BJ 939

The Hesse & Knipps BJ 939 belongs to the class of packaging and bonding equipment used after device fabrication to join chips, substrates, leads, or package elements into an assembled electronic unit. Machines of this class support back end assembly by forming controlled connections that must meet requirements for alignment, bond integrity, and handling of delicate parts.

Machines of this class generally combine precision motion, part presentation, workpiece fixturing, and a bond head that applies a joining action at a defined location. The joining action may rely on force, heat, ultrasonic energy, or a controlled combination of these, depending on the bonding method. Process control focuses on placing the interconnect material or bonded surfaces accurately, making contact under repeatable conditions, and then releasing the completed joint without damaging neighboring features.

Such systems typically use optical alignment and programmable motion to register bond points on the die, leadframe, substrate, or package body. Material is fed or presented to the bond site, the machine executes the bond sequence, and the finished connection is then inspected through in process sensing or operator review. At the class level, stable bonding depends on cleanliness, bond surface condition, tool condition, and consistent control of motion and energy delivery.