Semiconductor Gas Manifold CNC Machining
A gas manifold for semiconductor equipment is a block whose passages have to meet on purpose, with seal lands that do not leak and edges that do not shed particles. A burr in a gas line is not a cosmetic defect. It is contamination waiting to move.
Hole size on every port is not the same as a working manifold. Two holes can be the right diameter and still dump particles into a chamber if the groove edge is rolled or a crossing is left dirty.
This page is how we approach semiconductor gas manifold CNC machining: map the passages, cut the groove last, treat wash and caps as operations, then check that intended crossings are open. It is not a named customer story. Drawings and production photos stay in the shop.
What fails first on a gas block
Not the outside cube. The usual failures are a seal land that weeps because the last pass rolled the edge; two passages that should meet and don’t; a long hole that walked into a groove; chips that survive a visual on the faces and move the first time gas flows.
Helium leak, electropolish and a named clean spec are extra lines. We do them when they are on the purchase order. We do not print a leak rate we do not test, and we do not claim a cleanroom certificate we do not hold.
Drawing review
Crossing map first — which hole feeds which, which must stay isolated. Then the seal: O-ring groove, face-seal land, or a customer form. Then port style and the finish on that land.
Long holes need a depth and a method on the plan, not a short peck and hope. Material comes off the print: 6061 on non-corrosive service, 316 / 316L when the gas list asks for stainless. We do not upgrade the alloy because the part is “semiconductor.”
Bag-and-tag, no-silicone, or a particle note belongs on the order. If it is not written, it is not in the quote.
Blank
Sawed aluminum or stainless block. Not a casting. Not a forging unless the envelope is odd. Mill certs travel when the PO asks.
How the passages are cut
Square the faces. Datum the mounting or seal face if that is how the block sits. Main passages first, crossings second — same reason as a hydraulic block. Burrs belong where we can still reach them.
Long holes get a rigid peck or a deep-hole drill when length-to-diameter asks for it. Seal grooves last, sharp tool, no rolled edge on the land.
We mill these on 4-axis and 3+2. Envelope on the 5-axis side is 650 × 550 × 450 mm. A gas cube does not need simultaneous 5-axis because it has six faces.
Groove, wash, cap
The land is a sealing feature. We do not stone a leak into spec. If the edge is rolled, it is recut.
Blow the intended circuits. Wash until the passages come out clean. Dry. Cap every port. No oil film left as a protective coat unless the customer asked for it.
What we verify
Groove position and land condition. Port threads. Blow-through of intended paths; isolated holes stay isolated.
CMM on first article when the drawing, PO or inspection plan asks for it. Electropolish or a leak test only when specified.
First lot and a repeating lot
| Prototype / small lot | Repeating lot | |
| Blank | Sawed 6061 or 316/316L | Same, certified stock if required |
| Holes | Main first, crossings second | Same locked sequence |
| Seals | Groove last, sharp tool | Same; EP / leak test only if quoted |
| Inside | Blow-through + wash on early pieces | Written wash spec |
| Lead time | About 15 working days after the crossing map is locked and stock is in | Plus clean pack or EP if on the PO |
Fifteen working days is a planning reference. A dense block or an added clean spec takes longer.
Problems we look for before the crate leaves
Groove edge rolled
Re-cut with a sharp tool. Do not dress it until it “looks sealed.”
Two holes fail to meet
Depth error. Catch it on blow-through, not at the tool.
The RFQ names a leak rate with no test on the order
We will not put that number on a cert.
Why there are no customer photos on this page
Gas manifolds are customer-specific. We do not publish crossing maps or production photos without permission.
What to send for a quote
2D and STEP. Crossing map. Material. Clean-pack, electropolish or leak-test yes or no. Quantity.
No minimum order.
Related: Semiconductor Equipment Machining · 5-Axis CNC Machining Services · Hydraulic Manifold CNC Machining
FAQ
Do you machine 316L gas manifolds?
Yes, when the print names 316 or 316L. We do not swap aluminum for stainless on our own.
Do you helium-leak every block?
When the purchase order or inspection plan specifies it.
Does a gas cube need simultaneous 5-axis?
Usually not. 4-axis or 3+2 keeps the faces square.