Zephyrtronics Equipment is Engineered and Manufactured in the United States of America.

PCB Rework Pre-heater    Bottom-Side Preheating     Pre-heat for Heavy Ground Planes    Lead-Free PreHeat Rework

No One Knows More About Preheating PCB's Than Zephyrtronics!
ZT-1-BGS BIG-GRID™ DIGITAL PRE-HEATER AIRBATH
Effective, Bottom-Side Convection Pre-Heating for PCB, Thru Hole, SMD, SMT, QFN & BGA Rework & Repair

Big 16 Square Inch Preheating Grid (110 Sq. cm) With 1,500 Watt Power, 50 CFM Air Supply (1,415 Liters/Minute)

Zephyrtronics' AirBath “bathes the circuit board in warm air to reduce thermal stresses
to the board and its components.”-- NASA Report, January 9, 2004

Our ZT-1-BGS-DPU BigGrid™ AirBath features big 16-square inch (110 sq. cm) preheating grid with 1,500 watts of power, plus 50 CFM (1,415 liters per minute) of air supply for preheating and cooling. Introduced in 1998, this is the second largest AirBath™ manufactured on earth by Zephyrtronics, the recognized pioneer and world leader in PCB preheating technology.

This is the same BigGrid™ AirBath used by NASA and JPL for preheating the PCB's on the two Mars Rovers that were so successful on the Red Planet!  The BigGrid™ is manufactured in our state-of-art factory in California, has a two-year limited warranty and is ideal for large PCB's or with high copper content, heat-sinks, large ground or back planes. It's a workhorse!

The patent protected technology of the BigGrid™ AirBath™ is the most effective PCB preheat solution during prototyping or rework at the bench for thru-hole and surface mount technology including Ball Grid Arrays.

Chosen By Boeing for the
International Space Station Project.

For Thru-Hole, SMT & BGA Preheating Tasks: The BGS Series AirBath Preheating Systems is ideal for all PCB challenges from low-volume production runs, prototyping during design or during rework with all SMD packages such as BGA, CSP, QFP, QFN, TSOP, PLCC, SOIC, SOL, LCC, Flip Chip and Glob Top components. Still, the AirBath  is not limited to only SMD devices: Don't overlook the superb benefit the AirBath  preheating boost brings to your tough through-hole (PTH) soldering and de-soldering tasks! Plus, it easily handles all substrates including FR-4, polyimide, composites, flex circuits and ceramic boards.

The Many Benefits of Preheating Your PCB: The benefits of preheat are multiple and compounding. 1.) Preheating or "soaking" the assembly before reflow activates the flux that removes oxides and surface films thereby enhancing the wetting process and solder joint quality. 2.) Preheat permits lower soldering reflow temperatures. 3.) Preheat reduces "dwell time" at the final reflow stage. 4.) Preheat reduces thermal stresses to the PC substrate and components if localized reflow is made with soldering irons, de-soldering tools or hot air tools. 5.) Preheat gives a thermal boost for  RoHS lead-free solders without damaging the work!

Preheating PCB assemblies falls into four categories: 1.) hot plates, 2.) ovens, 3.)  IR systems, and 4.) forced convection (warm air) under the PCB: The short video at the right breaks down these four methods with video comparative demonstrations. While any preheat of your PCB prior to solder reflow is certainly better than none, an objective analysis of the various methods of preheating reveals that all preheating methods are not equally effective or beneficial:

1.) The Oven: Using ovens to pre-heat a PCB before reworking and initiating solder reflow for either removal and/or replacement of components can yield the most uniform temperature profile as it warms both the top and bottom of the PCB as ovens also do in high volume production equipment such as conveyor ovens and wave solder machines. It's just a little problematic to crawl inside an oven with your PCB to preheat while you perform selective soldering or desoldering tasks on one side of the board. Of course, one could preheat a PCB within an oven, and then afterward, rush it back to your bench, but it's hardly practical solution either.

2.) The IR Preheater: There are many drawbacks to infrared which is why it has really never completely caught on.  Some of drawbacks (enumerated in articles and white papers at electronic conventions) are the difficulty in ramping temps (some are better than others) and shadowing caused by high profile devices on PCB's. If the IR preheat grid is very large, it makes working on small PCB's very uncomfortable for a technician (a very common complaint).

Another quality disadvantage of IR preheaters is they cannot ever truly be "temperature controlled" without to taping an external thermocouple onto each board before working on it. This is a hassle and headache for the technician and filled with quality pitfalls, especially inconsistent results. There are more drawbacks, but these are some of the worst.

NASA & JPL: 'IR Preheaters Are Risky': Addressing the preheating rework process for heat sensitive chips in a 49-page published report, two JPL engineers, Dr. Rajenshuni Ramesham and Dr. R. David Gerke, wrote "Hot plates and infrared preheaters are not recommended for this type of rework. The reason that they should not be used is that the thermal reaction times, energy transfer rates and efficiency are never consistent. However, they can be used for large metal and ground-plane boards in limited applications, e.g., where the size of the board matches that of the preheater in area."

Citing the late William Scheu, the authors point to the superiority of preheating by bottom-side forced convection systems. The NASA Survey by JPL spotlighted still more of the deficiencies of IR preheating devices: "They have little capacity to ramp and soak to perform properly engineered repair scenarios or to support the creation and application of complicated thermal profiles. They also are limited in their ability to preheat beyond the physical dimensions of the heating surface. Hot-air preheating can be ramped, soaked and, on some systems, synchronized with the reflow process, permitting duplication of the actual profile used in manufacturing the assemblies. BGAs and photoelectrical parts are sensitive to higher temperatures and any attempt to preheat with marginally controllable sources is risky."-- NASA & JPL: Survey of Rework Methods & Equipment for Various Packaging Technologies" Aug.'05

Post-Cooling™ Mode Cools Down BGA's After Reflow Within 8 Seconds Allowing Quicker Lifting Hot Air Nozzles Preventing Bridging

Another real advantage of the AirBath™ is that with by flipping a switch the unit transforms into a post-cooler™ cooling down your PCB, components and your solder joints. Post-Cooling™ is essential to soldering of BGA's because hot air nozzles must not be lifted from above the BGA until all the balled joints have cooled so as not to cause unwanted bridging. It's important to point out the obvious: hot plates, static ovens and IR plates do not provide the critical post-cooling™ feature standard on every Zephyrtronics AirBath™. Again, our engineers introduced the concept of post-cooling™ to the benchtop clear back in 1994.

Our AirBaths™ can cool BGA's enough within only 8 second permitting the hot air nozzle to be lifted without fear of bridging. Without post-cooling™ a technician must wait for the ball/pad interface to solidify completely before lifting the nozzle to inspect. The Post-Cooling™ feature remedies this problem allowing rapid lifting of your hot air nozzles from over the BGA after soldering.