Method of producing a screen printable photocurable solder resist

Claim 2

A PROCESS FOR PREPARING A SCREENABLE LIQUID PHOTOCURABLE SOLDER RESIST INK FROM A LOW MOLECULAR WEIGHT PHOTOCURABLE COMPOSITION WHICH COMPRISES ADMIXING

Claim 3

A POLYENE SELECTED FROM THE GROUP CONSISTING OF

Claim 4

A POLYENE SELECTED FROM THE GROUP CONSISTING OF

Claim 5

UP TO 20 PERCENT OF A POLYTHIOL SUFFICIENT TO REACT STOICHIOMETRICALLY WITH SAID POLYENE 3. 3 TO 20 PARTS BY WEIGHT BASED ON THE WEIGHT OF (1) AND (2) OF SILICONE OIL AND 4. 0.05 TO 10 PARTS BY WEIGHT BASED ON THE WEIGHT OF (1) AND (2) OF A PHOTOCURING RATE ACCELERATOR, SUBJECTING SAID ADMIXTURE TO ACTINIC RADIATION AT A DOSE OF 0.0004 TO 6.0 WATTS/CM.2 FOR A PERIOD SUFFICIENT TO REACT SUBSTANTIALLY ALL OF THE POLYTHIOL PRESENT WITH A PORTION OF THE POLYENE WHEREBY THE VISCOSITY OF THE IRRADIATED ADMIXTURE IS INCREASED AND THEREAFTER IN THE ABSENCE OF ACTINIC RADIATION ADDING ADDITIONAL POLYTHIOL TO THE IRRADIATED ADMIXTURE IN AN AMOUNT SUFFICIENT TO CAUSE AT LEAST 50 PERCENT OF THE POLYENE BASED ON THE TOTAL INITIAL UNREACTED CONTENT TO REACT WITH SAID ADDED POLYTHIOL THEREBY FORMING A SCREENABLE PHOTOCURABLE SOLDER RESIST TANK INK HAVING A VISCOSITY IN THE RANGE OF 5,000-200,000 CENTIPOISES.

Claim 6

UP TO 20 PERCENT OF A POLYTHIOL SUFFICIENT TO REACT STOICHIOMETRICALLY WITH SAID POLYENE 3. 3 TO 20 PARTS BY WEIGHT BASED ON THE WEIGHT OF (1) AND (2) OF SILICONE OIL AND 4. 0.05 TO 10 PARTS BY WEIGHT BASED ON THE WEIGHT OF (1) AND (2) OF A PHOTOCURING RATE ACCELERATOR, SUBJECTING SAID ADMIXTURE TO ACTINIC RADIATION AT A DOSE OF 0.0004 TO 6.0 WATTS/CM.2 FOR A PERIOD SUFFICIENT TO REACT SUBSTANTIALLY ALL OF THE POLYTHIOL PRESENT WITH A PORTION OF THE POLYENE WHEREBY THE VISCOSITY OF THE IRRADIATED ADMIXTURE IS INCREASED AND THEREAFTER IN THE ABSENCE OF ACTINIC RADIATION ADDING ADDITIONAL POLYTHIOL TO THE IRRADIATED ADMIXTURE IN AN AMOUNT SUFFICIENT TO CAUSE AT LEAST 50 PERCENT OF THE POLYENE BASED ON THE TOTAL INITIAL UNREACTED CONTENT TO REACT WITH SAID ADDED POLYTHIOL THEREBY FORMING A SCREENABLE PHOTOCURABLE SOLDER RESIST TANK INK HAVING A VISCOSITY IN THE RANGE OF 5,000-200,000 CENTIPOISES.

Claim 7

Up to 20 percent of a polythiol sufficient to react stoichiometrically with said polyene

Claim 8

Up to 20 percent of a polythiol sufficient to react stoichiometrically with said polyene

Claim 9

3 to 20 parts by weight based on the weight of (1) and (2) of silicone oil and

Claim 10

3 to 20 parts by weight based on the weight of (1) and (2) of silicone oil and

Claim 11

0.05 to 10 parts by weight based on the weight of (1) and (2) of a photocuring rate accelerator, subjecting said admixture to actinic radiation at a dose of 0.0004 to 6.0 watts/cm.2 for a period sufficient to react substantially all of the polythiol present with a portion of the polyene whereby the viscosity of the irradiated admixture is increased and thereafter in the absence of actinic radiation adding additional polythiol to the irradiated admixture in an amount sufficient to cause at least 50 percent of the polyene based on the total initial unreacted content to react with said added polythiol thereby forming a screenable photocurable solder resist ink having a viscosity in the range of 5,000-200,000 centipoises.

Claim 12

0.05 to 10 parts by weight based on the weight of (1) and (2) of a photocuring rate accelerator, subjecting said admixture to actinic radiation at a dose of 0.0004 to 6.0 watts/cm.2 for a period sufficient to react substantially all of the polythiol present with a portion of the polyene whereby the viscosity of the irradiated admixture is increased and thereafter in the absence of actinic radiation adding additional polythiol to the irradiated admixture in an amount sufficient to cause at least 50 percent of the polyene based on the total initial unreacted content to react with said added polythiol thereby forming a screenable photocurable solder resist ink having a viscosity in the range of 5,000-200,000 centipoises.