Saturday, July 5, 2014

How to use Mentor LP Wizard

Mentor Graphics LP Wizard is a great PCB design tool that saves time and effort in the PCB design work. Many times you need to know the footprint pad size or land pattern for your components but often this information is just not available. Now you may become confused what to do. One thing you know is that the pad size should adhere to some standard, and that standard is the IPC standard.

What LP Wizard program does is it automatically calculates the IPC standard footprint size according to the component dimension and pin information that you input to the program.

This blog post illustrates an example on how to use the IPC Wizard for creating footprint or land pattern for a header connector.

Suppose we require and want to calculate the footprint required for JST's 2 pin connection header which is a SMD type because maybe you require it in your PCB design. To do this we can use the header footprint calculator available in LP Wizard.

Before we start how to use the calculator, we need to know the dimension and pin information for the component. For this you should download the datasheet. Here are some screenshot of this header that shows dimension and pin information-

JST's 2 pin connection header

JST's 2 pin connection header
JST's 2 pin connection header

Now once you have the datasheet in your hand start the LP Wizard. The calculators are available under calculate in the toolbar of the LP Wizard software.

Mentor LP Wizard tutorial

Choose the appropriate calculator, here the Connector Calculator. Then next the LP Wizard as for what kind of connector. Here choose Shrouded Header since we want the pad dimension for the JST 2-PIN 2mm Connector.

Mentor LP Wizard tutorial

Once you select this option it displays the following,

Mentor LP Wizard tutorial

The above picture shows a picture of  the initial Shrouded Header which now has to be changed. There are two parts we have to fill in, the pin related information and the body related information.

In the Pin tab you can see the pin pattern configuration, mount style, pin numbering, hole size and height. These information are all provided in the datasheet.

In the mount style select right angle because the pin is a right angled. There is only one row so enter 1 in the row section and since there are 2 pins specify 2 in the position field. And put 2mm in the position second field for the pitch of 2mm. Pin count is 2, hole size is 0.7mm and height is 8mm.

See these data entered in the picture.

Mentor LP Wizard tutorial

After entering the data click OK.

Mentor LP Wizard tutorial

As you can see the number of pins has changed.

Now we have to change the dimension of the body. These dimension can be again obtained from the datasheet and the values are shown in the figure below,

Mentor LP Wizard tutorial

Once the Pin and body dimension are entered, LP Wizard automatically calculates the footprint. Press the Land Pattern Tab for this-

Mentor LP Wizard tutorial

The footprint size shows the silkscreen and the courtyard dimension as per the IPC standard.

Now pressing on the View Pin and Padstack Data provides information about the Pins and Padstacks.

With few simple steps a complete footprint for the component was generated that is IPC complaint. The next step is to save the footprint and then import the footprint into the PCB software you are using such as Altium Designer, Orcad, PADS etc.

The next tutorial on how to use Mentor Graphics LP Wizard will show how to import the footprint into other PCB design software.

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