Call us Now
1300 36 00 31
Call us Now
1300 36 00 31
Call us Now
1300 36 00 31
Call us Now
1300 36 00 31
Call us Now
1300 36 00 31
Call us Now
1300 36 00 31
To help you get started with setting up your new convection oven, we have designed this quick start guide to provide you with a starting point.
On the reverse of this document (which has been designed to fold out as a poster), you will find information pertaining to popular T4 and T5 solders, both leaded and lead-free. A description is provided for each solder as well as information including the heat-up rate, cool down rate and time above liquidus (TAL). Underneath the description of each solder, there is a table containing the required temperature for each zone of both seven and nine zone ovens.
On the next page you will also find some tips on maintaining convection ovens, ensuring you maximise its longevity, which we hope youāll find useful.
Recommendation – Hawker Richardson recommends utilising a profiler to refine oven configurations including the temperature of the zones and conveyor belt speed, following start-up but before running a full batch.
There is no question that convection ovens are a huge investment and so it is important that ovens are kept optimised, not just for performance, but for longevity too. We have listed some tips below to help you achieve optimised performance consistently, and to ensure you benefit from this year after year.
Tip One: Perform Regular Maintenance:Ā Itās an obvious tip and probably the most important, but itās essential you perform regular maintenance on your oven. Not only will this process ensure you collect any chips that have fallen from the boards, but itāll give you the opportunity to remove the residue of any flux that has splattered during reflow ā especially if it includes rapid heating. Typically, newer ovens prevent flux build-up, but itās worth ensuring that this has been achieved adequately.
Tip Two: Apply Minimum Oil: Ensuring the ovenās Autolube is configured correctly is essential. Too much lubrication can cause contamination issues and result in inhibiting flux activity. It is better to apply minimum drops of oil to maintain chain lubrication to begin with.
Tip Three: Check Oven Exhaust Ports: Itās important to ensure the exhaust ports are working sufficiently i.e. enough to extract the gasses and fluxes, but not affect the temperature of the oven. Utilising a butterfly valve can help control the flow increments for finer adjustment. Installing a flow meter can help you to strike an even balance with flow rate, providing an objective measure to your process.
Tip Four: Check Cool Fans: Check fans are working properly and ensure each oven is configured at a cool-down rate of no more than 4Ā°C per second, otherwise it can result in thermal shock, having a negative effect on the intermetallic joins of the PCB.
Tip Five: Zone Fans: Similarly, check that the fan for each zone is working properly. If the flow circulation is inconsistent, it can cause temperature fluctuations resulting in issues such as pin holes due to outgassing.
The descriptions and tables below provide information on a range of T4 and T5 lead and lead-free solder pastes. Although the temperatures are largely the same for each brand, it needs to be noted that the temperatures below are only a guideline. The profiles have been tested on a Heller branded oven ā Zones 7 tables using a Heller 1707 MK5 and 9 Zones using a Heller 1809 MK5.
Each temperature represents both the bottom and top temperature and is documented in Degrees Celsius (Ā°C). Conveyor belt speed is documented in Centimetre per minute (CM/MIN). They have all been tested from an air oven with edge hold and mesh chain, and profiled with a Solderstar Smartlink – 6 channel system.
For optimum transfer efficiency and release of the solder paste from the stencil apertures, industry standard aperture and aspect ratio should be adhered to. For fine-chip components, a surface area reduction is recommended for apertures of 20mil pitch and finer. Utilise the temperatures below for each zone, however deviations may be required depending on board size, thickness, and density.
Available in lead or lead-free
To achieve better results with voiding or to reduce tombstoning, consider using a longer soaking zone, (170-2200C) for 60-90 seconds, with a more rapid pre-heat stage. If there is evidence of solder de-wetting, consider lowering the peak reflow temperature, or reduce the time above liquidus to <60 seconds.
Available in lead or lead-free
Available in lead or lead-free
A linear preheating ramp rate is recommended. However, high density boards may require a soak zone during the preheating stage to stabilise the temperature over the circuit board before peak flow.
Available in lead-free only
Ideally, profile measurements are to be collected on a populated assembly with the reflow profile recorded for each product being processed. It is common for the same profile settings to be used for multiple assemblies. Reflow profile data should be collected, analysed and recorded for each assembly part number at the beginning of individual production runs.
Available in lead-free only
Even if youāre confident youāve configured your oven for optimum performance, based on your board and solder specifications, it is worth considering utilising a thermal profiler. Not only will this give you confidence with data-based validation, but environmental factors can also change over time and periodic utilisation of a thermal profiler may ensure you adjust your settings accordingly. Not to mention component specifications constantly change in size and potentially thermal mass.
A thermal profiler is a unique hardware device that passes through the oven zones recording the temperatures using a data logger. The data loggers are protected in housing, shielding it from the extreme heat. Ideal for setting up convection ovens, thermal profilers such as the SolderStar PRO system supports 6 to 16 measurement channels, for accurate profiling of the most complex PCB assemblies.
For profile optimisation, the AutoSeeker Profile Optimiser can be added to the systems to provide rapid profile setup. Once a profile has been captured from the process, the AutoSeeker will search through millions of combinations of oven set points, to provide suggested settings for both temperature and speed.
The systems can optionally provide live profiling data direct to the engineer computer via our class leading 2.4 GHz wireless telemetry system. The bespoke system used in SolderStar products provide a full two-way link, resulting in no data loss during the streaming of live data. These profiling systems provide the engineer with all the necessary software tools for rapid profile setup and analysis, along with data management, profile simulations and integrated SPC charting tools. Available for all reflow oven types.
Itās essential you perform regular maintenance on your oven. Not only will this process ensure you collect any chips that have fallen from the boards, but itāll give you the opportunity to remove the residue of any flux that has splattered during reflow ā especially if it includes rapid heating. Typically, newer ovens prevent flux build-up, but itās worth ensuring that this has been achieved adequately.
