Layer Attributes in the Job Matrix

In the Job Matrix, the layer attribute columns represent layer properties that add intelligence to the step data.

Backdrill not Penetrate Layer Name

Name of the layer not to be penetrated by the backdrill.

Values

<Free text> (0 - 64 characters)

Bulk Resistivity

The ohmic resistance of the semiconductor material.

Values

0.0 - 10000 nano_ohm

Characteristic Impedance

The typical characteristic impedance (in ohms) required for a layer.

Values

0.0 - 10000.0 ohm

Default Value

0 ohm

Comment

Use for general textual comments.

Values

<Free text> (0 - 500 characters)

Copper Thickness

The weight of copper according to its units of measure.

This layer attribute reflects the density of the copper used. Copper Weight is measured in ounces per square feet.

Calculation

Copper Weight is calculated as <layer_thickness> / <copper_weight>.

layer_thickness

The value defined in EDA data for each layer. Each format may define this value using a proprietary keyword or field.

copper_weight

The layer thickness value divided by the value of the configuration parameter copper_weight (default value = 1.35). This value reflects the density of the copper used.

Display in the Job Matrix

Depending on the measurement units to which the display is set, the value of the layer attribute Copper Weight stored in the ODB++ product model may differ from the value displayed in the Job Matrix window.

Measurement Units

Display Formula

Imperial

The value is rounded to the nearest 0.5 oz/ft^2.

  • If the difference between the rounded value and the actual value is less than 0.2, the rounded value is displayed as is.

  • If the difference between the rounded value and the actual value is greater than 0.2, then it is rounded to the nearest two decimal places.

Metric

The value is displayed as is.

Examples

These examples use Cadence Allegro data with display in imperial units:

  • S!001!TOP!POSITIVE!!YES!1!341000.000000 mho/cm!1/1OZ_PLTD_CU_FOIL!NO!0.0921 w/cm-degC!1.600000 mil!CONDUCTOR!0!

    In the layer TOP, LAYER_THICKNESS = 1.6mil.

    This is divided by 1.35 to obtain a Copper Weight of 1.18519 oz/ft^2. This is the value stored in ODB++.

    For display, this is rounded to the nearest 0.5 oz, giving a value of 1.0 oz/ft^2. Since the difference between 1.18 and 1.0 is <0.2, the copper weight value displayed is 1.

  • S!011!BOTTOM!POSITIVE!!YES!1!580000.000000 mho/cm!2OZ_COPPER!NO!0.0911 w/cm-degC!2.400000 mil!CONDUCTOR!0!

    In the layer BOTTOM, LAYER_THICKNESS = 2.4mil.

    This is divided by 1.35 to obtain a Copper Weight of 1.7777 oz/ft^2. This is the value stored in ODB++.

    For display, this is rounded to the nearest 0.5, giving a value of 2.0 oz/ft^2. Since the difference between 1.77778 and 2 is >0.2, the copper weight value is rounded for display to two decimal points = 1.78.

Dielectric Constant (ER)

The ratio of the field without dielectric (Eo) to the net field (E) with dielectric. It is unitless and has a range value of 1 for metals. Typical values are 4 and 5.

Values

0.0 - 1000.0

Default Value

0

Dielectric Thickness

Applies to layers of type DIELECTRIC or SOLDERMASK in the layer matrix that contains the thickness of material according to its specified units of measure.

Values

0.0 - 0.5

Default Value

0

Drill vias filled

Indicates whether the via holes created by a drill layer are filled (rather than plated). This attribute is only suitable for drill layers.

Values

yes | no

Default Value

no

Embedded Passive Technology

Assigns a technology type attribute to an embedded components layer.

Values

none | additive | subtractive

Default Value

none

HDI Assembly Technology

Type of HDI assembly technology identified in the product model. If None, the special layer is not created.

Values

none | wirebond | flipchip | hybrid

Default Value

none

HDI Layer Type

An attribute added to a copper layer—not a dielectric layer—to distinguish buildup layers from core layers in HDI product models.

Values

buildup | core

Default Value

buildup

Impedance test width

Test width of routes used for the provided impedance result.

Values

-2147483648.0 - 2147483648.0 ml

Default Value

0 ml

Loss Tangent

The parameter of a dielectric material that quantifies its inherent dissipation of electromagnetic energy.

Values

0 - 100

Default Value

0