Low noise flip-chip packages and flip chips thereof
A flip chip comprises first and second circuitry portions formed in a substrate. The first and second circuitry portions are spaced apart from one another in a separation direction. A substrate-contact boundary is formed in the substrate between the first and second circuitry portions.
1. A flip chip, comprising:
a substrate having a thickness T; and
first and second circuitry portions formed in the substrate,
wherein;
the first and second circuitry portions are spaced apart from one another in a separation direction;
a substrate-contact boundary is formed in the substrate between the first and second circuitry portions; and
the substrate-contact boundary comprises a substrate contact having a width W in the separation direction large enough compared to the thickness T such that in use the substrate-contact boundary provides substantial noise isolation between the first and second circuitry portions.
2. The flip chip as claimed in claim 1 , wherein W≧T, and preferably wherein W≧2T, and more preferably wherein W≧4T.
3. The flip-chip as claimed in claim 1 or 2 , wherein:
the substrate contact is a first substrate contact;
the width W is a width W 1 ;
the substrate-contact boundary comprises a second substrate contact formed in the substrate between the first and second circuitry portions;
the second substrate contact has a width W 2 in the separation direction; and
a combination C of the widths W 1 and W 2 is large enough compared to the thickness T such that in use the substrate-contact boundary provides substantial noise isolation between the first and second circuitry portions.
4. The flip chip as claimed in claim 3 , wherein C≧T, and preferably wherein C≧2T, and more preferably wherein C≧4T.
5. The flip chip as claimed in claim 3 , wherein the first and second substrate contacts are spaced apart from one another in the separation direction.
6. The flip chip as claimed in claim 5 , wherein the first and second substrate contacts are spaced apart from one another in the separation direction by a separation width SW which is substantially small as compared to a sum of widths W 1 and W 2 .
7. The flip chip as claimed in claim 3 , wherein the width W 1 is substantially the same as the width W 2 .
8. The flip chip as claimed in claim 3 , wherein each of the first and second substrate contacts is generally elongate so as to form a wall between the first and second circuitry portions.
9. The flip chip as claimed in claim 1 or 2 , wherein the substrate contact is generally elongate so as to form a wall between said circuitry portions.
10. A flip chip, comprising:
a substrate having a thickness T; and
first and second circuitry portions formed in the substrate,
wherein:
the first and second circuitry portions are spaced apart from one another in a separation direction;
a substrate-contact boundary is formed in the substrate between the first and second circuitry portions; and
the substrate-contact boundary comprises a substrate contact having a width W in the separation direction, and the substrate contact is generally elongate so as to form a wall between the first and second circuitry portions, wherein W>2T.
11. The flip chip as claimed in claim 10 , wherein W≧4T.