| ??? 11/08/05 19:37 Modified: 11/08/05 19:39 Read: times Msg Score: +1 +1 Informative |
#103438 - thermal reliefs only ease soldering Responding to: ???'s previous message |
Suresh R said:
now my doubt is,
Should the thermal relief pads be used only at ground pins of components or even in vias which connect the top layer copper pour to the bottom layer copper pour (ground plane). The purpose of thermal reliefs is to aid in soldering. A large copper plane serves as an excellent heatsink, making soldered connections to the plane difficult. Even as the pin on the IC heats up as you solder, the pad connected to the plane tends to remain cooler. If you are not careful, you either end up damaging the IC due to overheating, or wind up with a cold joint. Given the purpose of the thermal reliefs, there is no point in using them for vias since you won't be soldering to them. As you select the design of your thermal reliefs, keep in mind that you are basically trading off between two attributes: electrical resistance of the connection vs. ease of soldering. Calculate the resistance of your thermal reliefs and see what you think. Be careful about using them for connections that will be carrying a lot of current. --Sasha Jevtic |
| Topic | Author | Date |
| two layer PCB | 01/01/70 00:00 | |
| +5VDC also drives PhotoMOS relays | 01/01/70 00:00 | |
| Solid ground plane is needed! | 01/01/70 00:00 | |
| what i have done is | 01/01/70 00:00 | |
| what you have done ... | 01/01/70 00:00 | |
| Thermal relief's | 01/01/70 00:00 | |
| You need a solid ground plane | 01/01/70 00:00 | |
| I want the best money can buy, but do no | 01/01/70 00:00 | |
| Thermal relief in PCB's | 01/01/70 00:00 | |
| An illustration... | 01/01/70 00:00 | |
| went through the design but | 01/01/70 00:00 | |
| Thermal reliefs were demonstrated | 01/01/70 00:00 | |
who are you posting to???? | 01/01/70 00:00 | |
| thermal reliefs only ease soldering | 01/01/70 00:00 | |
| Resistance calculation for thrmal relief | 01/01/70 00:00 | |
| you better read ..... | 01/01/70 00:00 |