IPC-TM-650 EN 2022 试验方法-- - 第298页
Where: D1 = H ole d iameter D2 = L and di ame t er L = L oad (force) The formula giv en utilizes the diameter of both the land and the hole in t he determination of the ar ea of the land, rather than the radius of each. …
1 Scope
This test method is to determine the land bond
strength of unsupported holes, after repeated soldering and
unsoldering, by mechanical pull in the perpendicular plane.
2 Applicable Documents
Generic Standard on Printed Board Design
3 Test Specimen
Any unsupported component hole
sample or test coupon ‘‘A’’ or ‘‘A/B’’ described in IPC-2221.
Three holes per sample or test coupon shall be tested.
4 Apparatus or Material
4.1 Soldering Iron
60-watt soldering iron capable of pro-
ducing a tip temperature of 232 °C to 260 °C [450 °F to
500 °F].
4.2 Force Tester
Vertical pull force tester capable of oper-
ating at a speed of 50.0 mm [2.0 in] per minute and measur-
ing up to 9 kg [20 pounds] load.
4.3
Tinned or solder coated copper wire.
5 Procedure
5.1 Preparation
5.1.1
If conductors are connected to the land area, the fol-
lowing procedure is to be followed:
Take a sharp model knife and cut conductor at least 6.0 mm
[0.2 in] away from the land. Place blade of knife on edge of
land area where conductor enters. While holding the blade
down, pull conductor to the land and use knife blade as ful-
crum to break conductor from land without disturbing bond of
the land.
5.1.2
Insert wire so that the portion extending from the sol-
dered side of the circuit may be fitted into the gripping mecha-
nism of a tensile tester. The wires shall have a diameter
between 150 µm and 500 µm [5,906 µin and 19,685 µin] less
than the diameter of the hole. The wires shall not be clinched.
Select suitable wire of sufficient length to connect to gripping
mechanism of bond strength tester.
5.1.3
Insert wire in holes in selected lands and solder to
lands by machine or hand, as applicable. The wire shall not be
clinched.
5.2 Soldering Cycles
5.2.1
The hand soldering and desoldering operation of the
wire shall be performed as follows:
Step 1: Solder wire into lands
Step 2: Remove (desolder) wire from lands
Step 3: Resolder wire into lands
Step 4: Remove (desolder) wire from lands
Step 5: Resolder wire into lands
During the desolder and solder steps, solder every other land
in the row and allow the specimen to cool to room tempera-
ture. Then solder the remaining lands.
5.2.2
During the solder and desoldering steps, the soldering
and/or desoldering iron shall have a tip temperature as follows
(see 6.1):
Method A: 260 °C [500 °F] - Default method
Method B: 315 °C [599 °F]
Method C: 371 °C [700 °F]
5.3 Pull Test
5.3.1
Following the fifth cycle, clamp the test specimen suf-
ficiently in the jaws of the bond tester to assure that the test
specimen is perpendicular to the direction of pull.
5.3.2
Apply a pull at the rate of 50.0 mm per minute [2.0 in
per minute] to the wire on the pattern side of the test speci-
men.
5.3.3
The load must be applied perpendicular to the major
surface of the land. The load shall be applied until failure
occurs or the minimum force as specified by the procurement
documentation is reached. The formula to calculate force for
circular lands is as follows:
4L
π (D2
2
– D1
2
)
3000 Lakeside Drive
Bannockburn, IL 60015-1249
IPC-TM-650
TEST METHODS MANUAL
Number
2.4.21
Subject
Land Bond Strength, Unsupported Component Hole
Date
01/07
Revision
F
Originating Task Group
Rigid Printed Board Performance Task Group
(D-33a)
ASSOCIATION CONNECTING
ELECTRONICS INDUSTRIES
®
IPC-2221
Material
/n
this
Test
Methods
Manual
was
voluntarily
established
by
Technical
Committees
of
I
PC.
This
material
/s
advisory
only
and
"s
use
or
adaptation
，
s
entirely
voluntary.
IPC
disclaims
all
liability
of
any
kind
as
to
the
use,
application,
or
adaptation
of
this
material.
Users
are
also
wholly
responsible
for
protecting
themselves
against
all
claims
or
liabilities
for
patent
infringement.
Equipment
referenced
/s
for
the
convenience
of
the
user
and
does
not
imply
endorsement
by
IPC.
Page
1
of
2
Where:
D1 = Hole diameter
D2 = Land diameter
L = Load (force)
The formula given utilizes the diameter of both the land
and the hole in the determination of the area of the land,
rather than the radius of each. Thus, a factor of four is applied
to the numerator as the area of a circle as defined by using
the diameter is (π * (diameter)
2
) / 4.
5.4 Evaluation
Examine test specimen for loosening of
bond and for loosening of the land from the base material. It
shall be considered a failure when a land around an unsup-
ported hole is loosened.
6 Notes
6.1
Breaking of a wire, or wire pull-out, shall not be consid-
ered a failure, but the wire shall be resoldered and pulled
again.
6.2
The following details are to be specified in the applicable
performance specification:
a. Test specimen, if other than specified in 3.
b. Force, if other than specified in 5.3.3.
Number
2.4.21
Subject
Land Bond Strength, Unsupported Component Hole
Date
01/07
Revision
F
IPC-TM-650
Note:
Page
2
of
2
IPC-T-50
IPC-TM-650
Figure 1 Box
BOW
2
1
With constraining force applied
to both corners of the same edge.
1 & 2 deflection from surface plane.
Figure 2 Twist
B
A
x
x
x
x
C
Points A, B, C
Touching Base
With constraining force
applied to one corner only.
Material in this Test Methods Manual was voluntarily established by Technical Committees of the IPC. This material is advisory only
and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this
material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.
Equipment referenced is for the convenience of the user and does not imply endorsement by the IPC.
Page 1 of 5
r
ASSOCIATION
CONNECTING
/
ELECTRONICS
INDUSTRIES
221
5
Sanders
Road
Northbrook,
IL
60062-6135
IPC-TM-650
TEST
METHODS
MANUAL
1
Scope
This
test
method
covers
three
procedures
used
to
determine
the
bow
and
twist
percentage
of
individual
rigid
printed
boards,
rigid
portions
of
rigid-flex
printed
boards,
and/or
multiple
printed
panels.
Measurements
on
non-
rectangular
samples
pose
a
unique
testing
problem
and
may
necessitate
careful
evaluation
of
the
requirements
imposed
by
the
users
of
this
test
method.
This
test
method
does
not
describe
the
special
considerations
necessary
when
testing
the
bow
and
twist
of
printed
board
assemblies
(i.e.,
compo¬
nent
placement
&
weight,
edge
supports
&
connectors,
etc.).
The
first
two
procedures
describe
production
(Go/No-Go)
methods
that
generally
characterize
the
bow
and
twist
as
being
no
more
than
a
specific
value.
The
other
procedure
is
a
referee
method
used
to
precisely
determine
the
twist.
1.1
Definitions
Bow
and
twist
are
defined
in
IPC-T-50.
The
definitions
are
repeated
in
this
test
method
for
conve¬
nience.
1.1.1
Bow
(Sheet,
Panel,
or
Printed
Board)
The
devia¬
tion
from
flatness
of
a
board
characterized
by
a
roughly
cylin¬
drical
or
spherical
curvature
such
that,
if
the
product
is
rect¬
angular,
its
four
corners
are
in
the
same
plane
(see
Figure
1).
I
PC-2422-1
Number
2.4.22
Subject
Bow
and
Twist
(Percentage)
Date
Revision
6/99
C
Originating
Task
Group
Rigid
Printed
Board
Test
Methods
Task
Group
(7-1
1d)
1.1.2
Twist
The
deformation
of
a
rectangular
sheet,
panel,
or
printed
board
that
occurs
parallel
to
a
diagonal
across
its
surface,
such
that
one
of
the
corners
of
the
sheet
is
not
in
the
plane
that
contains
the
other
three
corners
(see
Figure
2).
I
PC-2422-2
2
Applicable
Documents
Terms
and
Definitions
for
Interconnecting
and
Packaging
Electronic
Circuits
Test
Methods
3
Test
Specimens
The
test
specimens
shall
be
in
the
form
of
either
printed
boards
or
multiple
printed
panels
(single¬
sided,
double-sided,
multilayer,
or
rigid-flex
boards).
3.1
For
non-rectangular
test
specimens,
the
most
conve¬
nient
way
to
measure
bow
and
twist
is
approximating
a
rect¬
angle
over
the
test
specimen.
To
accomplish
this,
an
imagi¬
nary
rectangle
that
totally
encloses
the
sample
must
be
superimposed
over
the
test
specimen.
The
dimensions
of
this
superimposed
rectangle
should
be
the
smallest
that
will
fully
enclose
the
specimen.
Although
this
technique
will
give
an
approximation
of
bow
and
twist,
the
actual
noted
values
will
be
less
than
the
actual
bow
and
twist
of
the
sample.