SMD 2835 5050 3528 Which is the best choice?

Firstly what is SMD LED?
SMD stands for surface mount diode, specifically, through this process, chip is mounted onto a small “desk”, then becomes an LED.LED 2835
LED Encapsulation can be divided two categories: SMD and COB SMD LED encapsulation process takes three steps:
1. Mount the chip onto a desk with adhesive;
2. Connect the chip to system with bond wire;
3. Cover the chip with phosphor to make the colour.
Light-Evolution-BlogEach encapsulation process is named after the dimension of LED, e.g., 3528 meaning 3.5*2.8mm, 3014 3*1.4, 5050 5*5mm.
COB stands for chips on board, which is a different solution than SMD encapsulation. Generally, an SMD LED is mounted onto a desk, and then the desk is mounted onto a PCB. Instead, COB skips the middle step and mounts the chips onto PCB directly, and thus, the cost is lower. Saving money is merely one of the advantages of COB.
Which one should I choose?
Generally speaking, SMD 2835 Design is newer and more advanced than 3014 than 3528. Because 2835 has more effective thermal dissipation system, specifically, a larger heat sink than 3014 on the back, and 3528 has no back heat sink at all, therefore 2835 is able to take higher current and generates more luminous flux.

The form below is the common spec of these LED solutions in these days. The data is based on June, 2013.

LED 3014
We have introduced a range of the two SMD 2835 products as this is clearly the most efficient mainstream SMD LED so far to date.