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I want to know the difference between surface mount device and through hole components other than the mounting style.

Differences such as if the through hole counterpart of the surface mount device has has considerably more resistance or consumes more power etc.

Finally, I want to know if the SMD components can be totally replaced by through-hole in a circuit.

Thanks.

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    \$\begingroup\$ Generally speaking, SMD consumes less board space, is cheaper, has a wider device selection, and has lower pin inductance. There are exceptions to all of these. \$\endgroup\$
    – Reinderien
    Oct 16, 2020 at 12:36
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    \$\begingroup\$ This is very broad, I suggest that you pick a specific product example like an SMPS and limit the question to that context. Power and resistance generally aren't an issue, cost and form factor are. \$\endgroup\$
    – Bimpelrekkie
    Oct 16, 2020 at 12:37
  • \$\begingroup\$ Many devices exist in an smd and tht version and they often include the exact same die in different packages. \$\endgroup\$
    – Sim Son
    Oct 16, 2020 at 12:42
  • \$\begingroup\$ I'm trying to make a board for a microcontroller. THT components will exponentially simplify the soldering process. Ease of soldering is all I'm looking for. \$\endgroup\$
    – akshaykumark
    Oct 16, 2020 at 12:49
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    \$\begingroup\$ If you can get the parts and prefer through-hole, then go ahead; but these days I would say that it doesn't actually simplify soldering at all. You have to keep turning the board over. \$\endgroup\$
    – pjc50
    Oct 16, 2020 at 12:55

2 Answers 2

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SMD pros: smaller size, can be assembled by pick-and-place machine, no lead inductance or smaller inductance for packages containing leads.

Through-Hole pros: bigger package - better power dissipation (e.g. resistors). Although it depends on PCB design. If SMD component is mounted on copper plane it may have better thermal drain as mentioned in comments below.

Regarding cost - SMD mostly cheaper.

Replacing SMD with through-hole component is not always possible. For example in RF circuits, where lead inductance plays significant role.

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    \$\begingroup\$ SMD’s may have lower Rjc when surface mounted onto a ground plane than THT with no heat sink at 1/4 the size, so better power dissipation for THT is mot always the case(pun intended) given the same PCB surface area for SMT’s they will be much cooler, but at max case sizes possible TO3’s win. the biggest difference is all modern MOSFETS are avail with 50k varieties in SMT, vs hundreds in THT especially in low threshold where there are very few %THT of choices. And many VLSI, magnetic, etc , same deal. \$\endgroup\$
    – Tony Stewart EE75
    Oct 16, 2020 at 12:57
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    \$\begingroup\$ What Tony said. It's impossible to make a blanket claim that through-hole has better power dissipation. Even if they have more surface area, the device body is often hanging in the air, compared to an SMD that could be sitting right on a copper ground plane. \$\endgroup\$
    – Reinderien
    Oct 16, 2020 at 15:09
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    \$\begingroup\$ Gotta say though that is' way easier to heatsink a TO-220 than a D2Pak \$\endgroup\$
    – DKNguyen
    Oct 16, 2020 at 15:21
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SMT’s are cheaper, faster <1ns , better heat transfer to PCB ground plane, cheaper and have 10x more varieties and choices. For high volume SMD is cheaper production cost and there may be fewer companies with THT automation.

But for old school designs before the turn of century OK.

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  • \$\begingroup\$ Also hobbyist kits for hand soldering \$\endgroup\$
    – user253751
    Oct 16, 2020 at 16:18
  • \$\begingroup\$ yet Hobbyists have learned to reflow SMT solder with a hot plate and heat gun or other means \$\endgroup\$
    – Tony Stewart EE75
    Oct 17, 2020 at 1:36

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