NW-Bound
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
- Joined
- Jul 3, 2008
- Messages
- 35,712
Quite a bit off topic, and I hope the OP does not mind, but since we touched on the subject of how advanced electronics has gotten, and could knock the sock off workers in the field who left work for only a few years, I could not help mentioning this.
Per previous posts about how small chip packaging has become, I described how I was astounded when my son showed me what he worked on. The BGA chip mounting pads were so much smaller than anything I had seen.
Today, I got some numbers from him, and electronic engineers will appreciate this. The BGA I saw had a ball pitch (spacing between balls) of 140 microns, and the diameter of the balls was 100 microns. That's 5.5 mil, and 4 mil respectively (1 mil = 1 thousand of an inch). For reference, the thickness of a piece of common 8.5x11 paper is also 4 mil. The spacing between balls was 1.5mil, a fraction of a paper thickness! That's how precise the package must be positioned on a board for soldering.
The BGA packages I was familiar a few years ago had a ball pitch of 0.5mm or 500 microns, so would look huge compared to what my son was working on.
What was also peculiar was that the balls were not populated over all the grid positions, but sparsely populated at seemingly random spots. The package was obviously for a proprietary and unique chip for a special application. It was way too small and expensive to go into something like a TV. I am certain it was for a small state-of-the-art handheld gadget like a smartphone.
Per previous posts about how small chip packaging has become, I described how I was astounded when my son showed me what he worked on. The BGA chip mounting pads were so much smaller than anything I had seen.
Today, I got some numbers from him, and electronic engineers will appreciate this. The BGA I saw had a ball pitch (spacing between balls) of 140 microns, and the diameter of the balls was 100 microns. That's 5.5 mil, and 4 mil respectively (1 mil = 1 thousand of an inch). For reference, the thickness of a piece of common 8.5x11 paper is also 4 mil. The spacing between balls was 1.5mil, a fraction of a paper thickness! That's how precise the package must be positioned on a board for soldering.
The BGA packages I was familiar a few years ago had a ball pitch of 0.5mm or 500 microns, so would look huge compared to what my son was working on.
What was also peculiar was that the balls were not populated over all the grid positions, but sparsely populated at seemingly random spots. The package was obviously for a proprietary and unique chip for a special application. It was way too small and expensive to go into something like a TV. I am certain it was for a small state-of-the-art handheld gadget like a smartphone.
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