Why A Laminator Is Used With The "DirectEtch" Process Over An Iron
A few years back there was a revolutionary redesign change on the standard pouch laminator.
Pouch laminators just mean they use pre-made plastic pouches to insert a photo or a document instead of having large continuous rolls of plastic).
Now, Instead of heater plates positioned after the transport rollers used to seal plastic pouches (like all other pouch laminators), the heaters in this redesign concept have been formed into an arc and mounted above and below the two transport rollers. The heat is then radiated into the neoprene coated rollers very evenly as they continuously turn from the high-torque motor drive up to the correct temperature. This technique results in a very inexpensive "hot roll" laminator! This laminator approach results in the ideal "heat & pressure" for use with both of our products... making instant PCB's as well as creating real dry-transfer graphics with our revolutionary product called DecalProFX.
This new heater design concept of heated rollers is perfect for our application to provide high heat and pressure at the same time. This is an absolute must, which is why the old standard designed laminator (parallel heater plates between the transport rollers) will not work at all.
The only differences now between the newly designed "externally heated" pouch laminator and the internally heated "Hot Roll" laminator (left), is that the heater elements are mounted INSIDE the rollers which mechanically is a much more elaborate and expensive type of laminator that cost into the thousands of dollars.
Toner Image Applicator or "TIA" for short.
The BEST laminator to use?
GBC used to be the best laminator for our products. Up until a recent redesign in 2013 their model H-220 used to be the idal unit. They stopped prodution of this great unit and replaced it with their "Swingline" brand, "FUSION" models. Upon testing their losest cost units, they failed terribly for our use.
Currently, the IDEAL laminator to use is a unit called the APACHE, model AL13P available for an amazingly low price of under $80 through AMAZON.COM. It is an all-metal construction, heavy-duty drive motor/geartrain, adjustable roller pressure and temperature control (in Fº) up to 379ºF!
NOTE: There is only one very simple modification that must be done to this APACHE unit. There are 4 screws on the bottom of the unit that need to be tightened. The procedure is outlined here. (If you open this page, click your "Back" button to return to this page.)
For our Canadian customers, there is a very similar unit imported directly into Canada. Contact us for the vendor's name and contact info.
Why Use A Laminator over an Iron?
The simple answer is, it's the only cost effective, inexpensive, simple and reliable way to make absolutely perfect, repeatable circuit images "on the fly". An iron can be made to work, but there is a definite learning curve or 'trial 'n error' to get the iron calibrated so be able to get repeatable results MOST of the time. The laminator approach is the only truly serious tool to make the "DirectEtch" a viable alternative to every other board fabrication method out there. For a minimal expense, you can fabricate your own single & double-sided boards with total repeatability. There is no learning curve like that of using an iron. Turn on power, wait for the initial warm up cycle and you're in business. (GBC "H-220" laminator shown above.)
Q: Can I still use my iron?
A: Sure, but you must first "calibrate" your iron to be able to get consistent results. We have a calibration method outlined under the TECH SUPPORT > INSTRUCTIONS > USING AN IRON. Read the info first and then at the bottom of the page describes how to do the calibration. There is also an interesting method using a large diameter wooden dowel rod.
Here's the technical low-down of how toner works and why the laminator became the applicator of choice for our process
Since the early days back in 1992 when we first entered the market in the "DirectEtch" technique, our process revolved around using a house-hold iron to transfer the printed image to the copper surface. There was no better device on the market, plus, everyone had one so there was no added expense. It did, however, it was a far cry from the ideal situation, mainly because we didn't fully understand the dynamics of laser printer or photo-static copier powdered "toners".
Although it was an 'OK' process for the pure hobbyist in that day with a somewhat "hit 'n miss", trial & error method to be able to finally arrive at a usable board, the more serious hobbyists, Midnight Engineers, educators and real time engineers in R&D labs just couldn't take the process seriously. Something had to be done to turn it all around. We used to sell a highly modified pouch laminator that had no pressure and very high heat (400ºF) that worked better than an iron but with a price tag of $299, it only attracted the serious user. And even then, perfection was not always guaranteed.
The "DirectEtch" process was pure simplicity - we knew we had a winner but it was the finicky toner that was the "long pole in the tent" to achieve total acceptance by all involved in electronics. We had laser printers that could produce exceptional PCB images, we had the transfer paper that would release the toner with zero friction, but we couldn't quite get a handle on controlling the temperament of toner. That was the big weak link in the chain.
Our amateur research led us to understand a few very important correlations between three basic properties of toner:
1) HEAT & PRESSURE - makes toner sticky ("fuse")
2) PRESSURE - determines at what temperature toner will "fuse"
3) TEMPERATURE - determines at what point toner will "melt"
All of these sound somewhat unrelated but in fact they are all interconnected. Ok, so how do we put these rules into play? The answer was pretty obvious in hindsight. We first discovered there was a direct correlation between pressure and temperature. The greater the pressure, the lower the temperature needed to be to get toner to "fuse" permanently to anything. Secondly, the lower the temperature, the greater the spread between the "fusing" (sticky) point of toner and the sheer melting point of toner. That was it! If we can keep away from the melting point, the printed toner image will never get distorted! So, we need a huge amount of pressure with a temperature that was comfortably below the melting point of toner. (Are you still with me?!)
Now the problem was, what do we use to induce high pressure? We started with the iron. Instead of pushing down with arm pressure, we put it on the floor and stood directly on it. Each test was done with slightly higher temperature until we had a perfect transfer. On many tests the transfer was perfect but we kept ramping up the temperature until we hit the "melting" point of the toner so that we could tell how far the "spread" was. The temperature spread was indeed significant. Ok, so standing on the iron at 180# gave me only about 8psi on a standard sized iron. We needed a better technique... a device of some sort because standing on an iron is not a very professional approach to adopt. This would obviously be laughed at by the serious electronics tech.
The answer was to expose fewer square inches to be able to easily increase pressure slightly to result in a huge PSI when extrapolated over a distance. Thinking about this, I happed to look up on a shelf and saw an old "pouch laminator" and thought let's give it a try. Contrary to our old original "applicator" that used cold rollers, this newer GBC brand laminator used two heated rollers along with pretty good spring tension. It worked, it worked and it continued to work every time... we found the perfect device! What used to take nearly 400ºF on a household iron (very close to the toner's melting point) we have now perfectly fused toner at 270 ~ 300ºF. Perfect, reproducible images. Next was to find an inexpensive laminator. To our surprise, we tested 12 different manufacturer laminators to try to find "the" unit to give the best "bang-for-the-buck". Currently (as of 2013) the ideal laminator is the APACHE AL13P available direct through AMAZON.COM.