| ??? 03/07/06 00:41 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#111454 - Sockets, or how I lost the precision... Responding to: ???'s previous message |
Erik said:
The generation (which I inherited) using these micros use sockets and the problem with the ZIF is that it uses the bottom of the PLCC packages, where the non-ZIF use the sides which creates an "automatic scrape". The issues is clearly the "touch" contact of the ZIF. Yes, that's true, indeed! Earlier, when I needed to use PLCC sockets, I always cleaned contacts from (invisible) dust by the help of a anti-static brush before inserting the chip. Today, I always use SMD-packages, like TQFP, for instance, if possible. Isn't it amazing how much area you safe by using them?? Compared to a TQFP package, PLCC or even DIL40 looks like earliest stone age... Erik said:
The generation soon to be introduced is socketless, I detest sockets. I refused to use sockets even before the time SMD-packages were introduced. This from a bad experience with precision OPamps: I noticed, that offset voltage was changing, when slightly pressing on the OPamp, even if it was in the socket for days, weeks or months. And this even when a precision socket made of gold contacts was used. I don't know the actual reason for this strange performance, only that it disappeared, when the OPamp was soldered directly into the board. I could imagine, that this contact problem was a result from early oxidation of tinned pins of OPamp, equally whether the socket had gold contacts or not. This strange contact problem might be rather irrelevant for digital chips, but for analog ones it can become relevant. So, I migrated very early to avoid sockets at all. By the way, good sockets were very expensive, not seldom more expensive than the naked OPamp! Kai |
| Topic | Author | Date |
| AT89S52 signature | 01/01/70 00:00 | |
| Throw away... | 01/01/70 00:00 | |
| naah | 01/01/70 00:00 | |
| worse programmer? | 01/01/70 00:00 | |
| different messages, nothing else | 01/01/70 00:00 | |
| the original problem | 01/01/70 00:00 | |
| i tried to explain the whole situatuion | 01/01/70 00:00 | |
| do you have an oscilloscope? | 01/01/70 00:00 | |
| that would be a stupid chip design | 01/01/70 00:00 | |
Make that sense? | 01/01/70 00:00 | |
| Is it you, Erik Malund? | 01/01/70 00:00 | |
| it seems possible | 01/01/70 00:00 | |
| Why not using a fresh ZIF? | 01/01/70 00:00 | |
| the generation using these micros use so | 01/01/70 00:00 | |
| Sockets, or how I lost the precision... | 01/01/70 00:00 |