If you're looking for a meeting place or a good stop around ½ or halfway between San Francisco and Santa Clara, CA, you can try Redwood City, CA, which is about half an hour southeast of San Francisco, or about half an hour northwest of Santa Clara, CA.
About ⅓ or a third of the way, you can stop at San Mateo, CA. This is about 16 minutes south of San Francisco.
About ⅔ or two thirds of the way, you can stop at Palo Alto, CA. This is about half an hour southeast of San Francisco, or about 18 minutes northwest of Santa Clara, CA.
About ¾ or three fourths of the way, you can stop at Mountain View, CA. This is about half an hour southeast of San Francisco, or about 11 minutes west of Santa Clara, CA.
If you drive straight through without stopping at all, the total distance is 44 miles. The distances shown above don't include local roads to get into each town, so if you're planning a long road trip, make sure you factor in traffic and road conditions, rest stop breaks, and interesting detours along the way. If you're in a rush, you can do the trip with zero stops, and your total travel time would be around 50 minutes.