Is the die of SMD transistors different from die of DIP transistors with a unique part number?

Is the power transmission of a transistor dependent on its package type or chip type ?


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    \$\begingroup\$ DIP means "Dual In-line Package", and refers to a style of IC package. Perhaps you mean "through-hole package" transistor - the transistor leads are designed to be soldered into holes in the PC board. \$\endgroup\$ – Peter Bennett Jun 12 at 15:26

Assuming you're asking about the die, then parts with the same part number from the same manufacturer will typically have identical dice inside regardless of what package they use. There's no rule that says they have to, though; they could use specially-designed dice to fit more conveniently in different leadframes if they had reason to.

Economically it makes more sense to use one die design for multiple packages, however, if that's an option. Engineering a semiconductor die is not a trivial task, and has a lot of up-front cost associated with it, from paying the engineers designing it, to producing the photomasks for constructing it, to having to change tooling between runs of the two different types.

The package is typically what determines power dissipation. Packages that do a poor job of extracting heat (for example, TO-92 or SOT-23) will support a much higher temperature difference between the die and the ambient air, as the plastic they're made from is a thermal insulator. Packages like TO-220 or SOT-223, on the other hand, have a dedicated terminal that's thermally bonded to the die and that provides a path to conduct heat outside the package and to a heatsink.

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    \$\begingroup\$ +1 for correct pluralization of 'die'. \$\endgroup\$ – Phil G Jun 12 at 15:30
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    \$\begingroup\$ "The package is typically what determines power dissipation." The package certainly can determine power dissipation, if it happens to be the highest thermal resistance in the chain from the junction to case. But there's still measures that must be taken on the die design and construction once you get a really good package design. \$\endgroup\$ – TimWescott Jun 12 at 15:46
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    \$\begingroup\$ @TimWescott Fair point, now that you bring it up I suppose it would require some type of design consideration to make sure you can thermally bond the die to a pad like that, and you avoid hot spots... Still, after making such a die, you could put it in a leadframe for a TO-92 if you had reason to, and it would probably be better than engineering a different die for the through-hole low-power variant. \$\endgroup\$ – Hearth Jun 12 at 15:48
  • \$\begingroup\$ @mojtaba You're welcome. If you feel this adequately answers your question, you can mark the question as answered by clicking the check mark next to the answer. \$\endgroup\$ – Hearth Jun 13 at 21:36

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