Come talk with the experts in Non-Contact Metrology at Semicon West 2008. Directors from both Cyber Technologies and Fries Research and Technology will join me to discuss the importance of flux inspection and measurement in
Come talk with the experts in Non-Contact Metrology at Semicon West 2008. Directors from both Cyber Technologies and Fries Research and Technology will join me to discuss the importance of flux inspection and measurement in
My Dad’s soldering kit epitomizes the evolution of flux. He uses this old, dirty flux that must be from the 1970’s, I don’t know how it still works. Remembering the materials we work with everyday, I wonder if that ancient batch of flux was tested for viscosity or tack. I wonder if it was even tested at all? The materials we use at work share the same roots, but they are incomparable. What will we think of current fluxes three decades from now – will there still be a need for flux?
In a collaboration between Indium, Dek, and FRT, a team was formed to evaluate flux printing for wafer level packaging. The results of the testing last week will be presented at the International Wafer Level Packaging Conference (IWLPC) in October. The testing focused on evaluating 7 different fluxes printed onto wafers for wafer level sphere attachment. The FRT metrology equipment was used to measure the volume of these tiny (down to 50um diameter) translucent flux deposits.
Writing an article is the hardest part of writing an article. It must have been said before, but actually sitting down and capturing what has been physically done and mentally learned is tougher for most people than doing all the testing. I like to clear away all the other distractions, get a humungous soda, and after thinking about the results all day – just write down all my thoughts. First I go through the introduction and test procedure, then include what I learned from the trials. After the words are in place, I look for a way to illustrate my point through images, graphs, and charts. I’ll try to get away from the document at this point and clear my mind. When I come back to writing, the conclusion is usually obvious.
After the skeleton draft is in place I leave it for about a week, and then come back to it and look at it like it is someone else’s article. I fill in the blanks, take out the redundant statements, and send it off for further editing. Right now I’m in the meditation and ‘humungous soda’ stage, preparing to draw up an article on non-contact measurement and wafer spin coating fluxes.
Some failures are easy to spot at time zero, others can appear over time. The key is to be able to classify your products so you never have an embarrassing failure that makes it to your customer – like the one in the picture]]> As you may have seen on product data sheets or specifications, each flux is tested per industry standards for different parameters. One characteristic that is important to customers is viscosity. There are various ways to measure the viscosity of a tacky-type flux, the most common being the J-STD T-bar method. This testing uses a rotating spindle to feed-back the force needed to shear thought the flux. For a more application-realistic measurement, we also use the cone and plate method to test viscosity. This test method employs a rotating disc that works in a similar manner to T-bar feed-back, but tests a film of material between the base cup and the disc. I expect future test method standards to target the cone and plate method, once the industry catches up.
Dear Readers,
This is the Blog’s 100th entry, so I thought I’d let you all know a little about what goes through my mind when I write an entry.
Many readers ask “How do you come up with your ideas?”, or “What made you think of that?” It seems pretty simple, to me at least. Do you every find yourself saying something that is only interesting to people you work with when you are outside of work? Those are the things I like to write about. The things that I think of on my own free time. For instance, the entry “This Weekend Utica NY Hosted a Monster Truck Rally” was created when I was standing in front of a monster truck. It can seem ridiculous, but I always compare things in the world to semiconductor packaging. I know, it’s nerdy – but that’s how this whole blog seems to work.
Many times I look at an image - and the first way I relate it to our industry is what I write my next blog about. If you find yourself comparing the semiconductor industry to daily things, I would love to hear about it! (The sad part is that I will probably find it really cool…)
Thanks for the support,
~Jim
Last week, Michael Riddle (Cyber Technologies) and I experimented with liquid fluxes for spin coating / wafer bump reformation. We used a Cyberscan Vantage to examine the topography of the flux at different spin rates and times. The interesting findings will be explained in our upcoming article (placement to be determined).
Anyone working with BGA solder joint reliability should be used to X-ray detection, made possible by Si-Li and Ge-Li as well as Cd-Te and Cd-Zn-Te. These materials sense the X-rays and convert them into an electrical signal. X-ray equipment is great for classifying voids in BGA solder joints, some thermal interfaces, power die attach, and an array of different solder-related applications.
We’ve seen a lot of these x-ray images, and they usually tell a good story. If you’d like to share your x-ray story, send it to jhisert@indium.com. Disclosable stories can be shared on the blog.
Sometimes a new process goes against everything we know will work. Those applications are few, but revolutionary. Take, for instance, Package-on-Package assembly. As commonplace as it seems now, this is one of those things people disregarded without even realizing. Now the thought “we need more area on this board” is often substituted by “we need this package design stackable”. Thank you to everyone who thinks outside the box!