CN110673022A - Membrane keyboard PCBA testing device and method - Google Patents

Abstract

The invention discloses a film keyboard PCBA test device and method, including a test fixture, the test fixture is connected to the PCBA gold finger through a fixture probe, and is connected to a host computer; the test fixture includes a built-in test board, the built-in test board includes an MCU and a plurality of gate switch units, the fixture probe connects the PCBA key rows to different gate switch units respectively, the enable end and the gate control end of the gate switch unit are both connected to the MCU, the MCU controls the short-circuit conduction of the PCBA key rows, the host computer test program needs to be turned on before the film keyboard PCBA test, the film keyboard PCBA microprocessor unit synchronously uploads the test data to the host computer through USB communication or other wireless communication methods, and the host computer test software displays the test status and test results. The invention adopts one-key start, simulates the full function of all keyboard key tests, is simple to operate, and has high test efficiency.

Description

Membrane keyboard PCBA testing device and method

technical field

The invention relates to a membrane keyboard PCBA testing technology, in particular to a membrane keyboard PCBA testing device and method.

Background technique

As the most commonly used input device for computers and various automation equipment, keyboards are widely used in computers and various electronic products to input text and commands. Human-computer interaction between devices. The largest proportion of keyboards on the market is the ordinary membrane keyboard. In the production process of the membrane keyboard, it is necessary to install the upper cover, lower cover, keycap, membrane switch (Membrane Switch), PCBA (Printed Circuit Board+Assembly), rubber keys Module (Rubber Sheet), iron pressure strip, foot pad, USB cable or battery (wired keyboard uses USB cable, wireless keyboard uses battery), the key factor affecting the assembly yield is the keyboard printed circuit board assembly PCBA.

In order to ensure the quality of PCBA production, manufacturers usually test the PCBA with a fixture before shipment, but the existing keyboard PCBA test is to select 18 to 20 keys of the keyboard matrix for testing, as shown in Figure 1. One test method is to install 18 to 20 microswitches on the test fixture, and press the microswitches on the fixture one by one to check whether the PCBA function is intact. The test is complicated and inefficient. This test method is only for the open circuit test of the IC patch or IC Bonding on the PCBA. During the PCBA processing process, the I/O short circuit of the IC part cannot be detected. After the keyboard is assembled, it will cause poor keyboard connection, which not only affects the production quality rate, and dismantling heavy equipment will cause material scrap.

SUMMARY OF THE INVENTION

Purpose of the invention: In view of the above problems, the present invention proposes a membrane keyboard PCBA testing device and method, which uses one key to start, simulates all keys of the keyboard to test full functions, is simple to operate, and has high testing efficiency.

Technical solution: In order to achieve the purpose of the present invention, the technical solution adopted in the present invention is: a membrane keyboard PCBA test device, which is characterized in that it includes a host computer, a test fixture and a power supply; the test fixture includes a built-in test board , power interface, test switch, host computer interface and probe interface, the power interface, test switch and probe interface are all connected to the built-in test board, and the host computer interface is connected to the USB interface probe point of the membrane keyboard PCBA through the fixture probe; The test fixture is connected to the gold finger of the film keyboard PCBA through the fixture probe, the fixture probe is connected to the probe interface, the power supply is connected through the power interface, and the host computer is connected through the host computer interface; the test fixture is activated by the test switch , Test the PCBA, upload the test data to the host computer synchronously, and the host computer test software displays the test status and test results.

Further, the built-in test board includes an MCU, a power interface connector, a voltage conversion unit, a fixture probe connector and a plurality of gating switch units; the test switch is connected to the MCU; the power interface connector is connected to a voltage conversion unit The unit supplies power to the MCU and several gating switch units; the pins of the fixture probe connector are drawn out as probe interfaces, and the rows and columns of PCBA keys are respectively connected to the input ends of different gating switch units, and the common end of the gating switch units All are short-circuited together; the enabling terminal and the gating control terminal of the gating switch unit are both connected to the MCU, and the MCU controls the short-circuit conduction of the PCBA key row and column, and the test data is synchronously uploaded to the upper computer, and the upper computer test software displays the test status and test results.

Further, the test fixture further includes a firmware update interface, and the built-in test board further includes a firmware update interface connector, which is connected to the MCU.

A method for testing a membrane keyboard PCBA, comprising the steps:

(1) Insert the power supply into the power interface of the test fixture;

(2) The interface of the host computer of the test fixture is connected to the host computer;

(3) The test fixture probe interface is connected to the fixture probe, and the fixture probe is connected to the PCBA gold finger;

(4) Open the test program of the host computer, and then press the test switch on the test fixture to test.

Further, before the test, it also includes programming the lower computer program to the MCU of the test fixture through the firmware update interface.

Further, the lower computer program comprises the steps:

(1) Start the program and initialize it;

(2) Determine whether the test switch is turned on;

(3) If yes, run the row-column short-circuit procedure.

Further, the host computer test program comprises the steps:

(1) Start the program and initialize it;

(2) Judging whether the access of the test device is normal;

(3) If yes, run the key detection program.

Further, the key detection program comprises the steps:

(1) Run the input key time detection program;

(2) receive the word key code until the last check word key;

(3) Check whether the number of word keys is correct, and return the test result, indicating that the test is successful or the missing word key is displayed.

Further, the described input key time detection program comprises the steps:

(1) Obtain the input time of this word key;

(2) judge whether this key acquisition time is equal to the previous key acquisition time, if so, continue to step 3, if not, continue to step 4;

(3) Display the short-circuit error of the word key, and end the program;

(4) Judging whether the acquisition time of the word key this time minus the acquisition time of the last word key is greater than the set time threshold;

(5) If yes, display the word key input timeout; if not, store the variable of the last word key acquisition time as the current word key acquisition time.

Beneficial effects: The test method of the present invention adopts one-key start, simulates all keys of the keyboard to test full functions, has simple operation and high test efficiency.

Description of drawings

Fig. 1 is the matrix diagram of membrane keyboard;

Fig. 2 is the structure diagram of the membrane keyboard PCBA testing device of the present invention;

Figure 3 is the circuit diagram of the built-in test board;

Figure 4 is a schematic diagram of the fixture probe connector;

5 is a schematic diagram of a gating switch unit;

Figure 6 is the CD74HC4067 truth function table;

7 is a schematic diagram of a 5V voltage conversion unit;

Figure 8 is a schematic diagram of a 3.3V voltage conversion unit;

Fig. 9 is a schematic diagram of MCU;

Figure 10 is a schematic diagram of a firmware update interface connector;

Fig. 11 is the flow chart of the lower computer program;

Fig. 12 is the flow chart of the initialization procedure of the lower computer;

Figure 13 is a flow chart of a row-column short-circuit procedure;

Fig. 14 is the flow chart of the test procedure of the upper computer;

Figure 15 is the flow chart of the host computer test initialization program;

Fig. 16 is the key detection procedure flow chart;

Fig. 17 is the flow chart of input character key time detection program;

Fig. 18 is the simulation keyboard display interface.

Detailed ways

The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

As shown in Figure 2, the membrane keyboard PCBA test device of the present invention includes a membrane keyboard PCBA test fixture, and a test computer with a display is used as a host computer, which is connected to the test fixture through a USB wire; it also includes a DC9V power supply for testing. Jig power supply.

The test fixture includes a built-in test board, DC9V power interface, test switch S1, host computer interface and probe interface. The power interface, test switch S1 and probe interface are all connected to the built-in test board, and the host computer interface is connected through the fixture probe. Probe point on the USB interface of the PCBA. If it is a 2.4G or Bluetooth type membrane keyboard, a code-free receiver needs to be added to the test fixture, and the code-free receiver is connected to the USB interface of the test computer.

The test fixture is connected to the PCBA gold finger through the fixture probe, the fixture probe is connected to the probe interface, the power supply is connected through the power interface, and the host computer is connected through the host computer interface. The test fixture starts the built-in test board through the test switch, runs the test program on the PCBA, and uploads the test data to the upper computer synchronously, and the upper computer test software displays the test status and test results.

As shown in Figure 3, the built-in test board includes an MCU, a power interface connector J1, a voltage conversion unit, a fixture probe connector CN1, and several gate switch units. The test switch S1 is connected to the MCU, and the power interface connector J1 is connected to the voltage conversion unit to supply power to the MCU and several gate switch units.

As shown in Figure 4, the pin of the fixture probe connector CN1 is drawn out as a probe interface, and the rows and columns of the PCBA keys are respectively connected to the input terminals of different gating switch units, and the common terminals of the gating switch units are all short-circuited together .

As shown in Figure 5, it includes 3 gate switch units. The gate switch unit is CD74HC4067, which is a 16-to-1 switching element controlled by digital signals. The MCU controls the row (Row, U1) and column (Column, U2/U3) Short-circuit conduction, simulate the full-key test of the keyboard. The enable terminal and the gate control terminal of the gating switch unit are both connected to the MCU. The MCU controls the short-circuit conduction of the PCBA key row and column. E1~E3 are the CD74HC4067 enable pins, S10~S13, S20~S23, and S30~S33 numbers The signal selection Row and Column are short-circuited and turned on. The CD74HC4067 truth function table is shown in Figure 6.

As shown in Figure 7, the DC9V power supply supplies power to the test board, through the power interface connector J1 through the 5V voltage conversion unit, and then provides the VCC5V voltage for the CD74HC4067 to work. The 5V voltage conversion unit adopts 7805 voltage regulator. As shown in Figure 8, it is a 3.3V voltage conversion unit, VCC5V is supplied to the input terminal of XC6503D331, VCC5V is stepped down by XC6503D331 to provide 3.3V for MCU to work, and LED1 is a 3.3V voltage indicator.

As shown in Figure 9, the MCU is connected to the gate control terminals S10~S13, S20~S23, S30~S33 of the gate switch unit, and the Row and Column are selected for short-circuit conduction through digital signals. At the same time, the MCU is connected to the CD74HC4067 enable pins E1~ E3.

As shown in Figure 10, the test fixture further includes a firmware update interface, and the built-in test board also includes a firmware update interface connector J2, which is connected to the MCU.

The membrane keyboard PCBA to be tested needs to be programmed with the shipped firmware FW. The CD74HC4067 analog keyboard full-key test signal is processed by the MCU on the membrane keyboard PCBA, and then transmitted to the host computer system (Windows/IOS/Google, etc.) through USB for processing.

The membrane keyboard PCBA testing method of the present invention comprises the steps:

(1) Insert the DC9V power supply into the power interface of the test fixture to supply power to the test system;

(2) Insert one end of the USB cable into the USB interface of the test computer, connect the interface of the host computer of the test fixture to the host computer, and the test fixture communicates with the test computer;

(3) The test fixture probe interface connector CN1 on the built-in test board of the test fixture is connected to the fixture probe, and the fixture probe is connected to the PCBA gold finger;

(4) The lead of the test switch S1 on the built-in test board of the test fixture is installed on the panel of the test fixture, and the test switch S1 is the test button of the membrane keyboard PCBA board change;

(5) The gold fingers and test point pads on the PCBA of the membrane keyboard to be tested are connected one-to-one with the probes of the test fixture;

(6) Before testing the PCBA of the membrane keyboard to be tested, it is necessary to confirm that the power supply of the fixture is connected, the USB wire of the fixture is inserted into the USB interface of the test computer, and the test program (.exe) on the test computer side is opened; then the PCBA of the membrane keyboard to be tested is placed on the designated position, use the fixture link structure to make the probe and the test point contact and conduct, and then press the test switch S1 on the test fixture to test.

Before the test, it also includes burning the lower computer program to the MCU of the test fixture through the firmware update interface.

Among them, as shown in Figure 11, the lower computer program includes steps:

(1) Start the program and initialize it, as shown in Figure 12;

(2) Determine whether the test switch is turned on;

(3) If yes, run the row-column short-circuit procedure, as shown in Figure 13. Among them, when each row runs to the last column, a delay judgment is performed, and after a delay of 100ms, the column + 1 is performed, and the judgment of whether it is the last column is performed again.

Among them, as shown in Figure 14, the host computer test program includes steps:

(1) Start the program and initialize it, as shown in Figure 15;

(2) Judging whether the access of the test device is normal, including judging whether the USB is inserted, and HID consulting and checking;

(3) If yes, light up the LED indicator and run the key detection program;

(4) If there is an error in the HID consultation check, the HID error will be displayed.

As shown in Figure 16, the key detection procedure includes the steps:

(1) Run the input key time detection program;

(2) receive the word key code until the last check word key;

(3) Check whether the number of word keys is correct, and return the test result, indicating that the test is successful or the missing word key is displayed.

As shown in Figure 17, the input character key time detection program includes the steps:

(1) Obtain the input time of this word key;

(2) judge whether this key acquisition time is equal to the previous key acquisition time, if so, continue to step 3, if not, continue to step 4;

(3) Display the short-circuit error of the word key, and end the program;

(4) judging whether the acquisition time of the word key this time minus the acquisition time of the last word key is greater than the set time threshold;

(5) If yes, display the word key input timeout; if not, store the variable of the last word key acquisition time as the current word key acquisition time.

During the test, the test computer display interface can simulate the keyboard display interface, as shown in Figure 18, and light up the test keys one by one to check the test results clearly.

Claims (9)

1. a membrane keyboard PCBA test device, is characterized in that, comprises host computer, test fixture and power supply; Described test fixture comprises built-in test board, power supply interface, test switch, host computer interface and probe interface, power supply interface , The test switch and probe interface are connected to the built-in test board, and the host computer interface is connected to the USB interface probe point of the membrane keyboard PCBA through the fixture probe; The test fixture is connected to the gold finger of the membrane keyboard PCBA through the fixture probe, the fixture probe is connected to the probe interface, the power supply is connected through the power interface, and the upper computer is connected through the host computer interface; the test fixture passes the test switch. Start, test the PCBA, upload the test data to the host computer in real time, and the host computer test software displays the test status and test results. 2. The membrane keyboard PCBA test device according to claim 1, wherein the built-in test board comprises an MCU, a power interface connector, a voltage conversion unit, a fixture probe connector and several gate switch units; The test switch is connected to the MCU; The power interface connector is connected to the voltage conversion unit to supply power to the MCU and several gating switch units; The pins of the jig probe connector are drawn out as a probe interface, and the rows and columns of the PCBA keys are respectively connected to the input ends of different gating switch units, and the common ends of the gating switch units are all short-circuited together; The enabling end and the gating control end of the gating switch unit are both connected to the MCU, the MCU controls the short-circuit conduction of the PCBA key row and column, the test data is synchronously uploaded to the upper computer, and the upper computer test software displays the test status and test results. 3 . The membrane keyboard PCBA test device according to claim 1 , wherein the test fixture further comprises a firmware update interface, and the built-in test board further comprises a firmware update interface connector, which is connected to the MCU. 4 . 4. a membrane keyboard PCBA test method, utilizes the test device described in claim 1-3 to test, it is characterized in that, comprise the steps: (1) Insert the power supply into the power interface of the test fixture; (2) The interface of the host computer of the test fixture is connected to the host computer; (3) The test fixture probe interface is connected to the fixture probe, and the fixture probe is connected to the PCBA gold finger; (4) Open the test program of the host computer, and then press the test switch on the test fixture to test. 5. The method for testing membrane keyboard PCBA according to claim 4, characterized in that, before the test, it further comprises the MCU that burns the lower computer program to the test fixture through the firmware update interface. 6. membrane keyboard PCBA testing method according to claim 5, is characterized in that, described lower computer program comprises the steps: (1) Start the program and initialize it; (2) Determine whether the test switch is turned on; (3) If yes, run the row-column short-circuit procedure. 7. membrane keyboard PCBA testing method according to claim 4, is characterized in that, described host computer testing program comprises the steps: (1) Start the program and initialize it; (2) Judging whether the access of the test device is normal; (3) If yes, run the key detection program. 8. membrane keyboard PCBA testing method according to claim 7 is characterized in that, described key detection program comprises the steps: (1) Run the input key time detection program; (2) receive the word key code until the last check word key; (3) Check whether the number of word keys is correct, and return the test result, indicating that the test is successful or the missing word key is displayed. 9. membrane keyboard PCBA testing method according to claim 8, is characterized in that, described input character key time detection program comprises the steps: (1) Obtain the input time of this word key; (2) judge whether this key acquisition time is equal to the previous key acquisition time, if so, continue to step 3, if not, continue to step 4; (3) Display the short-circuit error of the word key, and end the program; (4) Judging whether the acquisition time of the word key this time minus the acquisition time of the last word key is greater than the set time threshold; (5) If yes, display the word key input timeout; if not, store the variable of the last word key acquisition time as the current word key acquisition time.

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