LGA COMPONENT PACKAGE

LGA Component Package

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Overview

NameLGA (Land Grid Array)
Image
Synonyms
Similar To

  • BGA (BGA has balls, LGA doesn’t)

  • PGA

VariantsMany
MountingSMD
Pin CountApprox 5-2000.
Pitch
SolderabilityCannot solder with a soldering iron, soldering with hot air or infrared is o.k., recommended practise is to use reflow techniques.
Thermal Resistance
Package Dimensions
Typical PCB Land Area
3D Models
Common Uses

  • CPUs

  • Cellular modems

  • WiFi modules

    • Comments

    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.

    A 3D render of an LGA component package.

    A 3D render of an LGA component package.

    CPU Variants:

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

    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.

    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. 150um[^bib-panasonic-pan9026-design-guide].

    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.

    References

    1. 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. ↩︎

    2. 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. ↩︎

    Authors

    Geoffrey Hunter

    Dude making stuff.

    Creative Commons License
    This work is licensed under a Creative Commons Attribution 4.0 International License .

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