IPC 7711A.pdf - 第301页
EVALUATION 1. Visual examination, dimensional requirement of pad diameter and inside diam- eter. 2. Electrical continuity measurement. IPC-7721A Number: 5.1 Revision: Date: 2/98 Subject: Plated Hole Repair , No Inner Lay…
FD Flange Diameter
The eyelet flange diameter should be small enough to prevent interference with adja-
cent pads or conductors.
OD Outside Diameter
The clearance hole should allow the eyelet to be inserted without force but should
not exceed 0.125 mm greater than the eyelet outside diameter.
NOTE
Be sure to select an eyelet meeting the proper criteria. An eyelet with an oversize
flange may interfere with adjacent conductors. An eyelet that is too short will not
protrude through the printed wiring board for proper setting.
PROCEDURE
1. Clean the area.
2. Select an eyelet using the Eyelet Selection Criteria. Use a pin gauge and caliper
to measure the existing plated hole dimensions.
3. Insert the appropriate ball mill into the hand held drill. Drill out the hole remov-
ing all the plating. The drilled hole should be 0.025 - 0.125 mm larger than the
eyelet O.D. (See Figure 1.)
CAUTION
This procedure may isolate internal connections on multilayer printed wiring
boards.
4. Clean the area.
5. Apply a small amount of liquid flux to the pad or conductor on the printed wir-
ing board surface, if any, and tin with solder using a soldering iron and solder.
Clean the area.
6. Insert the eyelet into the hole. If a new conductor is required, the new conduc-
tor may extend into the drilled hole and the flange of the eyelet will secure the
new conductor in place. (See Figure 2.) The eyelet may be inserted from either
side.
7. Select the proper setting tools and insert them into an eyelet press system. (See
Figure 3.)
8. Turn the printed wiring board over and rest the eyelet flange on the lower set-
ting tool.
9. Apply firm even pressure to form the eyelet barrel.
NOTE
Inspect the eyelet flange for evidence of damage. Refer to IPC-A-610 Accept-
ability of Electronic Assemblies.
10. Apply a small amount of liquid flux and solder the eyelet flanges to the pads on
the printed wiring board surface if necessary. Clean the area. Inspect for good
solder flow and wetting around the eyelet flanges and lands.
IPC-7721A
Number: 5.1
Revision:
Date: 2/98
Subject: Plated Hole Repair, No Inner Layer Connection
Page2of4
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---
EVALUATION
1. Visual examination, dimensional requirement of pad diameter and inside diam-
eter.
2. Electrical continuity measurement.
IPC-7721A
Number: 5.1
Revision:
Date: 2/98
Subject: Plated Hole Repair, No Inner Layer Connection
Page3of4
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---
NOTES
IPC-7721A
Number: 5.1
Revision:
Date: 2/98
Subject: Plated Hole Repair, No Inner Layer Connection
Page4of4
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---