Same explanation goes for T-bend and impact resistance which shows the same trend as scratch hardness test
. The tensile strength of the film increases considerably and elongation at break obviously decreases with increasing crosslinking.
IPC-4781, Table 3-1, Requirements of Qualification Requirement for Marking Type Requirement Type 1 Permanent No Type 3 Semi- Type 4 Permanent Electrical Permanent Temporary Direct Metal Metal Contact Contact Physical Hardness Yes Yes Yes No Adhesion to Yes Yes Yes AABUS * Solder Mask Materials Conformal AABUS AABUS AABUS No Coating Adhesion Flammability Yes Yes Yes No FTIR Yes Yes Yes Yes Environmental AABUS AABUS AABUS AABUS Compliance Testing and Inspection Requirement Paragraph IPC-TM-650 Other Test Methods Method Hardness 3.5.1 None ASTM D3363, Scratch Hardness Test
Adhesion to Solder 220.127.116.11 18.104.22.168 - Mask Materials Conformal Coating None AABUS Adhesion Flammability 3.6.3 None UL94 FTIR 22.214.171.124 None - Environmental 3.12 None - Compliance * AABUS: As agreed between user Table 2.
However, a tangential force is applied in the presence of a normal load for scratch hardness test
. In this paper, both indentation and scratch hardness tests
were evaluated; they are: Rockwell hardness, Durometer hardness, microhardness, and scratch hardness.