A Background to lead free solder
Antaya has 13 lead free solder alloys developed for the use in the automotive and solar panel markets. The alloys differ in cost and various properties, particularly solidus, liquidus, malleability and conductivity. Each alloy is designed to meet specific performance requirements that can be verified via a relevant test protocol.
For the purpose of clarity, alloys that pass one test protocol will not necessarily pass another and no such representation can be made.
Some of our lead free alloys are carefully formulated to meet certain performance standards while minimizing costs. Those alloys will not meet other standards that may have been provided by other customers or for other applications. Antaya alloys have been formulated for use in one or more of the following applications:
- Laminated automotive glass
- Annealed automotive glass
- Polycarbonate automotive glazing
- Silicon solar panels
- Proprietary photovoltaic material
- Thin film silicon based semiconductor layers
Antaya’s core competencies include the development of custom alloys. Customers are encouraged to send us your test protocols so that we may develop the most cost effective and environmentally friendly high performance solder alloy. We do not send out solder alloys for general investigation. We ask that our customers give us the standards and the tests to which alloys are to be subjected. We will then be in a position to send the most cost effective sample parts that are certified to meet the standards required by our customers.
- Introduction to solder on glass
Pre-soldered, pre-fluxed terminals, connectors and wire assemblies are used on automotive glass as follows:
- for supplying power to silver printed heat grids which serve as de-foggers or heated windscreens (front or more commonly rear).
- for making a signal contact to silver printed antenna patterns which may be used for GPS, AM/FM, Cell phone and remote starter devices...
Silver is an excellent conductor when screened and fired into the surface of the glass and pre-soldered, pre-fluxed contacts can be soldered to the silver layer. Typical solder alloys are a combination of tin, lead, bismuth, and silver with lead being the highest percentage element with at least 62 percent.
The lead is instrumental in the performance of the alloy due to its malleability which mitigates the stress created between the copper terminal and glass and prevents cracking of the glass due to the difference in coefficient of thermal expansion between the copper terminal and glass substrate.
- Lead Free Solder, The European Commission and Directive 2000/53/EC - the "ELV Directive".
Development of a lead free solder has been a goal of the OEMs, Glass suppliers, and Antaya Technologies for many years. On August 1st 2008 lead in solder for electrical connections on glass was banned by the European Commission through an amendment to Annex II of the Directive 2000/53/EC.
As a result of legislation and the Automakers move to environmentally friendly practices and materials Antaya Technologies has been asked by many of the automakers and glass manufacturers to develop a lead free solder that will perform as well or better than the widely used leaded version. Antaya has developed several alloys that meet this request.
The company’s development activities can be summarized as follows:
1. Replacing the lead with tin.
Our first attempt to develop a lead free solder began in 1994. This first approach was a result of benchmarking the electronics industry. Electronic component and printed circuit board manufacturers historically used leaded solders in their manufacturing process and recently had been successful in replacing the leaded alloys with high tin alloys.
Several high tin alloys were cast and fabricated into pre-soldered, pre-fluxed terminals and soldered to glass. These high tin alloys were unsuccessful due the stress created due to the difference in the coefficient of thermal expansion of the glass and tin. Without the malleability of the lead to absorb the stress high tin alloys caused the glass to crack.
2. Replacing the lead with indium
Our second attempt was to find an element to replace the lead that could be combined with tin, bismuth, and silver that would provide similar malleability to the leaded alloy. Indium was chosen as a replacement for the lead and terminals were fabricated and tested. These Indium alloys provided similar performance to the leaded alloys and were successfully implemented on Ford and GM heated windshield and windshield antenna assemblies. However, the high cost of indium prevented a large scale replacement of lead.
3. Matching the coefficient of thermal expansion (CTE)
In our third development program, instead of looking for an alloy with similar properties as the leaded or indium alloys, our approach was to develop an alloy that would eliminate the stress between the terminal and the glass by sufficiently matching the coefficient of thermal expansion of the glass and the solder. Silica spheres and nickel iron particles were mixed as additives to the solder to change the expansion properties of the alloy. While successful experiments were conducted in a laboratory setting, problems associated with transferring the technology to a large scale manufacturing process proved insurmountable.
4. Minimizing the percentage of indium
Our fourth and most recent development effort expanded on the success of the previous indium alloy development and focused on determining the least amount of indium required to provide sufficient malleability and prevent glass damage while providing adhesion and electrical performance to meet the OEM requirement. 23 alloys with different percentages of indium were cast and tested on a wide range of glass products. Glass that is particularly sensitive the damage with temperature change requires a higher percentage of indium and glass that is more damage resistant glass can be soldered with a lower percentage of Indium. No matter what the properties of the glass Antaya can recommend a functional alloy.
Cost Analysis - Worst case scenario (all automotive glass including non tempered)
Even by minimizing the percentage of indium, the resultant alloy represents a 2.5 to 3 times increase in the price of a pre-soldered, pre-fluxed blade or crimp terminal that incorporates lead. The terminal which is relatively inexpensive, is often sold to the glass supplier as part of a more expensive wire harness assembly, and is always sold as part of the glass assembly, so when measured as a percentage of total cost of the assembly (as opposed to the terminal), the percentage increase is very much lower.
The average price of a glass assembly complete with three “leaded” electrical terminals is $45.00. The estimated price increase for a glass assembly with three lead free electrical terminals is $0.73. This $0.73 or €0.61 is the predicted increase in the cost of the connectors for a typical car as a result of converting to the Antaya Indium Alloy terminal. This cost differential is subject to the fluctuations in the cost of Indium.
The lead free parts are attached to the glass in exactly the same way, using the same equipment as the leaded version. There is no increase in the installation cost and no change in the reliability of the installation process.
The above cost analysis reflects the worst case scenario with non tempered glass that is particularly sensitive to cracking due to the differences in the coefficient of thermal expansion (CTE). For tempered glass products which are less sensitive to variations in CTE, it should be noted that the concentration of indium, which is a significant driver in the cost of the parts, can be optimized to maintain performance and minimize costs for every application. The physical properties of the glass will determine how much indium is required.
Quality Control
The lead free parts can be manufactured in a reliable process controlled environment conforming to TS16949 including ISO9001 specifications. The lead free product additionally conforms to ISO14001 standard. Manufacturing capacity is available immediately.
Performance Testing
Antaya Technologies received accredited laboratory test results proving out the lead free product using a summary of test specifications collected from global OEMs and glass manufacturers. Both the test specifications and the third party test results are available in the technical section of our web site www.antaya.com.
Antaya Technologies – Company Profile
Antaya Technologies Corporation, based in Cranston, Rhode Island, USA, was founded in 1987. The principal activities of the company in the 80’s and early 90’s was the development work done for Ford Motor Company in the area of manufacture and solderability of electrical connectors for heated glass and on glass antennas. The company has grown significantly and is now the leading manufacturer and supplier of pre-soldered, pre-fluxed electrical connectors and controlled soldering equipment for automotive glass, electro chromic glass and solar panels. The company manufactures proprietary solders and specialty clad materials.
Since its inception with Ford Motor Company Antaya has expanded globally to supply all major glass manufactures and OEMs in all markets. Customers include: Pilkington, Saint-Gobain, Asahi Glass, PPG Industries, Guardian, Nippon Sheet Glass, Central Glass, Visteon, Omron, and Lear, with products that can be found on vehicles produced by Ford, DCX, GM, BMW, Nissan, Honda, Toyota, Subaru, Opel, VW, Mazda, Volvo and PSA.
Antaya currently has 150 employees with two manufacturing facilities in Rhode Island, several contract manufacturers in Asia, and sales engineering offices in Hong Kong, Germany, England, Mexico and Chicago.
The company is privately held with institutional financial backing.
Summary
In conclusion, as a result of the development activities outlined above, Antaya Technologies Corp has developed the most cost effective lead free solder alloy to meet the performance requirements of the automotive glass industry. This alloy can be produced in a large scale manufacturing environment, is available immediately, and will have a minimal impact on the cost of a vehicle.
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