EMBEDDED PASSIVE DEVICE INTO PLATED THROUGH HOLES OF PRINTED CIRCUIT BOARD
Original Publication Date: 2003-Nov-20
Included in the Prior Art Database: 2003-Nov-20
Disclosed is a method on forming discrete devices (resistors, capacitors, inductors) in plated-thru holes so that they are placed optimally in a performance point of view on a PCB (printed circuit board). The invention consists in filling the plated thru-holes with a material having appropriate properties in order to create different value of reference (Ohm, Farad, Henry).
EMBEDDED PASSIVE DEVICE INTO PLATED THROUGH HOLES OF PRINTED
For high speed interconnect circuits the location of discrete and passive components like resistors, capacitors and/or inductors is dramatically important for the performance of the circuit (i.e. Serial resistor as close as possible to the driver, termination bridge as close as possible to the receiver, decoupling capacitor as close as possible to power pins of the module). With the high density/pincount of today's IC packages, those components have to be placed in the boundary of the IC packages which will have the effect that they are not sufficiently efficient or depending on rise times, stubs created by this placement could affect the performance of the circuit. Embedded passive devices in Printed Circuit Boards are existing solutions. However their location even embedded in the PCB is neither optimum and the subject of this invention is to find out a more relevant location as close as possible to the I/O pad of the IC module. In Figure 1 is shown a classical plated-thru hole via which makes the interconnection from the external pad of the IC package to one internal layer .
The invention consists to fill this plated-thru hole or any plated hole or via or microvia making an interconnection between any plane with a equivalent resistive, capacitive or inductive material to create the desired value and so that t...