4 ms·

Also dumb question: Why do dies need to be square? Wouldn't you get less waste at the edges with a hex shape?

• fanf2 6y ago
  I expect that would be too difficult to cut up
• jl6 6y ago
  That’s a great question. I would guess that dies are built from modular sections (e.g. SRAM cells), and it’s important that two identical modules perform identically - signal propagation time is relevant at this scale, so the shape and layout of each module must be identical. I would further guess that rectangular layouts are easiest to reason about, easiest to make masks for, easiest to pack efficiently at the transistor level, and easiest to test. But I don’t know of a fundamental reason why a sufficiently advanced VHDL “compiler” couldn’t produce hex-cell or even circular layouts.
  • TheOtherHobbes 6y ago
    Chip dicing hardware can produce hex-cells, or any other cell with straight edges. (Not circular - that's not a good shape to expect from crystalline silicon.) But - as you say - the modular sections are rectangular, and for most applications there's no good reason to make the dies any other shape. There's actually a patent for hex-cell chips, but it doesn't seem to have been used for any significant projects. https://patents.google.com/patent/US6030885A/en https://patents.google.com/patent/US6030885A/en
  • sbierwagen 6y ago
    Could do triangular chips instead, they would be easier to dice.
• deleted 6y ago
  [deleted]