LGA Component Package

Authors:

Geoffrey Hunter

Published On:

Apr 4, 2015

Last Updated:

Apr 16, 2024

A 3D render of an LGA component package.

The LGA package is is a surface mount package with pads on the underside of the package. It is very similar to the BGA package, except is does not have any balls, instead plain flat pads are used. An LGA package may also differ from BGA with the addition of arbitrary sized pads for purposes such as grounding, thermal dissipation, shielding and mechanical strength. An LGA package can be made from a PCB, thus many LGA components are actually entire “modules” made from a PCB and a number of components. This modular form is commonly seen with cellular modem and WiFi components.

CPU Variants:

Code	Socket Name
LGA 771	Intel Socket J
LGA 775	Intel Socket T
LGA 1150	Intel Socket H3
LGA 1155	Intel Socket H2
LGA 1156	Intel Socket H
LGA 1207	AMD Socket F, AMD Socket C32
LGA 1356	Intel Socket B2
LGA 1366	Intel Socket B
LGA 1944	AMD Socket G34
LGA 2011	Intel Socket R

The LGA package comes in many different variants, all which have a different number of pins and a different pin configuration. The pins are normally lines up in a grid of x columns and y rows, but not every position may have a pad. Therefore you can get variants with the same LGA package width and length.

Cannot solder with a soldering iron, soldering with hot air or infrared is o.k., recommended practise is to use reflow techniques.

Like BGAs, LGA packages can withstand up to 50% mis-alignment when soldering (50% of the distance between consecutive pads, i.e. it’s pitch), as the package will automatically align itself¹. LGA packages can be connected to the PCB either with a socket or direct soldering. Intel has popularised the package by using it on some of it’s CPU families.

Socket

Socket for the LGA-775 component package.

Shifted Solder Mask Layouts

Sometimes LGA components recommend unique paste mask designs with “shifted” openings, as shown below.

The recommended paste mask layout (Panasonic labels this the “solder mask”, but they are really talking about what most people call the paste mask!) for the Panasonic PAN9026. Notice the unequal shifting of approx. 150um².

Common Uses

CPUs
Cellular modems
WiFi modules

Similar To

BGA: A BGA has balls on the underside pads, while a LGA doesn’t.
PGA

References

NXP (2009, Oct). AN3241: Land Grid Array (LGA) Package Rework. Retrieved 2022-04-19, from https://www.nxp.com/docs/en/application-note/AN3241.pdf. ↩
Panasonic. PAN9026: Wi-Fi Dual Band 2.4/5 GHz and Bluetooth Module. Design Guide. Rev. 1.1.. Retrieved 2022-04-19, from https://mediap.industry.panasonic.eu/assets/custom-upload/Devices/Wireless%20Connectivity/Wi-Fi%20Modules/PAN9026/WM%20PAN9026%20Design%20Guide.pdf. ↩