Editing Surface-mount technology (section)

== Disadvantages ==

* SMT may be unsuitable as the sole attachment method for components subject to frequent mechanical stress, such as connectors used to interface with external devices that are frequently attached and detached.{{citation needed|date=March 2019}}
* SMDs' solder connections may be damaged by [[Potting (electronics)|potting]] compounds going through thermal cycling.
* Manual prototype assembly or component-level repair is more difficult and requires skilled operators and more expensive tools, due to the small sizes and lead spacings of many SMDs.<ref name="JuddBrindley">{{cite book |last1=Judd |first1=Mike |last2=Brindley |first2=Keith |title=Soldering in Electronics Assembly |chapter=CS soldering processes |edition=2 |publisher=[[Elsevier|Newnes]] |year=1999 |page=128 |isbn=978-0750635455 }}</ref> Handling of small SMT components can be difficult, requiring tweezers, unlike nearly all through-hole components. Whereas through-hole components will stay in place (under gravitational force) once inserted and can be mechanically secured prior to soldering by bending out two leads on the solder side of the board, SMDs are easily moved out of place by a touch of a soldering iron. Without developed skill, when manually soldering or desoldering a component, it is easy to accidentally reflow the solder of an adjacent SMT component and unintentionally displace it, something that is almost impossible to do with through-hole components.
* Many types of SMT component packages cannot be installed in [[CPU socket|socket]]s, which provide for easy installation or exchange of components to modify a circuit and easy replacement of failed components.  (Virtually all through-hole components can be socketed.)
* SMDs cannot be used directly with plug-in [[breadboard]]s (a quick snap-and-play prototyping tool), requiring either a custom PCB for every prototype or the mounting of the SMD upon a pin-leaded carrier. For prototyping around a specific SMD component, a less-expensive [[breakout board]] may be used. Additionally, [[stripboard]] style protoboards can be used, some of which include pads for standard-sized SMD components. For prototyping, "[[Breadboard#High frequencies and dead bugs|dead bug]]" breadboarding can be used.<ref name="LinearAN47">{{cite book |last1=Williams |first1=Jim |url=http://cds.linear.com/docs/en/application-note/an47fa.pdf |title=High Speed Amplifier Techniques - A Designer's Companion for Wideband Circuitry |work=Application Notes |publisher=[[Linear Technology]] |year=1991 |pages=26–29, 98–121 |url-status=live |archive-url=https://web.archive.org/web/20151228191937/http://cds.linear.com/docs/en/application-note/an47fa.pdf |archive-date=2015-12-28 |access-date=2015-12-28 }}</ref>
* Solder joint dimensions in SMT quickly become much smaller as advances are made toward ultra-fine pitch technology. The reliability of solder joints becomes more of a concern as less and less solder is allowed for each joint. Voiding is a fault commonly associated with solder joints, especially when reflowing a solder paste in the SMT application. The presence of voids can deteriorate the joint strength and eventually lead to joint failure.<ref name="Indium1993">{{cite journal |title=Voiding Mechanisms in SMT |journal=Indium Corporation Tech Paper |year=1993 |last1=Dr. Lee |first1=Ning-Cheng |last2=Hance |first2=Wanda B. |url=http://www.indium.com/technical-documents/whitepaper/voiding-mechanisms-in-smt |access-date=2015-12-28 }}</ref><ref name="RPS1983">{{cite journal |title=The Effects of Entrapped Bubbles in Solder Used for the Attachment of Leadless Ceramic Chip Carriers |journal=Reliability Physics Symposium |year=1983 |last1=DerMarderosian |first1=Aaron |last2=Gionet |first2=Vincent |pages=235–241 |doi=10.1109/IRPS.1983.361989 }}</ref>
* SMDs, usually being smaller than equivalent through-hole components, have less surface area for marking, requiring marked part ID codes or component values to be more cryptic and smaller, often requiring magnification to be read, whereas a larger through-hole component could be read and identified by the unaided eye.  This is a disadvantage for prototyping, repair, rework, reverse engineering, and possibly for production set-up.