Hand Soldering SMD Components

hand soldered

In this month's blog we are looking at Hand Soldering SMD Components, many surface mount assembly instructions require specialist equipment such as; hot air stations, reflow ovens and solder pastes which are not readily available and often require training before use. This guide aims to equip the reader with a few useful tips for assembling surface mount PCB’s by hand using only a soldering iron and a few other common bits of equipment - just download our step-by-step guide below.

Tools required:

  • Soldering Iron
  • Solder
  • Solder Wick
  • Fine Nose Tweezers
  • Flux Pen (non – essential)

Download the guide HERE


Another Happy Customer - UCL

MEDL have carried out extensive design, development and procured manufacture for some innovative control electronics for our research project. Their work has been efficient, cost effective and they have always conducted themselves with high levels of professionalism. We could not be happier with the results of their work and would recommend them highly.

- Dr Tom Mason, Chemical Engineering, UCL.


A Tremendous 2 Years!

Robert has now been with us for a tremendous 2 years! He has learnt a lot since his first engineering job alongside school to now, where he is a director here at MEDL.

Robert started out in engineering by working for a small Thermal and Power Electronics Company during his school holidays and other free time. His keen interest in engineering would lead him to study for an honours degree in electronic and electrical engineering. After completing his degree, Robert moved to Birmingham and took the role of design engineer at a leading LED and Lighting company. Robert was mainly responsible for developing new technology for the company.Putting LED lighting aside for a while Robert joined an electricity metering company as a design engineer focused on the development of smart meters.

In 2015 Robert joined Minster Electronic Designs Ltd as a Director and is currently hands on with the day to day running of the company as well as the design and development of new products and customer focused projects. Here's to many more tremendous years!


Innovate UK Funded Project

innovate uk logo

Minster Electronic Designs are proud to announce their participation in their second innovate UK funded project, alongside Surface Technology International.  Building on from a previous project, which involved hydrogen fuel cells and green energy, MEDL will be influential in the design and development of bespoke control electronics and software required in the application of hydrogen fuel cells for renewable energy generation. This is an exciting project at the forefront of green technology with an outcome that will create cleaner and safer environments across the world. 


In this month’s blog, we are looking at IGBT/MOSFET testers, how to use them and also how to design and assemble your own with a step-by-step guide. We’ve even included our design plans in the link which can be found beneath this blog.

IGBT/MOSFET Tester

IGBT and MOSFET transistors have many uses within electronics but find themselves mainly used in high power switching applications. When used under these conditions IGBT and MOSFET devices often require heat sinking and or clamping in place to ensure adequate thermal performance during operation. This can vary from a simple strip of aluminium on a T0-220 device to a multi stack heat sink assembly for large IGBT modules that can take many hours to assemble. Due to the nature of these applications it is important to ensure that each device is operating correctly before assembly and testing commences.

This simple IGBT/MOSFET tester can be used to test each device (single switch) separately to ensure basic operation and check for the common failure modes; collector to emitter short circuit and collector to gate short circuit.

IGBT/MOSFET Tester – Schematic:

igbt tester

The schematic for the IGBT tester is shown above. The component list is show below.

Designator Description Part
9V Battery Standard 9 Volt Battery Any
R1 500 ohm resistor 0.25W
R2 500 ohm resistor 0.25W
R3 5K ohm resistor 0.25W
SW1 Push-To-Make switch 7mm Panel mount
LED1 5mm through-hole LED 5mm 20mA LED
Battery Clip (not shown) 9V Battery clip on leads Any
3 crocodile clips (not shown) Any Any
Various multicore wire Any Any
M3X8 self tapping screws Optional (for case) Any

IGBT/MOSFET Tester – Operation:

  1. Connect the red collector lead to the collector of the IGBT (drain of MOSFET), the yellow gate lead to the gate of the IGBT/MOSFET and the black emitter lead to the emitter of the IGBT (source of MOSFET).
  2. Before pressing the switch check that the LED is not illuminated. If it is glowing brightly the device may have a short circuit from the collector to the emitter. If it is glowing dimly the device may have a short circuit from the collector to the gate.
  3. Pressing the switch will saturate the gate of the device with at least 8V. If the device is operating correctly the LED should illuminate when the switch is closed and turn off when the switch is open.
  4. To test the devices body diode; swap the collector and emitter leads after the previous test has been successful. If the LED illuminates the body diode is present and operating correctly. If there is no illumination either the body diode is not present or it has a fault.

Download the zip file HERE


Dino hunting on the south coast


Rob enjoyed a well-earned break last week and headed for the glorious South Coast. But his holiday was filled with adventure searching for pre-historic beasts and with some great success!

dino3Dino1

Our great explorer and his partner were lucky enough to uncover some real gems including the images herewith. These have been catalogued and sent to the Natural History Museum. We have since heard back from the Natural History Museum that this find was infact part of an ichthyosaur jaw bone. These beasts lived from 250 – 90 million years ago - how amazing is that?


Another happy customer - Baniftec Ltd


Working with Minster Electronic Designs has been refreshing and straightforward. Together we quickly refined the board’s exact specification, selected the best choice of microcontroller, and defined and agreed the exact footprint for the finished board. Minster’s Engineer then worked on the detailed design to quickly produce a prototype, using their in-house capability, thus greatly speeding up the process and allowing the board to be swiftly tested with other related hardware to ensure everything worked as intended. This allowed us to proceed straight to a production build of the board. The finished board is very neat and takes only one third of the size of the product we had been using previously.  This favourable experience encourages us to work with them on designing further new products. Their quick and efficient approach is what we needed and they certainly delivered this for us.

- Richard, Baniftec Ltd.


Tutorial: How to build a cheap hand built PCB

We are often asked advice and guidance from our clients and people we meet, so over the coming months, we aim to include in our blogs some tutorials and tips and hints for those commonly asked questions. We hope that you find our tutorials useful and please feel free to share a link to our website if you think this may be of interest to others too.

Disclaimer: This tutorial is aimed at those already familiar with the use of etching chemicals to produce PCB’s. Always wear appropriate safety equipment when handling chemicals and do not try this at home unless you are confident with the process of etching PCB’s.

What you will need:

  • · Single sided copper clad FR4 – large enough for your design
  • · Glossy photo paper – we use 180g/m2
  • · Laser printer
  • · No steam Iron
  • · Fine sanding block
  • · General purpose solvent
  • · Etch tank

Process:

1. Design your PCB: Create your PCB design in any of the PCB CAD software packages. We advise maintaining a minimum track width and gap of 0.25mm.

2. Print your PCB on to glossy photo paper: Set your print to output a mirror image of your design – this ensures it is the correct orientation when you transfer the design to your bare copper board. Print only the copper layer, in mono, and set the scale of the print to be 1 to 1. We suggest using a LASER printer for this process as the results vary greatly with other types of printer. If possible print as a panel to save on paper use.

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2b

3. Cut the copper board slightly larger than your design: This will allow enough room to place your design correctly – excess board can be trimmed after the etching process.

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4. Buff the copper using a fine grit sanding block: This helps the toner to mate with the copper during the transfer process. Clean using solvent after buffing to remove any copper dust

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5. Place your design toner side down onto the copper surface: Try to keep the design as central as possible this will make trimming excess board easier

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6. Transfer your design to the copper board using an iron: Iron your design on to the copper by maintaining a firm downward pressure with the iron at its highest temperature setting. Do this for 2 – 5 minutes ensuring to cover the whole design numerous times. Care should be taken at the start of this process to ensure the design does not move around on top of the copper.

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7. Place the finished transfer into a jug of cold water to cool off:

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8. Once cool remove excess paper from copper leaving only the toner: This can be done by running the copper board under cold water and using your thumb to remove the paper and any residue. Be thorough with this as excess paper or residue will impede the quality of the finished PCB.

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9. Place in etching tank to remove unwanted copper: check often to ensure the PCB does not over etch through the toner.

10. After washing the toner should still be clearly visible while the unwanted copper should have been completely etched away: This is the best time to inspect the board and see how well the etching process has performed.

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11. Remove toner using solvent to leave only the bare copper tracks below:

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12. Cut to size and assemble!

12a

12b

Thanks for taking the time to read our tutorial.  Please do sign up for our newsletter, to hear about the upcoming blogs first – which include: How to test IGBT’s, 3D printing tips and tricks, Soldering Techniques, Hand Winding transformers and so much more.  If you have a suggestion you would like to see here why not email the team at This email address is being protected from spambots. You need JavaScript enabled to view it.