TL;DR — Direct answer: A semiconductor packaging and testing plant needs very clean, dry air at 6 to 7 bar for die bonding, wire bonding, moulding, testing and handling, with a pressure dew point of minus 40 degrees C from a desiccant dryer and filtration to 0.01 micron so no oil, water or particles reach a die, a bond wire or a test socket. Size on the coincident peak of assembly and testing, commonly 4 to 10 cubic metres per minute for a mid-size plant, and use a variable speed drive because test lines run in batches. QiAir, a Chinese screw compressor manufacturer and supplier, builds oil-free machines with desiccant drying for semiconductor packaging and testing.
Semiconductor packaging and testing is where a chip becomes a product, and the air behind it has to be cleaner than in almost any other factory. Dies are bonded to substrates, wire bonds connect them, moulding compound seals the package, and test handlers cycle each chip through electrical tests before it ships. Compressed air drives die bonders, wire bonders, moulding presses, pick-and-place heads and test handlers, and a single particle or a puff of moisture can scrap a die worth far more than the air that damaged it. A pressure dip at the wrong moment can stall a handler mid-test and lose a batch of results, and oil in the line can contaminate a bond pad and cause a latent failure in the field. QiAir is a Chinese manufacturer and supplier of screw air compressors, and its oil-free machines for packaging and testing are specified around cleanliness, dryness and stability first and flow second.
The trap in packaging and testing is sizing air like a general electronics utility. Assembly is steady, testing is batchy with sharp peaks when handlers index, and the cleanroom environment means the compressor room and the air treatment chain sit outside the clean area, with long pipe runs to the tools. The compressor must cover the coincident peak without sagging below 6 bar at the farthest test handler, and the treatment chain must hold the dew point and particle level steady through the hottest, most humid month. This guide maps the air users on a packaging and testing line, explains how to size for assembly and test peaks, sets the cleanliness standard that protects dies and bonds, and shows what to put on a sizing sheet for a China supplier.
Where Air Is Used: Bonding, Moulding, Testing and Handling
Die bonding and wire bonding are the most sensitive users. Die bonders place a die on a substrate with micron accuracy, wire bonders connect it with gold or copper wire, and both need clean dry air at a stable pressure, because a pressure swing changes the bonding force and a particle on a bond pad causes a weak joint. A packaging hall with ten to thirty bonders can pull its peak when several bonders index together, and a compressor sized on average flow will sag exactly then. Keep the pressure at the bonder within a narrow band, and fit a dedicated receiver near the packaging hall if the header run is long, because a local receiver is cheaper than upsizing the whole system.
Moulding, testing and handling take the most air. Moulding presses use air for clamp control and ejection, test handlers use it for socket actuation and chip handling, and pick-and-place heads use vacuum and air for moving dies and packages. These users are spread across a cleanroom, so the farthest handler is the one that suffers first when pressure falls. A plant that maps every user, including the small air tools used for cleaning, usually finds 15 to 20 percent more demand than the original estimate, and that gap is where pressure problems start.
- Bonding: die bonders and wire bonders where a pressure dip changes bonding force.
- Moulding: press clamp control and ejection where moisture can spoil moulding compound.
- Testing and handling: test handlers, socket actuation and pick-and-place heads at stable pressure.
Sizing for Assembly and Test Line Peaks
List every line with its flow at peak and at steady running, because the two differ sharply in packaging and testing work. A mid-size plant with ten to thirty bonders, a moulding area and two to four test lines typically peaks at 4 to 10 cubic metres per minute at 6 to 7 bar, which is roughly a 30 to 55 kW oil-free screw compressor, and the peak usually lands when test handlers index together and the moulding presses eject. A variable speed drive earns its keep here: it follows the batch pattern instead of loading and unloading a fixed-speed machine dozens of times a shift, and it holds pressure within the narrow band that bonding and testing prefer.
Keep the pressure drop to the farthest test handler under 0.3 bar at peak flow, and fit a receiver of 500 to 1000 litres per 10 cubic metres per minute to absorb handler spikes. A ring main helps when the packaging hall and the test area sit in different wings of the building. Log pressure at the test line during a full production run for a week, because that log is the honest record of whether the compressor is big enough, and it settles arguments faster than any catalogue figure. Never raise the set point to mask a sag: every extra bar adds roughly 7 percent to power use and hides the real fault, which is usually a clogged filter or an undersized pipe.
- Size on the coincident peak of bonding, moulding and testing, not on steady-state average flow.
- Use a variable speed drive for batch test loads, and keep far-end pressure drop under 0.3 bar.
- Log test-line pressure during production for a week to prove the sizing in real use.
Cleanliness and Dryness: Protecting Dies and Bonds
A die is a fragile, expensive object, and the air that touches it must be treated as a cleanroom utility. The standard is a treatment chain, not a single filter: a pre-filter, a desiccant dryer to minus 40 degrees C pressure dew point, a coalescing filter to 0.01 micron, and an after-filter, with a dew point monitor and alarm on the dryer outlet. For packaging and testing lines, an oil-free screw compressor is the standard choice, because it removes the oil risk at source rather than filtering it out, and oil on a bond pad is a latent failure that may only show up after the chip ships.
Maintenance is what keeps that chain honest. Regenerate desiccant on schedule, change coalescing elements on pressure drop, and test the air at the packaging hall and the test line quarterly for oil, moisture and particles. Drain condensate with automatic zero-loss drains, slope lines to drain legs, and keep the compressor room clean, ventilated and cool so the machine does not breathe its own hot air or the dust of the plant. Keep the compressor intake away from the moulding area and the loading dock, check the intake filter weekly in the first months, and keep a spare on the shelf.
- Fit pre-filter, desiccant dryer to minus 40 degrees C, 0.01 micron coalescing filter and after-filter.
- Use an oil-free screw compressor, because oil on a bond pad causes latent field failures.
- Monitor dew point continuously with an alarm, and test air at the packaging hall and test line quarterly.
Buying from China: Sizing Sheet for a Semiconductor Packaging Plant Compressor
QiAir is a Chinese manufacturer and supplier of screw air compressors, and a semiconductor packaging order should start with a sizing sheet that names the cleanliness requirement. Send the supplier the number of bonders and test lines, the coincident peak at 6 to 7 bar, the air-quality standard the process specification requires, ambient temperature and humidity, and the distance to the farthest test handler. Ask for a quotation that states the oil-free machine, dryer duty and filtration grades explicitly, and ask what documentation, test records and spare-parts lists ship with the system, because a semiconductor buyer will need them for its own quality file.
Agree the acceptance test before shipment: a full-load run at rated pressure, a dew point reading at the dryer outlet, and an oil-aerosol check at the final filter outlet. On arrival, install on a level plinth with clear cooler airflow, connect drains before the first run, and survey pressure at the test line during the first full production week. Keep a log of pressure, dew point and filter changes, and review it monthly, because a slow rise in dew point is the earliest sign that a dryer needs attention before dies start failing test.
- Send the supplier bonder and test line counts, coincident peak, required air-quality standard and farthest-handler distance.
- Ask for the oil-free machine, dryer duty and filtration grades in writing, with documentation listed.
- Accept on a full-load test plus dew point and oil-aerosol checks, then survey pressure at the test line in week one.
Frequently asked questions
What air quality does semiconductor packaging and testing need?
Packaging and testing lines need very dry air at a minus 40 degree C pressure dew point from a desiccant dryer, with coalescing filtration to 0.01 micron and an after-filter. An oil-free screw compressor is the standard choice, because oil on a bond pad causes latent failures, and the air should be tested quarterly for oil, moisture and particles.
What size screw compressor does a packaging and testing plant need?
A mid-size semiconductor packaging and testing plant with ten to thirty bonders and two to four test lines typically needs 4 to 10 cubic metres per minute at 6 to 7 bar, roughly a 30 to 55 kW oil-free screw compressor. Size on the coincident peak of bonding, moulding and testing, and use a variable speed drive to follow the batch pattern.
Why does moisture damage semiconductor packaging?
Moisture in the air line can spoil moulding compound, corrode bond wires and cause weak joints that fail in the field. A desiccant dryer to minus 40 degrees C, a 0.01 micron coalescing filter and a dew point monitor with an alarm prevent most of it, and the air should be tested at the packaging hall and the test line every quarter.
Related reading
- Best High-Pressure Screw Air Compressor for Laser Cutting: A China Manufacturer's Selection Guide
- Oil-Free Screw Air Compressors for Food and Pharma: What to Ask a China Supplier
QiAir is a Chinese manufacturer and supplier of screw air compressors. If you are sourcing a screw compressor from China — for a factory, a food plant, a construction site or a new production line — contact QiAir for a sized quotation, documented performance data and export support.