Engineered Solders Blog
Recent Entries
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Meet the Bloggers at SMTAI
Posted by Amanda M. Hartnett
August 15th, 2008
This week at SMTAI we will be discussing hot topics with some of the electronic industy's most knowledgable representatives. Please Stop by to see us!
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Solder Alloy Density Calculator
Posted by Amanda M. Hartnett
August 11th, 2008
Looking for the density of a solder alloy? Many of you already know the density equation for an alloy, but if you want a quick way to do this simple calculation, you can use Indium’s Solder Alloy Density Calculator. This quick and easy-to-use tool was developed by Indium’s own Dr. Ron Lasky and has quickly been requested by many customers. -
Maximum Solder Temperature
Posted by Amanda M. Hartnett
July 18th, 2008
As a person with more information and numbers thrown at me in a day than I can manage to store, I am a lover of rules of thumb. They come in very handy as an engineer when I am traveling off site and need to determine what solder to use and in assisting customers on the fly. One which I use on a daily basis and advise to all my customers to whom it applies is:
The operating temperature of a device, in Kelvin, should NOT be greater than 90% of the melting temperature of the solder used.
When the device operates at temperatures too close to the melting point of solder, many stresses are applied to the joint which negatively affect its quality. Excessive intermetallic growth is likely and interfacial cracking becomes a threat. -
Determine Solidus and Liquidus Temperatures of Solder Alloys
Posted by Amanda M. Hartnett
July 16th, 2008
As previously posted, Indium’s Table of Specialty Alloys and solders contains hundreds of solder alloys and for each of them, we have listed melting temperatures. The method by which these were calculated is a repeatable one using a piece of equipment called a Differential Scanning Calorimeter.
In this method, a small sample of the solder alloy is input into the system and slowly heated until the solder alloy melts. Throughout the reading, a graph is created, from which the solidus and liquidus temperatures are interpreted.
The graph appears as a steady baseline, and at the melting point of the solder alloy, a peak is generated (See Image). At the point where the peak first deviates from the baseline, the solder alloy has begun to melt and this is the solidus point. At the point where the deviation returns to the baseline, the solder alloy is completely molten and this is the liquidus point. The entire deviation period is defined as a phase change period.
The tolerance of the scan is related to the scan rate. The slower the scan, the more accurate the reading. The tolerance on a typical reading is +/- 3ºC.
If you have a question about the melting temperature of any of our solder alloys or a solder alloy you are purchasing from us, we will be happy to share the differential scanning calorimeter readings with you for your personal interpretation. -
Meet the Bloggers!
Posted by Paul Socha
July 8th, 2008
Indium Corporation’s industry leading semiconductor bloggers are hosting a Meet the Bloggers session on Tuesday, July 15, 2008 at Indium Corporation’s Semicon West exhibit, booth #7834, from 2-3pm PST.
The technology experts will lead discussions on topics including:
· Flux deposit measurement using non-contact metrology
· Two upcoming white papers (currently under development):
- Wafer Flux Spin-Coating Topography
- Wafer-Level Flux Printing
· Recent hot semiconductor blog topics, including:
- Semiconductor assembly materials
- Future trends in first- and second-level assembly
- Halogen-free semiconductor assembly materials
- Engineered solders in MEMS assembly
- Thermal interface issues
- Solar device assembly
Indium personnel who will be discussing these topics include Jim Hisert, Paul Socha, Fez Sayed, Dr. Andy Mackie, and Rick Short.
All attendees are welcome to participate in, or observe, the session. Snacks will be served, too!
Indium’s blogs can be seen at www.indium.com/blogs
- Wafer Flux Spin-Coating Topography
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When the Bargain Bin is Not What You Bargained For
Posted by Amanda M. Hartnett
July 3rd, 2008
Jim Hisert's Dad demonstrating a jar of old flux which pales in comparison to Indium's new advanced flux technologies.
I’ve learned this lesson time and time again that a lower price does not make for a better deal. I learned this lesson yet again as I bought my cedar summer
This lesson should go without saying, but it applies to products of all types. That is, it also encompasses solders and their fluxes.
Jim Hisert recently posted this image of his dad with some OLD flux in his July blog posting titled, “Juxtaposition.” This got me thinking because just the other day I was shopping at my local home store and saw the rack of fluxes and solders made for soldering home water pipes. A jar of flux was in the $10 price range.
Coming from the industry of electronic-grade solders, this at first seems like the bargain of a lifetime. When investigated further however, it is quickly realized what technology went into making this versus the attentiveness we put into our materials and it is apparent that this bargain is not a bargain at all outside the old pipe soldering industry. There is no comparison
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Why use flux?
Posted by Paul Socha
June 10th, 2008
Flux & Substrate Compatibility
Flux is a liquid, solid or gaseous material which, when heated, speeds up and/or promotes wetting of the base material(s) by the flux’s removal of any surface oxides on the base material. Flux will protect against further oxidation during the soldering process.
Flux is an important component of most soldering operations. Using the correct flux for the application is essential to insure that a reliable joint is made.
To the right is a chart to help you choose the correct flux type for your application. Most post reflow flux residues need to be removed either to avoid corrosion or for reasons of appearance.
Reducing Gas Atmosphere is a gaseous atmosphere comprised of one or more gases, generally hydrogen and inert filler gas, such as nitrogen. Used where standard fluxes are ineffective at removing and preventing surface oxides. Hydrogen, for example, reduces the oxides, while nitrogen remains inert. It is recommended that both gases be present to effect a “fluxing” action. About 350°C is best. -
Indium Compressed into Hermetic Seals
Posted by Amanda M. Hartnett
May 16th, 2008
Compress indium between the arrows to form a hermetic seal
Have you ever tried to form a seal using an epoxy where you dispense the material, clamp the seal shut, and VOILA! It’s attached!?
You can do the same thing with indium in a wire, washer, or frame form. The process is no more difficult, it’s cleaner, and with some control, the seal is hermetic.
This process has been used by many who have looked for a high reliability seal that doesn’t leak yet many of you are still asking questions about it. If you have a sealing application and would like more information on this process, feel free to contact me or look over our indium sealing application note.
Image from penforhire.wordpress.com/.../ -
Engineered Solders with a European Flavour
Posted by Carol Gowans
April 30th, 2008
Alan Fairbairn
Guest Blogger
European Business Development Manager
Engineered Solders MaterialsI hope I can bring a European flavour to Engineered Solders and give you a taste of the activities that are happening in this vibrant and diverse area. It is difficult to look at Europe as a whole because although the European Community is a strong economic and political union (in their 51st year), the many countries of Europe still have their own long-standing identities and industries.
For example, watch making is a key industry in Switzerland but really nowhere else in Europe. Germany is known for their medical and automotive markets. Even the small countries have their focal points. The Netherlands is the home to a major electronics manufacturer; Sweden and Finland both have cell phone manufacturing as major industries. Even Denmark hosts a major wind turbine manufacturer.
All of these industries can use Engineered Solders. The addition of preforms to solder paste gives joints the added solder volume they need. This solder fortification application is widely used by a variety of circuit board makers. Thermal applications are also growing as the dissipation of heat becomes more and more important. Indium metal has a thermal conductivity of 0.87W/cm-C making it an excellent thermal interface.
The applications are virtually endless as we find new and growing applications every day.
The European office, based in the UK, was opened in 1990 and has been growing ever since by supporting the European Community with manufacturing and technical support.
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InTEGRATED Solder Preforms
Posted by Paul Socha
April 18th, 2008
Have you ever had to hand-place solder washer preforms on the pins of a connector and found it to be very labor intensive? Indium Corporation has a product called InTEGRATED Preforms which enable the user to place multiple preforms at one time in less than 15 seconds.
InTEGRATED Preforms are joined in a matrix by fine, precise strands of solder which, during the soldering process, melt and flow to adjacent pads to give complete preform separation.
In addition to time saved, the quality of the joint is assured because only one preform is delivered to each joint eliminating the chance that a pin will be missed or two washers placed on the same pin. Each scenario will create a quality problem that reduces the yield and increases the time spent on rework.
Unique preform designs and complicated configurations can simplify difficult soldering jobs. An example is a thru-hole connector with multiple rows of long pins that are difficult to reach in the center with hand soldering. InTEGRATED Preforms eliminate the need to reach these remote areas. The connected washers can be placed on top of the board, under the connector. After reflow, equal volumes of solder are delivered to each of the pins in the connector.
In order to get the full benefit of InTEGRATED Preforms they must be uniformly fluxed on both sides including the connecting strands. Also, they need to be flat in the application and uniform heat must be used to reflow them.
Many printed circuit boards have mixed technology. The surface mount components can be placed in the paste first followed by the thru-hole components using InTEGRATED Preforms. The board can then be reflowed and cleaned once, eliminating time consuming steps.
To learn more about this time saving product patented by Indium Corporation, please contact the Applications Engineering Staff at Indium Corporation.and we would be happy to design an InTEGRATED Preform to fit your solder requirements.
For additional information regarding reflow methods using InTEGRATED Preforms, check out the June 2007 issue of SMT Magazine.
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