CN105578775B - A kind of changing liquid automatically device and method of printed circuit board corrosive liquid - Google Patents

Abstract

The invention relates to an automatic liquid exchange device and method for a printed circuit board corrosive liquid, which belongs to the field of printed circuit board manufacturing, and includes a box for containing the corrosive liquid and a single-chip microcomputer located outside the box. Camera, one side of the box body is respectively provided with water outlet and water inlet, and the other side is provided with high and low water level sensors, and near the top of the box body is also provided with a corrosive agent automatic adding device connected with a single-chip microcomputer. The invention uses a camera to take pictures of the corrosive liquid for data collection, and the single-chip microcomputer analyzes the color of the corrosive liquid in the picture to determine the concentration of divalent copper ions in the corrosive liquid, and makes an instruction whether to replace the corrosive liquid, through the water level sensor, electric valve and corrosive agent Automatic adding device to realize automatic replacement of corrosive liquid.

Description

An automatic liquid exchange device and method for printed circuit board corrosion liquid

technical field

The invention relates to an automatic liquid changing device and a liquid changing method for a printed circuit board corrosion liquid, belonging to the field of printed circuit board manufacturing.

Background technique

The formation of the circuit on the printed circuit board is often to first use a resist to cover the pattern that needs to be retained on the copper clad board, and use a corrosive solution to etch the copper that is not covered by the resist and not to be retained, and finally form the design circuit pattern and pad.

The commonly used corrosive solution is an aqueous solution of ferric chloride. During the etching process, as the chemical reaction proceeds, the concentration of iron ions in the corrosive solution decreases continuously, while the concentration of copper ions increases continuously, and the etching reaction rate also decreases continuously. , when the etching rate is significantly reduced, it is necessary to replace the etching solution in time. Existing replacement of corrosive liquid is usually done manually to determine whether it is necessary to change the liquid, and the replacement of the liquid is done manually by stopping the machine.

The above-mentioned replacement of the corrosive solution is manually judged, with large errors and strong randomness, which is not conducive to automated production management. At the same time, the replacement of the corrosive solution requires manual work, which is time-consuming and laborious, and the production efficiency is low.

Contents of the invention

In view of the above-mentioned shortcomings, the present invention provides a device that can judge when to change the liquid and automatically complete the liquid change, which effectively makes up for the shortcomings of the prior art.

In order to achieve the above object, the technical solution adopted in the present invention is:

An automatic liquid changing device for printed circuit board corrosive liquid, comprising a box containing the corrosive liquid and a single-chip microcomputer located outside the box. A camera connected to the single-chip microcomputer is installed outside the box. The water outlet of the water pipe, the water inlet connected to the water inlet pipe is set above the water outlet, the electric valve connected to the single-chip microcomputer is installed on the water inlet pipe and the water outlet pipe, and the low water level sensor connected to the single-chip microcomputer is installed in the box on the side opposite to the water outlet A high water level sensor connected to the single chip microcomputer is installed in the box on the side opposite to the water inlet.

Further optimize the settings on the basis of the above scheme:

The corrosive agent automatic adding device includes a box containing corrosive agent, an electric valve to control the opening and closing of the box, a buzzer for alarming, an infrared transmitter and an infrared receiving head for detecting the presence or absence of corrosive agent in the box, an electric valve, a buzzer, etc. The buzzer, the infrared transmitter and the infrared receiver are all connected with the single-chip microcomputer.

The box is made of transparent material.

The camera adopts OV7670 camera module.

The camera realizes data transmission through the IIC and the single-chip microcomputer.

The single-chip microcomputer adopts STM32F103 chip.

Both the high water level sensor and the low water level sensor realize the data transmission with the single-chip microcomputer through serial port communication.

The power supply converts 220V voltage to 5V voltage.

The box is made of transparent material.

The present invention also provides a liquid changing method of an automatic liquid changing device based on the above-mentioned printed circuit board corrosive liquid, comprising the following steps:

Step 1) Use the camera to collect the pictures of the corrosion solution from time to time, and transmit the collected picture information to the single-chip microcomputer;

Step 2) The single-chip microcomputer analyzes the blueness in the collected pictures, and compares it with the blueness warning value preset in the single-chip;

Step 3) When the analysis result shows that the blue level in the picture does not reach the warning value, the camera continues to collect without affecting the corrosion of the printed circuit board; when the analysis result shows that the blue level in the picture reaches or exceeds the warning value, the microcontroller starts The electric valve on the water outlet pipe opens the water outlet to discharge the corrosive liquid;

Step 4) When the corrosive liquid is discharged, the low water level sensor at the bottom of the device sends a detection signal to the single-chip microcomputer, and the single-chip microcomputer closes the electric valve on the water outlet pipe, and at the same time opens the electric valve on the water inlet pipe, and puts in clean water;

Step 5) When the clean water put in reaches the position of the high water level sensor, the high water level sensor will send a detection signal to the single chip microcomputer, and the single chip microcomputer closes the electric valve on the water inlet pipe, and at the same time starts the electric valve in the corrosive agent automatic adding device, and the water filled with corrosive agent When the box is opened, a preset amount of corrosive agent is poured into the clean water to complete the automatic replacement of corrosive liquid.

The invention uses a camera to take pictures of the corrosive liquid for data collection, and the single-chip microcomputer analyzes the color of the corrosive liquid in the picture to determine the concentration of divalent copper ions in the corrosive liquid, and makes an instruction whether to replace the corrosive liquid, through the water level sensor, electric valve and corrosive agent Automatic adding device to realize automatic replacement of corrosive liquid. In this way, the user can save a lot of time spent on replacing the corrosive liquid, and can also speed up the chemical reaction rate of corrosion.

The present invention will be further elaborated below through the accompanying drawings and specific embodiments.

Description of drawings:

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a flow chart of the automatic liquid exchange method of the present invention.

Label description:

Tank 1, low water level sensor 21, high water level sensor 22, water inlet 31, water outlet 32, water inlet pipe 311, water outlet pipe 321, electric valve 41 on the water inlet pipe, electric valve 42 on the water outlet pipe, automatic corrosive agent adding device 5. Camera 6.

Detailed ways:

As shown in Fig. 1, a kind of automatic liquid changing device of printed circuit board corrosive liquid provided by the present invention includes a transparent box 1 for containing corrosive liquid and a single-chip microcomputer located outside the box 1, and the outside of the box 1 is equipped with a The connected camera 6, the box body 1 is provided with a water outlet 32 connected to the water outlet pipe 321 near the bottom side, and the water inlet 31 connected to the water inlet pipe 311 is arranged above the water outlet 32, and the water inlet pipe 311 is provided with an electric valve 41, and the water outlet pipe 321 is provided with an electric valve 42, and the electric valve 41 and the electric valve 42 are all connected with the single-chip microcomputer; a low water level sensor 21 connected to the single-chip microcomputer is also installed in the side box 1 opposite to the water outlet 32, and a water inlet 31 relative to the A high water level sensor 22 connected to a single-chip microcomputer is installed in the side box 1. The power supply converts the 220V voltage into a 5V voltage to supply power to the single-chip microcomputer, the high water level sensor 22 and the low water level sensor 21. There is also a water level sensor connected to the single chip microcomputer near the top of the box body 1. Corrosive agent automatic adding device 5.

The corrosive agent automatic adding device 5 in the above scheme includes a transparent box for containing the corrosive agent, an electric valve for controlling the opening and closing of the box, a buzzer for alarming, an infrared emitting head and an infrared receiving head for detecting the presence or absence of corrosive agent in the box, The electric valve, the buzzer, the infrared emitting head and the infrared receiving head are all connected with the single-chip microcomputer. When the box is filled with corrosive agent, the signal sent by the infrared emitter is blocked by the corrosive agent in the box, and the infrared receiver cannot receive the emission signal from the infrared emitter, then the single-chip microcomputer will not activate the electric valve; if the corrosive agent in the box is consumed, the infrared The receiving head receives the transmission signal from the infrared emitting head through the box and feeds it back to the single-chip microcomputer, and the single-chip microcomputer sends an instruction to the buzzer to alarm, reminding the staff to add corrosive agent to the box in time.

Camera 6 in this embodiment has adopted OV7670 camera module, and this module adopts OV7670CAMERACHIPTM image sensor, has the characteristics of small size, low working voltage, can provide all functions of single-chip VGA camera and image processor. The image sensor uses unique sensor technology to improve image quality by reducing or eliminating optical or electronic defects such as fixed pattern noise, tailing, floating, etc., and obtains clear and stable color images. Controlled by the SCCB bus, it can output eight-bit impact data with various resolutions such as full frame, sub-sampling, and windowing. The VGA image of this product can reach up to 30 frames per second, and the user can fully control the image quality, data format and transmission method. All image processing functions, including gamma curve, white balance, saturation, chroma, etc., can be programmed through the SCCB interface, compatible with the ICC interface, and can be directly connected to the microcontroller through the IIC to realize data transmission.

The single-chip microcomputer used adopts STM32F103 chip, which has a maximum operating frequency of 72MHz, and can reach 1.25DMips/MHZ (DhrystONe2.1) when accessing the memory with 0 waiting period. And it provides a wealth of peripherals: timer, ADC, SPI, USB, IIC and UART, to meet the needs of this device.

The single-chip microcomputer realizes data transmission with the high water level sensor 22 and the low water level sensor 21 through serial port communication. The high water level sensor 22 and the low water level sensor 21 of the device respectively provide four pins VCC, GND, TXD, RXD, which can be connected with corresponding pins of the single chip microcomputer module to realize data transmission.

The image collection principle of the camera 6 of the present invention is as follows: the reflected light of the corrosive liquid is transmitted to the lens of the camera 6, and is focused on the CCD chip through the lens, and the CCD accumulates corresponding charges according to the intensity of the light, and through periodic discharge, a picture is generated to represent The electrical signal of a picture is amplified by the pre-charge and discharge circuit and AGC automatic gain control. Since the image processing chip processes digital signals, the image digital signal processing IC (DSP) is obtained through analog-to-digital conversion. The synchronous signal generator mainly generates the synchronous signal clock, that is, generates vertical and horizontal scanning driving signals to the image processing IC. Then, a standard composite video signal is output to the single-chip microcomputer through the output terminal through the digital-to-analog conversion circuit.

The single-chip microcomputer analyzes the blue degree in the color of the corrosion liquid in the picture. When the blue degree does not reach the preset blue degree warning value, the camera 6 continues to take the picture information; when the blue degree of the corrosion liquid reaches the warning value, the single-chip microcomputer Control the electric valve 42 on the water outlet to open the water outlet 32, and the corrosive liquid is discharged along the water outlet pipe 312. When the low water level sensor 21 detects that there is no corrosive liquid in the corrosion device, it sends a signal to the single-chip microcomputer. After the single-chip microcomputer receives the signal, it closes the outlet. The electric valve 42 on the water inlet opens the electric valve 41 on the water inlet simultaneously and puts into clear water. After the water level reaches the position of the high water level sensor 22, the high water level sensor 22 sends a signal to the single-chip microcomputer, and after the single-chip microcomputer receives the signal, closes the electric valve 41 on the water inlet. At this point, the water change is over. Then, the single-chip microcomputer controls the electric valve in the corrosive agent automatic adding device 5, opens the box containing the corrosive agent, and adds an appropriate amount of corrosive agent to the clear water in the box body 1 according to preset, and like this, the replacement of the printed circuit board corrosive solution is completed.

The above embodiments are only used to illustrate the technical solution of the present invention without limitation. Other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solution of the present invention should be covered as long as they do not depart from the spirit and scope of the technical solution of the present invention. Within the scope of the claims of the present invention.

Claims (10)

1. a kind of changing liquid automatically device of printed circuit board corrosive liquid, it is characterised in that：Including accommodate corrosive liquid babinet and Microcontroller outside babinet is equipped with the camera being connected with microcontroller outside babinet, and the close bottom side of babinet is set There are the water outlet of connection outlet pipe, the top setting of water outlet to connect the water inlet of water inlet pipe, be all provided on water inlet pipe and outlet pipe There is the motor-driven valve of connection microcontroller, the low water level sensing of connection microcontroller is also equipped in a side box body opposite with water outlet Device, is equipped with the high water level sensor of connection microcontroller in a side box body opposite with water inlet, and power supply is to microcontroller and high and low Water level sensor is powered, and the corrosive agent automatic adding device being connected with microcontroller is additionally provided at top in babinet.

2. a kind of changing liquid automatically device of printed circuit board corrosive liquid according to claim 1, it is characterised in that：The corruption Erosion agent automatic adding device includes the box for holding corrosive agent, the motor-driven valve of control box folding, the buzzer for alarm, use In detection box internal corrosion agent whether there is or not infrared emission head and infrared receiving terminal, motor-driven valve, buzzer, infrared emission head and infrared Head is received to be connected with microcontroller.

3. a kind of changing liquid automatically device of printed circuit board corrosive liquid according to claim 2, it is characterised in that：The box Son is transparent material.

4. a kind of changing liquid automatically device of printed circuit board corrosive liquid according to claim 1, it is characterised in that：It is described to take the photograph As head uses OV7670 camera modules.

5. a kind of changing liquid automatically device of printed circuit board corrosive liquid according to claim 4, it is characterised in that：It is described to take the photograph As head passes through IIC and chip microcontroller data transmission.

6. a kind of changing liquid automatically device of printed circuit board corrosive liquid according to claim 1, it is characterised in that：The list Piece machine uses STM32F103 chips.

7. a kind of changing liquid automatically device of printed circuit board corrosive liquid according to claim 1, it is characterised in that：The height Water level sensor and low water level sensor realize the data transmission with microcontroller by serial communication mode.

8. a kind of changing liquid automatically device of printed circuit board corrosive liquid according to claim 1, it is characterised in that：The electricity 220V voltages are converted into 5V voltages by source.

9. a kind of changing liquid automatically device of printed circuit board corrosive liquid according to claim 1, it is characterised in that：The case Body is transparent material.

10. a kind of changing liquid automatically method of printed circuit board corrosive liquid, it is characterised in that：It is any based on claim 1 to 9 The changing liquid automatically device of printed circuit board corrosive liquid changes liquid method, includes the following steps：

Step 1）The picture of corrosive liquid is acquired in real time with camera, collected pictorial information sends microcontroller to；

Step 2）Microcontroller analyzes the blue degree in collected picture, and with the indigo plant that is set in advance in microcontroller Color degree warning value is compared；

Step 3）When analysis result is not up to warning value for the blue degree in picture, then camera continues to acquire, and does not influence to print The corrosion of printed circuit board；When analysis result meets or exceeds warning value for the blue degree in picture, then microcontroller starts water outlet Motor-driven valve on pipe opens the discharge that water outlet carries out corrosive liquid；

Step 4）When corrosive liquid discharge finishes, the low water level sensor set on bottom of device is sent to microcontroller by signal is detected, Microcontroller closes the motor-driven valve on outlet pipe, opens simultaneously the motor-driven valve on water inlet pipe, is put into clear water；

Step 5）When the clear water being put into reaches high water level sensor position, high water level sensor is sent to list by signal is detected Piece machine, microcontroller closes the motor-driven valve on water inlet pipe, while starting the motor-driven valve in corrosive agent automatic adding device, will fill corruption The box of erosion agent opens the corrosive agent that predetermined amount is launched into clear water, completes the automatic replacement of corrosive liquid.