METHOD AND APPARATUS FOR MAKING INTEGRATED CIRCUIT PACKAGES
A method of making a plurality of integrated circuit (“IC”) packages includes picking up a plurality of physically unconnected IC components; and simultaneously placing each of the physically unconnected IC components on corresponding portions of an unsingulated IC package strip that includes a sheet of integrally connected leadframes.
There are many types of integrated circuit (“IC”) packages. Most IC packages include at least one leadframe and at least one die electrically connected to the leadframe, as by bond wires or clips. The electrical components of most IC packages are protected by an encapsulation layer of mold compound. Some IC packages, for example, Quad Flat No-Lead Packages (“QFNs”), include a leadframe with multiple dies that are electrically connected to the leadframe with multiple clips.
Usually, the production of IC packages involves mounting of IC components on each of a number of integrally connected leadframes on a leadframe strip. Typically each IC package component is mounted, one at a time, on each of the different leadframes. At the end of the component mounting and electrical connection processes the components mounted on each of the leadframes of the leadframe strip are encapsulated with mold compound that hardens into a protective coating. The encapsulated strip is then singulated (cut or diced) so as to separate the interconnected leadframes and the associated components mounted on each leadframe into separate IC packages.
A pick and place machine is used to pick up an object(s), move the object(s) to a desired location, and then release the object.
In the intermediate product assembly of
The various components of each component stack 70 are best illustrated in
The gang clip frame assembly 40 often causes mold flashing during the molding stage of the production process. Such mold flashing affects the components of the component stacks 70 located at an edge of the clip frame 40 member, e.g. 46, that is adjacent to the mold gate. During molding, the mold compound flow at this edge of the leadframe 40 is a high pressure, turbulent flow. This mold compound flow can cause some the components in the row positioned closest to this frame edge to be displaced. Such displacement may result in irregular package shapes and may also cause electrical failures.
Another problem is package chipping in which chips of the mold compound break off during singulation. Package chipping occurs primarily because of the relatively small distance between the top of the mold compound 80 and the tie bars 54 of the gang clip frame assembly 40, as best shown in
Exposed metal is another problem associated with the use of gang clip frame assemblies 40. The assemblies sometimes become misaligned with the rest of a stack assembly 70,
Clip warpage and misalignment and associated damage to electrical connection of clips to associated components may occur because of non-uniform expansion and contraction of the tie bars 54 during reflow heating.
A new method of gang mounting clips on QFN intermediate product assemblies, which reduces or eliminates some or all of the above explained problems will now be described.
An example embodiment of a new pick and place tool head 112 is illustrated in
In
A QFN 182 made by the process described above with reference to
A method similar to the method of gang mounting clips 150 on associated QFN stacks 170 described with reference to
The methods and structures described with reference to
Although certain embodiments of methods and apparatus for frameless gang mounting of components of an integrated circuit package have been described in detail above, it will occur to those skilled in the art, after reading this disclosure, that the expressly disclosed embodiments may be otherwise embodied. It is intended that the appended claims be broadly construed to cover all such alternative embodiments, except as limited by the prior art.
Claims
1. A pick and place machine for gang mounting integrated circuit (“IC”) package components on an array of partially assembled IC packages comprising a tool head plate with a plurality of holes extending therethrough that are arranged in an array of the same size and shape as said array of partially assembled IC packages.
2. The pick and place machine of claim 1 wherein said tool head plate is mounted on a tool head that is operably displaceable between a first operating position wherein said plurality of holes are aligned with corresponding ones of an array of singulated IC package components and a second operating position wherein said plurality of holes are aligned with corresponding ones of said array of partially assembled IC packages.
3. The pick and place machine of claim 1 wherein said holes are of a size and shape adapted to pick and place QFN clips of a preselected size and shape,
4. The pick and place machine of claim 1 wherein said holes are of a size and shape adapted to pick and place IC dies of a preselected size and shape.
5. A method of making integrated circuit (“IC”) packages comprising:
- providing a pick and place machine having a tool head with a plate that has a plurality of holes extending therethrough that are arranged in an array identical in size and shape to an array of partially assembled IC packages;
- positioning said tool head at a first position wherein said plurality of holes are aligned with corresponding ones of an array of singulated IC package components;
- applying a vacuum to said plurality of holes;
- positioning said tool head at a second position wherein said plurality of holes are aligned with corresponding ones of said array of partially assembled IC packages; and
- removing said vacuum from said plurality of holes.
6. The method of claim 5 further comprising singulating IC components attached to an IC component panel to provide said array of singulated IC package components.
7. The method of claim 6 further comprising applying solder paste to at least one of said array of singulated IC package components and said array of partially assembled IC packages.
8. The method of claim 7 further comprising reflowing said solder paste to bond corresponding ones of said array of singulated IC package components and said array of partially assembled IC packages.
9. The method of claim 5 wherein said positioning the tool head at a first position wherein said plurality of holes are aligned with corresponding ones of an array of singulated IC package components comprises positioning said tool head at a first position wherein said plurality of holes are aligned with corresponding ones of an array of singulated clips.
10. The method of claim 5 wherein said positioning the tool head at a first position wherein said plurality of holes are aligned with corresponding ones of an array of singulated IC package components comprises positioning said tool head at a first position wherein said plurality of holes are aligned with corresponding ones of an array of singulated IC dies.
11. An intermediate product assembly made in the production of Quad Flat No-lead Packages (“QFNs”) comprising:
- a pick and place machine tool head comprising an array of vacuum holes; and
- a plurality of singulated QFN components that are vacuum attached to said tool head in covering relationship with said plurality of vacuum holes.
12. The intermediate product assembly of claim 11 wherein said singulated QFN components are singulated clips.
13. The intermediate product assembly of claim 11 wherein said singulated QFN components are singulated Integrated Circuit (“IC”) dies.
14. The intermediate product assembly of claim 11 wherein said tool head and said plurality of singulated QFN components attached thereto are positioned above an unsingulated leadframe sheet having at least one plurality of other QFN components mounted on corresponding leadframe portions of said leadframe sheet.
15. The intermediate product assembly of claim 14 wherein at least one of said plurality of singulated QFN components or said at least one plurality of other QFN components have a coating of solder paste thereon.
16. The intermediate product assembly of claim 15 wherein said other plurality of QFN components comprise a plurality of first IC dies mounted on said corresponding leadframe portions.
17. The intermediate product assembly of claim 16 wherein said other plurality of QFN components further comprise a plurality of lower clips attached to corresponding ones of said first plurality of IC dies.
18. The intermediate product assembly of claim 17 wherein said other plurality of QFN components further comprise a plurality of upper dies attached to corresponding ones of said plurality of lower clips.
19. The intermediate product assembly of claim 18 wherein said plurality of singulated QFN components that are vacuum attached to said tool head in covering relationship with said plurality of vacuum holes comprise a plurality of upper clips.
20. The intermediate product assembly of claim 19 wherein said plurality of upper dies and said plurality of upper clips have a layer of solder paste sandwiched therebetween,
21. A method of making integrated circuit (“IC”) packages comprising:
- picking up a plurality of physically unconnected IC components; and
- simultaneously placing each of the physically unconnected IC components on corresponding portions of an unsingulated IC package strip that includes a sheet of integrally connected leadframes.
Type: Application
Filed: Mar 17, 2015
Publication Date: Sep 22, 2016
Inventors: Roxanna Bauzon Samson (Benguet), Ruby Ann Maya Merto (Baguio City), Lorraine Rivera Duldulao (City of San Fernando Pampanga), Jason Binay-an Colte (Benguet)
Application Number: 14/660,703