(redirected from Through-hole)


A circuit board packaging technique in which the leads (pins) on discrete components and chips are inserted through holes in the printed circuit board and soldered from beneath. Until the late 1980s and prior to surface mount technology, all devices on circuit boards were thru-hole. Although chips are mostly surface mounted these days, some chips are still thru-hole, and most discrete devices such as resistors and capacitors are thru-hole.

Thru-hole devices have a strong bond with the board but require an extra drilling step. They also eliminate the board real estate underneath from being used for other layers. See surface mount.

Through the Board
In this circuit board from an LED table clock made in 2005, not only the discrete components, but the chip, are thru-hole devices.

Thru-Hole vs. Surface Mount
The thru-hole chip is not only thicker than the surface mount chip, but it eliminates the real estate underneath because the pins stick through. The board designer must route any traces from other layers around that part of the board.
References in periodicals archive ?
The innovative new THR Series Through-Hole Type Electromechanical Relays from Excel Cell Electronic (Goodsky/ECE) now allow the GQ Series to withstand the harsh melting temperatures of the reflow soldering process.
Fine-Line Through-Hole Copper Filling in VCP for Next-Generation Packaging"
When these pins are pressed into a plated through-hole, the points (the major or circumscribed diameter) of the polygon are set or imbedded in the hole while the flat sides of the feature (minor or inscribed diameter) provide relief, allowing the remainder of the plated through-hole barrel to remain intact.
Mill-Max has added a through-hole version of 2 mm pitch spring-loaded connectors to complement the surface mount version.
With options suitable for automated reflow-solder assembly, the integrated magnetic jack provides OEMs with a high-speed assembly solution without compromising the robust and reliable through-hole PCB connection.
The through-hole design allows an OEM assembly to pass directly through the middle of the actuator, resulting in reduced weight, fewer parts and a more compact product overall.
Both through-hole and SMT terminations with the SMT products packaged on tape and reel.
India, July 2 -- Available in through-hole and surface mount packages, the expanded 60V StrongIRFET family includes the IRF7580M.
In many cases the power and ground planes under a BGA component have voids, as a result of through-hole vias.
Mercury Electronics Europe has introduced monolithic crystal filters (MCF) in surface mount and through-hole package styles for use in communications applications.
The 8360 non-contacting, through-hole position sensor series features 360[degrees] continuous rotational capabilities in a low-profile, through-hole package, providing an ideal solution for applications where space and sensor mounting flexibility are critical.
THE MICROSECTION IN FIGURE 1 was taken from the knee of a plated through-hole during board examination.