IPC-TM-650 EN 2022 试验方法.pdf - 第706页
Ultrasonic T est Data Record Name of tester Date Company Address Phone Fax Make and model of equipment T ank size Dimensions (cm cm x cm) Generator output power Frequency (KHz) No. of boards tested per trial Substrate Ex…
Figure
1
IPC-TM-650
Number
2.6.9.1
Subject
Test
to Determine Sensitivity of Electronic Assemblies to
Ultrasonic Energy
Date
1/95
Revision
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age4of5
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Ultrasonic
Test Data Record
Name
of tester
Date
Company
Address
Phone Fax
Make
and model of equipment
T
ank size
Dimensions
(cm cm x cm)
Generator
output power
Frequency
(KHz)
No.
of boards tested per trial
Substrate
Exposure
time
Other
stress testing (pre- or post-)
Describe
Component
tested No. tested Passed Failed Comments
Type Mfgr Part #
Mail
to: IPC Fax to: 847-509-9798
2215 Sanders Road
Northbrook, IL 60062-6135
Attn: Ultrasonic Cleaning Task Group
IPC-TM-650
Number
2.6.9.1
Subject
Test
to Determine Sensitivity of Electronic Assemblies to
Ultrasonic Energy
Date
1/95
Revision
P
age5of5
电子技术应用 ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ
1.0
Scope
The
purpose of this test method is to provide a
consistent procedure to test the sensitivity of electronic com-
ponents to ultrasonic energy. There has been reluctance in
the electronics industry to use ultrasonic energy for printed
board assembly cleaning because of the possibility of damage
to wire bonds in active, hermetically sealed components or
other damage that might cause latent failures.
Recent work has shown that electronic components have a
low potential for damage from ultrasonics (References 1-7)
under conditions seen in most cleaning processes. In addi-
tion, MIL-STD-2000 Rev. A and J-STD-001 now allow for the
use of ultrasonic cleaning, as does the proposal for IEC TC91
International Standards based on an updated revision of the
J-STD-001.
1.1
Definitions
Ultrasound:
All
sound in frequencies above the range of
human hearing. For the purpose of ultrasonic cleaning, fre-
quencies between 18-800 KHz are in commercial use. In the
lower frequency ranges, fluid cavitation is the primary agitation
method. In the higher frequency ranges, microstreaming
(i.e., fluid pumping) is believed to be the form of mechanical
agitation.
Frequency:
The
number of periodic oscillations, vibrations of
waves per unit of time, usually expressed in cycles per second
(Hertz).
Generator:
An
electronic system which converts the 50 or 60
Hz power line electricity into an ultrasonic frequency drive sig-
nal which powers the transducers in their resonant frequency
range.
T
ransducers:
Convert
electrical energy from the generator into
mechanical (vibratory) energy, producing high intensity sound
waves in a liquid and causing cavitation of microstreaming.
Transducers are primarily of two types, piezoelectric and mag-
netostrictive.
Piezoelectric:
Piezoelectric
ceramics, which change dimen-
sions in the presence of an electric field. Thickness varies in
response to an applied voltage. Conversion efficiency =
70-90%.
Magnetostrictive:
Made
of nickel or its alloys, it changes length
when placed in a magnetic field. Conversion efficiency =
20-50%.
Cavitation:
The
rapid formation and oscillation or violent col-
lapse of microscopic bubbles or cavities in a liquid, produced
by introducing high frequency (ultrasonic) sound waves into a
liquid. The agitation from countless implosions of these
bubbles create a highly effective scrubbing of both exposed
and hidden surfaces of parts immersed in the cleaning solu-
tion.
Degas:
The
act of removing entrained gas from cleaning fluid.
Gas bubbles tend to absorb ultrasonic energy, thereby
decreasing the amount of energy available for cleaning.
Power
Density:
Average
output power of ultrasonic generator
divided by total volume of liquid being sonified.
2.0
Applicable Documents
2.1 Institute for Interconnecting and Packaging Elec-
tronic Circuits (IPC)
IPC-T-50
Terms
and Definitions for Interconnecting and
Packaging Electronic Assemblies
IPC-CH-65
Guidelines
for Cleaning of Printed Boards and
Assemblies.
2.2
Joint Industry Standards
J-STD-001
Requirements
for Soldered Electrical and Elec-
tronic Assemblies
2.3
Military
MIL-STD-2000 Rev. A
Standard
Requirements for Soldered
Electrical and Electronic Assemblies
2.4
Other Publications
IEC-TC-91
Proposed
International Standard (based on
J-STD-001) International Requirements for Soldered Electrical
and Electronic Assemblies using Surface Mount and Related
Assembly Technologies.
3.0
Test Specimens
The
components to be tested should
be the exact type and package style the tester intends to use
in production. A statistically valid number of each type and
package style of interest should be tested.
4.0
Apparatus
The
Institute for Interconnecting and Packaging Electronic Circuits
2215 Sanders Road • Northbrook, IL 60062-6135
IPC-TM-650
TEST
METHODS MANUAL
Number
2.6.9.2
Subject
Test
to Determine Sensitivity of Electronic
Components to Ultrasonic Energy
Date
1/95
Revision
Originating Task Group
Ultrasonic Cleaning Task Group (5-31e)
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.
P
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