Product category:
PCB Assembly Equipment and Tools
News Release from: PDR SMT/BGA Rework Solutions | Subject: Focused IR technology
Edited by the Electronicstalk Editorial
Team on 14 April 2006
Focused infra-red simplifies lead-free
BGA rework
Some of the world's top OEMs and EMS providers rely on focused infra-red technology to simplify one of electronics manufacturing's riskiest, most demanding and unavoidable tasks.
The quality of BGA rework, so crucial to the profitability of any OEM or EMS provider and the single most important process in successful and profitable implementation of BGA technology, is down to mechanical accuracy, good materials and thermal control Not surprisingly, OEMs and EMS providers the world over spend a great deal of time developing thermal profiles for their rework that will guarantee the fastest, safest time to reflow
This article was originally published on Electronicstalk on 4 May 2007 at 8.00am (UK)
Related stories
Focused IR technology excites rework interest
Focused infra-red rework specialist PDR received much interest from visitors to its stand at this year's SMT exhibition.
Focused infra-red heating for "gentle" rework
PDR's IR-X400 focused IR SMT/BGA rework system incorporates patented focused infra-red (FIR) technology that offers a safe, simple and gentle heating method with precision process control.
Creating a profile, however, can be frustrating, time-consuming and expensive.
But it doesn't have to be: some of the world's top OEMs and EMS providers rely on UK company PDR and its focused infra-red (focused IR) technology to simplify one of electronics manufacturing's riskiest, most demanding and unavoidable tasks.
Eliminating the risk and guesswork from thermal profiling, focused IR uses infra-red light energy to take the board and component to a temperature that will not damage them, yet will melt the solder between them.
Further reading
Modular system expands with rework demands
Modular approach allows customers to decide how much they want to spend, selecting exactly what they need from a massive range of features.
IR handtool focuses on BGA rework
System is tip/nozzle free, gas free, instantly/precisely controllable, clean and produces high quality BGA rework without any complications.
Nickel layer stops packages sprouting tin whiskers
Agere Systems reckons its engineers have found the right mix of packaging ingredients to enable the semiconductor industry to successfully implement lead-free packaging.
Roger Gibbs, pioneer of focused IR technology and cofounder and Managing Director of PDR, explains how it works: "We call it passive heat, focused IR heats the object directly, rather than heating the air around it, so even though there is enough energy to get a component to the right temperature, you can safely put your hand in the beam, even at full power".
For topside heating, PDR uses a 150W IR lamp with short and medium length IR emissions are refocused by PDR's lens system into a visible spot the diameter of which can be adjusted manually to cover the component to be reworked.
This is facilitated by the distance of the lens system from the board, which enhances visibility and access.
The real secret to effective reflow, is in preheating the board, so PDR's BGA rework systems use a powerful 1600W medium-wave IR panel back heater that ensures even more control over how much energy is put into an assembly.
Control is essential to successful rework, especially when reflowing at the higher temperatures required by lead-free solders, and PDR's noncontact IR heat sensor is key, monitoring precisely the temperatures of the board and component in real-time.
"As these temperatures are directly related to solderball temperature, we know exactly when reflow occurs", explains Gibbs.
The real revolution, though, lies in combining the heat sensor with PDR's simple-to-use profiling software: with no need for tests or prior profiling work, the system automatically ensures that even a board and component that are completely new to it will ramp at the right rate to the right temperature and soak for the right time for their size and application, following a solder manufacturer's or PDR's own default profiles.
The system controls how much energy is required four times a second and keeps temperature at all times to within 2C of target profile.
Where soak times have to be altered, PDR's software and the real-time temperature feedback ensure accuracy while simplifying the operation.
Gibbs: "It's so simple it takes longer to work out how to align and place the component than it does to set up a thermal profile".
"Focused IR is ideal for professional BGA rework, large components need quite a lot of energy, which, for hot gas systems, means a higher gas flow".
"This can be a problem as BGAs are typically surrounded by small chips and resistors that can be blown away - a problem that increases when you get to higher temperature lead-free processes".
Accessibility on densely packed boards is an additional problem for hot gas systems, which call for a range of nozzle geometries for different component types.
With PDR's systems, the operator simply positions the heat energy spot and adjusts its size to the component to be reworked - no access problems and no nozzle changes.
The main advantage of focused IR, though, is that the temperature of replaced components can be measured in real-time using the noncontact heat sensor - something that is impossible with hot gas systems, yet which is essential when using the potentially damaging higher temperatures needed for lead-free solders, as Gibbs observes: "As it is gas that heats up the board and the component, the gas temperature must be beyond the target temperatures, creating a risk of heat damage".
"Some of the better systems avoid these problems with more effective back heating and better temperature control, but there are many more systems that could create damage".
Once you've got your thermal profiling under control, Gibbs believes you are 40% of the way to good rework quality.
Materials take you a further 40%, and the remaining 20% is down to good alignment and placement systems.
Here too, PDR has a solution: its top BGA systems come with easy to use split-beam prism alignment and placement features that guarantee damage-free component handling.
With its focused IR technology, noncontact heat sensor and profiling software, PDR has revolutionised rework, eliminating the guesswork and replacing it with real-time profiling for rework professionals, who are already using PDR's systems in their lead-free BGA processes around the world.
• PDR SMT/BGA Rework Solutions: contact details and other news
• Email this article to a colleague
• Register for the free Electronicstalk email newsletter
• Electronicstalk Home Page
Search the Pro-Talk network of sites
