A lot of first time LED DIYers focus on the LED chip make and quality, which is very important, but give little to no thought of the PCB design and build quality.
The PCB is the platform that holds the LED chip, contains all the circuitry, and dissipates the heat away from the chips so that they maintain a long life with consistent output. What you are seeing with
It’s really the only part of an LED strip or board that the component maker has any input or control over. The LEDs are made by multi-billion dollar manufacturers. - Samsung, Osram, Seoul Semi, Epistar, Bridgelux., and sold to the strip and board makers. Because of this, there is a tendency to lump all boards or strips that use the same LED chips together, and the cheapest supplier wins the sale.
Nothing could be farther from the truth. It’s a bit like saying any car with a Porsche engine is as good as a Porsche. The engine is important, very important. But so are the drive train and chassis, the gearbox and suspension, the weight distribution and aerodynamics. The fit and finish, and the quality of materials and engineering. All of it is required to make a Porsche.
The PCB can cost from 30-60% of the total fabrication cost of an LED strip or board, even when using the most expensive top bin LEDs. And because LED prices are more or less the same for all board makers, the PCB is where costs are cut when a cheap retail price is the main goal.
SolStrip strips and boards are built with 2.0 ounce (70µm thick or 2.8 mils) copper circuit layers. Two ounce CU production costs are higher than common 1 oz design but the performance is better than 1 oz PCBs. Current dynamics and thermal control is much better when run through circuitry that is twice as thick as the standard PCB.
Similarly, aluminum backing on strips and boards is the first line of defense in LED heat mitigation, which is absolutely critical to maintaining the life and consistent photonic output from LEDs:
SolStrip strips and boards use a 1.5mm aluminum backing. Many other bargain board and light makers use 1mm aluminum. They are happy to cut their heat mitigation capacity by 33%, and shorten the life of their boards, to save a buck.
Bridgelux, the low cost hero of the DIY scene, doesn’t even bother using aluminum backing on its EB strips. It uses ceramic PCBs, which are much cheaper than aluminum, on it’s low-power strips, choosing to forgo metal backing and spread its LEDs over a larger total area of ceramic to fight heat buildup.
@Misguided_USMC what you are experiencing with your Ebay strips is likely the result of thin copper traces and thin aluminum backing, plain and simple. Copper and aluminum is sold by weight, less metal in the PCB, less cost for the manufacturer, but less life and quality of output for the strip.