integrated circuit packaging In electronics manufacturing, integrated circuit packaging is the final stage of semiconductor device fabrication, in which the block of semiconductor material is encapsulated in a supporting case that prevents physical damage and corrosion. ...

, a solder ball, also a solder bump (ofter referred to simply as "ball" or "bumps") is a ball of

solder Solder (; NA: ) is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable ...

that provides the contact between the

chip package Integrated circuits are put into protective packages to allow easy handling and assembly onto printed circuit boards and to protect the devices from damage. A very large number of different types of package exist. Some package types have stand ...

and the

printed circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...

, as well as between stacked packages in

multichip module A multi-chip module (MCM) is generically an electronic assembly (such as a package with a number of conductor terminals or "pins") where multiple integrated circuits (ICs or "chips"), semiconductor dies and/or other discrete components are inte ...

s; in the latter case, they may be referred to as microbumps (μbumps, ubumps), since they are usually significantly smaller than the former. The solder balls can be placed manually or by automated equipment, and are held in place with a tacky flux.Soldering 101 - A Basic Overview
/ref> A coined solder ball is a solder ball subject to coining, i.e., flattening to a shape resembling that of a coin, to increase contact reliability. The

ball grid array A ball grid array (BGA) is a type of surface-mount packaging (a chip carrier) used for integrated circuits. BGA packages are used to permanently mount devices such as microprocessors. A BGA can provide more interconnection pins than can be p ...

chip-scale package A chip scale package or chip-scale package (CSP) is a type of integrated circuit package. Originally, CSP was the acronym for ''chip-size packaging.'' Since only a few packages are chip size, the meaning of the acronym was adapted to ''chip-scal ...

, and

flip chip Flip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to externa ...

packages generally use solder balls.

Underfill

After the solder balls are used to attach an integrated circuit chip to a PCB, often the remaining air gap between them is underfilled with epoxy. In some cases, there may be multiple layers of solder balls—for example, one layer of solder balls attaching a

to an

interposer An interposer is an electrical interface routing between one socket or connection to another. The purpose of an interposer is to spread a connection to a wider pitch or to reroute a connection to a different connection. Interposer comes from t ...

to form a BGA package, and a second layer of solder balls attaching that interposer to the PCB. Often both layers are underfilled."Underfill Applications, Materials & Methods"
2019.

Usage in
flip chip Flip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to externa ...
method

Image:Flip chip pads.svg, Pads Image:Flip chip flipped.svg, Balls Image:Flip chip mount 1.svg, Alignment Image:Flip chip mount 2.svg, Contact Image:Flip chip mount 3.svg, Solder reflow Image:Flip chip mount underfill.svg, Adhesive underfill Image:Flip chip mount final.svg, Final result

References

{{reflist Packaging (microfabrication) Soldering

Underfill

Usage in flip chip Flip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to externa ... method

See also

References

Usage in
flip chip Flip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to externa ...
method