Checking Finished PCB Holes for Press-Fit Connectors

A press-fit connector depends on a controlled interaction between its contact and the finished plated hole. Selecting a drill tool from the contact’s nominal width is not a sufficient design method. Start with the connector manufacturer’s application specification and keep the hole requirements connected to the exact contact family and board construction.

Use the complete component documentation

TE describes press-fit connections as solderless electrical and mechanical connections to a PCB. Its product pages provide application specifications alongside drawings, illustrating why a catalog dimension alone is not the complete installation requirement. Check the current documents for the selected part number and revision. TE: press-fit connection introduction; TE: example press-fit terminal documentation.

Extract the required finished-hole diameter and tolerance, applicable board thickness, hole plating and finish requirements, and any specified land geometry. Confirm whether the manufacturer’s dimensions refer to the finished plated hole or a fabrication-stage feature. Put the required finished condition on the drawing and let the fabricator propose its process to achieve it.

Review the array as well as the individual hole

• Check hole position and pattern tolerances against the connector drawing.
• Review board flatness and local mechanical support during insertion.
• Keep components and copper clear of required tooling contact areas.
• Confirm connector seating references and orientation.
• Identify any restrictions on removal, reinsertion, or repair.

For example, every hole in an array may meet its diameter requirement while the accumulated positional error makes the connector difficult to seat. The correct investigation includes the hole pattern, connector condition, tooling alignment, and board support. Enlarging all holes without consulting the application specification could compromise the intended contact interface.

Define evidence for the first build

Ask the fabrication supplier how finished holes will be measured and how the records will be tied to the lot. Coordinate this with the assembler’s insertion setup. Where the connector documentation requires a particular force, seating, or inspection method, include it in the process plan. Keep records of representative insertion behavior and inspect for damage using the agreed methods.

Control changes that affect the interface

A different board finish, plating process, contact suffix, or tooling arrangement can change the conditions qualified on the first build. Route those changes through an engineering review rather than treating them as unrelated purchasing details. Do not use a generic “standard hole tolerance” note when the connector requires something more specific. The release should make the required final interface clear while leaving the fabricator and assembler responsible for demonstrating that their processes can produce and install it consistently.