Saki’s Advanced Optical Inspection Boosts Quality Assurance at US-headquartered Smart Modular Technologies

Estimated reading time: 5 minutes

Saki Corporation, an innovator in the field of automated optical and X-ray inspection equipment, is pleased to announce that it has supplied inline optical inspection systems to Smart Modular Technologies, a Newark California based manufacturer of high-performance DRAM modules and solid-state disk drives (SSDs). The investment enables the company to deliver advanced products and assure customers of the highest quality and value, and to prepare for next-generation smart manufacturing.

Smart Modular provides standard, ruggedized and custom memory and storage solutions for computing applications such as IoT, big data analytics, cloud AI, financial trading, and networking and telecom. Like any manufacturing business, Smart Modular strives to maximize productivity by continuously improving cycle time, production quality, and end-of-line yield. At the same time, maintaining the company’s reputation for quality depends on identifying any defective units to prevent them from leaving the factory.

To ensure production reaches these ideals, Smart Modular invested in advanced inline inspection solution consisting of a solder-paste inspection (SPI) station and two automated optical inspection (AOI) systems from Saki.

Inline SPI provides a fast way to check for any problems with the printer, stencil, or cleaning regime, which can be seen in defects such as bridging, insufficient solder paste, and paste-on-pad errors before the boards are populated and reflowed. While many printers contain built-in paste-on-pad inspection, Saki's dedicated 3D SPI system offers advantages such as a mechanical structure shared in common with high-end inline AOI machines and also the software platform for unified machine operation and programming. The system can provide simultaneous 2D and 3D inspection of the entire PCB surface and there are additional features such as warpage management, coplanarity inspection, and SPC support.

Good boards, as checked by the Saki 3Si SPI system, are then passed forwards for components to be placed. To detect any placement errors and pinpoint the causes, the production team at Smart Modular chose Saki’s 3Di series inline AOI platform. They worked with technical and sales staff to configure an optimal solution that would meet their needs.

The 3D AOI series has great expandability and flexibility with the advanced optical head with Z-axis and quad side-camera options with full and deeper inspection coverage. This, combined with advanced inspection algorithms permits both high accuracy and a fast cycle time. While the cameras permit capturing fine details, the 3Di platform’s state-of-the-art image processing can capture a 25mm field of view in one scan which can be extended up to 40mm with Z-axis options. This helps inspect assemblies that contain tall components such as capacitors placed alongside lower-profile components such as leadless ICs and SMD passives. In addition, by also incorporating multi-angle lighting and a side-view camera, Saki’s 3Di machines are well equipped to inspect assemblies that contain densely spaced components of widely varying sizes.

Memory Module Inspection Challenges

Working with Saki to determine the ideal setup to meet their quality and productivity goals, Smart Modular added a second Saki 3Di AOI system to the line to inspect 100% of the boards emerging from the reflow oven. In addition to encountering typical soldering issues such as tombstoning, head-in-pillow, and solder spattering, which the 3Di detects using state-of-the-art algorithms, assemblies such as memory modules and peripheral cards can suffer from problems such as solder spots on gold contacts. These types of defects can compromise the durability of the low-ohmic gold finish, while also spoiling the appearance and so compromising the perception of product quality. In addition, thicker solder deposits can also impair insertion of the module during use.

These solder spots are known to be difficult to detect against a gold finish when using older AOI equipment. The lighting subsystems and detection algorithms can be relatively insensitive to the low contrast between the color and surface characteristics of the reflowed solder and the gold plating. Saki’s engineers have overcome this, enabling unwanted solder spots to be detected automatically so that affected units can be repaired before leaving the factory.

Now that the equipment is up and running in Smart Modular’s factory, operators have been able to assess its overall performance and contribution to enhancing the company’s output. They particularly appreciate the overall accuracy, detecting defects with a high level of certainty while also maintaining a very low number of incorrect no-go results.

“We have experienced very low numbers of “false positives”, which is a strength of the Saki 3Di systems that we strongly appreciate,” said Smart Modular’s Vejay Kumar, VP of WW Specialty Memory Manufacturing. “By creating a stable parts database, and with the flexibility of the repair station, we can run the line for extended periods without stoppages and without needing operators to intervene. The AOI supports the work of our trained inspectors and lets them perform their own assessments on the boards, carefully, at the end of the line without slowing down production.”

Future-Proof Flexibility

Saki also offers many flexible options and upgrades that help transition inspection capabilities as the company seeks to adopt smart manufacturing principles in its activities. “This is important to us as we are now bringing Industry 4.0 technologies into our production lines to achieve further increases in productivity and quality, and benefit from data-driven improvements to our products and processes,” explained Vejay.

Vejay also commented on the support and training Saki has provided, which helped the manufacturing team to get productive very quickly after the equipment had been installed in the line. “All the machines, including our 3Si SPI system and two 3Di AOI systems are very easy to use. We required only minimal support to get up and running and start using all the features effectively. The customer service from Saki has been attentive whenever we called. This assures us of the best and fastest return on our investment. All our training has been on-site, and their team customized the sessions to ensure all the aspects we need were covered optimally.”

“Saki’s 3D SPI and AOI systems provide a sound and durable hardware base while also giving us flexibility to scale and improve our capabilities by applying regular software updates,” concluded Vejay “We are now equipped to inspect our most advanced products with high accuracy, at high speed, and to detect even small cosmetic issues, without incorrectly failing good units. This has helped us to increase productivity and continue delivering the best possible quality and value for customers, and thereby uphold our great reputation in the marketplace.”