semi合集-English.pdf - 第6149页
SEMI G31-0997 © SE MI 1986, 1997 3 Figure 1 Orifice Abrasion Figure 2 Orifice Mo ld
SEMI G31-0997 © SEMI 1986, 1997 2
7.3.4 Preheat preformed material to the required
temperature.
7.3.5 Insert preheated material into transfer pot and
activate transfer ram (semi-automatic mode).
7.3.6 Start stopwatch when extrudate first appears.
Record total extrusion time.
7.3.7 Collect and weigh extrudate to nearest one tenth
of a gram. Record extrudate weight.
7.3.8 At the end of cure cycle, remo ve orifice from
retainer. Loosen set-screws to split orifice and, with
compressed air, blow out cured slug.
7.3.9 Ensure mating orifice halves are clean, realign
the halves and tighten set screws.
7.3.10 Place orifice in retainer and repeat steps 7.3.4
through 7.3.9.
7.3.11 Repeat steps 7.3.4 through 7.3.10 until a
minimum of 40 shots are run.
7.3.12 Record the following:
1. Original orifice weight
2. Shot number
3. Extruded weight per shot in grams
4. Cumulative extruded weight in grams
5. Orifice weight in grams
6. Orifice percent weight loss
7. Extrusion rate
8 Calculation
8.1 Orifice Weight Loss
I
O
− I
N
I
O
100%()= % wt. loss
I
O
= Initial orifice weight to ten thousandth of a gram
I
N
= Orifice weight after “N” number of shots to ten
thousandth of a gram
8.2 Plot on linear graph paper the orifice weight loss
vs. cumulative extruded weight.
8.3 Convert cumulative weight extruded to cumulative
volume extruded.
Example: Molding compound density 2.0 g/cm
3
cumulative weight = 2000 g
2000
2.0g
1000
3
3
g
cm
cm
×=
8.4 Convert cumulative volume extruded to equivalent
production mold shots.
Example: 28 mm × 28 mm × 3.4 mm - 208 Id PQFP
Package Volume:
28
1000
2 6656
3
mm × 28 mm × 3.4 mmx
cm
m
m
cm
3
3
=
.
Volume to shots:
1000 cm ×
sho
t
2.6656 cm
375 shots
3
3
=
8.5 Plot on linear graph paper the orifice weight loss
vs. equivalent production mold shots.
SEMI G31-0997 © SEMI 1986, 19973
Figure 1
Orifice Abrasion
Figure 2
Orifice Mold
SEMI G31-0997 © SEMI 1986, 1997 4
Figure 3
Top Plate
Figure 4
Orifice Holder