semi合集-English.pdf - 第6245页
SEMI G48-89 © SEMI 1989, 1996 2 4.1.8 Bottom Cavity Wid th (Section 5.8) 4.1.9 Ca vity Overl ap/Unde rlap (Section 5.9) 4.1.10 Cavity to Cavit y Mismatch (Sect ion 5.10) 4.1.11 Cavi ty Depth (Secti on 5.11) 4.1.12 M o ld…
SEMI G48-89 © SEMI 1989, 1996 1
SEMI G48-89
SPECIFICATION FOR MEASUREMENT METHOD FOR MOLDED
PLASTIC PACKAGE TOOLING
1 Preface
This document is prepared to enable standard
measurement techniques to be used. It is intended that
the measurement techniques described in the
specification will apply to all molded plastic package
tooling, i.e. DIPS, SIPS, PCC, SO, Quad, and TAB.
2 Applicable Documents
2.1 SEMI Specifications
SEMI G14 — Plastic Molded DIP Tooling
SEMI G16 — Plastic Chip Carrier Tooling
SEMI G36 — Plastic Molded High Density TAB Quad
Tooling
SEMI G37 — Plastic Molded SO Package Tooling
3 Basic Equipment
3.1 The following basic equipment is required to
perform the specified measurements:
3.1.1 Toolmaker’s Microscope — 3× objective and
10× eyepiece total 30× with X and Y axes digital
readouts reading to 0.0001" . Minimum travel of stage
must be 2.0" × 2.0" . Eyepiece must be ± 0.0002"
minimum. The toolmaker’s microscope should have a
goniometer on the eyepiece as will as on the stage.
Accuracy of the goniometer shall be 0.1. The TM
microscope should have a Z axis with a digital
measurement capability, reading in increments of
0.0001" . The objective lens must be 20× minimum
which will give 0.0005" accuracy to the Z axis
measurements.
3.1.2 Optical Comparator — Surface illumination. 10"
minimum screen with 3" × 8" minimum travel.
Magnification of 10×, 20× minimum required.
Accuracy of 10× is 0.001" ; accuracy of 20× is 0.0005" .
Some operators may be able to improve on this
accuracy, but this is the best expected from average
inspectors.
3.1.2.1 Overlays at 20× may be used for rapid mea-
surement. The user is cautioned that the thickness of the
line must be controlled. Line widths must not exceed
0.010" in width, which will give an inaccuracy of
0.0005" in the measurement. Overlays must have the
datum marks clearly labeled. Overlays are tools which
speed inspection; however, rejects must be verified by
toolmaker’s microscope measurements, which are more
accurate.
3.1.3 Digital Depth Indicator — Mounted on a stand.
Digital reading with a range of 2" is available. Readout
must display increments of 0.0001" with ± 1 digit
accuracy.
3.1.4 Micrometer — 0 to 1.0" . 0.250" diameter for
measuring to 0.001" accuracy.
3.1.5 Eight (8) inch dial calipers for measuring to
0.002" accuracy.
3.1.6 Granite Surface Plate — Minimum size 18" ×
28" , with a surface accuracy of 0.0002" or better.
3.1.7 Surface Finish
3.1.7.1 Charmille Visual Surface Finish Standard —
(For comparison of Electric Discharge Machined
(EDM) surface only.)
3.1.7.2 Surface Comparator Standards — (For other
machined surfaces.)
3.1.7.3 Surface Analyzer
3.1.8 Binocular, Zoom Microscope — 10—15× mag-
nification with vertical or near vertical lighting.
3.1.9 Dial Indicators — With accuracy of .0001 and
with force not to exceed 5 grams.
3.2 Alternative Equipment — Sophisticated, automatic
equipment is not excluded from use, but the user must
ensure that such equipment meets or exceeds the
accuracy of the basic equipment so that correlation
problems may be avoided.
3.3 Calibration — All equipment to be calibrated on a
regular schedule.
4 Measurements
4.1 The following measurements will be made:
4.1.1 Package Thickness (Section 5.1)
4.1.2 Package Length (Section 5.2)
4.1.3 Package Width (Section 5.3)
4.1.4 Leadframe to Cavity Offset (Section 5.4)
4.1.5 Top Cavity Length (Section 5.5)
4.1.6 Top Cavity Width (Section 5.6)
4.1.7 Bottom Cavity Length (Section 5.7)
SEMI G48-89 © SEMI 1989, 1996 2
4.1.8 Bottom Cavity Width (Section 5.8)
4.1.9 Cavity Overlap/Underlap (Section 5.9)
4.1.10 Cavity to Cavity Mismatch (Section 5.10)
4.1.11 Cavity Depth (Section 5.11)
4.1.12 Molding Protrusions (Section 5.12)
4.1.13 Pin Depths (Section 5.13)
4.1.14 Dambar Trimming Defects (Section 5.14)
4.1.15 Package Warpage (Section 5.15)
4.1.16 Lead Coplanarity (Section 5.16)
4.1.17 Shoulder Bend Location (Section 5.17)
4.1.18 Surface Finish (Section 5.18)
4.1.19 Radii (Section 5.19)
4.1.20 Lead Position (Section 5.20)
4.1.21 Draft Angles (Section 5.21)
4.1.22 Lead Spread (Section 5.22)
4.1.23 Foot Angle (Section 5.23)
4.1.24 Foot Length (Section 5.24)
4.1.25 Plastic Stand-off (Section 5.25)
4.2 Conditions
4.2.1 All measurements to be made on molded
components, which have been processed to agreed
conditions including post mold cure.
4.2.2 All measurements to be performed at a
temperature between 20° and 26.7° C (68° , 80° F).
4.2.3 Axis Definition
4.2.3.1 The X axis lies parallel to the rail of the frame
and the Y axis lies perpendicular to the rails of the
frame.
4.2.3.2 The package X and Y axes must be positioned
parallel to the X and Y axes of the measurement stage
travel to avoid measurement errors.
4.2.3.3 The datum of the X and Y axes is the pilot hole
of the leadframe, because it is the most accurate feature.
An additional pilot hole is required to establish the theta
datum.
4.2.3.4 The Z axis is perpendicular to the X and Y axis.
The datum is the leadframe or the top mold parting line,
unless otherwise specified.
5 Measurement
5.1 Package Thickness — (Figure 1)
5.1.1 Equipment — Micrometer
5.1.2 Using the micrometer, measure the thickness of
the package at three (3) places, diagonally across the
package, where the contours allow, at the top edge,
middle and bottom edge of the package. (Note: the top
is the pin 1 identifier edge.)
5.2 Package Length — (Figure 1)
5.2.1 Equipment — Optical Comparator at 10×.
5.2.2 Position the package so that the cross-sectional
view is presented for measurement. Use care to assure
the package is square to the datum plane.
5.2.3 Align the package side draft angle (see Section
5.21) where the draft angle intersects the leadframe.
This is the parting line (datum point). Measure the
overall width at the parting line, including cavity
mismatch.
5.3 Package Width — (Figure 1)
5.3.1 Equipment — Optical Comparator at 10×.
5.3.2 Position the package so that the cross-sectional
view is presented for measurement. Use care to assure
the package is square to the datum plane.
5.3.3 Align the package side draft angle (see Section
5.21) where the draft angle intersects the leadframe.
This is the parting line (datum point). Measure the
overall width at the parting line including cavity
mismatch.
5.4 Leadframe to Cavity Offset — (Figure 2)
5.4.1 Equipment — Toolmaker’s Microscope at 30×.
5.4.2 Position the circle (cross hair) of the filar
eyepiece of similar diameter to the leadframe pilot hole.
Zero the digital readout. Move the stage to the point
where the molded package meets the leadframe at the
parting line. Record digital readout reading as (T1).
Continue to move the stage until the point on the
opposite side where mold compound and leadframe
meet. Record digital readout reading as T2. Continue to
move stage to center of leadframe rail (usually also a
hole). Record the digital readout reading as T3.
5.4.3 Turn part over and BE SURE TO USE THE
SAME HOLE AND PART; repeat the three (3)
readings, B1, B2, and B3.
5.4.4 Derive the data from the readings as follows:
Top Centerline of Frame = (T3)/2
Bottom Centerline of Frame = (B3)/2
Measurement Error = (T3)/2 - (B3)/2
Frame Cavity Offset = (B3)/2 - (B2 + B1)/2
SEMI G48-89 © SEMI 1989, 1996 3
Centerline of Package = (T2 + T1)/2; (B2 + B1)/2.
(Relative to datum)
NOTE: Figure 2 calculations assume that the leadframe
centerline is equidistant between T3 and the zero datum point.
5.4.5 In lieu of the frame pilot hole, the dambar may be
used on the frame when measuring the offset; however,
the possibility of tolerance error may become
cumulative, particularly with etched rather than
stamped frames.
NOTE: By SEMI convention the offsets are defined in
relation to the bottom cavity of the mold.
5.5 Top Cavity Length “Y” Axis — (Figure 2)
5.5.1 Equipment — Toolmaker’s Microscope at 30×.
5.5.2 Focus the microscope on the leadframe datum
point. Zero the digital readout. Move the stage to the
intersection of the mold compound and the leadframe
parting line. Read and record. Continue to measure
across the package length to the intersection of the
mold compound and the leadframe parting line on the
opposite edge of the package. Read and record.
5.5.3 The cavity length is defined as (Ty2 – Ty1).
5.6 Top Cavity Width “X” Axis — (Figure 2)
5.6.1 Equipment — Toolmaker’s Microscope at 30×.
5.6.2 Focus the microscope on the leadframe datum
point. Zero the digital readout. Move the stage to the
intersection of the mold compound and the leadframe
parting line. Read and record the reading. Continue on
to the intersection of the mold compound and the
leadframe parting line on the opposite side. Read and
record.
5.6.3 The cavity width is defined as Tx2 – Tx1.
5.7 Bottom Cavity Length “X” Axis — (Figure 2)
5.7.1 Equipment — Toolmaker’s Microscope at 30×.
5.7.2 Focus the microscope on the same datum point
used for the top cavity length (remember the package
has been turned over). Zero the digital readout. Move to
the intersection of the mold compound and the
leadframe parting line. Read and record the reading.
Continue to the intersection of the mold compound and
the leadframe parting line on the opposite side. Read
and record. The bottom cavity length is the difference
of the two readings. Record the bottom cavity length
(By2 – By1).
5.8 Bottom Cavity Width “X” Axis — (Figure 2)
5.8.1 Equipment — Toolmaker’s Microscope at 30×.
5.8.2 Focus the microscope on the leadframe datum
point. Zero the digital readout. Move the stage to the
intersection of the mold compound and the leadframe
parting line. Read and record. The bottom cavity width
is the difference of the two readings (Bx2 – Bx1).
5.9 Cavity Overlap/Underlap — (Figure 4)
5.9.1 Compare the top cavity length to the bottom
cavity length and the top cavity width to the bottom
cavity width. The difference in the number is the
overlap/underlap for each axis.
5.10 Cavity to Cavity Mismatch — (Figure 2)
5.10.1 The comparison of the centerlines of the top
cavity length to the bottom cavity length and the top
cavity width to the bottom cavity width shall determine
the cavity to cavity mismatch.
Formula:
Cavity to Cavity Mismatch =
(B2 + B1)/2 – (T2 + T1)/2
5.11 Cavity Depth — (Figure 1)
5.11.1 Equipment — Depth Indicator
5.11.2 Top Cavity Depth — Measure the distance from
the top surface of the leadframe to the top of the unit,
place the indicator on the surface of the leadframe,
zeroing the readout, moving the part to a point where
the top of the unit can be indicated, and read and record
the readout.
5.11.3 Bottom Cavity Depth — The measurement is
performed in the same manner as the measurement in
Section 5.11.2 except the part is turned over and the
bottom surface of the leadframe to the bottom of the
unit is used.
5.11.4 The package depth is the sum of the frame
thickness and the top and bottom depth. (This
measurement should equal Section 5.1. Any variation
may be considered measurement error.)
5.12 Molding Protrusions Top/Bottom of Part —
(Figure 3)
5.12.1 Equipment — Digital depth indicator.
5.12.2 Place unit on the anvil and zero the indicator on
the package surface away from area of protrusion.
Carefully move the part to where the protrusion is
located. Carefully lower the indicator to the top of the
mold protrusion. Read and record the mold protrusion.
5.13 Pin Depths — (Figure 3)
5.13.1 Equipment — Depth indicator with a fine point
or “Z” axis reading toolmaker’s microscope.
5.13.2 The measurement is made from the nominal
plane of the package surface to the bottom of the design