Thursday, July 13, 2006
Capacitors cut high-frequency complexity
Land grid array capacitors achieve the equivalent high-frequency performance of complex eight-terminal interdigitated capacitors in a simple two terminal device.
Thanks to patented design innovations, land grid array (LGA) capacitors from AVX achieve the equivalent high-frequency performance of complex eight-terminal interdigitated capacitors (IDCs) in a simple two terminal device. Using a new fine copper termination construction process and modified internal design, LGA decoupling capacitors reduce internal inductance by 50% compared with capacitors using more traditional reverse geometry or the multiterminal IDC construction design. A two-terminal LGA capacitor using this process can achieve inductances down to 35pH.
This feature is especially important in semiconductor package-level decoupling applications where capacitors are placed on or very close to the processor die.
LGA capacitors reduce inductance by making the current loop of the mounted device as small as possible.
This is achieved by using vertical electrodes which can be terminated very close to the centre of the finished device.
Using land grid array terminations and designing the via connections underneath the device package will also reduce this current.
The pad requirements of the LGA can enable designers to place an 0204 capacitor into a similar PCB board area of a 0201 traditionally terminated MLCC, thereby significantly increasing the capacitance in the circuit.
There are four package versions in the initial product release, LG12 (0204), LG22 (0306), LG32 (0508) and LGC2 (0805).
The LC32 package offers typical inductances down to under 30pH.
At 4V, the LG12 has capacitance values up to 0.10uF, and the LG22 up to 0.47uF.
LGA capacitors come in thicknesses from 0.5 to 1.5mm
Thanks to patented design innovations, land grid array (LGA) capacitors from AVX achieve the equivalent high-frequency performance of complex eight-terminal interdigitated capacitors (IDCs) in a simple two terminal device. Using a new fine copper termination construction process and modified internal design, LGA decoupling capacitors reduce internal inductance by 50% compared with capacitors using more traditional reverse geometry or the multiterminal IDC construction design. A two-terminal LGA capacitor using this process can achieve inductances down to 35pH.
This feature is especially important in semiconductor package-level decoupling applications where capacitors are placed on or very close to the processor die.
LGA capacitors reduce inductance by making the current loop of the mounted device as small as possible.
This is achieved by using vertical electrodes which can be terminated very close to the centre of the finished device.
Using land grid array terminations and designing the via connections underneath the device package will also reduce this current.
The pad requirements of the LGA can enable designers to place an 0204 capacitor into a similar PCB board area of a 0201 traditionally terminated MLCC, thereby significantly increasing the capacitance in the circuit.
There are four package versions in the initial product release, LG12 (0204), LG22 (0306), LG32 (0508) and LGC2 (0805).
The LC32 package offers typical inductances down to under 30pH.
At 4V, the LG12 has capacitance values up to 0.10uF, and the LG22 up to 0.47uF.
LGA capacitors come in thicknesses from 0.5 to 1.5mm
# posted by Swathi @ 2:37 AM 
