Vectra® LCP Lead-Free Soldering

Vectra® LCP
Lead-Free Soldering
© 2013 Celanese EE-003 AM 10/13
Why is Electronics Going Lead-Free?
► Comply with RoHS – Restriction of hazardous substances
► Comply with WEEE – Waste from electrical/ electronic equipment
Fact – Lead ingestion in the body harms living things
Fact – Lead pollution in air and water has been tackled
Fact – Lead perceived by many environmentalists as
unconditionally “a bad thing”
Fact – Promotion of “lead-free” products has won
market share
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Wave Soldering
General view of inerted wave soldering machine
The wave solder profile
Source: Department of Computing & Electronic Technology - University of Bolton
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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The Reflow Process
There are four heating modes involved
with SMT reflow processes:
► Convection
► Conduction
► Latent heat
► Infrared radiation (IR)
These last three methods of heat transfer
can be implemented at all levels upwards
from low-volume batch systems.
“Cones” of hot gas from the plenum box
Convection is the main runner for larger
users and on high-volume flow-line
systems. It became popular because
blowing hot gas at the circuit provided
a more controllable and consistent
heating regime.
Source: Department of Computing & Electronic Technology - University of Bolton
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Lead-Free Solder – What is Changing?
Lead-Free Solder
Composition
Melting
Point Range
Comments
48 Sn/52 In
118°C eutectic
Low melting point, expensive, low strength
42 Sn/58 Bi
138°C eutectic
Established, availability concern of Bi
93.5 Sn/3Sb/2Bi/1.5 Cu
218°C eutectic
High strength, excellent thermal fatigue
95.5 Sn/3.5 Ag/1 Zn
218-221°C
High strength, good thermal fatigue
99.3 Sn/0.7 Cu
227°C
High strength and high melting point
95 Sn/5 Sb
232-240°C
Good shear strength and thermal fatigue
97 Sn/2 Cu/0.8 Sb/0.2 Ag 226-228°C
High melting point
96.5 Sn/3.5 Ag
High strength and high melting point
221°C eutectic
Peak Temp in Reflow
Soldering Process
Lead-Free Solder
250-260°C
Sn-Pb 220-230°C
Melting Point
Lead-Free Solder
210-230°C
Sn-Pb 183°C
Source: Department of Computing & Electronic Technology - University of Bolton
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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IR/Convection Reflow Profile
(IPC/JEDEC J-STD-020C)
Source: Department of Computing & Electronic Technology - University of Bolton
Temperatures vs. Time and Definitions
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Components
Through Hole – (also spelled “thru-hole”).
Of a component, having pins designed to
be inserted into holes and soldered to
pads on a printed board.
► High power design
► Hobbyist projects
► Component “shielded” by PCB during
soldering, not exposed to the high
temp of solder solution
SMD – A method of assembling printed
wiring boards or hybrid circuits, where
components are attached to pads on the
board surface.
► High density
► Smaller assemblies
► Low power
► Component exposed to direct high heat
Source: Department of Computing & Electronic Technology - University of Bolton
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Celanese Portfolio for E&E
Celanex® PBT
Fortron® PPS
Vectra® LCP
Vectra LCP
Ei and S Series
Temperature
Conventional
Lead Free
Temperature
Celanex PBT
Fortron PPS
Vectra LCP
Through Hole
© 2013 Celanese EE-003 AM 10/13
SMT
Vectra® LCP Lead-Free Soldering
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Vectra® Liquid Crystal Polymer
Halogen-Free. Always was – always will be.
You May Not Have Needed
Vectra® LCP from Celanese
Before Now, But…
Here’s the Halogen-Free
High-Performance Solution to
Drive Greener Electronics
2013Ticona
Celanese
EE-003
AMUS
10/13
©©2009
EE-003
10/09
EN
Vectra® LCP Lead-Free Soldering
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Lead-Free Soldering
Vectra® LCP vs. High Temperature Polymers
► Advantages
‒ High HDT/A
↔ No softness at Reflow Peak Temp
‒ High Tm
↔ Higher safety factor for LF Soldering
‒ High heat resistance
↔ Thinner walls and smaller parts
‒ Lower humidity absorption
↔ Less susceptible for blistering
‒ Higher flow
↔ Less internal part stress, lower warpage
‒ Low warpage
↔ Safety factor for assembly
‒ High dimensional stability
↔ Fewer risks of contact failure
‒ Low CTE variations
↔ Fewer risks of contact failure
‒ Inherent UL-94 V0
↔ FR additives could attack metal contacts
‒ Lower injection cycle time
↔ Lower price per part
► Considerations
‒ Design is critical
‒ Weaker welding lines
© 2013 Celanese EE-003 AM 10/13
↔ Optimum properties
↔ Design related
Vectra® LCP Lead-Free Soldering
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The Heat Deflection Temperature vs. Tm
Reflow Peak Temp
350
DTUL/A @ 1.8 MPa
330
310
290
270
Vectra® S135
PPS
PPA
PA HTN
PA 46
Vectra E130i
Reflow Peak Temp
PCT
250
Vectra A130
230
210
240
260
280
300
320
340
360
380
Melting Temperature °C
Note: Vectra LCP grades 30% GF Reinforced
Reflow Peak Temperature is a Big Factor for Failure
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Dimensional Stability
Stable dimensions after exposure to surface mount technology temperatures (reflow
soldering)
► Change of length vs. 4.149-inch tool dimension
► SIMM molded at manufacturer’s recommended conditions
► SMT simulated by hot oil bath exposure at 260°C
4.5
Shrinkage (mils/inch)
4
3.5
3
As molded
2.5
2
1.5
1
0.5
0
Vectra E130i
PPS 40GF
PPS 40GF HF PPA 33GF V0 HTN 35GF V0
Dimensional Variations Could Cause Contact Failure
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Dimensional Stability
0.20
@251oC
As-mold
After IR reflow
0.16
Warpage (mm)
@287oC
0.12
0.08
0.04
0.00
E130i
E471i
E480i
E488i
S135
S471
S475
“Low Warpage Grades” Smaller than “GF-reinforced Grades”
Vectra® E130i is Better Than Most High Temp Polymers But…
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Spiral Flow vs. Other Resins
Vectra E130i
PPS 40
PCT
PPA
PET FR
0
50
100
150
Spiral Flow (Inches)
Each molded at manufacturer’s recommended conditions and three injection
pressures normalized to 30 Kpsi. Cavity thickness = 0.125 in.
High Flow = Less Internal Stress, Thinner Walls
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Vectra® LCP: Flow Path Length
Flow path length of Vectra LCP as a function of polymer and
filler
Flowability (0.5 mm thickness) by Injection Pressure (MPa)
60 Mpa
100
80 Mpa
100 Mpa
90
Flow length (mm)
80
70
60
50
40
30
20
10
0
A130
E130i
E471i
S135
S471
S475
High Flow = Less Internal Stress, Thinner Walls
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Flatness
Typical convection oven
Typical convection oven
Contact
No-contact
Failure = Quality and Reliability Problems + Costs
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Key Factors Influencing Flatness
Material
Flowability
Deformation
Processing
Design
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Rework = Time and Cost
Cross-section of a hot-gas QFP removal tool
View of a QFP gas nozzle from underneath
Soldering iron rework of an SM assembly
Source: Department of Computing & Electronic Technology - University of Bolton
1 = quick change support
2 = vacuum cup
3 = nozzle nest (corresponds to the component housing)
4 = gas openings
Rework Can Damage Some Components, Increase Costs
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Water Absorption
Water Absorption (ppm)
40000
Cross section of blistering
sample (connector housing)
LCP GF30
PPS GF40
PA6TGF30
PA46 GF40
80
100
30000
25000
20000
15000
10000
5000
0
20
40
60
Time (hours)
40000
LCP GF30
PPS GF40
PA9T GF33
PA6TGF30
PA46 GF40
35000
Water Absorption (ppm)
PA9T GF33
35000
Condition: 60°C; 95%RH
30000
25000
20000
15000
10000
5000
0
20
40
60
80
100
PA 6T GF30FR
Condition:
Time (hours)
Condition: 35°C; 85%RH
PA 46 GF30FR
40°C; 95%RH; 96 hrs;
IR Reflow @ 265°C
High Water Absorption + Temp = Quality and Reliability Problems
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Vectra® LCP: Viscosity
Viscosity as a function of shear rate
1000
Viscosity (Pas)
LCP
Conventional polymer
100
10
1
10
100
1000
10000
Shear rate (1/sec )
Cost Saving: Low Viscosity = Small Machine
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Vectra® LCP: Wall Thickness
Effect of wall thickness on rigidity
(Vectra E130i natural)
Tensile strength
250
200
150
100
50
0
4mm
3.2mm
1.6mm
0.8mm
0.7mm
0.6mm
Thickness of the test bar
Material Saving: Low Wall Thickness is an Advantage
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Vectra® LCP Grade Selection Guideline
E488i,
S471, S475,
V143LC
S471  S135
E130i
E471i  E473i
S471  S475
Flatness
Improvement
Heat Resistance
Improvement
Flow
Improvement
General Purpose
Standard Grade
S135
V143LC
E830i Pd
E820iLDS
E840iLDS
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
Weld or Knit Line
Improvement
Platable Grades
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V-0 Halogen-free Material Considerations
Wall thickness
Vectra S475 – Super flow; high temperature; low warp
<0.4 mm
Vectra S135 – High flow; highest HDT
Vectra E473i – Good flow; low warp
Vectra E471i – Good balance of flow, flatness and HDT
Vectra E130i – High flow; high HDT
≥0.4 mm
≥0.8 mm
Vectra E488i – Good flow; low warp
Vectra V143LC – Good flow; high weldline strength
Chlorine Level
< 900 (ppm)
Fortron 1140LC6 – Good flow; high mechanical strength
Chlorine Level
< 900 (ppm)
Vectra E150i – Good flow; high stiffness
Celanex® XFR
Lead-Free Solderable
Not Lead-Free Solderable
Note: All grades Br free
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Vectra® LCP Production Advantages
► High productivity with rapid cycle times
‒ 30% to 50% of PPS, PPA, PCT
‒ 50% to 75% of PES, PEI, PSO
► Low injection pressures
‒ 50% of PPA
‒ 10% to 20% of PEI, PES, PSO, PCT
► Outstanding dimensional stability
‒ Low mold shrinkage (often <.001”)
‒ Low coefficient of thermal expansion
‒ Low warp
►
►
►
►
Low tool temperatures (50°F-200°F)
No outgassing, vent plugging or steel corrosion
No deflashing necessary
Extremely stable – Use of up to 50% regrind
Delivers Total Lower Per-Part Cost
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Contact Information
Disclaimer
This publication was printed on 1 October 2013 based on
Celanese’s present state of knowledge, and Celanese
undertakes no obligation to update it. Because conditions of
product use are outside Celanese’s control, Celanese makes
no warranties, express or implied, and assumes no liability in
connection with any use of this information. Nothing herein is
intended as a license to operate under or a recommendation
to infringe any patents.
Copyright © 2013 Celanese or its affiliates.
All rights reserved.
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Product Information Service
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Customer Service
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Customer Service
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e: [email protected]
© 2013 Celanese EE-003 AM 10/13
Vectra® LCP Lead-Free Soldering
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Back-up Slides
© 2013 Celanese EE-003 AM 10/13
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RoHS Product Compliance
© 2013 Celanese EE-003 AM 10/13
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Glossary
► BGA = Ball Grid Array – A leadless IC package with a large number of terminations arranged in a matrix on
the bottom of the package. Connections are made through solder terminations on the underside of the array,
either in the form of solder balls (most common) or pillars. These are reflowed onto the board, forming pillars
between the board and component.
► Flux – A chemically active agent that speeds the wetting process of metals with molten solder: a short-form
way of describing a complex of rosin, activators and solvents. When heated, fluxes remove minor surface
oxidation, minimize oxidation of the base metal, and promote the formation of an intermetallic layer between
solder and base metal. Flux will not remove oils, dirt or fingerprints – only a solvent can remove these.
► IR Reflow – Use of infrared energy to bring solder to its melting point.
► JEDEC = Joint Electronic Device Engineering Council – JEDEC is the semiconductor engineering
standardization body of the Electronic Industries Association (EIA), and develops and publishes configuration
standards for semiconductor device packages.
► PCA = Printed Circuit Assembly – An assembly designed to perform a specific function, consisting of a
printed circuit board to which separately manufactured electrical, electromechanical and mechanical
component parts have been added.
► PCB = Printed Circuit (Board) – The generic term for completely processed “printed wiring,” where
predetermined conductive patterns are used to interconnect electronic components on a common insulating
base. It includes single-sided, double-sided and multilayer boards made with rigid, flexible and rigid-flex
materials, but the most usual PCB is a substrate of copper-clad epoxy-glass laminate material which has been
etched to form a pattern of conductive traces. More correctly, but less usually, referred to as a “Printed Wiring
Board” (PWB). Especially within the computer industry, the term is also loosely applied to a board onto which
semiconductor components are connected, although this is properly called a Printed Circuit Assembly (PCA).
► Reflow Soldering – A process of joining metallic surfaces (without melting the base metals) through the mass
heating of pre-placed solder (usually in the form of paste) to create solder fillets in the metallized areas.
Source: Department of Computing & Electronic Technology - University of Bolton
© 2013 Celanese EE-003 AM 10/13
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Glossary
► RoHS (Restriction of Hazardous Substances)
EU Directive No. 2002/95/EC passed Feb-2003 restricts use of:
(4) Heavy Metals: Lead, Mercury, Cadmium, Hexavalent Chromium
(2) FR’s: Polybrominated Biphenyls (PBB’s), Polybrominated Diphenylethers (PBDE’s)
Effective Date: July 1, 2006 for all E/E products sold to customers in EU countries
► Solder – A fusible alloy used to join two or more metals at temperatures below their individual melting points. Solders
which melt readily are “soft solders,” others fusing at a higher temperature (usually taken as above 425°C) are “hard
solders.” Solders consisting mostly of tin and lead are normally used for soldering electronic assemblies. The tin in solder
forms an intermetallic with copper (or nickel) in the surface being bonded.
► Solder Balls – Small spheres of solder which have separated from the main body of the solder joint and adhere to
laminate, mask or conductors. Most often associated with the use of solder paste containing excessive oxides or
moisture. Baking of paste may minimize formation of solder balls, but over-baking may cause excessive balling.
► Solder Paste (cream) – A homogeneous combination of minute spherical solder particles, flux, solvent and a gelling or
suspension agent, which has the consistency and viscosity of a paste and is used in surface mount reflow soldering.
Solder paste can be deposited on a substrate by solder dispensing and screen or stencil printing.
► Soldering – Process by which two or more metal surfaces are bonded together via an intermediary alloy called a solder.
► SMD (SMC) = Surface Mount Device (Component) – An electronic device designed for mounting onto lands on the
surface of a substrate rather than by insertion into holes in the substrate. SMD is a registered service mark of North
American Philips Corp. (Assembléon) to denote resistors, capacitors, SOICs and SOTs.
► SMT = Surface Mount Technology – A method of assembling printed wiring boards or hybrid circuits, where
components are attached to pads on the board surface, as distinct from through-hole technology, where component
leads are inserted into holes. The result is higher component density, and smaller assemblies.
► Through-Hole – 1) (noun) A hole that extends though the entire circuit board, which may or may not be plated,
depending on its function. Plated through-holes are used for the attachment and electrical connection to the printed board
of component terminations, including pins and wires. 2) (adjective) (also spelled ‘thru-hole’). Of a component, having pins
designed to be inserted into holes and soldered to pads on a printed board. Contrast with surface mount.
Source: Department of Computing & Electronic Technology - University of Bolton
© 2013 Celanese EE-003 AM 10/13
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Glossary
► Through-Hole Technology – The science applied to making electrical connection of components to and
through the surface of a conductive pattern using component holes (in contrast to SMT).
► Wave Soldering – A method of soldering components to printed circuit boards by moving the boards over a
continuously flowing and circulating wave of molten solder in a solder bath. The process permits precise control
of the depth of immersion in the molten solder and minimizes heating of the board. SMDs are held in place
during wave soldering with adhesives and are mounted on the secondary side (wave side) of the PCB.
► WEEE (Waste Electrical and Electronic Equipment)
EU Directive No. 2002/96/EC passed Feb-2003 requires producers to:
Set up systems to provide for the treatment of WEEE products
Effective Date: 08/13/05
► Wetting – In general, wetting is the ability of a liquid to flow across a surface as opposed to sticking to itself.
Wetting occurs when the attraction between liquid and surface is greater than the surface energy of the liquid,
drawing a molecularly thin layer across itself. Wetting in soldering applies to molten solder spreading along the
base metal/metallization surfaces to produce a relatively uniform, smooth, unbroken and adherent film of
solder. A good intermetallic bond between surfaces is formed. One action of flux is to reduce the surface
tension of the solder to enhance wetting. Good wetting is indicated by a low “contact angle” (positive wetting
angle) between the solder fillet and the base metal/metallization.
► Whisker – A slender needle-shaped growth between conductors and lands which occurs after the printed board
has been manufactured.
Source: Department of Computing & Electronic Technology - University of Bolton
© 2013 Celanese EE-003 AM 10/13
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