Saki Corporation designs and manufactures automated optical systems for the inspection and measurement of printed circuit boards which are used in the production of electronic products throughout the world. Saki machines can inspect all size components such as 01005, 0201, and 0402s and packages like BGAs, CSPs, LGAs, PoPs, and QFNs for applications that include smart phones, tablet terminals, laptops, cloud servers, base stations, facility equipment, navigation systems, on-vehicle modules, and aircraft devices.
Saki's systems are designed for versatility. They can be used in critical inspection and measurement environments where high reliability is essential and failure is not an option -- like medical, automotive, military, and aerospace. They also fit the simpler "golden board" environments. The intuitive programming software of the algorithm-based system lets the operator zero-in on the areas that need a closer look and lets the user perform many of the functions of a programmer, even without being one. Saki's software packages offer extensive peripherals for repair, remote monitoring, and SPC. This gives the flexibility to just do a simple inspection of a golden board or the option to use the algorithms to delve much deeper into the actual measurements of the solder paste or component or explore a particular area.
Saki's knowledge of 2D and 3D technology and systems has been applied in partnership with major manufacturers of placement equipment, screen printers, and other systems for machine-2-machine communication in the SMT line to realize a highly productive, efficient manufacturing process. Saki is part of the Fuji Machine Manufacturing's "FUJI Smart Factory with Nexim" initiative.
Types of inspection systems
There are basically 3 types of inspection systems:
- 3D solder paste inspection (SPI)
- 2D and 3D automated optical inspection (AOI)
- 3D automated x-ray inspection (AXI)
Saki's systems are based on Saki's innovative and unique Line Scanning Technology--a proprietary, high-speed imaging technology which scans an entire printed circuit board (PCB) and captures its image, on-the-fly, in just one pass, similar to the way a copy machine scans a document. This revolutionary technology increases the speed of the inspection process by 55%. Line Scanning Technology still forms the basis of Saki's 2D systems.
Line Scanning Technology makes it possible to completely capture and process the images for a 330 x 250mm substrate within 4 seconds and a 500 x 460mm substrate within 7 seconds. Saki's high-speed processing technology can handle any super high-speed production line in the industry, without compromising quality.
True height measurement
Saki's 3D-AOI systems don't just inspect, they measure components with a height range between 0 and 20mm, achieving 1-micron height resolution and a false call rate of less than 100 ppm with 0 escapes for the highest level of quality and accuracy in the industry. Measurement results are evaluated in real time and combined to automatically generate a height map. Real measurement data can be obtained even inside a shield case or between connectors. True height measurement enables actual verification of defects and gives greater inspection, measurement, and reliability than 2D AOI.
Phase Measurement Profilometry with Liquid Crystal on Silicon (LCoS) technology
Circuit boards today are smaller, denser, and are populated with components with great variation in heights, shapes, and sizes. Saki has successfully developed its active projection technology, Phase Measurement Profilometry with LCoS technology, which projects various lighting patterns to capture everything located on a substrate with a height range measurement of 0-500 microns, in 3D, clearly, and without shadows. It benefits a wide range of applications, such as smart phone substrates with micro-sized parts, on-vehicle substrates, industrial device substrates with tall parts, and power supply circuit integrated server substrates.
Through high-speed switching of projection patterns in real-time, and combining both a narrow and wide range of measurement, Saki's machines realize broad dynamic ranges. The rigid gantry system on all Saki inspection equipment provides stability for sharp, reliable images. Phase Measurement Profilometry with LCoS technology was originally developed for Saki's automated optical inspection systems and has now been optimized for measurement of solder paste after printing.
Coaxial Overhead Lighting
Another Saki advantage is its coaxial overhead lighting that creates an image for every field of view without using directed lighting and without creating the shadows that usually result from light deflected by taller components on the board. Overhead lighting is essential for proper inspection of microchips located between connectors on high density boards and is effective for solder fillet inspection that is dependent on the relationship between the tilt angle and brightness. With coaxial overhead lighting, inspection data can be applied to similar components, facilitating inspection data management and speeding-up production start-up.
Advanced lighting and optics
Saki's innovative AOI systems consist of an optical head, side-angle cameras showing side views that previously weren't visible, 4-stage ring lighting that consists of RGB step lighting plus an in-line illumination source that incorporates the light into the optical train of the machine vision lens for optimum illumination and better visual image capture for all PCB configurations. Saki's unique Phase Measurement Profilometry technology provides the 3rd dimension of the Z axis, using wavelength programmable and projected stripe patterns to precisely determine the height of features on the PCB. Circular lighting gives more consistent illumination throughout the field of view, with brightness controlled and shadows eliminated no matter the component height or density.
Saki's new positioning system improves yield and cycle time
Speed is an important criterion for AOI, especially in high volume manufacturing of consumer products. Saki's engineers developed a new positioning system that improves positioning speed by 50% and overall cycle time by 15%. The system can be configured with dual lanes that double throughput or for XL (686 x 870mm: 27 x 34.3 in.) size boards.
Double-Sided and Double-sided Simultaneous Inspection
Saki's 2D line scanning technology uses a simple one-axis structure and low vibration so both sides of the board can be inspected simultaneously. This is especially beneficial for final confirmation after selective soldering of defective components. The machine's compact footprint and safety features support easy installation into a production line or production cell configuration.
Double-sided Simultaneous Inspection
In Saki's unique double-sided simultaneous inspection system, one AOI machine provides the function of two. Both sides of the board are inspected simultaneously to cut inspection time almost in half. It avoids mishandling, reduces the number of operations needed, and eliminates the need for a board flipper.
Saki's unique Fujiyama algorithm verifies five critical aspects of through-hole solder joints, thereby providing thorough inspection of through-hole solder joints to ensure quality for not only SMT solder joints, but for all solder joints in mixed technology applications. Saki's FUJIYAMA algorithm enables solder inspection after wave soldering to check for extra components, dropped components, stray components, and solder balls.
ECD (Extra Component Detection)
Saki's ECD (Extra Component Detection) algorithm inspects for stray components, solder balls, and foreign materials across the entire surface of the circuit board and can detect objects of 300 microns or less, thereby eliminating these defects. ECD provides further assurance of product quality. Saki's ECD is incorporated into both its 2D and 3D AOI systems.
Built for high performance, efficiency, and ease-of-use
Saki has developed its own advanced image processing and inspection algorithms to minimize programming time and false calls, library management, SPC quality management systems, and closed-loop functions to work in conjunction with other placement equipment. Saki's inspection systems are designed and constructed for simplicity, efficiency, ease of operation, high performance, and durability. They have a long service life, with machines operating in the field for more than 22 years.