8 Libraries

8 Libraries

8.1 Materials Library

8.1.1 Purpose of the Materials Library

The Materials Library contains information about materials used for microelectronic packages and the materials' properties. It can be used to select appropriate materials for package design. You cannot edit the data for materials already resident in the library which are color coded black. The user can however add additional materials to the database which will be color coded gray. While you can edit any of the added materials' property fields, you cannot delete or add material property categories. The stress/strain properties are over a range of input. The range can be viewed with the Edit command in the Material option.

Warning: Whenever you begin work on a design, whether it is new or an earlier one, CADMP will use the most recently input material properties. This will affect the reliability assessment of previous designs if the material properties values are different from the ones used previously. You should make sure the material properties used in a design are accurate before performing reliability assessments.

8.1.2 The Materials Library Menu

In the CADMP Manager, select the Materials option under the Libraries header (see Figure 1).
The Materials Library screen appears. The screen contains six options:

Figure 1. The Materials Library option

Library enables you to load files and save altered files.
Material enables you to edit material properties and modify dependent parameter ranges.
Query enables you to search the Library for materials by name or ranges of material property values. Sort enables you to specify which material property will be the basis for ranking materials.
Fields enables you to choose the active fields for each material file

Report enables you to generate reports based on information in the materials database. Xit allows you to leave the Materials Library.

Some of the materials in the Materials Library lack some of the properties necessary for analysis. This is because many material electronic properties are either unknown or poorly documented and may not be used to optimize design or predict reliability. The distribution of material property data is key to reliable electronic component design and accurate reliability modeling. Variability data is lacking for most component and sub-assembly properties. In addition, test methods are not standardized, resulting in poorly documented physical property values. CALCE EPRC has written several proposals to address this problem and is in the process of establishing a national resource center for material characterization and a comprehensive database.

8.1.2.1 The Library Option

The Library option menu contains five commands:

Load activates files of classes of materials.
Save saves all changes made to a file.
Copy copies a file to another file
New enables you to create a new file
Delete deletes a file

8.1.2.1.1 The Load Command

Select the Load command from the File option menu. The window in Figure 2 appears.

Figure 2. The Load material categories list

Select the material category you want to use. The previously grayed out menu choices in Figure 2 now become viable choices as in Figure 3.

Figure 3. The Material Option

You can alter the temperature for which material properties are displayed if you wish by typing a new temperature value. Select the Update or Close hot keys to confirm the new value. The material category name appears on the menu bar If you don't want to alter the temperature dependency, press Esc. Either choice returns you to the Materials Library screen. When you have finished modifying a file, press Esc to leave the screen. A message will prompt you with the filename and remind you that it has not been saved. You will be asked at this time if you wish to save your changes. Press yes to save the changes and no to save the unmodified version of the file.

8.1.2.1.2 The Save Command

Use the Save command to save changes you may make to a file.

Select the Save command from the File option menu.
No prompt will appear. A message, "Current file being saved," appears in the help message bar.
You will be returned to the Materials Library screen.

8.1.2.2 The Material Option

Use the Material option to edit material files after using the Load command in the File option to activate the file you want to edit. The Material option contains two commands (see Figure 3):

Edit/display attributes enables you to change material properties.
Select attributes enables you to determine which material properties will be displayed on the screen.

8.1.2.2.1 The Edit/display attributes Command

Select the Edit/display attributes command from the Material option menu. A spreadsheet appears (see Figure 4). Any numbers colored red have been assigned a dependency. See the next page for an explanation of dependencies. Those columns that are green are not pertinent to the chosen failure mechanisms.

Figure 4. The Edit/display attributes Command

Select the material property you wish to change. You cannot edit properties of materials which are color coded gray. The range of allowed values for the selected material property is shown at the bottom of the screen. Type the new value.

Tab

Shift-Tab

You can also use five hot keys at the top of the spreadsheet to further edit the database. The Note hot key enables you to access or write brief notes about the material properties, such as how they were calculated or obtained. To use the Note hot key:

Click on the Note hot key or press Alt-N. The text window in Figure 5 appears.
You can read the note or edit the note about the item in the field. Select Close to save the note, Esc to cancel. Either action returns you to the spreadsheet.

Figure 5. The Note hot key text window

The Dependencies key enables you to modify material property temperature, frequency, moisture, and strain-rate dependencies. Because the Dependencies hot key controls several options, it is discussed in the next section.
The Add hot key enables you to add materials to the database.
The Remove hot key enables you to remove materials from the database.

The Copy hot key enables you to copy materials in the database.

Close to save your changes. Press Esc to cancel.