What is IC packaging?
IC (Integrated Circuit) is one of the most important electronic components, due to the complex functions and uses involved, there are many types of ICs. In order to facilitate the management, IC chips were defined as various standard packages.
IC packaging indicates the dimension and shape of a chip. Chips with the same electronic parameters may have different IC packages. IC package types are mainly divided into traditional DIP dual-in-line and SMD chip package, they are soldered by different methods (Wave soldering & Reflow soldering).
DIP (Double In-line Package)
The leads are led out from both sides of the body, the materials include plastic and ceramic. DIP applications include standard logic ICs, memory LSIs, and microcomputer circuits.
The pin pitch of DIP is typically 15.2mm. Some packages with widths of 7.52mm and 10.16mm are called skinny DIP and slim DIP (narrow-body DIP). However, in most cases, it is not differentiated and is simply referred to as DIP.
SOP/SOIC/SO (Small Outline Package)
The pins are drawn in an L shape from both sides of the body, the materials include plastic and ceramic. In addition to being used for memory LSI, SOP is also widely used in circuits such as ASSP that is not too large. The pin pitch is 1.27mm and the number of pins is from 8 to 44.
SOP derives some more IC packaging types, as follows:
SOJ (Small Out-Line J-Leaded Package): J-lead small outline package
TSOP (Thin Small Outline Package): This IC packaging is thinner than SOP with a pin pitch of 1.27mm
SSOP (Shrink Small Outline Package): Pin pitch is 0.635mm
TSSOP (Thin Shrink Small Outline Package): This IC package type is thinner than SOP with a pitch of 0.65mm
QSOP (Quarter-size Small Outline Package): Pin pitch is 0.635 mm
VSOP (Very Small Outline Package): It is smaller than QSOP and has a pitch of 0.4, 0.5 or 0.65 mm
QFP (Quad Flat Package)
The leads are led out from four sides in an L-shape, the materials are ceramic, metal and plastic, among which, plastic packaging accounts for the vast majority.
The pin pitches include 1.0mm, 0.8mm, 0.65mm, 0.5mm, 0.4mm, 0.3mm and other specifications. The maximum number of pins of 0.65mm package is 304.
Depending on the thickness of the package body, QFP currently has the following variants:
LQFP (Flat Quad Flat Pack): The height of the IC packaging body is 1.4 mm
TQFP (Thin Quad Flat Pack): Height is 1.0mm
PQFP (Plastic Quad Flat Package): PQFP package has a small pitch and a very small pin. Generally, large-scale or very large-scale integrated circuits use this IC packaging, and the pin count is generally above 100
CQFP (Ceramic Quare Flat Package): Ceramic version of PQFP
BQFP (Quad Flat Package with Bumper): This package has protrusions (cushions) at the four corners to prevent bending deformation of the pins during shipping. The pin pitch is 0.635mm, and the number of pins is from 84 to 196
QFN/LCC (Quad Flat Non-leaded Package)
The four sides of this IC packaging are equipped with electrode contacts. Due to the absence of leads, the mounting area is smaller than QFP and the height is lower than QFP.
The number of electrode contacts is generally from 14 to 100, the materials are ceramic and plastic. When there is an LCC mark, it is basically a ceramic QFN, of which the spacing of electrode contacts is 1.27 mm.
Plastic QFN has different pin pitches of 0.65mm, 0.5mm, and 1.27mm, this package is also known as PLCC.
BGA (Ball Grid Array Package)
Spherical bumps are formed on the back surface of the printed substrate to replace the lead, and the LSI chip is mounted on the front surface of the PCB board, and then sealed by a molding resin or a potting method, the pins can exceed 200.
The package body can be made smaller than QFP and the BGA does not have to worry about pin deformation problems like QFP.
The BGA package currently has the following variations:
CBGA (Ceramic BGA)
FBGA (Fine BGA)
LBGA (Low-profile BGA)
LFBGA (Low-profile Fine-pitch BGA)
MBGA (Micro Ball Grid Array)
MAPBGA (Moulded Array Process BGA)
PBGA (Plastic BGA)
TBGA (Tape BGA)
TEPBGA (Thermally Enhanced Plastic BGA)
UBGA (Ultra Fine BGA)
CSP (Chip Scale Package)
This IC packaging can reach close to 1:1 ratio of chip area to package. The absolute size is only 32 square millimeters, which is about 1/3 of the ordinary BGA, 1/6 of the chip area of TSOP memory. Compared to the BGA, the CSP package in the same space can increase the storage capacity by three times.
CSP is just an IC packaging standard, every package type than reach this ratio can be called CSP. Whether a PCB assembly house is able to deal with the CSP IC packaging or not reflects its assembly capabilities.