Unbelievable things you never knew about PCB Hole Wall Rough

2018-11-26 11:22Writer: qyadminReading:

  Hole Wall Roughness Testing Method

The irregularities generated on the hole wall by the drilling process are called "hole wall roughness".Hole wall roughness is measured after the plating.The hole wall is inspected after cross section and the depth of the concave portion is measured from the base line as shown in the figure below.When stack drilling has been used, all the PWB panels are measured.The maximum roughness points are measured around final hit hit counts.

Hole Wall Roughness Testing Method

 

  Cross-section

The hole wall roughness values are higher in the 45 deg. plane against the glass fiber. (A 90 deg. cross-section is gives smaller values)Hole wall roughness is measured on the full diameter point. (50% of the hole is ground back) It should be noted that the roughness varies according to the cross-sectioned point.

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