1996 NH Pollution Prevention Internship Program
Internship Project Final Report
September 8, 1997
Project Title:
Examining the Usage of Lead-Free Solder, No-Clean/VOC-Free
Flux and No-Clean Solder Paste in the Manufacturing of PCB’s;
Along with several side projects
Intern:
David A. Teixeira
Facility:
Cirtronics Corporation
PO Box 130, Elm Street
Milford, NH 03055
Contact Person:
Jon Bates
Production Coordinator
Phone: 603-868-9764
Phone: 603-654-6125
2
Table of Contents
Executive Summary
Introduction
Objectives
Methodology
Chemical Usage/Equipment Needs
Releases/Waste Generated
Results
Pollution Prevention Benefits
Future Efforts
References
Appendices
3
3
3
4
5
6
6
9
10
10
11
3
Executive Summary
Cirtronics Corporation is an assembly house for printed circuit boards (PCB’s). In an
effort to reduce waste and become a more environmentally “friendly” facility several
pollution prevention (P2) projects were undertaken this past summer. These projects
included a search into the use of lead-free solder, no-clean/VOC-free solder and no-clean
solder paste, evaluating the efficiency of the current lighting system, locating a vendor for
the reuse and recycling of toner cartridges, determining a means of recycling integrated
circuit (IC) tubes and researching the options for implementing a conformal coating
process. Samples were obtained for lead-free wire solder, no-clean/VOC-free flux and
no-clean solder paste. Only the no-clean solder paste was able to be tested. The paste
was tested on fourteen boards for a customer and met with the customer’s approval.
Evaluation of the lighting system revealed a possible reduction of 51457 kWh/yr. This
energy reduction could lead to a reduction of 5% in the amount of greenhouse gases,
produced by Public Service of New Hampshire (PSNH), that can be related to Cirtronics.
Quality Re-Inking was established as the vendor for the reuse and recycling of toner
cartridges. The ground-work was started for the establishment of a consortium for the
collection of IC tubes within the state of New Hampshire. Finally, the recommended
means for conformal coating was concluded to be the use of a 100% solids coating
applied via an automated spraying system.
Introduction
Cirtronics Corporation is a contract manufacturer of printed circuit boards (PCB’s).
Manufacturing is divided between turn-key and consignment, with roughly sixty percent
(60%) turn-key and forty percent (40%) consignment. The majority of Cirtronics
products employ mixed technology. Mixed technology describes the process of
producing PCB’s with both surface mount technology (SMT) and through-hole
technology. Cirtronics is located in Milford, New Hampshire and is composed of
approximately one hundred employees.
Objectives
The project initially consisted of four goals. The goals included researching, evaluating
and possibly experimenting with lead-free solder, no-clean and VOC-free flux and noclean solder paste, and examining the current artificial lighting system. As time
progressed additional goals were incorporated into the project. The additional goals
included locating a vendor for the reusing and recycling of printer ribbons and toner
cartridges, establishing alternative methods for the removal of integrated circuit (IC)
tubes and researching the requirements, feasibility and most environmentally “friendly”
means of adding a conformal coating process.
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Note: Without the use of no-clean products the manufacturing of PCB’s require a
washing step to remove residue and active chemicals. At Cirtronics this washing step is
provided by an aqueous cleaner.
Methodology
Researching, evaluating and the possible experimentation of lead-free solder, noclean/VOC-free flux and no-clean solder paste were the primary goals of the project. A
literature review and internet search of lead-free solder, no-clean/VOC-free flux and noclean solder paste was performed in order to become familiar with the availability,
variety, positive and negative aspects of each product and any possible additional
equipment that may be required. Once the literature review and internet search were
completed the appropriate vendors were contacted and asked for information on and
samples of their desired product(s).
Included in the researching of lead-free solder and no-clean/VOC-free flux was one week
spent training on the wave machine. The training allowed for a greater appreciation and
understanding about how the effects that different fluxes and solder alloys have on the
production of PCB’s.
The idea for examining the efficiency of the artificial lighting system at Cirtronics was
initiated through a meeting with representatives from Public Service of New Hampshire
(PSNH). The meeting was set-up due to PSNH supplying a portion of the funds required
for the inclusion of a Pollution Prevention Intern at Cirtronics. During the meeting it was
learned that PSNH supplied a free evaluation of artificial lighting systems. A time and
date was established for an EnergyCHECK Engineer to visit the facility. The visit
consisted of dividing the facility into specific areas and determining the type of artificial
lighting and the amount of time the artificial lighting was in usage within those areas.
This information was then entered, on site, into a computer program. The program
produced three energy saving options for each specific area, providing alternative lighting
fixtures and bulbs and an estimated return time on the cost of the change ( the return time
included an estimated cost of labor). Option consisting of the shortest return time of the
three was then selected. PSNH supplied a final report, which included a summary of the
optimal options.
In locating a vendor for the reusing and recycling of toner cartridges and printer ribbons
several were contacted. The vendors were then evaluated base on their ability to refill
toner cartridges, re-ink printer ribbons and the cost of the service.
The first step taken in establishing alternative methods for the removal of IC tubes was
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determining the type of plastic the tubes were constructed from. Melissa Waleryszak,
Pollution Prevention Specialist from the NH Department of Environmental Services,
provided this information. In was concluded that the majority of the IC tubes were of
type “3” plastic, or polyvinyl chloride (PVC). Melissa also provided information on
producers of PVC products. “WasteNotes” was also searched for possible consumers of
PVC. Finally an employee of Cirtronics was able to locate a recycling company in North
Carolina.
The initial step taken in locating information on conformal coating was a literature review
and internet search for information on the process. The next step was contacting the
previous company contracted by Cirtronics to provide the conformal coating process and
a customer currently using a conformal coating process. Vendors were contacted as well.
Chemical Usage, Equipment Needs
Table 1
Product
Lonco 373
Additive
Lonco Neutral
Flux 373
Alphametals
SMT-Core Plus
Solder Wire
Alphametals
Pure Core Wire
Solder
Kester “331”
Flux Cored
Solder
Chemicals
Cas Number
wt %
67-63-0
99+
67-63-0
56-81-5
83
3
65997-06-0
1-3
Soldering
Iron
Rosin Amine
(Flux)
51344-62-8
<2
Soldering
Iron
Carboxylic
Acids,
Polyglycol
Vehicle
Beta Terpineol,
nonionic
Surfactant
68937-68-8
25322-68-3
<1
<3
Soldering
Iron
<5
<5
Stencils,
Squeegee
and Reflow
Oven*
Isopropyl
Alcohol
Isopropyl
Alcohol,
Glycerine
Hydrogenated
Rosin (Flux)
Alphametals
8000-41-7
Aqualine WS68439-49-6
609 Solder
Cream
* = Heller 1500 Reflow Oven
** = Dover-Soltec Wave Soldering Machine Model 6521CC
Equipment
Needs
Wave
Machine **
Wave
Machine **
6
Releases/Wastes Generated
Table 2
Waste Generated
Solid Hazardous Waste
-Lead Clippings
-Soldering Sponges
-Solder Contaminated
Clean Wipes
Hazardous Liquid Waste
-Outdated Flux and
Thinner
VOC Emissions (2Propanol)
Drum = 55 gallons
Source(s)
Rate
1 drum/yr
-Universal VCD, Amistar A1-800 Axial
Inserter and Work Stations
-Work Stations
-Print-Perfect-System (Solder Paste
Application)
1 drum/yr
-Work Stations, SMT area and Wave
Machine
Wave Machine Fluxing Unit
10 lbs/yr
Project Results
Lead-Free Solder: The literature review and internet search revealed no lead-free
substitute alloy equivalent to lead-based solder. Alternatives for lead include silver,
bismuth and indium. If the electronics industry were to consume silver and bismuth on a
major level, the world supply would come into question (Litton Industries). Additionally
bismuth is a lead-ore by product and contributes to brittleness (Litton Industries). Indium
forms a weaker alloy with poorer corrosion resistance when used in significant
concentrations (Litton Industries). Finally, most alternative alloys are not compatible
with the standard 60/40 tin-lead alloys, which would lead to difficulties in repair work
(Cross Talk).
Despite the numerous drawbacks a sample of lead-free/no-clean wire solder from
Alphametals was ordered. The alloy composition is 96.5 tin and 3.5 silver.
No-Clean/VOC-free Flux: The literature review and internet search of no-clean/VOCfree fluxes revealed a 15 lbs/day of VOC emissions allowed by the EPA for manufactures
of PCB’s (Scheiner). It was calculated that in a worst case situation Cirtronics generated
approximately 10 lbs/day of VOC emissions. Despite falling under the legal limits for
VOC emission the effort to locate a no-clean/VOC-free flux continued. During a site
visit to one of Cirtronics customers it was learned that the customer currently used a noclean/VOC-free flux in their wave soldering operations and had very little difficulty in
7
switching over to the no-clean/VOC-free flux. Based on the recommendation of this
customer two samples of no-clean/VOC-free flux were ordered from Alphametals.
No-Clean Solder Paste: After concluding the literature review and internet search
samples of no-clean solder paste were ordered from three different vendors. The vendors
consisted of Kester, Alphametals and ESP. It was decided to seek the permission of one
particular customer to test the pastes on their product. This customer was determined
because they have a particular PCB model that does not require the use of wave soldering
due to a lack of through-hole parts. Therefore, this would lead to these particular boards
from being rinsed in the aqueous cleaner.
The customer was contacted and gave permission to run test with the sample from Kester
only. Fourteen PCB’s were processed with the no-cleans solder paste from Kester. The
PCB’s were then sent to the customer and met with their approval.
Lighting Efficiency: In the final report presented by PSNH it was concluded that if all
the optimal options selected were installed at Cirtronics there would be an energy savings
of 51457 kWh/yr. A reduction of this magnitude, as shown in table 3, would lead to a
reduction of 5% in the amount of greenhouse gases produced by PSNH that are a result of
supplying energy to Cirtronics.
Table 3
Green
House
Gases
CO2
SO2
NOx
Emissions Factor
Energy
Emissions kWh/y Reductio Percent
from Marginal Consumption Generated r saved
n
Reductio
Station [lbs/kWh] [kWh/yr]
[lbs/yr]
[lbs/yr]
n ***
0.17
434988
73948
51457
8748
5%
*
0.0016
434988
696
51457
82
5%
0.000367
434988
160
51457
19
5%
* Marginal Station is least efficient power station in
use by PSNH
*** Assumed only 40% of power derived from green
(60%
PSNH power
house of
producing
plantsderived from Nuclear)
Note: Emissions
Factor data provided by Robert S. Leatherbee, P.E., C.E.M.; Senior
Power Plants)
Engineer for PSNH.
Toner Cartridge Reuse and Recycling: As stated before, several vendors were contacted.
Only three responded, from these three Quality Re-Inking out of Clairmont, NH was
chosen. The reason for this selection, as shown in table 4, was the fact that Quality ReInking was the only vendor, which supplied services for refilling toner cartridges and reinking printer ribbons.
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Table 4
Re-ink: add ink to existing ribbon fabric
Reload: add toner to cartridge
Current Cost
Quality ReReliable
Cartridge
for new ribbons inking
Technologies,
Warehouse
and toner kits
Contact: Walt Inc.
Contact:
Gobin
Contact: Mike Norman Head
Lambert
Phone: 603Phone: 603679-8690
542-2811
Phone: 800346-7890
Epson 7753
Re-ink: $2.00
New: $4.25
New: $7.08
(ribbon)
Reload: $3.00
Okidata
$12.28
Reload &
New: $9.99
New: $9.45
590/591
Recharge
(ribbon)
inking mech.:
$3.00
Ahearn &
will investigate Not Available
New: $11.58
Soper
(ribbon)
HP LJ 5P
$90.00
Reman: $37.50 New: $79.00
Reman: $59.00
(toner)
HP LJ 5L
$90.00
Reman: $37.50 New: $79.00
Reman: $59.00
(toner)
Okidata 810e
$19.95
Reman: $15.00 New: $22.00
New: $25.00
(toner)
(double check
Generic
about new)
replacement:
$18.50
Konica
$80.00
Not available
New: $53.00
New: $60.70
3135/4145
5+ $70.00
(toner)
10+ $59.00
Panafax UF$36.00
Recharge:
New: $25.00
Reman: $14.50
322
$9.00
(toner) note:
uses HP
cartridge
Panafax UF$250.00
Not available
New: $195.00 New: $215.00
550
(double check)
(toner)
Panafax UF$61.00 (toner)
Generic
Reman: $30.35
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733
(toner)
$380.00
(process kit:
drum &
developer)
replacement:
$29.50
IC Tubes: Polymer Reclaim and Exchange was the recycling company located out of
North Carolina. Geoff Southworth was the contact person from Polymer Reclaim and
Exchange. A meeting with Geoff Southworth, Barbara Bernstein from WasteCap and
Dennis Amell of Revamp Inc. was established. At this meeting it was determined that
a small company such as Cirtronics did not posses a large enough volume of IC tubes
to represent a viable source of raw material for Polymer Reclaim and Exchange.
Instead the first step were taken in establishing a consortium for the collection of IC
tubes within the state of New Hampshire. The criterion for acceptable IC tubes was
also established. IC tubes must be of type “3” plastic, contain no paper labels,
stoppers or pins and must be clear or blue tinted in color.
Conformal Coating: Completion of the literature review and internet search revealed the
most economical, worker “friendly” and environmentally “safe” means of implementing a
conformal coating process was through the use of a100% solid conformal coating and
applying the coating with a automated spraying system. The 100% solid coatings contain
no solvents and therefore produce no VOC’s. An automated spraying system allows for
the minimal amount of employee contact with the coating and applies the coating in the
most efficient manner.
Pollution Prevention Benefits
Lead-free Solder: Reduces lead waste stream and reduces intimate contact between
employees and lead-based products
No-Clean/VOC-Free Flux: Virtual Elimination of VOC emissions and reduced workload
on the aqueous cleaner. The aqueous cleaner is closed-loop system, therefore there is no
water waste stream. However, a carbon column and two anion/cation columns are
employed for the aqueous cleaner and are properly cleaned by a vendor. A reduction in
the workload of the aqueous cleaner will reduce the amount of waste generated by this
particular vendor.
No-Clean Solder Paste: Reduction in workload of aqueous cleaner.
Lighting Efficiency: Reduction in pollutants generated by local power stations.
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0
Toner Cartridge Reusing and Recycling: Reduction in toner cartridge and printer ribbon
waste stream.
IC Tube Recycling: Transformation of IC tube waste stream into valuable raw material.
Conformal Coating Process: If and when the process is incorporated, the use of 100%
solids coating and an automated spraying system will generate the least amount of waste.
Future Efforts
The complete conversion to a no-clean process would greatly enhance performance at
Cirtronics. No-clean wire solder is already used, therefore a conversion to no-clean
solder paste and no-clean flux will removed the need of the aqueous cleaner. Eliminating
the aqueous cleaner removes an entire process step, reduces energy and water
consumption, frees up vital floor space and eliminates waste generated from the carbon
and anion/cation columns.
To assist in the efforts to switch over to a complete no-clean process the implementation
of a nitrogen inerting process for the wave machine is recommended. This involves
applying a nitrogen blanket over the solder wave in the wave machine. The nitrogen
atmosphere removes the worry of oxidation during soldering, which enhances the
performance of a no-clean flux. Along with assisting the no-clean flux, the nitrogen
atmosphere eliminates dross.
The final future recommendation is the retrofitting of the wave machine with a force
convection pre-heat, assuming the use of a VOC-free flux. A VOC-free flux uses DI
water as thinner, without force convection a layer of super-saturated air can form above
the PCB. This layer of super-saturated air prevents the complete burn-off of the DI water.
If the DI water remains on the PCB when it comes into contact with the solder wave the
DI water will volatilize and cause solder balls, which can lead to shorts. The force
convection pre-heat will remove this layer of super-saturated air.
References
Litton Industries, Inc., Kester Solder Division, “Lead Free Alloy Position Paper”,
http://www.metcal.com/kester/ledfree.html
Cross Talk, “Lead-Free Solder? – Not Yet!”,
http://www.afcee.brooks.af.mil/pro_act/main/cross/ed20/ED20_5.HTM
Scheiner, Assistant Manager, Market Technology Kester Solder Division, Litton
1
1
Industries, “Manufacturing Considerations When Implementing VOC-Free Flux
Technology”, http://www.metcal.com/kester/vocfree.html
Appendices
Contact Person
Amell, Dennis
Bernstein, Barbara
D.
Fedock, Joe
Gobin, Walt
Head, Norman
Lambert, Mike
Leatherbee, Robert
S.
Matson, Amanda
McCallum, Daniel
R.
Odoardi, Jim
Company & Title
Revamp, Inc.,
General Manager
WasteCap, Director
Address
8 McGuire St.
Concord, NH 03301
122 No. Main St.
Concord, NH 03301
4 John Tyler St.
Unit F Merrimack,
NH 03054
Hi-Teck
Automation Inc.,
Sales and
Engineering Support
Quality Re-Inking
Clairmont, NH
Cartridge
Warehouse
Reliable
55 So. Commercial
Technologies, Inc.
St. Manchester, NH
03101
PSNH, Senior
1000 Elm St. P.O.
Engineer
Box 330
Manchester, NH
03105-0330
EnergyCHECK
PO Box 330
Engineer, PSNH
Manchester, NH
03105-0330
PSNH, Account
370 Amherst St.
Executive
Nashua, NH 03063
Jaro Corp.,
President
15 Spring St. Unit 1
Peabody, Ma 01960
Phone & Fax
Tel:(603) 228-5211
Fax:(603) 228-5333
Tel:(603) 224-5388
Fax:(603) 224-2872
Tel:(603) 880-9050
Fax:(603) 880-9505
Tel:(603) 542-2811
Tel:(603) 679-8690
Tel:(603) 644-2528
Tel:(603) 634-2458
Fax:(603) 634-2449
Tel:(603) 634-2894
Fax:(603) 634-2449
Tel:(603) 886-1387
Ext. 5280
Fax:(603) 886-4655
Tel:(508) 532-2717
Fax:(508) 532-3533
1
2
Southworth, Geoff
Polymer Reclaim &
Exchange,
Waleryszak, Melissa NH DES, Pollution
Prevention
Specialist
674 Gilmer St.
Burlington, NC
27217
6 Hazen Drive
Concord, NH
03301-6509
Tel:(212) 769-4081
Fax:(212) 769-0784
Tel:(603) 271-6460