An optical transmitter may include a chip stack that includes an electrical IC that is mounted using solder balls to a photonic chip. These solder connections permit the electrical IC and the photonic chip to communicate. In addition, the transmitter may include a PCB coupled to the stack so that electrical signals in the PCB are transmitted to the IC and photonic chip (and vice versa). Instead of coupling the PCB to the stack using wire bonds attached to pads on a surface of the photonic chip, at least a portion of the PCB is disposed between the photonic chip and electrical IC. The PCB may also include bond pads used to form a direct solder connection to the electrical IC. As such, the electrical IC may include direct solder connections to both the PCB and the photonic chip.