# SAM-500 Scanning Acoustic Microscope

> See the delamination X-ray cannot


A scanning acoustic microscope answers the one question X-ray cannot: is there a gap at an interface that should be bonded? Sound reflects almost completely at a solid-to-air boundary, so a delamination, a crack or an unbonded die attach returns a signal far stronger than the surrounding material.

The SAM-500 is built as a production cell rather than a laboratory instrument. A 450 × 300 mm envelope takes JEDEC trays, 300 mm wafers and custom fixtures; the inverted-jet option scans power modules without a water bath; and every accept-or-reject call is written to MES against the part serial.

The table gives the target build for the first unit. Transducer set, scan envelope and repeatability are confirmed at acceptance test against the part numbers the cell is bought for.


## Overview

The SAM-500 images internal interfaces with high-frequency ultrasound, so air gaps — delamination, voids, cracks and unbonded die attach — return a strong signal where X-ray passes straight through. The configuration below is the target build for the first production unit; final values are confirmed at factory acceptance test against your part numbers.

## Highlights

- **Air-gap contrast**: Sound stops at an air gap. A 20 µm delamination under a die returns full contrast where X-ray sees only density.
- **Built for the line**: Tray handling, serial traceability, sorting and MES output are part of the cell, not a later integration project.
- **Calls you can defend**: Acceptance follows MIL-STD-883 TM2030 and your void limit, stored against the part serial.

## Technical data

| Parameter | Value |
|---|---|
| Transducer range | 10–300 MHz, selected per part |
| Scan envelope | 450 × 300 × 120 mm |
| Max scan speed | 1,200 mm/s |
| Repeatability | ±0.5 µm (X/Y) |
| Imaging modes | A / B / C / D / T-scan |
| Coupling | Water immersion or inverted jet |
| Carrier | JEDEC tray, 300 mm wafer, custom fixture |
| Interface | TCP/IP, Modbus, SECS/GEM optional |
| Acceptance basis | MIL-STD-883 TM2030; J-STD-035 / J-STD-020 |

## FAQ

### What defects can a scanning acoustic microscope detect?

Anything that traps air at an interface: delamination between moulding compound and die, voids and unbonded areas in die attach, cracks in ceramic, layer separation in MLCCs, and voids in the solder layer between a power die and its substrate. Electrical faults, broken wire bonds and bridged solder joints are outside its range, because they do not create an acoustic gap.

### Does SAM replace X-ray inspection?

No, and treating the two as alternatives is how defects get missed. X-ray resolves density: solder voiding, wire sweep, foreign metal. Acoustic microscopy resolves interfaces: delamination and micro-cracks that X-ray passes through without contrast. Most programmes run both, X-ray for the joint and acoustic for the bond.

### Can it inspect MLCCs at production speed?

It depends on which question you are answering. Offline sampling and failure analysis run at laboratory pace. Tray batch scanning covers incoming and final inspection. True 100 % inline screening is a different machine class, with parallel transducers and part handling designed around the feeder, and the rate has to be measured on your case size before anyone quotes a number.

### Does the part get wet during inspection?

Immersion scanning couples through a water bath, which is fine for bare ceramic, wafers and most passives. Power modules are usually scanned with an inverted jet or a local water column from below, so the module body and terminals stay dry and no cleaning step is added to the line.

### Which acceptance standards apply?

MIL-STD-883 Method 2030 sets die-attach limits: total voids above 50 % of the interface, a single void above 15 %, a corner void above 10 %, or any quadrant above 70 % is a reject. J-STD-035 covers the acoustic method for non-hermetic packages and J-STD-020 section 6.2.1 supplies the delamination criteria. Automotive power programmes usually tighten the void limit to 2–3 % and add a maximum single-void size.

### Can the results go into our MES or SPC system?

Yes. Results are written per part serial over TCP/IP or Modbus, with SECS/GEM available where the line requires it, so void rate and delamination area land in the same SPC chart as the rest of the process rather than in a standalone report.