Laminate for use in manufacturing of ink jet printheads

PCT No. PCT/GB91/02093 Sec. 371 Date May 27, 1993 Sec. 102(e) Date May 27, 1993 PCT Filed Nov. 27, 1991 PCT Pub. No. WO92/09436 PCT Pub. Date Jun. 11, 1992.A co-fired laminate (10) for use in printheads for drop-on-demand ink jet printers has two inner layers (12, 14) of piezoelectric material which are thickness poled in opposite senses, two outer layers (11, 15) of inactive material and a fifth layer (13) disposed between the inner layers which is electrically insulating under the printhead operating conditions and conductive under the poling conditions of the inner layers. The fifth layer preferably is an N.T.C. material with its critical temperature between the operating and poling temperatures. After poling of the inner layers further manufacture of the printhead from one side thereof can be effected as described.