Probably basic but I'm having trouble with it...
I'm trying to find mica insulators (if someone knows something better please advise) for Toshiba's 2SA1987's and their complementary pair. It seems their package is the 2-21F1A, which is the same as TO-3P(L) as per some thread I found here.
But looking around at mica insulators in most common electronics sites I couldn't find any insulator specific for this package. Does anyone know what are the differences between all of the above packages ? And can I use insulators for TO-3P or TO-3PBL (that's what I found on BDent...).
THanks!
I'm trying to find mica insulators (if someone knows something better please advise) for Toshiba's 2SA1987's and their complementary pair. It seems their package is the 2-21F1A, which is the same as TO-3P(L) as per some thread I found here.
But looking around at mica insulators in most common electronics sites I couldn't find any insulator specific for this package. Does anyone know what are the differences between all of the above packages ? And can I use insulators for TO-3P or TO-3PBL (that's what I found on BDent...).
THanks!
You could easily make your own from; Heatsink Tape for use with Heatsink | RS Components
or Heatsink Mounting Accessories | RS Components
or this is excellent for flat TO3 P type transistor even though most now just need heat sink compound as they are insulated; HF-S43 | Heatsink Double Sided Tape for use with Heatsink | RS Components
https://uk.farnell.com/c/cooling-th...hlookahead&product-range=heat-sinks-hs-series
can also be useful.
https://uk.farnell.com/c/cooling-th...ECO-ALL-coo-the-man_hea-sin_nat-con-hea-sin_7
The semiconductor supplier will be able to supply thermal pads for the transistors when you order them.
or Heatsink Mounting Accessories | RS Components
or this is excellent for flat TO3 P type transistor even though most now just need heat sink compound as they are insulated; HF-S43 | Heatsink Double Sided Tape for use with Heatsink | RS Components
https://uk.farnell.com/c/cooling-th...hlookahead&product-range=heat-sinks-hs-series
can also be useful.
https://uk.farnell.com/c/cooling-th...ECO-ALL-coo-the-man_hea-sin_nat-con-hea-sin_7
The semiconductor supplier will be able to supply thermal pads for the transistors when you order them.
Bergquist K10 Sil-pads (greaseless, easy to work with). You can get them for most packages (except the Sanken MT-200). They make a slightly different size for TO-3P (TO-247) and TO-3P-L (TO-264). Of course you can use the bigger ones for both. Several thicknesses available. They also have 11x12” sheets of it for about $60, which makes a lot of insulators of any size (best option of the old Sankens). I use that cut in strips for entire banks of TO-264’s. You can get it with or without adhesive on one side. The usual suppliers, digikey, Mouser, etc. They also have a line of Kapton insulators, if you really prefer something closer to mica/grease. As well as more advanced phase-change materials if you really need lower Rth.
I still use mica and grease for TO-3’s, but only because I have THOUSANDS of them I bought from Skycraft, and most of my TO-3 work is either repairs or small onsey-twosey DIY projects where I don’t have to handle 50 of them. For bigger more serious projects I’ve gotten away from both mica/grease and TO-3’s.
I still use mica and grease for TO-3’s, but only because I have THOUSANDS of them I bought from Skycraft, and most of my TO-3 work is either repairs or small onsey-twosey DIY projects where I don’t have to handle 50 of them. For bigger more serious projects I’ve gotten away from both mica/grease and TO-3’s.
Thanks. Wow, hold on a second, you mean the SA1987 might be insulated already ? I couldn't find anything about it in the datasheet. I think I've seen some people using insulators for them but then again maybe I was half asleep in the middle of the night...
Yes, just the hole is insulated. All current TO-3P-ish types have an insulated hole and don’t require the insulating bushing under the screw. But most need an insulator for the backside - the A1987 included. There are some types in a similar “full-pack” that has no exposed metal, but those are almost all high voltage switching types, with the exception of a few general purpose low power full-pack TO-220’s. The full epoxy case degrades the thermals, but really helps Safety wise when the collector is at 400 volts and the heatsink grounded.