PCBA Tech - SMT placement equipment and AOI automatic optical instrument

SMT equipment is actually the machine required by surface mount technology. Generally, a whole SMT line usually includes the following equipment:

Board loading machine, printing machine, connection station, SPI, placement machine, plug-in machine, reflow soldering, wave soldering, AOI, X-ray, loading machine and other equipment, the above equipment is a relatively complete smt wiring list equipment, Different factories can add or delete related equipment according to actual product needs. The equipment that must be owned includes printers, placement machines, and reflow soldering.

SMT is the abbreviation of English (Surface Mounter Technology). Further reading: What is SMT? What does smt do and what does smt patch mean?

Translated into Chinese is the surface mount technology. The internal circuit boards of various digital home appliances and other electronic products that are common in daily life are realized through this technology. The electronic components are mounted on the circuit light board through the placement machine in the smt device. After soldering in a reflow oven, it will eventually become a motherboard. SMT plays a huge role in today's electronics industry. Let me introduce what SMT equipment contains.

smt device

SMT production equipment: dispenser, solder paste printer, placement machine, reflow soldering, wave soldering

SMT testing equipment: SPI solder paste thickness tester, furnace temperature curve tester, AOI optical tester, ICT online tester, X-RAY test system, ATE test system

SMT peripheral equipment:

Solder paste mixer, connecting table, splitting machine, loading and unloading machine, loading and unloading machine, buffer machine

SMT accessories: thermocouple/thermal resistance, heating tube, scraper/template, suction nozzle, dispensing needle, dispenser barrel accessories, wave soldering gun tube, feeder

SMT welding consumables: solder paste/solder bar, patch glue, flux

SMT electrical tools: anti-static soldering iron, suction soldering iron, tin melting furnace, chip retention tongs, foaming furnace

SMT cleaning equipment: ultrasonic cleaning machine, PCBA cleaning machine

Anti-static products: anti-static human body protection, anti-static tools, anti-static turnover boxes, anti-static packaging, anti-static testing instruments.

Detection method and process of AOI automatic optical instrument

The full name of AOI (Automatic Optic Inspection) is automatic optical inspection, which is based on optical principles to detect common defects encountered in welding production, such as online monitoring and inspection of PCBA boards (PCBA is the abbreviation of English Printed circuit board+assembly), That is to say, the empty PCB board passes through the SMT loading, and then goes through the entire production process of the DIP plug-in, referred to as PCBA board).

More and more factories are equipped with AOI testing equipment to ensure the quality of products. The basic principle is to use light reflection to check whether components such as BGA are placed correctly, whether the soldering is good, whether there is missing, reverse or short-circuit phenomenon, etc. bad. When a defect occurs through the AOI inspection, the on-site staff is required to make a visual judgment. After the judged good product, the test result is manually modified to be qualified, and the subsequent production is continued, while the defective product is repaired.

However, when the SMT is bad in the latter part of the feedback, more straightforward bad parts such as missing parts, reverse parts, and wrong parts are occasionally found. These defects are reported in the AOI test, but they are misjudged by the on-site operator and flow into the follow-up production.

AOI technology realization elements:

The technical problem to be solved by the present invention is to provide an AOI detection method, which can reduce the probability of misjudgment by field operators and greatly improve product quality.

To achieve the above purpose, an AOI detection method, which is executed by an AOI detection device, is used to detect the PCBA board to be tested, which includes the following steps:

a. Start an AOI inspection program to inspect the components on the PCBA board to be tested to obtain inspection data;

b. Determine whether the detected data exceeds a preset first threshold, if yes, execute step c, if otherwise, execute step f;

c. Determine whether the detection data of the PCBA board to be tested is greater than a preset second threshold, if yes, perform step d, if otherwise, perform step e;

d. Determine the PCBA board to be tested as a substandard product and store the test results of the PCBA board to be tested;

e. Store the test results of the PCBA board to be tested according to the input information of the on-site operator; and

f. Determine that the PCBA board to be tested is a qualified product and store the test results of the PCBA board to be tested.