Inline X-ray on the PCB line: closing the gap after automotive electronics scale-up

Royma Industrial CT offers the RMLVX1850 as an inline 2D X-ray station for printed circuit board assembly (PCBA) lines, so that automotive electronics makers can inspect hidden solder joints and connectors on the line itself rather than in occasional manual samples. The machine combines a microfocus X-ray source of up to 110 kV and 20 W with a four-axis motion system and a stated measurement precision of 10 µm, for boards and assemblies up to 200 × 200 mm and 5 kg.

The RMLVX1850 runs in two modes: as an inline station built into the production line, or at-line beside it for sampled and follow-up checks. The same programmed inspection task serves both, so a plant can start at-line and move the station into the line without rewriting its test programmes.

Hidden joints become a routine measurement

Many of the joints that decide the reliability of an engine control unit or a power module sit where no camera can see them. Ball grid arrays, bottom-terminated components and press-fit or soldered connectors hide their joints under the package body. X-ray passes through the component and shows the joint itself.

The RMLVX1850 is built for exactly this kind of feature. Its typical inspection tasks are:

• hidden solder-joint defects under packages and in through-hole joints
• connector defects and missing or misplaced parts
• dimensional deviations of internal features, measured against the programmed nominal

“An inline X-ray station turns the solder joint from something you sample into something you measure on every board you choose to inspect,” says Gabor Szabo, Sales Director Europe, Royma Europe. “The line engineer gets the result at the station, and the quality engineer gets an image record behind it.”

Four axes for the view the joint needs

A single straight-through image is often not enough to judge a joint on a double-sided board. The RMLVX1850 moves the sample in X, Y and Z and adds a rotation axis. The inspection programme can therefore approach a joint from the angle that separates it from components on the other side of the board, and repeat that view on every board of the batch.

The X-ray source covers 40 to 110 kV. The lower end suits fine-pitch joints on thin boards; the upper end gives the penetration needed for thicker multilayer boards, shielded modules and assemblies with metal carriers. The maximum sample size of 200 × 200 mm and 5 kg takes typical automotive control-unit boards and compact sub-assemblies.

Traceable results for every board inspected

Automotive customers expect each board to be traceable to its inspection result. The RMLVX1850 software reads the barcode of each sample, runs the programmed inspection task, controls the sample motion and stores the images and results in a database. Results can be traced back by serial number when a field return or an audit asks what the board looked like when it left the line.

Inspection tasks are programmable, so the station is set up once per product and the same checks run on every board of that product.

Built for the production floor

The RMLVX1850 is a full lead-shielded cabinet with a safety interlock and CE certification, with stated X-ray leakage below 1 µSv/h. It occupies 2300 × 1400 × 2000 mm and weighs 2000 kg, a footprint that plans into a PCBA line like any other station.

“Before a station goes into a line, we want to see the customer’s own boards,” adds Szabo. “The part, the joints that matter and the cycle time available decide how the inspection programme is built, and we test that on real assemblies first.”

For inspection tasks that need a full 3D volume, such as layer-by-layer analysis of multilayer boards, Royma also offers planar CT for electronics. More applications are shown under automotive and consumer electronics.

Test inspections of customer boards

Royma Europe offers test inspections of customer boards and assemblies on the RMLVX1850, with an evaluation of which defects the station detects and how the inspection programme would run in the line. Contact Gabor Szabo, Sales Director Europe, Royma Europe, gabor_szabo@roymatek.eu, +49 15156503316, www.roymatek.eu.

Royma Europe, Leibniz Universität Hannover – Institut für Produktentwicklung und Gerätebau, Gebäude 8143, An d. Universität 1, 30823 Garbsen, Germany.