IPC9850_Surface Mount Equipment Characterization.pdf - 第32页

IPC-9850 Official Proposal May 2001 32 6.4 Sticky Media Application To maintain the components in location on the glass panel, a double-sided sticky media adhesive is applied to the glass verification panel area between …

IPC-9850

Official Proposal

May 2001

Figure 6-7 BGA228 Slug for Chrome Leads With No Background

IPC-9850

Official Proposal

May 2001

6.4 Sticky Media Application

To maintain the components in location on the glass panel, a double-sided sticky media adhesive is applied to the

glass verification panel area between the fiducial markings. There are two important requirements for the sticky

media. The first is the consistency by which the sticky material is applied to the glass verification panel surface. It is

important that the adhesive be applied evenly across the entire surface of the glass while providing sufficient clarity

for the CMM back light. The second requirement is the stability of the sticky material once it is applied to the glass

media. The adhesive must maintain the components in position during the placement cycle, where the glass

verification panel may be exposed to rapid accelerations. It must also keep the components in position throughout

the evaluation procedure as time and environmental conditions change from the placement machine location to the

CMM location.

The application of the sticky media to the glass verification panel requires significant care and experience. The

application procedure of the sticky media is not specified (it is not possible to improve test results by improper

application--only worse results). It is left up to the user to determine the proper application of the adhesive.

Details and suggestions are provided in Appendix C.

6.5 Placement Program

6.5.1 1608C Component

The placement layout for 1608C components was designed to exercise the placement machine's capability at placing

components at various distances from each other, so all machine axis are exercised, see Figure 6-8. The components

are placed at the four most common placement angles -- 0, 90, 180 270 degrees -- and the placement order and the

number of supporting feeders is to be determined by each individual machine vendor with the goal of optimizing

placement rate and accuracy for a specific machine type. Appendix E presents the positions of the components with

respect of the fiducials in numeric format.

IPC-9850

Official Proposal

May 2001

Figure 6-8 Component Location Layout for 1608C Components