Thursday 05 September 2019
Following from the C.I.F CF02 reflow oven heater module upgrade post in February our C.I.F reflow oven, which has had several rebuilds over the past six years, started to fail when reflowing our boards and so we decided it was time to replace it with a new model rather than spending more money on the old oven to keep it running for a few more months again.
We looked at several options to replace the C.I.F CF02 oven but due to space restrictions and power constraints we couldn’t get a small belt reflow oven and had to go with another small batch reflow oven to build our circuit boards.
We decided to buy a C.I.F FT 03 Batch reflow oven with forced air convection which is a newer model of our previous oven. The FT 03 has a smaller overall footprint but is higher than the previous oven.
||190 mm x 290 mm
|Quartz heating elements
||2 x 1 KW
||up to 300°C
|Thermic stabilisation time
||about 3 minutes
||< 50 dBA
||230 V -50/60Hz
|Dimensions L x W x H
||300 x 420 x 385 mm
The oven has the same issues as the first C.I.F oven where you have to force cool the oven area when it has completed a cooking cycle in order to bring the temperature down to 110C before it will allow you to start reflowing the next batch of boards.
The old oven had a pair of roller bearings on the drawer runners which made it slightly smoother when opening and closing the PCB drawer but the new oven does not have these and the drawer runs on a pair of stainless steel rails and is very jumpy if you try to close it by pushing the front handle. If you are not careful this can dislodge components on unsoldered PCB’s. To avoid this, you need to lift the front of the drawer slightly when closing it which reduces the vibration to the unsoldered boards.
The oven reflows the boards on a three stage processes with a pre-heat stage, full temperature stage and a cooling stage but as there are not any external vents or fans in the oven area the oven only drops to around 170C after the “cooling” stage and this has to be dropped to below 110C before you can start the next reflow cycle.
We accomplished this using the same 12V server fan which we used previously, but we had to move it to the side of our oven box and direct the air to the PCB drawer using some 40mm plastic waste pipe from a local hardware store.
To avoid fumes and hot air coming back into the room, the oven box has a high temperature extraction fan at the back and at the front of the box in the door area we have a second Perspex door which directs fumes and hot air up and over the oven to the extractor fan when the cooling fan is running.
Front view of the oven
Rear View of the oven
The power supply for the oven is via a IEC mains connector with a 13 amp fuse in the supplied plug with a very thin looking power cable.
The old C.I.F CF02 model had a very thick mains cable built into the machine and was supplied with a 16 amp mains plug.
Side view of the oven
Forced air cooling for the oven
The new oven installed on our "oven box" with the cooling pipes at the front.
We have now used the new reflow oven for several board builds, and found that you can use approximately two thirds of the available space on the PCB drawer to successfully reflow the boards.
If they are outside of this area the soldering results are not consistent and some boards are only partially reflowed with manual soldering having to be done after the cooling cycle to fix any issues. This is the same as the previous reflow oven model we have used for the past 6+ years.