Why transistor manufacturing videos are not available!

Thread Starter

Willen

Joined Nov 13, 2015
294
Hello,
Being a hobbyist I always love analog electronics and the most attractive part to me is TO-92 transistors! Seller like eBay sells 100 pcs of them (not branded though) at less than USD 1. VERY cheap! I am curious on them always! I can see videos of manufacturing advanced CPUs in YouTube but never saw making small transistors, diodes etc. Do they still think some other manufacture may leak the ideas of making these so cheap parts? And they keep it secret?
 

MrChips

Joined Oct 2, 2009
21,373
Fabricating transistors is a lot easier than making ICs because there are fewer steps. Making transistors from silicon wafers follow the same basic principles.

 

Thread Starter

Willen

Joined Nov 13, 2015
294
All the videos are really interesting! I don't know why YouTube was not showing me these, with "transistor manufacture" key word.

Hi AG,
An engineer from UK gave me 500 pcs of 2N2222 from eBay and he said it costs less than 5 or 4 USD. I checked random 10 pcs of 500 and every pcs are working very well.

Compared to Fairchild or National transistors, these cheap transistors have very shiny leads and looks not suitable for outdoor devices in high humidity environment.

I guess they (probably Chinese manufacturer) use same transistor chip to make various types of TO-92 so many of such transistors (S9014, BC547, 2N2222 2N3904 etc) so that they have similar hFE.

Another, I also got a bag of 100pcs of 78L05 from a guy from eBay costs less than USD 2 and these are working well.

I am getting a seller in AliExpress selling HT7550 (100mA LDO 5.0V LDO regulator TO-92) at USD 0.80. Buyer are writing good review as a feedback.
 
Last edited:

Wolframore

Joined Jan 21, 2019
1,748
There's a difference between some of those transistors, similar in that they are transistors but also different characteristics. The 3904 has similar hFE to the 2222 but huge difference in the amount of collector current they can safely switch. There are other differences in linearity and capacitance since everything is a tradeoff. But it amazes me how inexpensive some of these jellybean parts are out of China.
 

SamR

Joined Mar 19, 2019
2,259
The "problem" with chinesium parts is mostly in the vendors who know absolutely nothing about what they are selling other than their profit margin. No documentation, no product support, 0 technical support. They are merely brokering a sale from an undocumented source to make a profit. I am convinced some do not even stock the parts but merely take orders to tell them what they need to buy on the market that day to ship to a customer (yes, I have actually had this happen to me). Very strange behavior compared to what most of us have experienced buying from US sources. You could be buying good quality parts or it could be electronic scrap. In one instance where a vendor sold me parts he did not have in actual inventory and bought on the spot market, they were inoperable worthless scrap. Yes, I was refunded but lost over a month of my time dealing with waiting for bad parts and getting refunded.
 

nsaspook

Joined Aug 27, 2009
7,356
The "problem" with chinesium parts is mostly in the vendors who know absolutely nothing about what they are selling other than their profit margin. No documentation, no product support, 0 technical support. They are merely brokering a sale from an undocumented source to make a profit. I am convinced some do not even stock the parts but merely take orders to tell them what they need to buy on the market that day to ship to a customer (yes, I have actually had this happen to me). Very strange behavior compared to what most of us have experienced buying from US sources. You could be buying good quality parts or it could be electronic scrap. In one instance where a vendor sold me parts he did not have in actual inventory and bought on the spot market, they were inoperable worthless scrap. Yes, I was refunded but lost over a month of my time dealing with waiting for bad parts and getting refunded.
It's a Pig in the Poke.

Lots of parts that are actually built in quality fabs are tested and packaged in large Asian final test facilities because of the labor intensive nature of the inspection jobs. Under spec parts don't usually get scrapped, they are sold for pennies on the dollar (usually just the die) for use in non-critical, one-use type applications like cheap toys to brokers. Counterfeiting actual parts by making them is expensive, junk back-door substitution is a lot more profitable for the pirates.
 

Wolframore

Joined Jan 21, 2019
1,748
They can't be making that much... 5000 transistors for $15. I have yet to have any real issues except when they put a fake logo and counterfeit chips... this I can't stand even if they work ok.
 

SamR

Joined Mar 19, 2019
2,259
They actually buy and market name brand parts that they buy from importers who buy in bulk. Marketing there is "very unusual" to what we here in the US/Europe are accustomed to. There is no "stand by your brand name". Instead it is very much buyer beware because all they are doing is remarketing parts THEY bought cheap without any provenance. They could be real legitimate parts, generic good parts, Rebranded counterfeit parts, or simply scrap defective "looks OK to me" untested parts. They are not very savy in this respect many times. There are very legitimate Asian sellers and there are clueless "mom and pop" sellers who don't know what they are selling. Hard to tell who is who with the plethora of vendors in the market.
 

Wolframore

Joined Jan 21, 2019
1,748
It all depends on what you're building for... you would never be able to use any of this stuff in automotive, defense, medical or other critical end use... plenty of hobbyists and consumer stuff where they pose no danger and work fine.
 

SamR

Joined Mar 19, 2019
2,259
I would avoid it like the plague for commercial use at this point. But I do like the cheap prices just to play around with but you have to "roll with the punches" dealing with them.
 

Wolframore

Joined Jan 21, 2019
1,748
Aliexpress and ebay are not authorized vendors... I just did a complete BOM purchase through another site. We shall see, this source appears to be more like our digikey.

lcsc.com
 

SamR

Joined Mar 19, 2019
2,259
They do claim to have anti-counterfeiting/stolen intellectual property programs but all it does is eliminate the offending vendor. Who simply change their name and go right back at it.
 
Top