Capacitor 0603 vs 0402Glenn,

0603's rarely, if ever, fail due to thermal stress or board flexing.
Therefore, I would scratch that as a benefit. I have seen a number of OEM's
struggle with failed capacitors with high capacitance (thin dielectric
layers). That seems to have a greater effect on cap failure rate due to
manufacturer defects than size of the cap.

Best Regards
Craig
  -----Original Message-----
  From: TechNet [mailto:[log in to unmask]]On Behalf Of Pelkey, Glenn
  Sent: Wednesday, August 08, 2001 3:56 PM
  To: [log in to unmask]
  Subject: [TN] Capacitor 0603 vs 0402


  Hi all,

          I'm brainstorming on risks and benefits of 0603 caps vs 0402 caps.
If the cap value, voltage rating, dielectric material, terminations, and use
conditions are the same, would one be better than the other?  My thoughts
are it would be a wash or at least not significant.  Here's what I have so
far:

  Benefits of 0402 vs 0603:
  Smaller size reduces thermal stress/strain on solder joints from CTE or
board flexing.
  Smaller size uses less real estate on board

  Risks of 0402 vs 0603:
  Equipment may have difficulty placing
  Thinner dielectric spacing to achieve same capacitance, cap higher failure
rate
  Smaller size, cracks easier to develop
  Higher risk of tombstoning

          What do you all think?  I'm sure I missed something, maybe even
wrong on some of the above.

  Thanks,

  Glenn