Can I get 300,000 views by October ?

 

                                               Dear Readers. 

                                   

                                               Make my day. 

28 Sept 2025. - Update 

We have close to 280,000 views. Average daily views of almost 1000. At this rate, hitting 300,000 views by October is definitely achievable and worth celebrating !

 

What a typical PCB experiences day in day out as far as temperature changes go.

 

Imagine this  modern day PCB motherboard, this is a multi-layer one which has numerous materials layered over each other, for example :

1. FR4 ( polyimide substrate)

2. copper foil laminate

3. solder masks

4. silk screen

5. ceramic substrate.

If this is your handphone or laptop PCs, there is daily temperature cycles going on when you power up your PC from sleep, or 'off' more. The temperature will go from (say) 23 C (inside the casing of your laptop) to maybe as much as 40 C in the course of the day.

When it is powered off, the temperature inside the laptop (PCB) will then slowly go back to 23 C in the evening.

Now, the key to this post is this. In the event, during the heatup phase, the temperature of the board rises. The  COEFFICIENTS OF THERMAL EXPANSION is different for all of the 5 different materials above, and hence some would expand faster than others, thereby pulling the neighbouring material.

When cooling down, the reverse effect is there, and hence there will be faster cooling of some materials than others.

When repeated hundreds of times a year (there are 365 days per year) then there is a chance than the incessant heat cool heat cool will result in BREAKAGES in the connection between the materials of the PCB motherboard, resulting in an open circuit and hence non functioning of the PCB motherboard.

Material selection is key and the QA and QC tests of temperature cycles is necessary to ensure that there are no catastrophic failures due to this repeated temperature cycles for at least 10,000 cycles or the expected lifespan of the laptop (say 5 years).

It is advised to do selective temperature cycling of PCB motherboard (powered up no less) in Test Labs or in house BEFORE the boards are shipped out to the next partner in the electronic supply chain to ensure 

> Quality

> Reliability

of the product is upheld.

What do I think of when I run ? A Repost from Nov 2022

This is an very interesting question which I do ask myself from time to time. Do I go into a 'robot mode' and just switch off everything or do I let some thoughts invade into the zonal spaced out state of mind which sometimes freaks me out at the sheer clarity of thought ? The 'Aha moment' which only comes when I am is truly at peace with myself and shut out everything ?

                                               My 8 K run last year on my birthday 

The answer is a bit of both. To be frank, when I set out, I actually zone out and focus on 3 aspects of my self. This is the intial part of my run until I find a rhythm to run at a pace which I am comfortable. 

a) My focus on the road ahead

I am super focussed and just stare straight ahead through my Oakley sunglasses (I have over 20 pairs) and subconsciously avoid the strollers, prams, small children, elderly people and slower runners either going in my direction of coming at me. 

My recent familiar runs are either at East Coast Park (B1 carpark vicinity start) or Pandan Reservoir and the runs are 6 K to 8K in length. 

There were numerous close calls and even one where I caused an aspiring rollerblader to fall flat on his face, much to his girlfriend's angst !

While my pace has slowed down a lot, I am still hopeful of bumping up the velocity or pace to something like 6: 00 mins per km or 10 km / hr. 

b) My breathing.

I usually start out the run by concentrating on my breathing ensuring that each breath is measured and I am amazed by the fresh air I can actually intake. I breathe deeply to the extent that my lungs ache. Which is a good thing, in my opinion. We, so often, take for granted our ability to do the simple task of breathing that when you focus on it, you actually appreciate the one of 3 organs which fundamentally keeps us alive (the other 2 being the heart and brain). 

c) My legs.

I have always had strong and stiff legs. They have been both my boon and my bane. They were and still are very strong. I always thought I had iron legs. In my teenage years, my swim club mates called be "Stiff Austin" (a joke about the 6 Million Dollar Man Steve Austin who had bionic lags haha) because well my legs were really stiff and hard. I recall playing football in the courtyard of the Club way back in the mid 70s and I didn't wear shoes.

So one time, I recall, I kicked hard at the rubber ball at the goal, and MISSED. Instead, my leg kicked the huge exposed root of the 160 year old tree. The bark of the tree actually came off and my leg though sore, was still intact.

Thats how strong my legs were !

After the first 2 things are settled, I will just go into a Zen Like Zone and run without paying much attention to my surroundings. However, as the kms go by my mind will start to wander and normally things so random will just pop into the mindfulness zone.

Here is one such thought. I dreamt up a decision tree process while I was running. Only today 10th July have I had the courage to write it down.

Please take a look at my innermost thoughts when I run.

In a nutshell, running on a Saturday leaves me happy, and ecstatic. So I will run based on my decision tree logic as shown above.  

Multilateralism

9 months into the Trump presidency, and the world is still reeling from the come and go up and down tariff rates emnating from the White House. It upends global businesses who depend on :

- stability of trade relations between blocs or countries

- a free world with as little conflict as possible

- trust between long established partners who have had successful win - win trade arrangements for multiple decades since WW2.

All 3 of the above factors are thrown out the window. The case is now for multilateralism and small countries like Singapore as especially vulnerable to the 'changes in the wind'. 

Chamber Repair Services, we provide in 10 countries in Asia and 12 in Europe

What we can and should do ? Embrace Multilateralism and Run with the Ball

1. Companies (small in particular) - to come together, network and work together to form strategic alliances across continents for the mutual advancement of their goals.

We currently are signing 2 MOUs and agreements with some players in the more established part of the world in our field of biomedical testing to promote shared goods and services. 

2. Adoption of :

Digitization in Company Systems 

My company is embarking on this now, to put into place a document management system on the cloud as well as digitization of reports and data for data retrieval in the long run.

AI for marketing for social media maximization

The world needs access to the best and most competitive goods and services. If your company is a major player in a small niche, advertise the fact regionally and globally. 

Scale up the business to capture global demand. 

We secure business from Europe, US and Australia apart from Asia nowadays quite regularly. This is unheard of for us 10 years ago.

Connect with Big Players for funds, experience and opportunities.

There is no time better than now to do this. Reach out the big players who have decades more experience and reach in the industry you specialise, and connect.

You will be surprised at what may turn out. 

  

ASTM F 1980 - 16 video ; your questions answered right here

 

Here is a short video of how the ASTM F 1980 - 16 functions, the key takeaways, the effectiveness and how clients in biomedical industries perform these tests, the durations, the typical temperatures set, the humidities set, all the key questions are answered by me. 

My experience in serving more than 15 years in this very rigid and demanding industry is here for sharing.

Carpe Diem.

 

Temperature Pressure and Humidity Changes for Aircraft Components

Parts manufacturers around the world, if they are serious about their quality and reliability testing. They MUST do Transport Simulation testing - and very rigorously too. Let me run through the temperature, humidity and pressure changes. 

Say the aircraft A320 is sitting on the tarmac, and the engine is started, everything is ready to go. The tarmac is in the hot Doha desert, and the temperature is a sweltering 60 C. Humidity is in the mid 70%. Air pressure is at sea level or 1000 mbar (1 bar). 

Once the control tower gives the signal, the plane does a few turns to proceed to the correct runway, the temperature is still the same as above. 

In the space of 15 minutes, when the plane takes off from the runway to the cruising altitude of say 35,000 feet (11100 m), the temperature drops drastically to -40 C, there is almost no humidity and the air pressure is dropped down to say 300 mbar. The plane is at 35000 feet.

That means to simulate this condition in the Lab, the settings on the chamber to test component parts of the plane engine or exterior (such as rudder, fluid manifolds etc) must resemble something like this.

Time 0 

Temp  : 60 C

RH      : 70%

Press  : 1000 mbar (1 atm)

Time 15 

Temp  : -40

RH     : 10%

Pressure : 235 mbar (0.235 atm)

 

Hence the chamber MUST replicate the change rate of +60 + 40 or 100 C in 15 minutes, that is approx. 6.67 C / min change rate

Pressure needs to also get down pretty quickly to 235 mbar.

The chamber required just to follow the environmental changes is what we call the Environmental Stress Screening Chamber or ESS chamber which QRA can provide for a competitive price.

We occasionally also offer ESS services to customers although the costs of running these tests are not inexpensive, owing to the high electricity usage, the machine maintenance costs and the number of cycles and total test time.

For more information, consult the experts, 

https://www.qra.com.sg/our-services

https://www.qra.com.sg/our-products

 

Key Parameters to Control for Environmental Testing of Products for Quality and Reliabillity

There are 4 Key Parameters which manufacturers must bear in mind when designing a robust product - this is based on decades of experience working with the best in class and industry for electronics, aerospace and defence and automotive.

1. Temperature Extremes.

2. Dwell Times at the Extreme Temperatures

3. Rates of Change in deg C / min from Hot Extreme to Cold Extreme

4. Duration of One Cycle and Number of Cycles Run in total.

Temperature Extremes. 

Typically if a manufacturer wishes to do environmental simulation, they must simulate the condition which the product is being subjected to, plus add further extremes just to ensure that the product can perform wider than the expected range of usage.

Dwell Times at Extreme Temperatures.

How long the products are kept at the temperature extremes is dependent on the product itself. From experience, the dwell times at the extreme temperature zones do not go beyond 6 hours, before, moving up or down to the next extremes.

A simple analogy of a robust product you (as a person) can try for yourself. If you have strong immunity, and you are daily subjected to temperature cycling, from airconditioned room at 23 C to cold bath, to hot morning of 30 to 35 C, enter the car at 25 C and then down to 20 C (air cond takes effect), to the office and so on and so forth. 

Your body is subjected to temperature cycling though not as extreme as some products, so if your immune system is strong, then nothing happens.

If you are weak, you will fall sick.

Its as simple as that.

Robust products will need to be subjected to temperature cycling to ensure their 

a) useability and functionality 

b) robustness 

during the most strenuous of times, and temperature cycling does that. 

Rates of Change in C / min. 

Typically a gentle temperature cycles is from 1 C / min to 3 C / min. 

More severe change rates can range from 5 C / min to 20 C / min.

The change rate of Temp / min is to stimulate FAILURES in the product (for QA), these failures are attributed to the different Coefficient of Thermal Expansions of the materials used for the product such as 

- polyimide base (PCB)

- nickel/gold underfill solder bumps

- gold wire connections

- epoxy substrate for ICs.

Number of Cycles Run 

500 to 1000 cycles run are common numbers for manufacturers who want to test run their products resilience and robustness.

QA Sampling (What Percentage ?) 

5 to 10 % of the first batch should be sufficient to qualify the reliability - provided that the yield of 95% is attained.

So for a first batch of 1000 product run.

50 to 100 samples are chosen and tested under QA set conditions.

Of the (say) 100, 95% must PASS the QA test for the rest of the production run to continue and then ship out.

This is only a rule of thumb. 

It is by no means reflective of any one industry which MAY be much more stringent or less stringent depending on which industry.

CARPE DIEM. 

https://www.qra.com.sg/

Email : mark@qra.com.sg