Challenger 300
Flight Crew Air Transport Pilot (ATP)
Confusion; Communication Breakdown; Fatigue; Situational Awareness
Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Airport; Human Factors
We were cleared to taxi to Runway 30L at SJC.  After arrival at the hold short line Tower cleared us to cross 30L.  He said; 'cleared to cross 30L and sort of angle to the right across to hold short of Runway 30R at taxiway Alpha.'  I taxied across and turned 45 degrees right; and  looked for the 'A' sign.  I only saw one taxiway Alpha sign; straight ahead; and briefly continued towards it.  I then realized that the sign I was looking at was on the far side of runway 30R and that the hold short line I had crossed was not the exit one for 30 left; but the approaching one for 30 right.  I immediately executed a hard right turn and returned the aircraft behind the line.  We had gone over the hold short line by a bit over one plane length.  After the event; I realized that I would have had to turn a hard 90 degree right turn to have seen the taxiway sign we were intended to see;  and that it was not easily visible once past the hold line for 30 left.  The Controller's instructions to angle across the hold area were a bit confusing; the distance between the two hold lines is not much wider than the airplane is long; which would not allow you to turn at an angle less than 90 degrees.  As soon as I had turned 45 degrees right to follow the 'angle' instructions the front of the airplane was past the hold short line.  Confusion as to the location of the intended alpha sign was a distraction; I was focused on the location of the sign rather than the  hold short lines.  We had been told to expect a 30 left departure; so the monitoring pilot had looked down at his iPad to check the runway length and departure  procedure; and only for a few seconds.Any time a controller says something that is not standard it should cause the crew to be extra careful before trying to follow it.  Runway changes require the crew to check performance; change the box; maneuver the airplane; and splits the attention of the crew.  Slow down and don't feel pressured to be ready for an immediate takeoff.  There was no hot spot chart indicator for this location on the airport; that combined with our expecting to take off 30L meant we had not briefed that area of the ground chart.  I could or should have held position until we had both looked at the chart.  Just crossing a runway  and holding short of the next one is not usually that confusing; so it did not seem necessary.  I have never had a runway incursion before.  I was too complacent about presuming how to follow the 'just angle across' instructions.  I was  overconfident.  We had duty days of 13;12;10;11;12 the first five days of rotation.  Day six we did not fly; but I could still tell I was tired this morning; day  seven.  We were originally supposed to end up the week close to home tonight after one leg; but the sched changed with a repo leg today and  found out day 8 was going to be a long road show day ending up far from home late in the day.  Some distraction from this.  Not sure how to  avoid other than don't let the busy sched distract you.
CL300 Captain reports a runway incursion while attempting to hold short of Runway 30R at SJC.  The taxi instructions were to cross Runway 30L (at B) and angle to hold short of 30R at A.  The hold line for 30R was crossed while attempting to locate Taxiway A.