In this blog post,we will share PCB assembly machine guide.
Surface Mount PCB (SMT)
Surface mounting (or SMT technology) is becoming an increasingly common way to assemble electronic assemblies on printed circuit boards.
Unlike traditional mounting methods, where elements were inserted into holes on printed circuit boards, surface mounting involves placing components on pads.
This greatly simplifies the process. And the use of automatic installers allows you to significantly speed up it, and also increase productivity.
Five Significant Benefits
Surface mounting of printed circuit boards has a number of design and technological advantages.
- Miniaturization of printed circuit boards. For surface mounting, you can use components that are lighter than those used for hole mounting. In addition, SMT mounting involves installing components on both sides of the board. That is, the size of the board itself can be made smaller and, as a result, the size of the entire printed circuit assembly can be reduced.
- Reducing the complexity of operations. It is no longer necessary to prepare leads before installation and install them in holes. Everything is much simpler – the components are fixed with solder paste or glue and aligned during soldering, and this is done not by people, but by automated systems. At the same time, the installation speed increases significantly.
- Improving the quality of signal transmission. By tighter component placement (on both sides) and shorter lead lengths, the electrical performance of PCBs is greatly improved.
- Improving maintainability. Surface mounting of printed circuit boards allows, if necessary, to quickly remove and reinstall components without damage. This does not require evenly warming up the solder inside the element extraction hole, then cleaning this solder. For SMT mounting, it is sufficient to heat the surface with hot air or nitrogen.
- Cost reduction. By reducing the size of printed circuit boards, the consumption of materials used is reduced. Reduced packaging costs. And full automation of the process not only increases productivity, but also reduces the risk of rejects. Thus, costs are reduced due to the “human factor”.
Necessary Equipments
In order for surface mounting of printed circuit boards to be of a high level and meet all quality standards, specialized equipment is needed – automatic installers of SMD components.
Thus, in the choice of equipment, the manufacturer can focus solely on his field of application.
Someone needs an installer for small-scale production, someone – for large-scale production.
But it is worth noting that automatic installers of SMD components, in any case, have significant advantages over manual production:
- High speed of component installation;
- Simple programming modes;
- Reliability and ease of use;
- High precision of work;
- PC compatibility.
The automation of the installation process of SMD components has become possible due to their case structure.
And today, almost all automatic installers who carry out surface mounting of printed circuit boards can work with any type of SMD components.
The production process includes several stages.
INPUT PACKAGE CONTROL
- Visual control workplace
Visual control workplace
Designed specifically for quality control of assembly of PCB assemblies with surface mount components. Visual magnification up to 80x , the ability to connect a digital camera.
- LCR – meter
The device is designed to control the resistance, capacitance and inductance of passive components, taking into account the statistical reliability of checks.
- Dry storage cabinet for moisture-sensitive electronic components
- Universal counter for radial and axial components with adapter for SMD components
Maximum number of components to be counted: 9,999 pcs.
SURFACE MOUNTING AND MELTING
Surface mount line
- Automatic stencil printer for solder paste application
Cycle time – 8 sec , high application accuracy – up to 10 microns , the printer is equipped with a flat image recognition system, which allows achieving a high level of print repeatability and avoiding defects when applying solder paste.
High Speed Surface Mount Component Installer
Productivity up to 40,000 components per hour. The installation accuracy is at least 65 microns, the presence of a parallel conveyor allows the simultaneous assembly of 2 products, 2 installations heads with 6 vacuum nozzles each, belt feeders with a width of 8 mm to 32 mm are used, the possibility of feeding elements from sticks (canisters). The ability to install both standard chip components and microcircuits with a pin pitch of 0.5 mm.
Surface Mount Component Installer Multifunctional
Productivity up to 31,000 components per hour. The ability to install components of any complexity (such as BGA, QFP, etc.).
Installation accuracy of complex components is at least 25 microns at 3 sigma. Three vacuum nozzles on each of the two working heads, belt feeders with widths from 8 mm to 32 mm are used.
The ability to install more than 20 different types of components from pallets and cases during the assembly of one product.
- Reflow conveyor furnace
Reflow conveyor furnace
Seven heating and cooling zones, an average cycle time of 25 seconds, a thermal profiling system allows you to preset the optimal temperature regime for each specific product.
Technical Process Control
Installation of automatic optical inspection
Designed to detect surface mounting defects, such as raised leads, coplanar contacts of microcircuits and connectors, offset and incorrect polarity of the element, quality control of soldering, etc. Meets all modern PCB inspection standards.
It has a short cycle time of 10-20 sec. The built-in defect marker automatically places a marker at the location of the defect.
PCB Cleaning
4-stage cleaning system
Designed for cleaning the remains of solder flux from printed circuit boards.
Equipped with computer controlled process, ultrasonic bath, hot air drying.
Sensitive components are protected. It is possible to create a variety of cleaning programs depending on the process requirements. Maximum cleaning speed up to 60 boards per hour.
Mounted Mounting
Soldering stations
Soldering stations with tip and heating element of the improved type, using composite materials. Heating range 200-400 ° C, full protection against static electricity. They make it possible to install and replace components of any complexity.
Repair center
A workstation for a radio installer with a repair center for installing and removing components (including metal screens).
Heating range 100-500 ° C, alignment accuracy 25 microns at 6 sigma.
The repair center enables the repair of BGAs and other components of complex geometry. High accuracy is achieved both in the geometry of the setting and in the temperature profile.
In-Circuit and Functional Testing
Test system with four movable probes
Serves for a complete electrical check of assembled products and has the ability to functional testing with the creation of databases of product characteristics.
The use of this system makes it possible to exclude such defects as short circuits, lack of contact and deviation from the required rating or active characteristics of the element.
It supports work with boards of complex geometry and multilevel products.
4 independent movable probes, 2 on each side, 2 digital optical inspection cameras for the immediate location of the defect.
The minimum size of the contact area is 50 x 50 microns. The minimum distance between the centers of the contact pads is 0.1 mm.
X-RAY Control
Quality control of assembly of components with contacts located under the element body or other assembly elements.
It also detects possible inhomogeneities in the soldering of complex components, such as: short circuits, lack of solder, poor contact between the solder and the pad, internal fillet defects (cracks and microbubbles).
The detected defect can be easily eliminated by the installer.
Magnification up to 1590 times
TECHNOLOGICAL POSSIBILITIES OF OUR PRODUCTION
- One-sided and two-sided mounting
- Automatic soldering on SMD assembly line
- Wave soldering
- Manual assembly
- The range of components to be installed from 0201 (0.6mm x 0.3mm) to 45mm x 45mm with a maximum height of 15mm; QFP etc. lead pitch up to 0.3mm; SOIC, PLCC, TSOP, CSP, BGA ball pitch up to 0.5mm
- X-ray control possibility
- Repair and installation of BGA cases of microcircuits at a repair station
- The ability to control with flying probes
- Carrying out operations of functional control of electronic modules
There’re many kinds of different applications such as aviation, medicine, automotive and power supply, PCBMay provides the Premium PCB/PCB assembly service, where PCB manufacturing processes are compliant with some of the world’s most stringent standards such as RoHS, UL, ISO9001,REACH and COC, so that we may bring to you quality and reliable PCBs, no matter whether you are a professional engineer or an aspiring maker.