FAQ

Why do AI server PCBAs typically add an AXI (Automated X-ray Inspection) machine to the line?

server boards are the most inspection-critical products in SMT today, and that is why inline AXI (Automated X-ray Inspection) has become standard on their assembly lines. The reasons come down to what is actually on the board:

1. The critical solder joints are optically invisible.
AI accelerators rely on HBM memory, GPUs/CPUs and high-density BGAs. Their microbumps and ball grids sit completely concealed beneath the chip and substrate, so AOI (optical inspection) can only see the peripheral fillet — it is blind to what matters underneath.

2. Hidden sub-surface defects kill field reliability.
X-rays penetrate the package and reveal defects that no camera can catch: solder voids, BGA micro-shorts, head-in-pillow (HiP), and insufficient wetting. Voids in particular cause latent failures at power-up and in the field.

3. AI silicon demands tighter void limits than IPC allows.
General IPC standards tolerate up to ~25% voiding by area, but AI hardware suppliers typically cap it at **below 10–15%** on power pins to avoid thermal hotspots and resistance increases — a level that only quantitative X-ray measurement can verify.

4. Reliability is business-critical.
AI servers run 24/7 in data centers; a single hidden solder failure on a high-value board is extremely expensive in rework and downtime. AXI catches defects before boards leave your facility, protecting both quality and margin.

Bottom line: When you move from standard SMT products to AI-server PCBA, the density, BGA content and reliability demands make sub-surface X-ray inspection a necessity — not an option. We supply and support 3D AXI systems sized for AI-server lines.

How fast is the PARMI Xceed 3D AOI? What is its inspection speed and cycle time?

The PARMI Xceed 3D AOI delivers industry-leading inspection speed of 65 cm²/sec at 14 × 14 µm resolution. Using laser-line 3D scanning, it achieves a full cycle time of about 10 seconds for a 260 mm (L) × 200 mm (W) PCB, including loading and unloading time.

Key points:

· Speed: 65 cm²/sec @ 14 × 14 µm — among the fastest in its class for true 3D inspection.

· Cycle time: ~10 sec for a 260 × 200 mm board (load + inspect + unload).
· Technology: laser-line scan gives accurate 3D measurement regardless of board material, surface or color.
· Actual throughput depends on panel size, component density and the inspection program — share your board layout and we will provide a realistic cycle time for your line.

What is the difference between AOI and SPI, and do I need both?

AOI (Automated Optical Inspection) and SPI (Solder Paste Inspection) inspect different stages of the SMT line and are complementary.

SPI is installed right after the solder paste printer. It measures the paste volume, height, area and position of every pad before components are placed, catching under-print, over-print, bridging and misalignment at the very first step.
AOI runs after reflow (and optionally after placement) and inspects the assembled board — component presence, polarity, orientation, offset, and solder joint quality.

A full inline solution uses both: SPI prevents paste defects upstream, AOI catches final assembly defects downstream. For automotive and high-reliability boards, this dual inspection is standard practice and significantly reduces escapes to ICT/functional test.