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SEMI G58-94 © SEMI 1994 3 6.4.2 Finis h — Lead bon d areas. 6.4.2.1 Metallization — Aluminum. 6.4.2.1.1 Thicknes s — 100 – 600 mi croi n c hes (0.0025 – 0.015 mm ). 6.4.2.1.2 C overage — Total coverage fo r a distance of…

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SEMI G58-94 © SEMI 1994 2
3.8 foreign material — an adherent particle that is not
parent material of the component. Adherence means
that the particle cannot be removed by an air or nitrogen
blast at 20 psi.
3.9 glass flow — on a semiconductor package or cap,
the heating process which just removes all the screen
printing mesh marks in the sealing glass when viewed
at 10× magnification.
3.10 glass void — the absence of a sealing glass layer
from a designated area.
3.11 metallization void — the absence of a clad,
evaporated, plated or screen-printed metal layer or
braze from a designated area.
3.12 non-critical seal area — on a semiconductor
package that uses a lid, cap, or cover to effect the seal,
the area of the sealing surface outside the critical
sealing area. (See Figure 2.)
3.13 overhang — on a semiconductor package, the
horizontal extension of the sealing glass past the
vertical wall of a cavity cut into the ceramic layer on
which the glass is printed. (See Figure 3.)
3.14 peeling (flaking) — any separation of a plated,
vacuum deposited, or clad metal layer from the base
metal of a leadframe, pin, heatsink, or seal ring, from an
underplate, or from a refractory metal on a ceramic
package. Peeling exposes the underlying metal.
3.15 projection — on a semiconductor package
(plastic or ceramic), leadframe or preform, and
irregularly raised portion of a surface indiginous to the
parent material.
3.16 pullback — on a semiconductor package, the
linear distance between the edge of a cavity cut into a
ceramic layer and the first measureable glass or
metallization layer interface coated onto the top surface
of that layer. The total pullback may be the result of the
high temperature processing required to manufacture
the package or to coat the surface. It may also be the
result of design considerations. (See Figure 3.)
3.17 rundown — on a semiconductor package, the
linear distance from the upper surface of a ceramic
cavity layer to the bottom point of the overhang into the
cavity, of a sealing glass or metallization layer that has
been screened onto that surface. (See Figure 3.)
4 Ordering Information
Purchase orders for cerquad packages and caps
furnished to this specification shall include the
following items:
4.1 Package description
4.2 Current drawing revision detai ling
All dimensions
Type and color of ceramic
Type and thickness of sealant glass
Leadframe material type and design
Type and thickness of metallization in the lead
bond area
Type and thickness of external lead plating, if
applicable
Type and thickness of die attach metalization
4.3 Vendor certification requirements
4.4 Any additions to, or variations from, this
specification
5 Dimensions
The component described in this specification shall
produce packaged devices that conform to the outline
dimesnions and lead numbering for Cerquad Package
Constructions detailed in: JEDEC Publication 95; EIAJ;
MILSTD1835. Package manufacturing tolerances shall
be agreed between vendor and customer.
6 Materials
The definitions, defect criteria, and functional tests
described in this specification relate to package
components made with the following materials:
6.1 Base, Window Frame, and Cap
6.1.1 Material
6.1.1.1 Alumina — Content to be 90% minimum, or
6.1.1.2 Beryllia — Content to be agreed between
vendor and customer.
6.1.2 Color
6.1.2.1 Alumina — Black, dark brown, or violet.
6.1.2.2 Beryllia — White.
6.2 Sealant — A solder glass suitable for hermetic
sealing shall be specified.
6.3 Die Attach Pad Metallization — Gold or any other
suitable material shall be specified.
6.4 Leadframe
6.4.1 Base Material
6.4.1.1 Thickness — Shall be specified.
6.4.1.2 Composition — Iron-Nickel-Cobalt alloy per
MIL-M-38510, Type A or Iron-Nickel alloy per MIL-
M-38510, Type B shall be specified.
SEMI G58-94 © SEMI 19943
6.4.2 Finish — Lead bond areas.
6.4.2.1 Metallization — Aluminum.
6.4.2.1.1 Thickness — 100 – 600 microinches (0.0025
– 0.015 mm).
6.4.2.1.2 Coverage — Total coverage for a distance of
0.030" (0.762mm) minimum as measured from the lead
tip. Maximum length is defined by the lead bond cavity
size.
6.4.2.1.3 Composition — 99.4% minimum for clad
aluminum, 99.99% minimum for vapor deposited
aluminum.
6.4.2.2 Metallization — Gold.
6.4.2.2.1 Thickness — 50 – 225 microinches (0.0013 –
0.0057mm).
6.4.2.2.2 Coverage — See paragraph 6.4.2.1.2.
6.4.2.2.3 Composition — See SEMI G21 and MIL-G-
45204.
6.4.3 Leadframe Finish — External areas (if
specified).
6.4.3.1 Metallization — Gold (see Section 6.4.2.2).
7 Defect Limits
The following defects shall be rejected if the limits
shown are exceeded:
NOTE 3: The criteria apply to purchased pre-assemblies or,
where applicable, to units assembled by the customer to
process conditions agreed between vendor and customer.
7.1 Ceramic Components
7.1.1 Cracks — Not allowed.
7.1.2 Chips — See Figures 1 and 2.
7.1.2.1 Corner Chips — 0.030" (0.762 mm) × 0.030"
(0.762 mm) × 25% of package element thickness.
7.1.2.2 Edge Chips — 0.060" (1.524 mm) × 0.030"
(0.762 mm) × 25% of package element thickness.
7.1.2.3 Critical Seal Area — Chips must not reduce
the critical seal path length, at any point, to less than
one-half the nominal design dimension. No more than
four chips are allowed in this area regardless of loss of
seal length.
7.1.3 Burrs, Projections (Fins), and Blisters
7.1.3.1 Base, Window Frame, and Cap — 0.005"
(0.127 mm) maximum allowable dimension or greater
than 0.003" (0.076 mm) height.
7.1.3.2 Die Attach Surface — 0.001" (0.025 mm)
maximum above the metallization surface excluding a
zone, 0.010" (0.25 mm) wide, around the periphery of
the cavity maximum allowable dimension is 0.005"
(0.127 mm).
7.1.4 Camber — Shall be specified on the component
drawing.
7.2 Glass Sealant
7.2.1 Chips and Voids — 0.010" (0.254 mm)
maximum allowable dimension, with exposed or
covered ceramic. No more than four chips or voids are
allowed in the critical seal area. These defects must also
meet the requirements of Table 1 in Section 7.2.2.4.
7.2.2 Glass Misalignment (after glass flow) — See
Figure 3.
7.2.2.1 Glass Overhang — 0.15" (0.381 mm)
maximum extension from the ceramic edge.
7.2.2.2 External Rundown — 50% of component
thickness maximum.
7.2.2.3 Rundown into Lead Bond Cavity — 0.010"
(0.254 mm) maximum extension from the top surface
of the cavity.
7.2.2.4 Pullback — See Table 1.
Table 1 Maximum Allowable Pullback
External 0.015" (0.381 mm)
Internal 0.101" (0.254 mm)
NOTE 3: Glass pullback, at any point, shall not reduce the
critical seal path width to less than one-half the designed
width. (See Figure 2.)
7.2.2.5 Foreign Material — 0.020" (0.508 mm)
maximum allowable dimension but 0.010" (0.254 mm)
in the critical seal area, with no more than four sites
allowed and a minimum separation of 0.030" (0.762
mm) between sites.
7.3 Die Attach Cavity Metallization — Excluding a
0.010" (0.254 mm) wide zone around the periphery of
the cavity, the following criteria apply:
7.3.1 Foreign Material, including Glass Splatters —
no more than four areas with 0.005" (0.13 mm)
maximum dimension or greater than 0.001" (0.025 mm)
height.
7.3.2 Metallization Lumps — No more than four
allowed. If the metallization is Gold and eutectic Gold-
Silicon die attach is to be used, then the lumps may not
exceed 0.010" (0.254 mm) in diameter and 0.005"
(0.127 mm) height. If eutectic bonding is not used, then
the lumps will be treated as foreign material per Section
7.3.1
SEMI G58-94 © SEMI 1994 4
7.3.3 Voids — 0.005" (0.127 mm) maximum
allowable dimension with no more than four allowed
and a minimum separation of 0.030" (0.762 mm)
between sites.
7.4 Leadframe
7.4.1 Lead Bond Areas — the minimum lead bond
area on the lead tip is defined in Figure 4.
In these bond areas, the following defects are not
allowed:
7.4.1.1 Voids or Pits — Exposure of base material
with any dimension larger than 0.001" (0.0254 mm).
7.4.1.2 Discoloration, Blistering, or Peeling of the
Metallization
7.4.1.3 Scratches or Scrapes — Any build-up of the
metallization, or exposure of the base material.
7.4.1.4 Foreign Material including Glass Splatter or
Projections — No more than four sites, each with a
maximum dimension of 0.001" (0.0254 mm).
7.4.1.5 Glass Wetting or Cracking — Any lead finger
which is not firmly embedded in the glass.
7.4.1.6 Glass Pullback from the Lead Tip — Greater
than 0.010" (0.254 mm).
7.4.1.7 Glass Bulge between Lead Fingers — Greater
than 0.005" (0.127 mm) height above the fingers except
as agreed between vendor and customer for narrow
pitch leads where this limit may cause wire bond
interference problems.
7.4.1.8 Lead Tip Coplanarity (Pre-assembled Bases,
Leadframes, and Window Frames) — Greater than
0.006" (0.15 mm) difference in the position of the top
surface of the lead from highest lead to lowest lead.
7.4.1.9 Lead Tip Pitch — Greater than ± 0.002" (0.051
mm) variation from true position.
7.4.2 I nternal Lead Areas, excluding Lead Bond Areas
— In these areas, the following defects are not allowed:
7.4.2.1 Burrs and Projections or Pits — With a
maximum dimension greater than 0.002" (0.0508 mm)
in height or depth.
7.4.2.2 Foreign Material (including Plating
Discoloration) — With a major dimension in the
surface plane greater than 0.015" (0.381 mm) or
exceeding 0.002" (0.0508 mm) in height.
7.4.2.3 Voids which Expose Base Metal — With a
major dimension greater than 0.002" (0.0508 mm).
7.4.2.4 Blistering or Peeling of Metallization
7.4.2.5 Scratches and scrapes which cause metal build-
up or expose base material.
7.4.3 External Lead Areas
NOTE 4: Non-functional areas of the leadframe, such as tie-
bars, shall not be subjected to inspection.
7.4.3.1 Unplated Leads
NOTE 5: Plated leads shall also be required to pass these
criteria.
7.4.3.1.1 Scratches — Causing loss of more than 25%
of the leadframe thickness.
7.4.3.1.2 Voids — In violation of Section 7.4.3.1.1 or
loss of more than 10% of the design width of a
leadframe detail.
7.4.3.1.3 Burrs — In excess of 0.002" (0.051 mm) in
height and 0.005" (0.127 mm) in the major dimension.
7.4.3.2 Plated Leads
7.4.3.2.1 Scratches and Scrapes — Exposure of base
material or loss of plating integrity over 5% of the area
of a lead finger.
7.4.3.2.2 Voids — Exposure of base material.
7.4.3.2.3 Blistering or Peeling
7.4.3.2.4 Staining, Foreign Material, or
Contamination — In excess of 5% of the area of a lead
finger.
7.4.4 Lead Assembly
7.4.4.1 Lead Tip Overhang — 0.010" (0.254 mm)
maximum from the cavity wall, see Figure 5.
7.4.4.2 Lead Misalignment — 0.010" (0.254 mm)
maximum, see Figure 6.
7.4.5 Window Assembly Misalignme nt — 0.015"
(0.381 mm) maximum, see Figure 7.
8 Incoming Inspection and Functional Tests
8.1 Incoming Inspection
8.1.1 Dimensional inspection per Section 6.
8.1.2 Visual inspection per Section 7 at 10×
magnification with vertical lighting.
8.1.3 Metallization
8.1.3.1 Die Attach Metallization — Thickness shall be
measured by standard cross-sectioning without
smearing or by X-Ray fluorescence.
8.1.3.2 Lead Bond Metallization — Thickness shall be
measured by X-ray fluorescence.