| The MC3 integrated vacuum generator is suited for high-speed, pick-and-place applications such as circuit-board assembly and chip testing. |
Like most manufacturers today, the trend among semiconductor-device companies is to raise productivity. But speeding up machines to generate more chips per hour increases the chances of damage to delicate chips. Vacuum handling systems provide the ideal solution, according to Bob Buerkel of the Parker Hannifin Pneumatic Div., Richland, Mich. Compared with mechanical grippers, soft vacuum cups are gentle and nondestructive, as well as simple and economical, he explains.
The challenge of late, says Buerkel, has been to design vacuum systems that meet OEM demands for higher speeds. Parker has recently introduced several fast-acting devices such as the MC3 high-speed integrated venturi, VA01 vacuum valve for centralized vacuum systems, and pressure sensors that address these needs.
The Convum MC3 integrated vacuum generator features a vacuum-generating pilot valve and direct vacuum blow-off valve that minimize response times. It is said to be ideal for high-speed, pick-and-place functions such as surface-mount chip placement, testing, and bonding.
The MC3 is highly responsive in both creating vacuum to lift parts and removing vacuum to release them. Precise control on release is critical because the goal is to raise pressure to atmospheric and break the suction-cup seal as quickly as possible, without raising pressure too much and forcefully ejecting parts. A regulating blow-off needle lets users precisely tailor valve performance, producing vacuum response times of as little as 20 msec from 0 to 25-in. Hg.
The MC3 can mount directly on the moving head of a chip mounter, tester, or other related equipment. Direct mounting eliminates piping resistance, which leads to faster response in high-speed pick-and-place systems. The generators can be assembled into a maximum eight-station manifold. And the unit's 10-mm thickness makes it one-third smaller and lighter than conventional vacuum generators, letting it be located close to the suction cup for maximum performance.
The MC3 also has an integrated sensor to confirm vacuum levels and eliminate delays. The company's Convum pressure sensors have a response time <2.0 msec and offer a wide range of features, including npn/pnp and analog outputs, up to seven-segment output LEDs, quick-connect or grommet electrical connections, and up to an IP67 rating. Programmable outputs include normally open, normally closed, and hysteresis and comparative (high/low setting) modes.
In addition to silicon-chip manufacturing, they are used in packaging, factory automation, process control, and other applications requiring accurate outputs. Sensors designed for gases have a silicon diaphragm, while those for fluids feature a stainless-steel diaphragm. Twelve different models, all using piezoelectric technology, offer pressure ranges from -14.7 to 8,820 psi.
Some chip manufactures opt for centralized vacuum systems. Such setups use fast-acting valves for control rather than individual vacuum generators. With a solenoid response time of 5 msec, Parker's VA01 eliminates the need for two three-way valves when centralized vacuum systems are used in conjunction with part blow-off. The VA01 poppet control valve features a vacuum valve and direct adjustable blow-off valve with an atmospheric-release mechanism in a single body. The atmospheric-release mechanism reduces variation of breaking time and overshoot of blow-off. The 10-mm-wide valve can be mounted in-line or on manifolds directly on the moving head of the chip mounter, tester, or other related equipment.