3M Novec HFE

Engineered Fluid
3M™ Novec™ HFE
For defluxing
and decontamination
of electronic circuits
3Innovation
A Balanced
Solution...
3MTM NovecTM HFE (hydrofluoroethers)
Before, the choice of a solvent was relatively simple and it was easy to find a
product with good performance at a convenient price.
But, in today’s strongly regulated world, just good performance is no longer
sufficient.
International regulations, workers and customers safety require the use of
products with no health and safety risks, that also respect the environment.
From now on you have to be sure that your substitution products are efficient
and safe to use.
Environmental and toxicological constraints lead regulatory bodies to regulate
the use of many solvents. This leads electronics and electronic assembly
companies to reconsider their cleaning and defluxing process of printed circuit
boards.
3MTM NovecTM HFE* Physical properties (Measured at 25°C)
61
-135
1,52
13,6
202
0,61
30
HFE-7200
76
-138
1,43
13,6
109
0,61
30
HFE-71IPA
54.8
-42
1,48
14,5
207
0,75
39.5
HFE-71IDA
40
-29
1,33
16,4
381
0,45
50
)
n
io
at
riz
os
po
sc
va
of
at
He
ur
po
Va
1 - Critical solution temperature
2 - Cal @ boiling point
* Not for specification purposes
(2
)
Ps
(c
ity
m
(m
su
pr
es
Vi
re
n
io
ns
te
ce
rfa
Su
Hg
m)
(m
ity
ns
De
po
ur
Po
N/
(g
/l)
t °
C
in
t °
C
in
po
ng
Bo
ili
1
)
HFE-7100
2
3M™ Novec™
HFE
Contamination type
Proposed products
Lubricants and traces of
grease
RMA flux
RA flux
R flux
Aqueous flux
No clean flux
Adhesive residue
Particulate contamination
Ionic contamination
Waxes
3M™ Novec™ HFE-7100
Co-solvent system
3M™ Novec™ HFE-71IPA
3M™ Novec™ HFE-71DA
3M has developed a new generation of solvents, 3MTM NovecTM HFE (HFE for
hydrofluoroether), focussing on products that are safe to use, respecting the environment
and offering optimal cleaning performance. 3MTM NovecTM HFE solvents offer a long time
sustainable solution to replace a broad range of solvents, from CFC’s to HCFC’s,
chlorinated and brominated solvents. Moreover, these solvents are non-flammable and
have no flashpoint.
For cleaning and defluxing operations, the hydrofluoroethers are used in vapour
degreasers, with or without ultrasonics, either pure or in combination with a high boiling
hydrocarbon co-solvent. The hydrocarbon co-solvent is used for its strong solvency, and
the HFE vapour phase provides a final precision rinse.
All types of fluxes, RMA, RA, R, aqueous and no clean, can be cleaned, as well as ionic
contamination, waxes and traces of grease.
Ionic decontamination
Co-solvent with Avantec Topclean EL20A and 3M Novec HFE-71IPA
Kester 256 solder paste
Cycle: 4 minutes in co-solvent bath • 2 minutes in HFE-71IPA rince bath • 2 minutes in vapour phase • 1 minute drying
2
1,5
1
0,5
0
HFE-71IPA
HFE-71IPA and
Topclean co-solvent
system
No
decontamination
Board without
components
3
3M™ Novec™
HFE
3M™ Novec™
created for the future
HCFC 141b and the Montreal Protocol
CFC’s have been banned for production and use since 1996 in developed countries and
since 2002 in developing countries.
Substitutes like HCFC 141b and others are also being regulated and phased out under
the Montreal Protocol since they are ozone depletion substances as well.
The revision of article 5 of directive EC 3094/95 specifies the elimination of HCFC’s as
solvents for parts cleaning and solvent use in general since 1 January 2002. The only
exception is parts cleaning for aerospace and aeronautics applications, where the phaseout date is 31 December 2007.
3MTM NovecTM HFE and the Environment
3MTM NovecTM HFE’s do not deplete the ozone layer since they don’t contain chlorine,
and are therefore not covered by the Montreal Protocol.
They are also not covered by the Kyoto Protocol.
Moreover, they have a very short atmospheric lifetime compared to CFC’s, HCFC’s and
other solvents.
Environmental properties
Ozone
depletion
potential
Global
warming
potential(2)
Atmospheric
lifetime
3MTM NovecTM HFE-7100
0
320
4,1
3MTM NovecTM HFE-71DA
0
170
4,1
0
300
4,1
0
55
0,8
CFC113*
0,8
6000
85
HCFC 141b
0,1
700
9,2
0
1700
17,1
0,026
0,31
0,03
3M
TM
Novec
TM
HFE-71IPA
3MTM NovecTM HFE-7200
HFC-4310mee
nPB
(1) *CFC-11 = 1
(2) ITH (integrated time horizon) 100 years
(3) Years
4
2
3M™ Novec™
HFE
The Kyoto protocol
The Kyoto protocol is an international treaty, proposing an
emission reduction schedule of global warming gases that are
considered to be a cause of climate change. The protocol was
negotiated in Kyoto in December 1997.
In this protocol, 38 industrialized countries agreed to reduce their
greenhouse gas emissions between 2008 and 2012 with 5,2%
compared to 1990.
Global warming potential
Chemicals covered by the Kyoto protocol are:
Carbon dioxide (CO2)
Sulphur hexafluoride (SF6)
Hydrofluorocarbons (HFC)
Perfluorocarbons (PFC)
Methane (CH4)
Nitrous oxide (N20)
52
3M™ Novec™
HFE
3M™ Novec™ HFE
Sustainable
solutions
Evolution of Trichloroethylene and 1-Bromopropane
(nPB) classification.
The European solvents directive on carcinogenic, mutagenic or reproductive
toxins, and its translation in national legislations, call for a mandatory
substitution of those types of solvents wherever possible and as fast as possible,
as described in paragraphes 37-42 of European directive 199/13/EC.
All products labeled with risk phrases R40, R45, R46, R49, R60, R61 are
covered by this legislation. This includes solvents like trichloroethylene and 1bromopropane (nPB).
3MTM NovecTM HFE’s are successfully used in several industries and sub
contractors in sectors like electronics, aeronautics, automotive, military, space,
medical, etc…showing their performance and allowing for cost reductions,
while working within the European legislation.
HFE’s have very high exposure limits and are substitutes for solvents currently
used that expose workers to health and safety risks.
The new labeling for 1-Bromopropane (nPB)
R11 :
Highly flammable
R36/37/38 :
Irritating to eyes, respiratory system and skin
R48/20 :
Harmful: danger of serious damage to health by prolonged exposure
through inhalation
R60 :
May impair fertility
R63 :
Possible risk of harm to the unborn child
R67 :
Vapours may cause drowsiness and dizziness
6
2
3M™ Novec™
HFE
Health and safety
Under normal use conditions, operators are exposed to small quantities
of cleaning solvent vapours. Studies have shown that, in suitable
cleaning equipment, vapour concentrations in the operator’s breathing
zone are limited to values between 5 and 30 ppm.
The advantage of Hydrofluoroethers is that their exposure limits are far
above those concentrations.
On the other hand, toxicology tests conducted by 3M show a very low
toxicity for Novec HFE. The Hydrofluoroethers don’t cause eye or skin
irritation, cardiac sensitization or mutagenicity. They are non toxic by
inhalation or for reproduction.
Security: toxicity
Security: flammability
HFE-7100
HFE-7200
CFC-113
HCFC-141b
>100,000
>50,000
>55,000
>62,000
No
No
No
No
No
No
No
No
No
No
Yes
No
>100,000
49,000
10,000
10,000
Eye irritation
No
No
No
No
Skin irritation
No
No
No
No
750 ppm
200 ppm
1000 ppm
500 ppm
Lethal
concentration (ppm)
Carcinogenic
Ames
Chromosomal aberration
Mouse micronucleaus
Cardiac
HFE-7100 HFE-7200 CFC-113 HCFC-141b
Flashpoint,
closed cup
No
No
No
No
Flashpoint,
Open cup
No
No
No
No
Flammability range
in air (mg/l)
No
210-1070
No
270-710
Sustains burning
No
No
No
No
NFPA index
0
1
0
1
sensitization (ppm)
Average
exposure (8 h/day)
7
2
3M™ Novec™
HFE
3M™ Novec™ HFE : which
solution to choose?
3M Novec HFE
Pure HFE
The Hydrofluoroethers are pure products and have a very high thermal and
chemical stability. They are compatible with a wide range of materials and don’t
degrade electronic coatings.
Pure HFE can be used to clean particles, light oils and halogenated compounds
such as fluorinated oils, greases and particles.
HFE in non flammable azeotropic mixtures
Mixtures HFE / organic solvents have a constant boining point (azeotropes) and are
per definition stable. They are selected to clean impurities such as solder flux
residues or medium oils. These azeotropes are non flammable.
8
3M™ Novec™
HFE
HFE and Trans dichloroethylene
Chlorinated solvents (trichloroethylene, perchloroethylene, methylene chloride, etc)
are well known for being strong degreasing solvents, but also for their generally
high toxicity.
To increase the solvency of HFE, 3M added azeotropic mixtures to the product range,
more specifically mixtures containing 1,2 transdichloroethylene. These products are
known as HFE-71DE, HFE-71DA, HFE-72DE and HFE-72DA.
1,2 transdichloroethylene is an isomer of dichloroethylene with a lower toxicity, and, as
a result to toxicology testing, its mixtures with HFE are not classed Xn, R20 or R36/38.
Remark:
Masked flashpoint
An important safety aspect is linked to the handling and use of non flammable
products, defined as such by their flashpoint.
The addition of small quantities of certain halogenated solvents (chlorinated,
fluorinated or brominated) to flammable solvents increases or makes even disappear
the flashpoint of the mixture. The user needs to be aware of this phenomenon, known
as flashpoint masking. Certain solvent mixtures, considered as non flammable based
upon their initial composition may become flammable after selective evaporation of
one of their components. In practice: mixtures may become flammable under certain
conditions (drums kept open for a long time, impregnated cloths, presence of ignition
sources, …) This can create a dangerous situation, as the user believes the mixture
to be non flammable, just like the halogenated hydrocarbons that are being replaced
The use of azeotropic mixtures eliminates all risks of selective evaporation since, by
definition, this is a mixture that upon evaporation creates vapours with the same
composition as the liquid (no selective evaporation).
The mixtures based or on trans dichloroethylene, or on ethanol or on
isopropylalcohol of the 3M Novec HFE product range are all azeotropic
mixtures and as such non flammable.
9
3M™ Novec™
HFE
3MTM NovecTM HFE : which
solution to choose?
Performance: Co-solvent system
Lid
Extended
freeboard
Rinsing vapour
Condensing
coils
Water separator and
condensate return
Step 1:
Defluxing and cleaning
Hydrocarbon
in the co-solvent + HFE solvent
HFE rinse
Step 2:
HFE rinse
+ HFE
Heating elements
Ultrasonics
Co-solvent system:
For the cleanliness required in electronics (ionic
contamination test, surface insulation resistivity test
etc…) HFE can be used in a co-solvent system. The
schematic shows the principle of a co-solvent cleaning
system. The same equipment is used with pure HFE or
with azeotropic HFE mixtures. The only difference is an
additional immersion in the co-solvent/HFE mixture for
defluxing. In this system the liquid hydrofluoroether
serves as rinsing agent while its high density vapour
phase provides the system safety by inerting.
0.4
0.3
0.2
0.1
0.0
60 65 70 75 80 85 90 95 100 105
Boiling temperature
of the mixture in °C
10
3M™ Novec™
HFE
Increasing solvency
Co solvent volume fraction
The azeotropic liquids 3MTM NovecTM HFE (HFE-71DE, HFE-71DA, HFE-72DE, HFE-72DA) need to
be tested for compatibility before use on plastic or elastomer parts since they contain an organic
solvent. Their impact on those materials depends on the solvent temperature, and the contact time
between the part and the solvent.
Co-solvent cleaning is easy to use. It allows solvent boiling temperature modifications in the cleaning
machine in function of the application. The safety and environmental profile is similar to cleaning
processes using 3MTM NovecTM HFE, neat or the azeotropic mixtures. The co solvent system utilizes 2
fluids: an high boiling, high solvency hydrocarbon
1.0
solvent capable of degreasing and decontaminating
TM
TM
0.9
surfaces, and a 3M Novec HFE-7100 or HFE0.8
71IPA as rinsing agent. The co solvents
0.7
recommended by 3M are products from the
0.6
company Avantec under the name Topklean.
0.5
Examples of recommended co solvents
Avantec Topklean™ EL 20A
Avantec Topklean™ EL 20C
Avantec Topklean™ EL 20F
Materials compatibility
Hydrofluoroether 3MTM NovecTM HFE-7100 tests show good compatibility with a
broad range of metals, plastics and elastomers, similar to the performance of
perfluorinated liquids. A good compatibility with particularly sensitive plastics like
polycarbonate and polymethylmetacrylate allows cleaning of assemblies
containing many composite materials. Like most fluorinated liquids, 3MTM NovecTM
HFE fluids tend to get absorbed by fluorinated plastics and elastomers during
prolonged exposure.
Comparison of materials compatibility
Compatibility after one hour exposure at
boiling temperature. Butyl rubber is preferred
for prolonged exposure >1 month. Exception:
swelling of PTFE and silicone rubber. Note a
slight surface oxidation on copper parts during
ageing.
Metals
Plastics
Aluminium
Elastomers
Acrylic (PMMA)
Butyl rubber
polyethylene
Natural rubber
Carbon steel
Polypropylene
EPDM rubber
Stainless steel 302
Polycarbonate
Copper
Brass
Polyester
Molybdenum
Epoxy
Tantalum PTE
PET
Tungsten ABS
ABS
CuBeC172 alloy
Mg AZ32B alloy
11
3M™ Novec™
HFE
Loss reduction equals
cost reduction !
Solvent consumption in an ultrasonic vapour degreaser is a function of the vapour
pressure (volatility) of the solvent used, its boiling temperature, but also its surface
tension (the lower the surface tension, the easier the solvent drains from the part
resulting in lower drag out losses). But more importantly, the machine needs to be
adapted to the use of this new type of solvent.
Several techniques for vapour containment and condensation are applied in modern
machines. Since HFE is less volatile than other solvents like 141b or CFC’s, losses
become minimum, making the use of hydrofluoroethers an economically viable
solution. Under those conditions, the initial cost of the solvent is compensated by
the low exploitation cost of the HFE in a new machine.
Evaporative losses
(cleaning cost)
Non modified equipment
Typical losses with different solvents
CFC-113
= 0,5 - 1 kg/h/m2
HCFC-141b
= 1 - 2 kg/h/m2
n-Propyl Bromide
= 1 - 2 kg/h/m2
HFE-7100 neat and co solvent = 0,15 - 0,4 kg/h/m2
HFE-71D azeotrope
New equipment with HFE
Losses below 0,1 kg/h/m2
12
3M™ Novec™
HFE
= 0,2 - 0,5 kg/h/m2
Choosing an adapted machine is choosing for
consumption reduction.
Reducing vapour losses leads to cost reduction and a reduced
environmental impact. This applies to whatever solvent is used.
Establishing and applying procedures for vapour containment and
reduction of drag out losses leads to correct solvent consumption
management. To improve the confinement of 3MTM NovecTM HFE
fluids, the following recommendations need to be observed:
Automated basket: because it is difficult to manually control
the descent and ascent of the basket with the parts to clean, it
is preferred to choose for a basket operated by a robot (with a
maximum speed of 3 m/minute) for complete draining to
reduce drag out losses to a minimum. This is particularly
important when cleaning parts with complex geometries. Such
automation also reduces turbulences in the vapour zone to a
minimum so that vapours don’t move outside of the
confined zone.
A primary set of cooling coils above the vapour zone capable
of keeping a temperature of –30°C, and a secondary set of
cooling coils with a system to eliminate air humidity to prevent
frost formation that would deteriorate the performance of the
cooling system.
A leak detector for halogenated solvents to help finding and
repairing eventual invisible leaks.
Extended freeboard representing 100 – 125% of the bath.
Welded or EPDM joints: leaks are a potential source of solvent
loss. The low surface tension of 3MTM NovecTM HFE fluids that
lets them easily penetrate in parts with complex geometries
also lets them penetrate in microcracks or faulty joints, leading
to losses. This risk can be overcome by using EPDM or
fluorelastomer joints, or even better by using welded joints.
A horizontally sliding lid avoids turbulences in the
vapour zone.
Comparison
1
0,5
0,2
0,1
0,05
0,03
Losses per m2/h/kg
Drag out losses
5
HCFC-141b
nFB
CFC-113
HCFC-225
HFC-4310
3M TM HFE-7100
4.5
4
3.5
3
2.5
2
Residual solvent (g)
1.5
1
0.5
0
0
1
2
3
Time minutes
13
3M™ Novec™
HFE
4
5
HFE’s are
a solution for
the future
HFE based liquids used for precision cleaning in electronics have a set of
favourable properties that are close to solvents like HCFC-141b that will soon no
longer be usable for environmental reasons, or nPB having toxicology risks. HFE
has a very favourable environmental profile, as they do not destroy the ozone layer,
have a short atmospheric lifetime and a low global warming potential. The toxicity
of HFE is generally low.
By choosing the appropriate cleaning process – neat HFE, HFE azeotrope or
HFE/co solvent, a broad range of contaminants can be cleaned.
The compromise between cleaning efficiency, materials compatibility and short
cycle time makes that without process change, the broad application range of
solvents like HCFC-141b or CFC’s can be covered.
HFE solvents are cleaning and degreasing products that offer the best compromise
between efficiency, safety and environment.
14
3M™ Novec™
HFE
Why choose 3MTM NovecTM
HFE fluids?
■
Cleaning performance
■
non flammable
■
Low toxicity
■
Low operating cost
Important Notice to Purchaser:
The information in this publication is based on tests that we believe are reliable. Your
results may vary due to differences in test types and conditions. You must evaluate
and determine whether the product is suitable for your intended application.
SINCE CONDITIONS OF PRODUCT USE ARE OUTSIDE OF OUR CONTROL AND
VARY WIDELY, THE FOLLOWING IS MADE IN LIEU OF ALL EXPRESS OR IMPLIED
WARRANTIES (INCLUDING THE WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE): 3M’s ONLY OBLIGATION AND YOUR
ONLY REMEDY IS REPLACEMENT OF PRODUCT THAT IS SHOWN TO BE
DEFECTIVE WHEN YOU RECEIVE IT.
In no case will 3M be liable for any special, incidental, or consequential damages
based on breach of warranty for contract, negligence, strict tort, or any other theory.
3
3M Electronics
3M Belgium N.V.
Haven 1005
Canadastraat 11
B-2070 Zwijndrecht
Tel: +32 3 2507862
www.3m.com/electronics