Design methodology
Insight SiP’s methodology is based on a user
extendable library of physical objects for which the
electrical models are created automatically for a given
stack-up and/or technology. Thus any design that is
initially made for a particular supplier can easily be
re-tuned for an alternative source.
The method uses a combination of circuit and EM simulations
to create a design progressively from basic schematic
representation to a complete layout.
2.5D or 3D EM simulations are used for the passive
integrated functions (laminate, IPD, LTCC, PCB) and
harmonic balance or device modeling for the active
circuits. The functionality that is contained within buried
functions inside the substrate is created using an
iterative process.
- First step:
It is to create for a given technology a range of
parameterized mechanical objects.
These objects allow simple RF functions, such as
capacitors, inductors and resonators, to be created.
- Second step:
It is to couple the technology file for the target process
to the mechanical objects.
A series of batch based electromagnetic simulations of the
mechanical objects within the desired technology file
framework creates data for a look-up table based model for
each component (L, C or more complex resonator
element).
It allows for the creation of a set of project and
technology related schematic objects that can be optimized
to produce the required RF functionality.
Simulations using these models can be carried out in both
the frequency domain and the time domain.
At this level of the design, circuit optimization is
carried out to determine the parameters of the
schematic/mechanical object. This process is quite similar
to that carried out in semiconductor design using library
based objects that have electrical performance and create
layout.
- Third step:
The third step of the process is to create complete
sections of physical layout with the mechanical objects
using the circuit optimization parameters.
A closed loop iterative process is used to obtain final
layout that has the same electrical performance as the sum
of the modelled portions.
At this stage coupling effects between blocks are
compensated for. This has the advantage of allowing the
mechanical objects to be placed close together without any
risk of causing unseen effects. This makes the designs
created by this method more compact than those using a
“P Cell” approach with large keep-out zones to
avoid coupling.
Example - Design methodology applied to a GSM Low Pass Filter
- Build a parameterized component library (cf. 1st
step)
- Simulate the inductor and capacitor components using
Momentum 2.5D simulator for various geometrical parameters
(Width, Diameter, ...)
- Optional: Extract equivalent model parameters for each
geometry
- Build a parameterized simulation model based on
individual geometries
- Choose a filter topology (Chebychev for ex.) with
ideal lumped components
- Optimize L, C component values to match
specifications
- Generate the target schematic for the filter (cf.
2nd step)
- with the parameterized library component
- Tune/optimize the object dimensions to match ideal
s-parameter response
- Preliminary layout/ Fast iterative process/
Final layout (cf. 3rd step)
- Generate a preliminary layout and simulate
- Optimize the component dimensions in order to match
the target response
- Final momentum simulations
- Gerber file generations
