The Lead Design button in Package displays a 3-D graphical representation of the lead type which you can use to edit the lead dimension and view lead and solder material properties (see Figure 44). This screen explains the graphical representation that appears when you select the Package Lead Design button.

• Select the Lead option from the CADMP Manager Design option header menu. A 3-D graphical representation of the assigned lead type appears. A window displays the lead and solder materials and the critical lead dimensions (see Figure 44). Values appearing in black can be edited, but not values appearing in gray. For BGA’s only two attributes are displayed, ball material and ball diameter.
Figure 44. A lead graphical representation  
• Select the Lead and Solder Material fields to display lists of materials (see Figure 45). To assign new materials, select the material and then select the OK button. To view material properties, select the Property button. A view-only window appears (see Figure 46). Selecting Notes in this window provides the user with guidelines for the use of this material.
Figure 45. The Lead Material field picklist Figure 46. The Lead Material Data window

 

• Edit the numerical values in the dimension fields, if you wish. Acceptable ranges appear at the bottom of the window. CADMP-II calculates the new effective area value.

Selecting Rotate allows you to move the lead in three dimensions in order to view it from many angles. Motion is accomplished by moving the mouse. Use the right mouse button or Esc to exit this option.
 

• Select the OK button to accept your changes, Cancel to cancel. You return to CADMP-II Manager.

Select the Lead Seal command from the upper right quadrant to edit lead seal information. The lower right quadrant window will be activated (see Figure 47). You can now vary the thickness of the lead seal using the techniques you learned in Section 6.3.4.5.

The contact area and angle of contact are not shown on the software.

Editing the Lead Seal parameters

• Select the Parameters button to the right of the Lead Seal command in the upper right quadrant. An editing Lead Seal window appears (see Figure 48). Its fields are defined below.
• Edit the fields if you wish. Select the Accept button to accept the new data, Cancel to cancel. You return to the Package screen.

Definitions for Lead Seal Window

Lead seal material: The material used for the lead seal. This is a picklist field. You can view the material properties of the lead seal material by selecting the Property button, calling a Material Property window. The fields in the window are defined in the Glossary.

Lead seal diameter: The diameter, in mils, of the lead seal. This is an entry field. The range for this field is 1 to 100 mils.

Area: The mating surface area between lead-glass meniscus in the lead seal. Determined by the formula S = 2p (r)h.

Angle of Contact: The angle between the glass meniscus and the lead at the glass-lead interface.