• Home
  • About
  • Forums
  • Articles/Blogs
  • Ask the Guru
  • Profiling Guru Survey
You are here: Home / Archives for flip chip

Tips on Cooking Both a Perfect Thanksgiving Turkey and a PCB

November 23, 2011 by Profiling Guru Leave a Comment

Tweet

Why does it take half a day to cook a Thanksgiving turkey?  The answer is simple ― you have 20 lb of bird that simply cannot just be nuked in a microwave like last night’s dinner.  If not properly thawed, prepared and monitored, you either have an overcooked, dried-out bird or worse: Salmonella. Strangely enough, as you will see in a moment, PCBs are not that much different.

Let’s say you skip the thawing process and in your haste stick a frozen bird in the oven.  What happens?  The bird may look properly cooked on the outside, but as soon as you try your skill with the carving knife, you either hit bedrock or the inside is completely raw. OK, I will admit I speak from personal experience on this one (please do not bring this up with my wife).  Are PCBs any different?  Well, your reflow profile has a preheat phase, with the purpose of bringing your PCB to temperature. In other words, the entire mass of the board with all its components is gradually brought to equilibrium. If you do not do this, you run the risk of thermally shocking your components when they hit reflow and peak.  Thawing your bird and preheating your PCB ― you have the same objective in mind.

So, for the vast majority of us, we really have no idea when the turkey is fully cooked until getting an internal reading. A PCB is no different. On the surface, both might look great, but upon closer inspection, you discover some components have defects due to improper reflow or, for that matter, when you cut into a turkey that is still pink it really hits home that you aren’t cooking a TV dinner.

turkey-in-Spec_SM01

Because of this, as we all know, a 20 lb turkey requires a thermometer. I will concede that some of you use the old “poke the bird and check for pink until done” trick. Let’s assume you are not as skilled, like me, for example. Would you seriously cook a turkey by relying solely on the oven’s temperature reading on your stovetop?  Of course not, but why do some of you profile your PCB by relying on your reflow oven’s reported readings? Are either situation that much different?  Actually, yes. Your nice self-contained turkey cooking oven is more of a steady state, but there remains a large difference between what is reported by the oven and the internal temperature of your turkey. In contrast, your PCB is exposed to anything but a steady state environment because it rides on a conveyor through different heated zones with blowers, extraction systems and both ends of the oven even open to the elements!  For this reason, any oven manufacturer will adamantly tell you to profile and with regularity. Alright, you may have learned how to cook a turkey in your Mama’s kitchen and, in fact, be skilled at not using a thermometer; however, I doubt any serious SMT manufacturer would take a similar approach, checking your PCBs regularly for “doneness” in your reflow process.

What about placing the fate of your Thanksgiving feast on the cheap-o plastic pop-up indicator that likely came with the turkey? Do not laugh. How many of us use the trailing wires that came with the reflow oven?  Now to be fair, both work in principal; otherwise, you would have the likes of Purdue Farms with food poisoning lawsuits on their hands, but they only give you ballpark readings in many cases. By design, the turkey is going to be a little overdone and dried out.  Your PCB, on the other hand, cannot afford to be a little overdone or it is simply OUT of spec.  You can get by with eating the overcooked turkey … the gravy and mashed potatoes are there to make up for less than a perfectly cooked bird. But your PCB will not be as forgiving.  Trailing wires, never mind being cumbersome to use, have a tendency to kink and stretch, which compromise their readings.  They also are susceptible to 50 or 60 cycle noise from some reflow oven environments, further questioning their accuracy in some cases.

So you want to cook the perfect bird. Who doesn’t? So you pony up for a stainless steel large-dial meat thermometer to accurately read the internal temperature of your 20 lb bird. You also pony up for a KIC Explorer with Navigator because you want to create the perfect deep-in spec reflow profile. It will not only tell you the specific temperature of the joints of your $500 BGAs, but it also will find a balance that does not overcook them or any of your other temperature-sensitive components on the PCB.  No pop-up indicator profiler needs to apply since the KIC Explorer with Navigator will go the extra mile and tell you not only if you are in-spec but how DEEP in-spec your profile is, along with what can you do to improve the profile in minutes, if not seconds.  Now do you know of any turkey thermometers that can do that?

So when you prepare your Thanksgiving turkey, and as you pause to give thanks, consider applying the same care and consideration that you have given to your family’s feast as you do to your PCBs.

Happy Thanksgiving – Profilingguru

Share

Filed Under: Featured, Improve, Reflow, TC's Tagged With: AOI, BGA, BGA Profiling, ceramic packages, cost-based tools, electronics manufacturing services, energy efficiency, flip chip, maximize throughput, Process monitoring, Process Window, profiling, profiling software, Reflow, reflow oven, reflow ovens, reflow process, reflow profiling, SMT, SMT and standards, SMT Reflow, soldering, SPI, surface mount technology, Thermal Management, thermal process, thermal profiling, thermocouple attachment

Reducing Reflow Product Changeover Time

November 7, 2009 by Profiling Guru Leave a Comment

Tweet

2009 Presentation at SMT Long Island on how to reduce the changeover time from one reflow profile recipe to another.  If you ever opened up your reflow oven to dump all its heat to lessen downtime, this 4 min video is for you!!!

To view the complete video series (click here).

To subscribe to my Podcast for iTunes (click here).

https://profilingguru.com/podcasts/Product_Changeover.m4v

Podcast: Play in new window | Download (Duration: 3:40 — 16.9MB)

Share

Filed Under: Improve, Podcasts, Process Window, Reflow Tagged With: AOI, BGA, BGA Profiling, ceramic packages, cost-based tools, electronics manufacturing services, energy efficiency, flip chip, maximize throughput, Process monitoring, Process Window, profiling, profiling software, Reflow, reflow oven, reflow ovens, reflow process, reflow profiling, SMT, SMT and standards, SMT Reflow, soldering, SPI, surface mount technology, Thermal Management, thermal process, thermal profiling, thermocouple attachment

SMT related Links to know

September 30, 2009 by Profiling Guru Leave a Comment

Tweet

RSS feeds, Tweets, blogs and newsletters, how do you keep up?   Well here is the latest on what’s available in the SMT industry.   I subscribe to all of these newsletters and regularly pick out areas of interest related to profiling for you.   I also comb the blogs though I only know of two, not including profilingguru, which is quite remarkable considering other industries have hundreds if not thousands.   The SMTA group forum on LinkedIn yields on occasion a nugget, but you need to build a profile to join.  SMTnet has always been a jewel.  Lastly, Twitter is a new phenomenon for many of us.   I am still trying to get the knack of it myself but it does have some value no doubt and will continue to grow.

On-line Newsletters:

Circuitnet

Electronics Production World

EMS Now

GlobalSMT

PCB Update

SMT Week

Blogs:

Circuits Assembly

SMT Editorial Blogspot

Forums:

SMTA on LinkedIn

SMTnet

Twitter:

Circuit Assembly

Global SMT

SMT Magazine

Share

Filed Under: Links Tagged With: AOI, BGA, BGA Profiling, ceramic packages, cost-based tools, electronics manufacturing services, energy efficiency, flip chip, maximize throughput, Process monitoring, Process Window, profiling, profiling software, Reflow, reflow oven, reflow ovens, reflow process, reflow profiling, SMT, SMT and standards, SMT Reflow, soldering, SPI, surface mount technology, Thermal Management, thermal process, thermal profiling, thermocouple attachment

Profiling guidelines for reflow of solder bump flip chip attach to organic and/or ceramic packages

June 24, 2009 by Profiling Guru Leave a Comment

Tweet

This post is in response to a suggested topic on this blog.  The following answer was provided by Brian J. Toleno, Ph.D., Director Technical Service at Henkel:

When profiling a flip-chip to an organic substrate you typically want the delta T across the component to be as low as possible in order to minimize stresses and warpage. Of course, like any good profile, making sure that the solder bumps and solder paste reach liquidus, stay above the liquidus temperature for the recommended time, and have a controlled cool down as possible are key.   In addition, if the flip chip device is going to be underfilled, then it is important that when using a no-clean flux solder paste that the solder paste is fully activated in order to minimize any possible flux/underfill interactions.    So making sure you measure the temperature at the flip-chip bump/solder paste/solder pad area is important.   You also want to make sure you measure the temperature at the centre and the corners (making sure they track close together).   While there typically is not as great of a chance of a large delta T, like there would be in a BGA or CSP device – when one does occur it can be more catastrophic.

Share

Filed Under: Define, Reflow Tagged With: BGA, BGA Profiling, ceramic packages, defect rates, efficiency, electronics manufacturing services, flip chip, profiling, Reflow, reflow profiling, SMT and standards, surface mount technology, thermal process, thermal profiling

Search Bar

Recent Posts

  • Profiling Guru Survey
  • Profiling Dual Lane Variable Speed Reflow Ovens
  • Tips on Cooking Both a Perfect Thanksgiving Turkey and a PCB
  • 2011 Profiling Guide
  • Man versus Forno de Refusão

Interesting Blogs

  • Circuits Assembly Blog
  • Rick Short – Indium Blog
  • SMT Editorial Blogspot

Resources

  • SMTnet
March 2023
M T W T F S S
 12345
6789101112
13141516171819
20212223242526
2728293031  
« Aug    

Return to top of page
Copyright © 2023. Corporate Child Theme on Genesis Framework · WordPress · Log in