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Lead frame of a surface-mount technology package. Most kinds of integrated circuit packaging are made by placing a silicon chip on a lead frame, wire bonding the chip to the metal leads of the lead frame, and covering the chip with plastic. The metal leads protruding from the plastic are then either "cut long" and bent to form through-hole pins ...
Lead frame for a QFP package, before encapsulation DIP 16 pin Lead frame, after encapsulation and before cutting/separation. The lead frame consists of a central die pad, where the die is placed, surrounded by leads, metal conductors leading away from the die to the outside world. The end of each lead closest to the die ends in a bond pad.
Lead counts range from 32 to 176. Body sizes range from 5 mm × 5 mm to 20 × 20 mm. Copper lead-frames are used in TQFPs. Lead pitches available for TQFPs are 0.4 mm, 0.5 mm, 0.65 mm, 0.8 mm, and 1.0 mm. PQFP, or plastic quad flat pack, is a type of QFP, as is the thinner TQFP package. PQFP packages can vary in thickness from 2.0 mm to 3.8 mm.
Flat no-lead is a near chip scale plastic encapsulated package made with a planar copper lead frame substrate. Perimeter lands on the package bottom provide electrical connections to the PCB. [1] Flat no-lead packages usually, but not always, include an exposed thermally conductive pad to improve heat transfer out of the IC (into the PCB).
Through-hole (leaded) resistors. In electronics, through-hole technology (also spelled "thru-hole") is a manufacturing scheme in which leads on the components are inserted through holes drilled in printed circuit boards (PCB) and soldered to pads on the opposite side, either by manual assembly (hand placement) or by the use of automated insertion mount machines.
The standard further defines different types with varying parameters which includes package body material, terminal location, package outline, lead form and terminal count. The main vehicle for testing of high reliability flatpack packages has been MIL-PRF-38534 (General Specification for Hybrid Microcircuits). This document outlines the ...
The Thin shrink small outline package has a smaller body and smaller lead pitch than the standard SOIC package. It is also smaller and thinner than a TSOP with the same lead count. Body widths are 3.0 mm, 4.4 mm and 6.1 mm. The lead counts range from 8 to 80 pins. The lead pitches are 0.5 or 0.65 mm.
The European Restriction of Hazardous Substances Directive (RoHS), which took effect on July 1, 2006, restricted the use of lead in various types of electronic and electrical equipment. This has driven the use of lead-free alloys with a focus on preventing whisker formation (see § Mitigation and elimination). Others have focused on the ...