FEAT: dielectric filled backdrill

src/pyedb/dotnet/database/edb_data/padstacks_data.py

@@ -1586,10 +1586,12 @@ def backdrill_parameters(self, params):
                 False,
             )
 
-    def set_back_drill_by_layer(self, drill_to_layer, diameter, offset):
+    def set_back_drill_by_layer(self, drill_to_layer, diameter, offset, from_bottom=True):
         """Method added to bring compatibility with grpc."""
-
-        self.set_backdrill_bottom(drill_depth=drill_to_layer.name, drill_diameter=diameter, offset=offset)
+        if from_bottom:
+            if not isinstance(drill_to_layer, str):
+                drill_to_layer = drill_to_layer.name
+            self.set_backdrill_bottom(drill_depth=drill_to_layer, drill_diameter=diameter, offset=offset)
 
     def set_backdrill_bottom(self, drill_depth, drill_diameter, offset=0.0):
         """Set backdrill from bottom.

src/pyedb/dotnet/database/padstack.py

@@ -26,7 +26,7 @@
 
 from collections import defaultdict
 import math
-from typing import Dict, List
+from typing import Dict, List, Optional, Union
 import warnings
 
 import numpy as np
@@ -442,6 +442,192 @@ def create_circular_padstack(
                 )
         PadStack.SetData(new_PadStackData)
 
+    def create_dielectric_filled_backdrills(
+        self,
+        layer: str,
+        diameter: Union[float, str],
+        material: str,
+        permittivity: float,
+        padstack_instances: Optional[List[EDBPadstackInstance]] = None,
+        padstack_definition: Optional[Union[str, List[str]]] = None,
+        dielectric_loss_tangent: Optional[float] = None,
+        nets: Optional[Union[str, List[str]]] = None,
+    ) -> bool:
+        r"""Create dielectric-filled back-drills for through-hole vias.
+
+        Back-drilling (a.k.a. controlled-depth drilling) is used to remove the
+        unused via stub that acts as an unterminated transmission-line segment,
+        thereby improving signal-integrity at high frequencies.  This routine
+        goes one step further: after the stub is removed the resulting cylindrical
+        cavity is **completely filled** with a user-specified dielectric.  The
+        fill material restores mechanical rigidity, prevents solder-wicking, and
+        keeps the original via’s electrical characteristics intact on the
+        remaining, still-plated, portion.
+
+        Selection criteria
+        ------------------
+        A via is processed only when **all** of the following are true:
+
+        1. It is a through-hole structure (spans at least three metal layers).
+        2. It includes the requested ``layer`` somewhere in its layer span.
+        3. It belongs to one of the supplied ``padstack_definition`` names
+           (or to *any* definition if the argument is omitted).
+        4. It is attached to one of the supplied ``nets`` (or to *any* net if
+           the argument is omitted).
+
+        Geometry that is created
+        ------------------------
+        For every qualified via the routine
+
+        * Generates a new pad-stack definition named ``<original_name>_BD``.
+          The definition is drilled from the **bottom-most signal layer** up to
+          and **including** ``layer``, uses the exact ``diameter`` supplied, and
+          is plated at 100 %.
+        * Places an additional pad-stack instance on top of the original via,
+          thereby filling the newly drilled cavity with the requested
+          ``material``.
+        * Leaves the original via untouched—only its unused stub is removed.
+
+        The back-drill is **not** subtracted from anti-pads or plane clearances;
+        the filling material is assumed to be electrically invisible at the
+        frequencies of interest.
+
+        Parameters
+        ----------
+        layer : :class:`str`
+            Signal layer name up to which the back-drill is performed (inclusive).
+            The drill always starts on the bottom-most signal layer of the stack-up.
+        diameter : :class:`float` or :class:`str`
+            Finished hole diameter for the back-drill.  A numeric value is
+            interpreted in the database length unit; a string such as
+            ``"0.3mm"`` is evaluated with units.
+        material : :class:`str`
+            Name of the dielectric material that fills the drilled cavity.  If the
+            material does not yet exist in the central material library it is
+            created on the fly.
+        permittivity : :class:`float`
+            Relative permittivity :math:`\varepsilon_{\mathrm{r}}` used when the
+            material has to be created.  Must be positive.
+        padstack_instances : :class:`list` [:class:`PadstackInstance` ], optional
+            Explicit list of via instances to process.  When provided,
+            ``padstack_definition`` and ``nets`` are ignored for filtering.
+        padstack_definition : :class:`str` or :class:`list` [:class:`str` ], optional
+            Pad-stack definition(s) to process.  If omitted, **all** through-hole
+            definitions are considered.
+        dielectric_loss_tangent : :class:`float`, optional
+            Loss tangent :math:`\tan\delta` used when the material has to be
+            created.  Defaults to ``0.0``.
+        nets : :class:`str` or :class:`list` [:class:`str` ], optional
+            Net name(s) used to filter vias.  If omitted, vias belonging to
+            **any** net are processed.
+
+        Returns
+        -------
+        :class:`bool`
+            ``True`` when at least one back-drill was successfully created.
+            ``False`` if no suitable via was found or any error occurred.
+
+        Raises
+        ------
+        ValueError
+            If ``material`` is empty or if ``permittivity`` is non-positive when a
+            new material must be created.
+
+        Notes
+        -----
+        * The routine is safe to call repeatedly: existing back-drills are **not**
+          duplicated because the ``*_BD`` definition name is deterministic.
+        * The original via keeps its pad-stack definition and net assignment; only
+          its unused stub is removed.
+        * The back-drill is **not** subtracted from anti-pads or plane clearances;
+          the filling material is assumed to be electrically invisible at the
+          frequencies of interest.
+
+        Examples
+        --------
+        Create back-drills on all vias belonging to two specific pad-stack
+        definitions and two DDR4 nets:
+
+        >>> edb.padstacks.create_dielectric_filled_backdrills(
+        ...     layer="L3",
+        ...     diameter="0.25mm",
+        ...     material="EPON_827",
+        ...     permittivity=3.8,
+        ...     dielectric_loss_tangent=0.015,
+        ...     padstack_definition=["VIA_10MIL", "VIA_16MIL"],
+        ...     nets=["DDR4_DQ0", "DDR4_DQ1"],
+        ... )
+        True
+        """
+        _padstack_instances = defaultdict(list)
+        if padstack_instances:
+            for inst in padstack_instances:
+                _padstack_instances[inst.padstack_definition].append(inst)
+        else:
+            if padstack_definition:
+                if isinstance(padstack_definition, str):
+                    padstack_definition = [padstack_definition]
+
+                padstack_definitions = [
+                    self.definitions.get(padstack_def, None) for padstack_def in padstack_definition
+                ]
+                if nets:
+                    if isinstance(nets, str):
+                        nets = [nets]
+                    for padstack_definition in padstack_definitions:
+                        _padstack_instances[padstack_definition.name] = self.get_instances(
+                            definition_name=padstack_definition.name, net_name=nets
+                        )
+                else:
+                    for padstack_definition in padstack_definitions:
+                        _padstack_instances[padstack_definition.name] = padstack_definition.instances
+            elif nets:
+                instances = self.get_instances(net_name=nets)
+                for inst in instances:
+                    padsatck_def_name = inst.padstack_definition
+                    padstack_def_layers = inst.layer_range_names
+                    if layer in padstack_def_layers and len(padstack_def_layers) >= 3:
+                        if not padsatck_def_name in _padstack_instances:
+                            _padstack_instances[padsatck_def_name] = [inst]
+                        else:
+                            _padstack_instances[padsatck_def_name].append(inst)
+                    else:
+                        self._pedb.logger.info(
+                            f"Drill layer {layer} not in padstack definition layers "
+                            f"or layer number = {len(padstack_def_layers)} "
+                            f"for padstack definition {padsatck_def_name}, skipping for backdrills"
+                        )
+        if not material:
+            raise ValueError("`material` must be specified")
+        if not material in self._pedb.materials:
+            if not dielectric_loss_tangent:
+                dielectric_loss_tangent = 0.0
+            self._pedb.materials.add_dielectric_material(
+                name=material, permittivity=permittivity, dielectric_loss_tangent=dielectric_loss_tangent
+            )
+        for def_name, instances in _padstack_instances.items():
+            padstack_def_backdrill_name = f"{def_name}_BD"
+            start_layer = list(self._pedb.stackup.signal_layers.keys())[-1]  # bottom layer
+            self.create(
+                padstackname=padstack_def_backdrill_name,
+                holediam=self._pedb.value(diameter),
+                paddiam="0.0",
+                antipaddiam="0.0",
+                start_layer=start_layer,
+                stop_layer=layer,
+            )
+            self.definitions[padstack_def_backdrill_name].material = material
+            self.definitions[padstack_def_backdrill_name].hole_plating_ratio = 100.0
+            for inst in instances:
+                inst.set_back_drill_by_layer(drill_to_layer=layer, offset=0.0, diameter=self._pedb.value(diameter))
+                self.place(
+                    position=inst.position,
+                    definition_name=padstack_def_backdrill_name,
+                    fromlayer=start_layer,
+                    tolayer=layer,
+                )
+        return True
+
     def delete_padstack_instances(self, net_names):  # pragma: no cover
         """Delete padstack instances by net names.
 

src/pyedb/grpc/database/definition/materials.py

@@ -722,7 +722,7 @@ def add_dielectric_material(self, name, permittivity, dielectric_loss_tangent, *
         :class:`Material <pyedb.grpc.database.definition.materials.Material>`
             Material object.
         """
-        extended_kwargs = {key: value for (key, value) in kwargs.items()}
+        extended_kwargs = {key: value for (key, value) in kwargs.items() if not key == "name"}
         extended_kwargs["permittivity"] = permittivity
         extended_kwargs["dielectric_loss_tangent"] = dielectric_loss_tangent
         material = self.add_material(name, **extended_kwargs)

src/pyedb/grpc/database/definition/padstack_def.py

@@ -366,6 +366,22 @@ def via_stop_layer(self):
         warnings.warn("via_stop_layer is deprecated. Use stop_layer instead.", DeprecationWarning)
         return self.stop_layer
 
+    @property
+    def material(self):
+        """Return hole material name.
+
+        Returns
+        -------
+        str
+            Hole material name.
+        """
+        return self.data.material.value
+
+    @material.setter
+    def material(self, value):
+        if isinstance(value, str):
+            self.data.material = value
+
     @property
     def hole_diameter(self) -> float:
         """Hole diameter.
@@ -647,15 +663,6 @@ def hole_range(self, value):
             else:  # pragma no cover
                 self.data.hole_range = GrpcPadstackHoleRange.UNKNOWN_RANGE
 
-    @property
-    def material(self) -> str:
-        """Return hole material name."""
-        return self.data.material.value
-
-    @material.setter
-    def material(self, value):
-        self.data.material.value = value
-
     def convert_to_3d_microvias(
         self, convert_only_signal_vias=True, hole_wall_angle=15, delete_padstack_def=True
     ) -> bool: