Whether it is for office workers or student parties, U disk can be regarded as the most commonly used digital product. For digital products such as U disks or solid state drives, the barriers to production are actually relatively low. As long as the corresponding materials are purchased, it can be made even at home. For storage devices such as U disks or solid state drives, the main control chip and flash memory are the two main components.
Flash memory and master
We can regard the entire storage facility as a warehouse. Flash memory is the warehouse of this warehouse, and the main control chip is the administrator of the warehouse. The main control chip manages the in and out of data, and the data is stored in flash memory.
The main brands of flash memory chips are:Samsung, Kioxia (formerly “ToshibaMemory”),Western Digital(Acquired SanDisk), SK Hynix,Miko,Intel. It is worth noting that some so-called flash memory manufacturers are actually only responsible for the packaging of flash memory. They will buy the manufactured wafers from flash memory manufacturers like Toshiba, package them and sell them with their own logo (trademark) after taking them back.
The more common storage particles on the market can be divided into the following types: 3D XPoint, SLC, MLC, TLC and QLC. Among them, 3D XPoint is quite special. The only 3D XPoint products that can be seen on the market are Intel’s Optane series.
For SLC, MLC, TLC and QLC, the difference between them is relatively simple.
SLC: Each cell (Cell) can store 1bit (0 or 1) of information.
MLC: Each cell (Cell) can store 2bit information.
TLC: Each cell (Cell) can store 3bit information.
QLC: Each cell (Cell) can store 4bit information.
That is to say, from SLC to QLC, the storage capacity continues to grow, and the cost is also decreasing. However, performance and lifespan are sacrificed to a certain extent.
If SLC were to compete on the same stage with QLC, the result might be like this:
SLC: My performance is better than you.
QLC: I am cheaper than you.
SLC: I live longer than you.
QLC: I am cheaper than you.
Therefore, the loss of performance and life expectancy depends on the face of the wallet, not to mention acceptable, at least tolerable. Some consumer-grade QLCs can even provide a 5-year warranty, at least for the consumer-grade market, this life span is sufficient.
Objectively speaking, the introduction of TLC and QLC has enabled more consumers to buy solid state drives. For manufacturers, they can expand the production capacity of flash memory particles, so that the cost of flash memory particles will also be reduced. If you sell more, the cost can be lowered, which means you can make more money.
As for the master control, it can be simply divided into two categories: those used by the flash memory factory and those used by everyone.
The bulk of the cost of storage devices such as solid-state drives and U disks on the market is on flash memory, not on the main control chip. This has also resulted in flash memory manufacturers that are often U disk manufacturers or solid state hard disk manufacturers. After all, using their own manufacturing flash memory and then processing them into solid state hard drives can make more money. Based on this situation, large flash memory manufacturers often develop some master control chips by themselves, so that in addition to making more money, they can also improve the performance of storage products and add some functions they need (such as security and encryption).
The other type is the common main control chip, such as manufacturers like Yincan, Huirong, Phison. They will sell the main control chip to any storage device manufacturer that needs it, and then these storage device manufacturers will assemble the bought main control chip and flash memory into a solid-state hard drive or U disk and then sell it.
So since everyone can purchase flash memory, and everyone can purchase common main control chips, is it possible that the final solid-state hard drive product (the specifications are exactly the same)?
In fact, there are digital enthusiasts who have encountered it before and bought two solid-state hard drives of different brands and found that the model of the main control chip and the model of the flash memory particles are exactly the same.
After introducing these basic knowledge, let’s talk about how to make a USB flash drive.
The first step * select the appropriate flash memory and master
As far as making a USB flash drive is concerned, choosing a good flash memory and master control is half the battle. Not all master chips and flash memory are compatible with each other. So if you are going to start fromcell phoneOr remove the flash memory from the solid state drive to make a U disk, then you need to select the master according to the removed flash memory model.
If you are planning to buy flash memory and main control, it is recommended to choose a relatively popular main control and flash memory, so that you can generally find the corresponding solutions on the relevant forums if you encounter problems later.
Step 2*Draw the PCB and manufacture the main control board
Friends who like tossing can do this step, but those who don’t like tossing can skip this step by purchasing the main control board.
First, you need to obtain the circuit diagram of the selected main control board through forums and other channels, and then you can design and draw the PCB layout on EDA software such as Altium designer according to the circuit diagram.
After that, you can hand over the layout file to the PCB manufacturer for proofing (small batch production). Taking the G2 version as an example, the PCB size of a USB flash drive is approximately 1.4cm*3.3cm.
Take the current quotation of Jiali Chuang as an example, the price of such PCB version proofing (only 5 pieces) is 0 yuan. There is also no charge for changing the solder mask color (PCB version color).
If you have a small partner who really likes tossing, PCB boards of this specification can actually be made at home. After printing the PCB layout 1:1, it is transferred to the copper clad board, and then processed through etching and other processes.
Step 3: Plant tin or remove solder
After you have purchased the main control board and flash memory particles directly after the above steps, you can plant tin or remove the solder according to the situation.
Tin planting refers to the fact that there is no solder on the PCB or the main control board. We will apply a layer of solder in advance in order to make the blow soldering operation more convenient.
The specific operation method of tin planting is as follows: align the pads of the flash memory with the stencil of the corresponding model and press it, apply solder paste or use a solder ball of the corresponding size, wipe the excess solder paste and blow it with a hot air gun until it is melted.
If the main control board and flash memory that we have purchased have already been tinned, then it is generally recommended to remove the solder on one side in this case. If there are solder balls on both sides, the chip position will easily move during the subsequent blow soldering, causing soldering failure.
The specific operation to remove the solder is: apply flux to the existing solder and drag it with a knife-tip electric soldering iron to remove it.
For the flash memory removed from the mobile phone or solid state drive, if there is residual solder on the flash memory, the solder can be removed and then replanted by this operation.
Step 4*Blow soldering
If the main control board and flash memory you have purchased have solder on only one side (there is solder on the main control board pad or flash memory particles), then you can directly perform the blow soldering operation.
The flow of the blow-soldering operation is: After applying the flux, place the flash memory on the pad of the main control board and align it in the predetermined direction (refer to the main control instructions for details). Then use a hot air gun for blow welding, the air volume is about 3-4. If the solder used on the main control board or flash memory is lead solder (low melting point), you can try blow soldering at around 300 degrees. If the solder used on the main control board or flash memory is lead-free solder (high melting point), you can try to blow solder between 350 degrees and 400 degrees. The specific temperature can be adjusted according to the actual observation of the melting of the solder.
Step 5*Open the card
If you just solder the main control board and flash memory together, it cannot be used directly. You need to open the card (some called mass production) first, and write the corresponding information into the main control chip for initialization.
Simply put, the supporting software is enough. The main control used to make the U disk this time is Yincan IS903, so Yincan’s mass production tool is used to open the card. It is recommended to perform a “power erase” operation before officially opening the card, so as to avoid some errors that occur later.
After opening the card, install the shell, and the U disk can be used normally.
TechWeb article / New Kaya