CUSHIONING SHEET FOR DRILLING AND DRILLING METHOD Russian patent published in 2016 - IPC B26F1/16 

FIELD: materials.

SUBSTANCE: inventions relate to drilling materials using a cushioning sheet and can be used for drilling holes in laminated or multilayer printed circuit boards. Cushioning sheet contains a metal bearing foil and a layer of a polymer composition located onto at least one surface of the metal carrier foil. Polymer composition contains a cellulose derivative and a water-soluble polymer. Cellulose derivative is hydroxyalkyl cellulose and/or carboxyalkyl cellulose, which weight-average molecular weight is from 20,000 to 350,000, the cellulose derivative content ranges from 5 to 40 wt%. Content of the water-soluble polymer is from 60 to 95 wt%. in relation to 100 weight parts of the polymer composition.

EFFECT: provided are higher accuracy of the hole position, prevented breakage of the drill, reduced quantity of chips from drilling.

19 cl, 9 tbl, 1 dwg