It was in 2013, after the official formation of Neo Green Labs, we were seriously looking for grabbing new projects. Most of the time, we identify leads from internet and the done cold calling. In almost every calls, people hear us patiently, but when they come to know that we are new comers (almost freshers), they end the call. But we were optimistic about finding our hidden clients and we continued pitching through cold calls, talking  with people who are coming to buy electronics components in major component sellers in Kochi etc. The second way opened few opporunities to us. One of such good opportunity was an entry to a Goverment R&D lab. (I am unable to name the lab, but it was due the marketing skill of my partner Jestin Varghese, we reached there)

At that time, along with office administration and business development, being a technically oriented guy, I was designing the PCBs at NGL. I learned pcb designing by referring docs, there was no one to guide me at that time. I was doing single sided PCB mainly since our projects required that only. At the beginning the major mistakes happened in my layout design were on footprint dimensions and orientations. So, after few such mistakes I always used to cross verify the footprints. Slowly the knowledge improved and I started giving care to track width, spacing, shape, length, copper pours, return path considerations, AC-DC isolations, silk screen writing orientation etc etc. So by mid 2013, I was pretty confident on layout design. But today I must say,  that confidence was like a Frog in a well.

So, coming to the story, we got a pcb design, fab and assembly work for a government R&D lab. They give us schematics, we have to design layout, fabricate it, and assemble the components. We received the schematics, space constrains etc and both parties mutually agreed to go with two layer pcb (double sided pcb). That was the first every double layer pcb design in my life.

Till now, our team was designing the circuit and I was designing the layout. The circuit designer (my partner Shibili Rahman) used to gave me all the data about the circuit, like its working, current and power requirements, space constrains etc. So it was easy for me to design the layout.

But with this work, such data were available in the schematics as cad notes. Client told us, you guys check the cad notes, all requirement and constrains are there.  I checked it and designed the layout as per the given requirements and cosntrians. But to be honest, I haven’t checked the circuit working as well the current requirements of all components thinking that all such requirements were covered in the cad notes. Infact, some were specified in cad note.

So, we designed the layout, we reviewed internally, customer was not much interested in doing a review, so we released it for fab. It was fabricated at Bangalore, we received the PCBs. I was pretty happy to see my first double layer pcb, Awesome it was beautiful!

Still I was anxious about the footprint, but it was also perfect and the assembly went smoothly. And we have done a basic manual inspection and delivered the items to the customer. Being newbies, they , very supportive people asked us, Do you guys wish to join us for the testing? We said a big yes! The positive thing about that time was our attitude, we never missed a learning opportunity.

And we, together with the customer started testing. They have checked the PCBs again and seems satisfied. Powered the PCB, everything worked well, flashed the program, validated some interfaces, everything was working well. Viewing all these, I was in at the peak of happiness. My first double layer PCB is working well man! After some more interface and functionality validation, they said, everything seems working fine. lets connect the load. And they took a load which can draw 10A (if my memory is correct).

Connected the load, turned on the power… a few seconds, a small hissing sound, a little smoke. Suddenly we turned off the power and checked the PCB. The customer was thinking why the track has burnt? Immediately I understood my mistake. I haven’t considered the track width required to drive the load because it was not mentioned in the cad note. I was like, what a  fool I was. A simple carelessness, or I would say a simple negligence, lead to a serious failure.

Fortunately, for the testing purpose, we removed the solder mask and soldered a thick layer of lead over the track to tolerate the maximum current. But we were forced to redesign, fabricate, procure components and assemble them and deliver it to customer again, at our own expense. I think it costed around 35k at that time (it was my five months of salary at that time). But the positive side was, It was a big learning experience.

After that, I designed many double layer pcbs, four layer and 6 layer pcbs and but due to this early stage mistake, I used to review every layout designs multiple times.(we had a running checklist). I must mention the help of one of my mentor Mr. Prasannakumar P, whose support and guidance helped me to avoid mistakes.

Being a first generation, fresh graduate turned entrepreneur, I had lot of this kind of learning which costed us good amount, but given immense learning experiences.

Leave a Reply

Your email address will not be published. Required fields are marked *