a single-end test mode.
After the heat-sensitive sheet is welded with the flexible circuit board, whether the welding quality of the heat-sensitive sheet is qualified or not is tested, and at present, two main modes exist in China: one is a professional ICT (on-line tester) or ATE (on-line multifunctional tester), which is a manner in which a professional tester is matched with a computer and is expensive. The brand import machine types are above 10 ten thousand RMB, the domestic miscellaneous board machine types are above 3 ten thousand RMB, and software writing is carried out on test items by using special personnel, so that the occupied space is large, the instrument damage is required to return to factories for maintenance, the maintenance cost is high, and the test mode is generally difficult to popularize for small enterprises in the domestic thermal printer industry; the other mode is to measure by using a handheld universal meter, according to the principle of a thermosensitive sheet, the PIN of each golden finger led out from each welding point of the universal meter is grouped A, B by using networks with different adjacent PIN, two groups of red and black pen types corresponding to the universal pen are A, B, a universal meter buzzer is opened, whether the PIN of the adjacent different networks is short-circuited or not is tested, and if the PIN is short-circuited, the universal meter buzzer can ring. The test has a plurality of defects, namely:
1. whether the welding of the thermosensitive piece is open or not cannot be tested;
2. if the test probe is not contacted with the PIN corresponding to the golden finger of the flexible circuit board or the test probe is broken due to the fact that the PIN of the probe card or the PIN sleeve lead on the probe is broken, the universal meter can only detect short circuit and cannot detect open circuit, so that the buzzer does not sound and misjudgment is caused;
3. the heat-sensitive sheet is assembled in the subsequent process, and the heat-sensitive sheet is assembled in the subsequent process, so that the heat-sensitive sheet is assembled in the subsequent process, and the heat-sensitive sheet is assembled in the subsequent process.
Disclosure of Invention
The invention provides a testing device and a testing method for welding open-circuit single-end planting needles based on a thermosensitive piece, which are mainly used for solving the problems that the cost is too high, open-circuit testing cannot be carried out, the misjudgment rate is high, and excessive material resources, manpower and time are wasted.
The invention realizes the above purpose through the following technical scheme:
the test device comprises a test probe, a test circuit board, an external signal input circuit and a test result output circuit, wherein the test probe, the test circuit board, the external signal input circuit and the test result output circuit are arranged on a test tool, the test circuit board is contacted with one end of an FPC/FFC golden finger welded with the thermal pad through the test probe, an excitation source signal is output to the test circuit board, and the excitation source signal flows through a loop formed by an internal circuit of the thermal pad through an FPC/FFC circuit and is used for detecting the resistance value and voltage drop of a protection circuit between a PIN PIN and GND of an internal related signal of the thermal pad IC; after the test is finished, the test circuit board outputs a test result signal to the test result output circuit, and the test result output circuit outputs a test result;
the test circuit board comprises an MCU main control circuit, an excitation source circuit, an ADC data acquisition circuit, an input/output IO control module, an analog switch switching circuit and a voltage follower circuit, wherein the excitation source circuit provides a voltage stabilizing power supply for the test circuit board, the ADC data acquisition circuit is used for acquiring a real voltage signal of a tested target and feeding back the real voltage signal to the MCU main control circuit, the MCU main control circuit is connected with an external signal input circuit through the input/output IO control module, the analog switch switching circuit is connected with a test probe through a pin switching circuit, and the voltage follower circuit is connected with the excitation source circuit.
The further scheme is that a test probe needle die is arranged on the test tool, the test probe is placed in the test probe needle die, when the test is installed, a test product is placed in a needle die groove, the infrared sensor senses that the tested product is placed in the test probe needle die groove, then the air cylinder is triggered to press down, and the magnetic induction switch installed on one side of the air cylinder senses that the air cylinder is pressed down in place, so that the test is automatically started.
In a further scheme, the external signal input circuit comprises a switch key and an electromagnetic inductor, and the MCU main control circuit is respectively connected with the switch key and the electromagnetic inductor through the input/output IO control module.
The MCU main control circuit is respectively connected with the LCD display screen, the test result indicating lamp and the alarm unit.
A testing method based on a thermal-sensitive sheet welding open-short circuit single-ended planting needle is applied to the testing device based on the thermal-sensitive sheet welding open-short circuit single-ended planting needle for testing, and comprises the following steps:
providing an excitation source signal by a test circuit board, contacting one end of an FPC/FFC golden finger welded with a thermosensitive plate through a test probe, enabling the excitation source signal to flow through a loop formed by an internal circuit of the thermosensitive plate through an FPC/FFC circuit, detecting a resistance value and a voltage drop between a protection circuit between a PIN PIN and GND of a related signal in the thermosensitive plate IC, and judging whether the corresponding circuit has abnormal welding quality or not by switching the measurement of each PIN PIN according to a set normal threshold value; after the test is completed, outputting a test result through a test result output circuit;
after the software circuit board is welded on the heat-sensitive sheet, whether the welding open circuit or the short circuit abnormality exists when the heat-sensitive sheet is welded on the flat cable can be tested and judged by the test probe contacting with one end of the PIN finger of the flat cable, and the PIN foot test function of the corresponding heat-sensitive sheet can be modified by software to be matched with the heat-sensitive sheets of different types.
According to the testing method based on the open-short circuit single-end needle implantation of the thermal-sensitive sheet welding, unexpected short circuit phenomena on the thermal-sensitive sheet to be tested are tested when short circuit testing is carried out, the expected short circuit phenomena form a short circuit group, whether resistance values between the short circuit and other groups are smaller than standard values or not is measured according to a recursion algorithm when the short circuit testing is carried out, and if the resistance values are smaller than the group, the short circuit problem exists.
According to the testing method based on the open-circuit single-ended needle implantation of the thermal-sensitive sheet welding, when the open-circuit test of the thermal-sensitive sheet welding is carried out, whether the resistance value between the group and other PIN points is larger than a standard value or not is measured according to a recursion algorithm, and if the resistance value is larger than the standard value, the open-circuit problem exists.
According to the testing method based on the welding open-short circuit single-end planting needle of the thermosensitive plate, when the resistance is measured, an excitation source circuit of a testing circuit board sends a constant current source to a signal PIN of the thermosensitive plate to be measured, and the resistance value of the thermosensitive plate to be measured is calculated by measuring the voltages at two ends of the thermosensitive plate to be measured.
According to the testing method based on the thermal-sensitive-sheet welding open-short circuit single-ended planting needle, the positive input end of the excitation source circuit of the testing circuit board provides a testing current, the current flows to the A channel of the excitation source switching switch after flowing through the sampling resistor and then flows to the input end of the voltage follower circuit, flows to the A end of the pin switching circuit through the output end of the voltage follower circuit, and then flows to the PAD A pin welded by the thermal-sensitive sheet through the testing probe and the FFC/FPC connecting flat cable.
According to the testing method based on the welding open-circuit and short-circuit single-end planting needle of the thermosensitive sheet, if the welding is not open-circuit, testing current flows out from a PIN B PIN after flowing to an internal circuit of the thermosensitive sheet, flows out from a B end of a PIN switching circuit after being connected with a flat cable, and passes through a negative electrode input end of an excitation source circuit to GND after passing through a B channel of an excitation source switching switch.
Therefore, the test circuit board provided by the invention has the functions of hardware self-checking and PIN PIN point finding, and is simple and practical to maintain; after the heat-sensitive sheet is welded with the software circuit board, the device and the testing method thereof can test and judge whether the welding quality is abnormal or not when the heat-sensitive sheet is welded with the flat cable through the contact of the testing probe with the PIN end of the golden finger of the flat cable, and the corresponding PIN test function of each number of heat-sensitive sheet can be modified by software.
The invention is described in further detail below with reference to the drawings and the detailed description.
Drawings
FIG. 1 is a schematic diagram of an embodiment of a testing device for welding open-circuit single-ended planting needles based on a thermal sensitive sheet according to the present invention.
Fig. 2 is a schematic diagram of a test circuit board in an embodiment of a test device for soldering an open-circuit single-ended planting needle based on a thermal sensitive sheet according to the present invention.
FIG. 3 is a schematic diagram of detecting whether welding of a thermal sensitive plate and an FPC/FFC flat cable is abnormal in an embodiment of a testing device based on a thermal sensitive plate welding open-short circuit single-end planting needle.
Fig. 4 is a test flow chart of an embodiment of a test method for welding open-circuit single-ended planting needles based on a thermal sensitive sheet.
Fig. 5 is a schematic diagram of an open-circuit group in an embodiment of a testing method for welding open-circuit single-ended planting needles based on a thermal sensitive sheet according to the present invention.
FIG. 6 is a schematic diagram of a resistance test in an embodiment of a method for testing a single-ended needle based on thermal tab soldering.
FIG. 7 is a schematic diagram of a first test of a measurement clamp diode according to an embodiment of a method for testing a thermal pad-based solder open-short single-ended needle.
FIG. 8 is a second schematic diagram of a test method for measuring a clamp diode according to an embodiment of the present invention.
Fig. 9 is a schematic diagram of wiring inside a thermal chip IC according to an embodiment of a method for testing a thermal chip-based solder open-short circuit single-ended needle implantation of the present invention.
FIG. 10 is a schematic diagram of a test current flow circuit in an embodiment of a method for testing a thermal-sensitive-sheet-based solder-open-short single-ended implant.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without creative efforts, based on the described embodiments of the present invention fall within the protection scope of the present invention.
Testing device embodiment based on thermal-sensitive sheet welding open-short circuit single-ended planting needle
Referring to fig. 1, the testing device for welding open-circuit single-ended planting needles based on a thermosensitive piece according to the invention comprises: the test device comprises a test probe, a test circuit board, an external signal input circuit and a test result output circuit, wherein the test probe, the test circuit board, the external signal input circuit and the test result output circuit are arranged on a test tool, the test circuit board is contacted with one end of an FPC/FFC golden finger welded with a thermosensitive plate through the test probe and outputs an excitation source signal to the FPC/FFC golden finger, and the excitation source signal flows through a loop formed by an internal circuit of the thermosensitive plate through an FPC/FFC circuit and is used for detecting the resistance value and voltage drop of a protection circuit between a PIN PIN and GND of an internal related signal of the thermosensitive plate IC; after the test is finished, the test circuit board outputs a test result signal to the test result output circuit, and the test result output circuit outputs a test result.
As shown in fig. 2, the test circuit board includes an MCU main control circuit, an excitation source circuit, an ADC data acquisition circuit, an input/output IO control module, an analog switch switching circuit and a voltage follower circuit, where the excitation source circuit provides a regulated power supply for the test circuit board, the ADC data acquisition circuit is used to acquire a real voltage signal of a target to be tested and feed back to the MCU main control circuit, the MCU main control circuit is connected with an external signal input circuit through the input/output IO control module, the analog switch switching circuit is connected with a test probe through a pin switching circuit, and the voltage follower circuit is connected with the excitation source circuit.
The test fixture is provided with a test probe needle die, the test probe is placed in the test probe needle die, when the test fixture is installed and tested, a test product is placed in a needle die groove, the infrared sensor senses that the tested product is placed in the test fixture and then triggers the cylinder to press down, and the magnetic sensor switch installed on one side of the cylinder senses that the cylinder is pressed down in place, so that the test is automatically started.
In this embodiment, the external signal input circuit includes a switch key and an electromagnetic inductor, and the MCU main control circuit is connected to the switch key and the electromagnetic inductor through the input/output IO control module, respectively.
In this embodiment, the test result output circuit includes an LCD display screen, a test result indicator light, and an alarm unit, and the MCU main control circuit is connected to the LCD display screen, the test result indicator light, and the alarm unit, respectively.
Specifically, the testing device of this embodiment mainly comprises a testing circuit board, a DC24V power supply, a switch key, related connection cables/wires, a testing probe, a needle sleeve connecting wire, a testing result indicator lamp (red-green indicator lamp), an LCD display screen (12864), an infrared sensor, an electromagnetic sensor, a buzzer (on-board), and the like.
Wherein, test mainboard includes:
MCU master control circuit (model stm32f103 ze): realizing main logic function control processing and result judgment, outputting and displaying, collecting data, processing data and outputting control signals;
ADC data acquisition circuit (IC model AD 7190): the method is mainly used for realizing high-precision and high-real-time acquisition of real voltage feedback of a measured target, and transmitting the real voltage feedback back to the MCU for data processing and analysis;
input/output IO control module and analog switch switching circuit (by CD4052, CH446 IC model): because the IO output capability of the MCU is limited, the MCU cannot output power meeting the requirements and the anti-series interference of external equipment is removed, and the additional power output and the safety isolation are required;
excitation source circuit (composed of lm31117 IC and resistor divider circuit): the main power supply circuit of the MCU is used for mainly reducing and stabilizing the external voltage to 3.3V so as to ensure the MCU to work normally;
voltage follower circuit (composed of LM358 chip): the output and collection of the MCU are ensured not to be interfered by the outside.
Test method embodiment based on thermal-sensitive sheet welding open-short circuit single-ended planting needle
The test method based on the thermal-sensitive sheet welding open-short circuit single-ended planting needle is applied to the test device based on the thermal-sensitive sheet welding open-short circuit single-ended planting needle for testing, and comprises the following steps:
providing an excitation source signal by a test circuit board, contacting one end of an FPC/FFC golden finger welded with a thermosensitive plate through a test probe, enabling the excitation source signal to flow through a loop formed by an internal circuit of the thermosensitive plate through an FPC/FFC circuit, detecting a resistance value and a voltage drop between a protection circuit between a PIN PIN and GND of a related signal in the thermosensitive plate IC, and judging whether the corresponding circuit has abnormal welding quality or not by switching the measurement of each PIN PIN according to a set normal threshold value; and after the test is finished, outputting the test result through a test result output circuit.
As shown in FIG. 3, the test fixture only needs to put the test product into the needle mold groove, the infrared sensor senses that the product is put into the needle mold groove, the air cylinder is triggered to be pressed down, the magnetic induction switch arranged on the left side of the air cylinder senses that the air cylinder is pressed down in place, the test is automatically started, the result after the test is completed is displayed through the LED display screen and the red LED lamp and the green LED lamp, and the air cylinder automatically rises to wait for triggering the next test, so that the cycle is realized, and the operation is simple and practical.
After the software circuit board is welded on the heat-sensitive sheet, whether the welding open circuit or the short circuit abnormality exists when the heat-sensitive sheet is welded on the flat cable can be tested and judged by the test probe contacting with one end of the PIN finger of the flat cable, and the PIN foot test function of the corresponding heat-sensitive sheet can be modified by software to be matched with the heat-sensitive sheets of different types.
And when the short circuit test of the welding of the thermal sensitive sheet is carried out, the unexpected short circuit phenomenon on the thermal sensitive sheet to be tested is tested, the expected short circuit phenomenon is formed into a short circuit group, whether the resistance value between the short circuit and other groups is smaller than the standard value is measured according to a recursion algorithm when the short circuit test is carried out, and if the resistance value is smaller than the standard value, the short circuit problem exists.
And when an open circuit test of the thermal sensitive sheet welding is carried out, measuring whether the resistance value between the group and other PIN points is larger than a standard value according to a recursive algorithm, and if so, having the open circuit problem.
When measuring the resistance, the excitation circuit of the test circuit board sends a constant current source to the signal PIN of the thermal sensitive sheet to be measured, and the resistance value of the thermal sensitive sheet to be measured is calculated by measuring the voltages at two ends of the thermal sensitive sheet to be measured.
In this embodiment, a test current is provided from the positive input terminal of the excitation source circuit of the test circuit board, flows through the sampling resistor, flows to the a channel of the excitation source switch, flows to the input terminal of the voltage follower circuit, flows to the a terminal of the pin switch circuit through the output terminal, and flows to the PAD a pin welded to the heat sensitive sheet through the test probe and the FFC/FPC connection flat cable.
If the welding is not open, the test current flows to the internal circuit of the thermal sensitive sheet and then flows out from the PIN B, then flows out from the end B of the PIN switching circuit after being connected with the flat cable, and passes through the negative electrode input end of the excitation source circuit to GND after passing through the channel B of the excitation source switching switch.
Specifically, the embodiment provides a testing method with low cost and easy operation, which comprises the testing device based on the thermal sensitive sheet welding open-circuit single-end planting needle, wherein a testing circuit board provides relevant testing constant current (1-5 mA) or constant voltage (5V/3.3V/1.25V), the testing circuit board is contacted with one end of an FPC/FFC golden finger welded with the thermal sensitive sheet through a testing probe, a loop formed by the FPC/FFC circuit flowing through an internal circuit of the thermal sensitive sheet is detected, a normal threshold is set through software by detecting resistance values and voltage drops between protection circuits among PIN PINs of relevant signals in the loop, and whether the relevant circuit has abnormal welding open-circuit or short-circuit is judged through algorithm switching of PIN measurement. And finally outputting a test result through an LCD display screen and an LED (red and green) indicator lamp after the test is finished, and outputting a specific frequency to sound and alarm to prompt a user through a buzzer.
The test circuit board has a hardware self-checking function and a PIN PIN point finding function, and is simple and practical to maintain; the scheme can solve the problems that after a software circuit board (FFC/FPC flat cable) is welded on a heat-sensitive sheet, whether welding quality abnormality exists when the heat-sensitive sheet is welded on the flat cable can be tested and judged by contacting one end of a PIN of a golden finger of the flat cable through a test probe, and a corresponding PIN test function of each number of heat-sensitive sheet is modified through software.
Further, as shown in fig. 4, whether an open circuit, a tin short circuit, a cold joint, and a dislocation exist in the welding of the thermosensitive sheet and the FPC/FFC flat cable is detected.
Analyzing the related specification data of the thermosensitive sheet to be tested to obtain the following test items, test methods and test specifications, as shown in table (1):
watch (1)
OPEN/SHORT test principle: the short circuit test of the heat sensitive sheet welding is to test the Unexpected (Unexpected) short circuit phenomenon on the heat sensitive sheet to be tested, and some Expected (Expected) short circuits are usually also present on the heat sensitive sheet to be tested, such as the power supply terminals VH, GND or the same network as other adjacent signal PINs, and the like, which are smaller than the short circuit Threshold. Therefore, in the process of programming the singlechip software, an expected short circuit is formed into a short circuit group, whether the resistance value between the short circuit test and other groups is smaller than the standard value or not is measured according to a recursion algorithm, the short circuit problem exists when the resistance value is smaller than the standard value, and whether the resistance value between the short circuit test and other PIN points in the group is larger than the standard value or not is measured according to the recursion algorithm, and the open circuit problem exists when the resistance value is larger than the standard value; an example of the function thereof is shown in fig. 5, and an open short group ("{ }" indicates a short group).
As shown in FIG. 6, when measuring the resistance, a constant current source is sent to the signal PIN of the thermal film to be measured by the excitation source circuit of the test motherboard, and the resistance value of the thermal film to be measured is calculated by measuring the voltages at two ends of the thermal film to be measured.
The constant current output by the test main board excitation source circuit is I, and the resistance of the thermosensitive sheet to be tested is R X The voltage on the thermosensitive plate to be measured is V RX The resistance value of the thermosensitive sheet to be measured can be calculated by the following formula, and the calculation mode is as formula (1):
as shown in fig. 7, the test principle of the measurement clamp diode: most thermal chips have a protection diode added to the input/output PIN, and the main purpose is to use the voltage CLAMP as an example of a CMOS device.
Because the input end is the gate of MOS, gate is a "metal-SiO 2" electric capacity, wherein SiO2 is a film, if the voltage of gate is too high, will produce the large electric field and break down this SiO2 film like static, therefore need to limit the voltage to gate end, add the diode, but when the voltage of PIN is too high, easy to burn (there is large current to flow through the diode) of the diode, so connect the electric current limit to gate end in series, namely "protect gate of MOS with diode" and "protect diode with RS", clamp diode TEST utilize this diode characteristic, judge the PIN of the thermal film has empty welding method to produce 1.25V voltage (send out according to the input value) source in the control panel, in order to prevent the load from shorting out, must add the current limit (1 mA) at the same time, because the error of RS is large, and different with every brand, so need to take the larger error (0.3.8V) to the measuring value of the clamp diode, thus the voltage of the voltage source of the clamp diode is like, the voltage source is like V of the Vx is like in the control panel, the Vx is measured by the voltage source of the voltage of the bridge is like, the Vx-8.8.8, the voltage source is like, the Vx is measured by the TEST mode of the voltage source is like, the Vx is like, the value of the voltage of the TEST panel is like.
As shown in fig. 9, fig. 9 is a wiring diagram of the inside of the heat-sensitive sheet IC, and when the voltage drop is tested, the TEST principle is that the voltage drop of the protection diode between each signal PIN and GND in the heat-sensitive sheet IC is utilized, when a signal of 1.25V excitation source is sent from the TEST PIN to the PIN to be tested of the heat-sensitive sheet IC, other signal PINs of the heat-sensitive sheet IC are connected to the ground through the TEST PIN on the fix, if the PIN to be tested OPEN, vx cannot sense enough voltage because no signal is on the TEST PIN, and when the PIN is connected, vx can sense a voltage smaller than that when the IC OPEN is sensed because of the voltage drop between the heat-sensitive sheet signal and GND, so that whether the IC PIN has OPEN can be known according to the voltage.
As shown IN FIG. 10, the positive electrode of the excitation source circuit flows through the sampling resistor and then flows to the IN end of the excitation source switch (IC) A channel and then flows to the A end of the PIN switch through the OUT end, then flows to the PAD A PIN of the heat-sensitive sheet through the test probe and the FFC/FPC connecting flat cable, and flows OUT from the PIN B PIN after no OPEN current flows to the internal circuit of the heat-sensitive sheet if welding, flows OUT from the B end of the PIN switch chip after connecting the flat cable, and finally flows to GND through the excitation source IN-after passing through the B channel of the excitation source switch (IC);
therefore, the test circuit board provided by the invention has the functions of hardware self-checking and PIN PIN point finding, and is simple and practical to maintain; after the heat-sensitive sheet is welded with the software circuit board, the device and the testing method thereof can test and judge whether the welding quality is abnormal or not when the heat-sensitive sheet is welded with the flat cable through the contact of the testing probe with the PIN end of the golden finger of the flat cable, and the corresponding PIN test function of each number of heat-sensitive sheet can be modified by software.
The above embodiments are only preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, but any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention are intended to be within the scope of the present invention as claimed.
Claims (10)
1. A testing arrangement based on single-ended planting needle of thermal sensitive piece welding open circuit is characterized in that includes:
the test device comprises a test probe, a test circuit board, an external signal input circuit and a test result output circuit, wherein the test probe, the test circuit board, the external signal input circuit and the test result output circuit are arranged on a test tool, the test circuit board is contacted with one end of an FPC/FFC golden finger welded with a thermosensitive plate through the test probe, an excitation source signal is output to the test circuit board, and the excitation source signal flows through a loop formed by an internal circuit of the thermosensitive plate through an FPC/FFC circuit and is used for detecting the resistance value and voltage drop of a protection circuit between a PIN PIN and GND of an internal related signal of the thermosensitive plate IC; after the test is finished, the test circuit board outputs a test result signal to the test result output circuit, and the test result output circuit outputs a test result;
the test circuit board comprises an MCU main control circuit, an excitation source circuit, an ADC data acquisition circuit, an input/output IO control module, an analog switch switching circuit and a voltage follower circuit, wherein the excitation source circuit provides a voltage stabilizing power supply for the test circuit board, the ADC data acquisition circuit is used for acquiring a real voltage signal of a tested target and feeding back the real voltage signal to the MCU main control circuit, the MCU main control circuit is connected with an external signal input circuit through the input/output IO control module, the analog switch switching circuit is connected with a test probe through a pin switching circuit, and the voltage follower circuit is connected with the excitation source circuit.
2. The test device for welding open-circuit and short-circuit single-ended planting needles based on the thermosensitive sheet according to claim 1, wherein the test device comprises:
the test fixture is provided with a test probe needle die, the test probe is placed in the test probe needle die, when the test fixture is installed and tested, a test product is placed in a needle die groove, the infrared sensor senses that the tested product is placed in the test product and then triggers the cylinder to press down, and the magnetic sensing switch installed on one side of the cylinder senses that the test is started automatically when the magnetic sensing switch is arranged on one side of the cylinder to sense that the test probe is pressed down in place.
3. The test device for welding open-circuit and short-circuit single-ended planting needles based on the thermosensitive sheet according to claim 1, wherein the test device comprises:
the external signal input circuit comprises a switch key and an electromagnetic inductor, and the MCU main control circuit is respectively connected with the switch key and the electromagnetic inductor through the input/output IO control module.
4. The test device for welding open-circuit and short-circuit single-ended planting needles based on the thermosensitive sheet according to claim 1, wherein the test device comprises:
the MCU main control circuit is respectively connected with the LCD display screen, the test result indicator lamp and the alarm unit.
5. A testing method based on a thermal-sensitive-sheet-welded open-short single-ended needle implantation, which is characterized by being applied to the testing device based on the thermal-sensitive-sheet-welded open-short single-ended needle implantation according to any one of claims 1 to 4 for testing, and comprising the following steps:
providing an excitation source signal by a test circuit board, contacting one end of an FPC/FFC golden finger welded with a thermosensitive plate through a test probe, enabling the excitation source signal to flow through a loop formed by an internal circuit of the thermosensitive plate through an FPC/FFC circuit, detecting a resistance value and a voltage drop between a protection circuit between a PIN PIN and GND of a related signal in the thermosensitive plate IC, and judging whether the corresponding circuit has abnormal welding quality or not by switching the measurement of each PIN PIN according to a set normal threshold value; after the test is completed, outputting a test result through a test result output circuit;
after the software circuit board is welded on the heat-sensitive sheet, whether the welding open circuit or the short circuit abnormality exists when the heat-sensitive sheet is welded on the flat cable can be tested and judged by the test probe contacting with one end of the PIN finger of the flat cable, and the PIN foot test function of the corresponding heat-sensitive sheet can be modified by software to be matched with the heat-sensitive sheets of different types.
6. The test method for the open-circuit single-ended needle implantation based on the thermal-sensitive welding of the sheet according to claim 5, wherein the test method comprises the following steps:
and when the short circuit test of the welding of the thermal sensitive sheet is carried out, the unexpected short circuit phenomenon on the thermal sensitive sheet to be tested is tested, the expected short circuit phenomenon is formed into a short circuit group, whether the resistance value between the short circuit and other groups is smaller than the standard value is measured according to a recursion algorithm when the short circuit test is carried out, and if the resistance value is smaller than the standard value, the short circuit problem exists.
7. The test method for the open-circuit single-ended needle implantation based on the thermal-sensitive welding of the sheet according to claim 6, wherein the test method comprises the following steps:
and when an open circuit test of the thermal sensitive sheet welding is carried out, measuring whether the resistance value between the group and other PIN points is larger than a standard value according to a recursive algorithm, and if so, having the open circuit problem.
8. The test method for the open-circuit single-ended needle implantation based on the thermal-sensitive welding of the sheet according to claim 5, wherein the test method comprises the following steps:
when measuring the resistance, the excitation circuit of the test circuit board sends a constant current source to the signal PIN of the thermal sensitive sheet to be measured, and the resistance value of the thermal sensitive sheet to be measured is calculated by measuring the voltages at two ends of the thermal sensitive sheet to be measured.
9. The test method for the open-circuit single-ended needle implantation based on the thermal-sensitive welding of the sheet according to claim 5, wherein the test method comprises the following steps:
the positive input end of the excitation source circuit of the test circuit board provides a test current, the current flows to the A channel of the excitation source change-over switch after flowing through the sampling resistor, then flows to the input end of the voltage follower circuit, flows to the A end of the pin change-over circuit through the output end of the voltage follower circuit, and then flows to the PAD A pin welded on the thermosensitive plate through the test probe and the FFC/FPC connecting flat cable.
10. The test method for the open-circuit single-ended needle implantation based on the thermal-sensitive welding of the sheet according to claim 9, wherein the test method comprises the following steps:
if the welding is not open, the test current flows to the internal circuit of the thermal sensitive sheet and then flows out from the PIN B, then flows out from the end B of the PIN switching circuit after being connected with the flat cable, and passes through the negative electrode input end of the excitation source circuit to GND after passing through the channel B of the excitation source switching switch.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310203000.0A CN116381451A (en) | 2023-03-03 | 2023-03-03 | Testing device and method for welding open-circuit single-ended planting needle based on thermosensitive piece |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202310203000.0A CN116381451A (en) | 2023-03-03 | 2023-03-03 | Testing device and method for welding open-circuit single-ended planting needle based on thermosensitive piece |
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| CN116381451A true CN116381451A (en) | 2023-07-04 |
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