"Once the die is mounted in its case, the wires must be soldered to connect the chip and the pins. This operation can seem archaic compared with the processors used in PCs or smartphones, whose dies are connected via direct contact with bumps on their epoxy carriers." - The wire is not soldered to the pins but welded using an ultrasonic force + power - or Ultrasonic wirebonding. The head of the tool where the wire (either it is an Al or Au wire) comes out, generates this combination of ulrasonic energy to be able to connect the die pad and pins. If an Au wire is used, the process adds a thermal property, which is also called thermosonic bonding. CPU and smart phone chips (and virtually all chips) uses the same process. However, most assembly uses Au wire or Cu wire, instead of Al wire. Another process that is used o intorconnect chips to substrate is called flip-chip bonding, or soldering or ILB (inner lead bonding), and then going into the process of underfilling, to protect these interconnects.