PCB Technical - What production equipment is needed for PCBA processing

Before understanding or choosing the strength of a PCBA processing factory, it is necessary to understand certain PCBA processing production equipment and SMT chip processing production technology, so that when choosing a PCBA processing factory, you can know it well. The main equipment of SMT chip processing production line includes solder paste printer, SMT chip machine, reflow oven, AOI automatic optical detector, etc. Wanlong Lean provides intelligent manufacturing services such as PCB design, PCB board production and processing, circuit board welding, SMT chip processing, PCBA processing, PCBA foundry and other materials.

Wanlong Lean now has 4 SMT production lines, 2 DIP soldering lines, 1 wave soldering line, 2 20-meter assembly production lines, and 4 new intelligent SMT production lines, realizing the realization from the board/printing/ patching/ Inspection/reflow to the fully automated production process of receiving the board.

Wanlong Lean SMT chip process equipment introduction:

1. Template: (Steel mesh) First, determine whether to process the template according to the designed PCB. If the SMD components on the PCB are only resistors, capacitors, and the package is 1206 or more, you do not need to make a template, and use a syringe or automatic dispensing equipment for solder paste coating; when the PCB contains SOT, SOP, PQFP, PLCC and BGA packaged chips, resistors, and capacitors must be made into templates for packages below 0805. General templates are divided into chemically etched copper templates (low price, suitable for small batches, tests, and chip pin spacing> 0.635mm); laser-etched stainless steel templates (high precision, high price, suitable for large-volume, automatic production lines and chip pins) Spacing <0.5mm). For R&D, small batch production or spacing >0.5mm, our company recommends to use etched stainless steel template; for mass production or spacing <0.5mm, use laser-cut stainless steel template. The external size is 370*470 (unit: mm), and the effective area is 300*400 (unit: mm).

2. Silk screen: (GKG G5 automatic printing machine) Its function is to use a squeegee to print the solder paste or patch glue onto the PCB pads to prepare for the placement of components. The equipment used is a manual screen printing table (screen printing machine), template and scraper (metal or rubber), located at the forefront of the SMT production line. Our company uses a medium-sized screen printing table and a precision semi-automatic screen printing machine to fix the template on the screen printing table. Use the up and down and left and right knobs on the manual screen printing table to determine the position of the PCB on the screen printing platform, and fix this position; The coated PCB is placed between the screen printing platform and the template, and solder paste is placed on the screen (at room temperature), keeping the template and PCB parallel, and using a scraper to evenly coat the solder paste on the PCB. In the process of use, pay attention to timely cleaning the template with alcohol to prevent the solder paste from clogging the leakage holes of the template.

3. Placement: (Yamaha placement machine, Panasonic placement machine) Its function is to accurately install surface mount components to a fixed position on the PCB. The equipment used is a placement machine (automatic, semi-automatic or manual), vacuum suction pen or tweezers, located behind the screen printing table in the SMT production line. For laboratory or small batches, our company generally recommends the use of a double-tip anti-static vacuum suction pen. In order to solve the problem of placement and alignment of high-precision chips (chip pin spacing <0.5mm), our company recommends the use of South Korea's Samsung automatic multi-function high-precision placement machine (model SM421 can improve efficiency and placement accuracy). The vacuum suction pen can directly pick up resistors, capacitors and chips from the component material rack. Because the solder paste has a certain viscosity, it can be directly placed on the required position for resistors and capacitors; for chips, a suction cup can be added to the vacuum suction pen tip. The suction power can be adjusted by the knob. Remember that no matter what kind of components are placed, pay attention to the alignment position. If the positions are misaligned, you must clean the PCB with alcohol, re-screen and re-position the components.

4. Reflow soldering: (new US imported HELLER reflow soldering) Its function is to melt the solder paste, so that the surface mount components and the PCB are firmly brazed to achieve the electrical performance required by the design and are precisely controlled in accordance with the international standard curve., Can effectively prevent thermal damage and deformation of PCB and components. The equipment used is a reflow oven (automatic infrared/hot air reflow oven), located behind the placement machine in the SMT production line.

5. Cleaning: Its function is to remove the substances that affect the electrical performance or solder residues such as flux on the mounted PCBA board. If you use no-clean solder, it is generally not necessary to clean. Products that require micro-power consumption or products with good high-frequency characteristics should be cleaned, and general products can be cleaned-free. The equipment used is an ultrasonic cleaning machine or directly manually cleaned with alcohol, and the position can be not fixed.

6. Inspection: (Fully automatic optical AOI detector) Its function is to inspect the welding quality and assembly quality of the mounted PCB board. The equipment used is a magnifying glass and a microscope, and the position can be configured in a suitable place of the production line according to the needs of the inspection.

7. Rework: Its function is to rework the PCBA that has detected faults, such as solder balls, solder bridges, open circuits and other defects. The tools used are smart soldering iron, rework station, bga rework station, etc.