USB Flash Drives PCB, COB, UDP
This is a USB stick using the PCB method:
USB Printed Circuit Board
This is a USB stick using the COB method:
USB Chip On Disk
This is a USB stick using the UDP method:
USB Disk in Package
This is a USB stick using the PCB method:
Using the Printed Circuit Board method for construction is the original method and design for a flash drive. In addition, this is the only design which up holds to all of the USB-IF specifications for a universal serial buss flash device. This method uses solder and IC components to mount the circuitry to the board. Typically a flash drive is a two layer board and ones which confirm to the USB-IF specification will have a four layer printed circuit board. This design provides the highest level of performance and reliability.
This is a USB stick using the COB method:
Using a Chip On Disk design means the USB controller or the NAND memory create electrical contact through circuits underneath the chip. For construction of the device, there are no external circuits which bond the component together, rather an encapsulation material is placed over the component to create the bond. The COB is a durable method of design for flash memory, but does not provide the highest level of performance or reliability such as a PCB design method. The primary reason for the development of the COB is to create a faster manufacturing time, at a reduced cost and ultimately provide a smaller footprint for the USB device.
This is a USB stick using the UDP method:
Using the USB Disk in Package method is a self-contained product where the NAND memory, controller and electrical circuits are contained within one enclosure. If you look closing at the above picture you can see the trace lines of the internal circuitry for the UDP device. This design further reduces the size of the device and in addition brings a higher level of durability, most notably the USB becomes highly water resistant.
Other sites have reported that COB is the cheapest to manufacturer and UDP is the most expensive, but the biggest determining factor for the cost of a USB is the quality of flash memory used. In our opinion, it is always best to purchase the highest grade memory possible for your budget.
