semi合集-English.pdf - 第4289页
SEMI F81-1103 © SEMI 2003 4 5.1.61 welder — a person w ho does welding (sometimes us ed to refe r to a wel d ing machine or power supply ). 5.1.62 welding equipment — power supply, weld heads, torches, and associ ated ca…
SEMI F81-1103 © SEMI 2003 3
5.1.30 heat tint/color — non-standard term for
discoloration resulting from welding procedure.
5.1.31 heat-affected zone (HAZ)(2) — the portion of
the base metal whose mechanical properties or
microstructure have been altered by the heat of
welding.
5.1.32 inclusion(2) — entrapped foreign solid material,
such as slag, flux, tungsten, or oxide.
5.1.33 inert gas — a gas that normally does not
combine chemically with materials. A protective
atmosphere.
5.1.34 inspector — a person who verifies that all
required examinations and testing have been completed,
and who inspects the assembly to the extent necessary
to be satisfied that it conforms to all applicable
examination requirements. The inspector performs
quality assurance for the owner. The inspector is
designated by the owner and shall be the owner, an
employee of the owner, an employee of an engineering
or scientific organization, or of a recognized insurance
or inspection company acting as the owner’s agent.
5.1.35 lathe welding — automatic or machine welding
of tubes or pipes in which the electrode is stationary
and the weld joint rotates. Lathe welding as defined
here is a fusion process without the addition of filler.
5.1.36 liquid(1) — having its molecules moving freely
with respect to each other so as to flow readily, unlike a
solid, but because of cohesive forces not expanding
infinitely like a gas.
5.1.37 liquid cylinder — often referred to as a dewar,
an insulated and pressure controlled metal cylinder used
to store fluids in their liquid form.
5.1.38 meandering(3) — of or pertaining to a weld
bead that deviates from side to side across the weld
joint rather than tracking the joint precisely.
5.1.39 orbital welding(3) — automatic or machine
welding of tubes or pipes in-place with the electrode
rotating (or orbiting) around the work. Orbital welding,
as it applies to this standard, is a fusion process without
the addition of filler.
5.1.40 oxidation(3) — the formation of an oxide layer
on a metal surface. When excessive oxidation occurs as
a result of welding, it is visible as discoloration.
5.1.41 oxide island — non-standard term for slag.
5.1.42 pressure cylinder — a metal cylinder used to
store gases under pressure.
5.1.43 profile defect — any defect or discontinuity that
reduces the wall thickness below that of the parent
metal.
5.1.44 pulsed gas tungsten arc welding — a gas
tungsten arc welding process variation in which the
current is varied in regular intervals.
5.1.45 purge gas — an inert gas (or gas mixture) used
to displace the ambient atmosphere from the inside (ID)
of the weld joint.
5.1.46 purge — the application of an inert gas (or gas
mixture) to the OD or ID surface of the weld joint to
displace non-inert atmospheric gases.
5.1.47 root — non-standard term for root surface.
5.1.48 root surface(2) — the exposed surface of a weld
opposite the side from which the welding was done.
5.1.49 rotation delay — time delay between when the
arc is initiated and the rotor begins to turn.
5.1.50 shield gas — inert gas (or gas mixture) that
protects the electrode and molten puddle from
atmosphere and provides the required arc
characteristics.
5.1.51 slag(2) — a non-metallic product resulting from
the mutual dissolution of non-metallic impurities in
some welding processes.
5.1.52 tack weld(2) — a weld made to hold the parts of
a weldment in proper alignment until the final welds are
made.
5.1.53 tail-out(2) — non-standard term for automatic
arc welding downslope.
5.1.54 tungsten — non-standard term for tungsten
electrode.
5.1.55 tungsten electrode(2) — a component of the
electrical circuit that terminates at the arc, molten
conductive slag, or base metal. A non-filler electrode
made principally of tungsten and used in arc welding.
5.1.56 undercut(2) — a groove adjacent to the base
metal at the edge of the weld left unfilled by weld
metal.
5.1.57 underfill(2) — a groove weld condition in
which the weld face or root surface is below the
adjacent surface of the base metal.
5.1.58 weld bead(2) — a weld resulting from a weld
pass.
5.1.59 weld level — a segment or portion of a weld
schedule in which one or more weld parameters can be
changed independently; part of a weld sequence.
5.1.60 weld sequence — a series of steps executed by
the welding power supply to make a particular orbital
weld.
SEMI F81-1103 © SEMI 2003 4
5.1.61 welder — a person who does welding
(sometimes used to refer to a welding machine or
power supply).
5.1.62 welding equipment — power supply, weld
heads, torches, and associated cables and accessories
used for welding.
5.1.63 welding operator — a person who welds with
an orbital or machine welding system.
6 Ordering Information
6.1 The purchase order for services to be supplied in
compliance with this specification shall include the
following information:
6.1.1 Purchase order number
6.1.2 Reference to applicable specifications
6.1.3 Documentation and certification requirements
6.1.3.1 Disposition of documentation and coupons
6.1.3.2 Disposition of nonconforming product
6.1.4 Inspection methods and tools
6.1.4.1 Qualifications for inspector/examiner; for
example, ASNT SNT-TC-1A or AWS QC-1
6.1.4.2 % level inspection for quality assurance or
quality control
7 Requirements
7.1 Welds shall be produced in conformance with the
procedures and requirements outlined in SEMI F78
“Practice for Gas Tungsten Arc (GTA) Welding of
Fluid Distribution Systems in Semiconductor
Manufacturing Applications.” All weld beads shall
conform to the following specifications:
7.1.1 All welds shall exhibit complete penetration
around the entire internal surface. Penetration and bead
width shall be uniform throughout the entire weld.
7.1.2 Welds shall have no visible surface cracks,
porosity or inclusions under magnification. (Refer to
Section 8.1 of this standard.) See also Section 7.1.9.
7.1.3 No profile defect reducing the minimum wall
thickness T
min
below that of the parent metal is
permitted at any point in the weld (Figure 1). Undercut
and centerline shrinkage shall not be accepted. ID
concavity is not permitted.
7.1.4 Outer diameter (OD) concavity shall not exceed
10% of the nominal tube wall thickness T on tubing 1
in. (25 mm) and larger. No OD concavity is allowed on
tubing under 1 in. (25 mm) OD convexity shall not
exceed 10% of the nominal wall thickness T (Figure 2).
7.1.5 Inner diameter (ID) convexity shall not exceed
10% of the nominal wall thickness T (Figure 3).
7.1.6 Minimum ID weld bead width shall be 1.0 times
the nominal wall thickness T. Maximum ID bead width
shall be 2.5 times the nominal wall thickness T.
7.1.7 In any individual weld, maximum ID bead width
shall not exceed 1.25 times the minimum bead width
(Figure 4).
7.1.8 ID and OD weld bead meander shall not exceed
35% of the nominal wall thickness T (Figure 5).
7.1.9 The ID weld root surface shall have no porosity,
inclusions or slag when viewed without magnification.
A small slag inclusion at the end of the downslope, with
a diameter less that 10% of the nominal wall thickness
T, that does not affect weld integrity may be acceptable.
7.1.10 The OD weld face width shall be a minimum of
two (2) times the nominal wall thickness T.
7.1.11 Weld bead overlap (the percentage of the first
weld pulse that is covered by the subsequent weld
pulse) shall be at a minimum 80% on the OD and 70%
on the ID along the complete length except the
downslope (Figure 6).
7.1.12 Tack welds must be totally consumed and
undetectable in or around the OD or ID weld bead
(Figure 7).
7.1.13 The OD weld face shall be free of oxidation
except a light straw color is permissible. Light external
oxidation may be removed with a stainless steel wire
brush immediately after welding unless prohibited by
the end user.
7.1.14 There shall be no visible discoloration on the
tube ID or weld ID when viewed under a bright
fluorescent light without magnification (HP and UHP
systems only). Above 2 in. (50 mm) in diameter, a
slight blue color may be acceptable.
7.1.15 Axial misalignment shall not exceed 10% of the
nominal wall thickness T (Figure 8).
7.1.16 Angular misalignment shall not exceed ± ½
degree (1/8 in. per foot or 10 mm per m) (Figure 9).
7.1.17 The weld downslope must be present and of
sufficient length to prevent a crater at the end of the
weld. The distance between the ID downslope and the
OD downslope shall be a minimum of 3 times the
nominal wall thickness T (Figure 10).
8 Inspection Tools and Methods
8.1 Acceptable tools, magnification, and illumination
shall be specified and agreed upon between the supplier
and purchaser, per Section 6.1.4 of this document.
SEMI F81-1103 © SEMI 2003 5
8.2 Examples of acceptable tools, magnification, and
illumination include, but are not limited to, the
following:
8.2.1 Tools — sight pipe; rigid borescope; calipers; v-
blocks; dial indicators; comparators
8.2.2 Magnification — magnifying glass; optical
microscope (2 to 40×)
8.2.3 Illumination — flashlight; bright fluorescent
light; natural (ambient) light; white paper (for
background illumination)
8.3 All tools shall be used without damaging or
contaminating the wetted surface of production
weldments. Tools may touch the wetted surface of
coupons.
9 Certification
9.1 Upon request of the purchaser in the contract or
order, a manufacturer' s or supplier' s certification that
the product was manufactured and tested in accordance
with this specification, together with a report of the test
results, shall be furnished at the time of shipment.
9.2 If desired, the supplier and purchaser may agree
that the product shall be certified as “capable of
meeting” certain requirements. In this context,
“capable of meeting” shall signify that the supplier is
not required to perform the appropriate tests. However,
if the purchaser performs the test(s) and the product
fails to meet the requirement(s), the product may be
subject to rejection.