Outline
This procedure covers the use of an eyelet for the repair of a damaged land on a plated hole that has an inner layer connection.Caution: This method is used to restore the integrity of a through connection on a multilayer circuit board, having an inner layer connect, but ONLY if the full barrel of the plated through hole remains intact. If there is barrel damage, see the appropriate procedure. Caution: This method will reduce the inside diameter of the hole. The minimum hole size requirement must be checked for acceptance.
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Images and Figures![]()
Damaged Plated Hole with Inner Layer Connection.
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Figure 1: Insert the eyelet into the hole.
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Figure 2: Set the eyelet using an Eyelet Press or using a Tool Grip and Setting Tools.
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Figure 3: The small cone tip end of the lower Setting Tool faces up. The large cone end of the upper setting tool faces down.
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Figure 4: Flare the eyelet barrel using the flared end of the setting tool.
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Figure 5: Flatten the eyelet barrel using the flat end of the setting tool.
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Figure 6: Completed repair.
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Figure 7: Flat flange eyelet.
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Figure 8: Funnel flange eyelet.
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Procedure
Eyelet Selection Criteria
ID - Inside Diameter The eyelet inside diameter should be .075 - .500 mm (.003"-.020") greater than the component lead diameter. OD - Outside Diameter The clearance hole drilled through the circuit board should allow the eyelet to be inserted without force but should not exceed .125 mm (.005") greater than the eyelet's outside diameter. LUF - Length Under Flange The length of the eyelet barrel under the flange should be .630 - .890 mm (.025" - 035"), greater than the thickness of the circuit board. This added length allows for proper protrusion when setting the eyelet. FD - Flange Diameter The eyelet flange diameter should be small enough to prevent interference with adjacent lands or circuits. Note: Be sure to select an eyelet meeting the proper criteria. An eyelet with an oversize flange may interfere with adjacent circuits. An eyelet that is too short will not protrude through the circuit board for proper setting. Procedure
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