Pick Height on SMT Feeders: 5 Setup Rules

Pick height is the Z position at which the vacuum nozzle meets the component inside the tape pocket. The machine closes the vacuum at that point and waits for a pressure switch or a flow sensor to confirm that a part is on the tip. If the nozzle never reaches the component, the confirmation never comes and the machine reports a pickup error after a short timeout.

It is one of the few settings that can be taught in a minute and then quietly cost a shift of lost components. Pick height decides how hard the tip presses, whether the part is centred when it leaves the tape, and how much of the nozzle and the feeder wear out over a year of production.

What Pick Height Actually Controls

The setting controls two things at once. The first is reach, because the tip has to touch the top surface of the component before the vacuum can hold it. The second is force, because the nozzle travels a fraction of a millimetre past first contact and the pocket floor takes the load. Both effects come from the same number.

That travel is invisible on a robust package, which is why a bad value can survive for months. On a fragile part it shows immediately, and the damage is usually found much later, after reflow has opened the crack. The rule is therefore to set the height for the most fragile part on the feeder, not for the average one.

The Reference Surface: Feeder Plate and Tape Pocket

The reference for pick height is the feeder plate, not the machine table. Carrier tape runs in a channel, and the pocket depth follows the tape standard for the package size. A component in a deep pocket sits lower than the same component in a shallow pocket, so the machine has to be told where the top surface is.

Pocket depth also varies with tape thickness class and with the tape supplier. Where the machine learns the position automatically, it reads the pocket and stores the number. Where the position is set by hand, the operator jogs the nozzle down until the tip touches the part and reads the value from the axis counter.

When the Nozzle Goes Too Low

A pick height that is too low shows up first as damage to the part. Ceramic capacitors lose a corner near the electrode, and the crack opens during reflow. The tape suffers as well, because the tip shaves a groove in the pocket floor and the debris enters the vacuum path, where it reduces flow and makes the next pickup less reliable.

Fragile packages such as LEDs, crystal resonators and taped bare die fail even earlier. On these parts the pick height should be set so that the tip touches with no measurable travel, and the placement force should be reduced at the same time, because the two limits interact. Setting one without the other moves the damage rather than removing it.

When the Nozzle Stops Too High

A pick height that is too high leaves the tip short of the component. The vacuum reaches the pocket but not the part surface, so the machine either picks nothing or picks the part late, after the cover tape has started to peel. The result is a component that arrives at the board rotated, off centre or missing.

A high setting also lets the component ride on the pocket edge, and the tip can catch the top of the tape. Where the machine confirms pickup by vacuum, the first symptom is a rising error count on the smallest chips, because a small chip seals less well around the tip and leaks more air.

<img src="https://www.gopcba.com/wp-content/uploads/2026/08/1783933913008.jpg" alt="Feeder pickup position teach screen beside a nozzle touching a component in tape” />

Teaching the Pickup Position on the Machine

Machines offer two methods. Automatic teach uses the vision camera to find the pocket centre, then lowers the nozzle until the vacuum confirms contact and stores the result. Manual teach requires the operator to jog the Z axis down in small steps until the part lifts, then to back off by the margin the machine recommends.

The pickup position must be taught for the feeder type, the tape width and the nozzle in use, because tip length changes the effective height. A nozzle swapped without a new teach is one of the most common causes of a burst of pickup errors after changeover, and the nozzle wear record usually shows the swap that caused it.

Witness Checks That Prove the Setting

A witness check makes the setting visible. A thin film of marking ink on the tip leaves a print on the component when contact is made, and the size of that print shows how hard the tip pressed. The pocket floor can be checked the same way for a groove that should not be there.

Vacuum readings are the second witness. A pickup that takes longer to reach the set vacuum is losing air, which points to a tip that is not seated on the part. Recording both readings at changeover builds a history, and that history separates a feeder fault from a nozzle fault. The feeder calibration routine should include both numbers.

Feeder Wear and Tape Tolerance

Pick height is only as repeatable as the feeder that holds the tape. A worn feeder plate lowers the tape, a bent frame tilts it, and a tired spring changes how the pocket sits at the pickup point. Two feeders of the same model can need values that differ by tens of micrometres.

Tape tolerances add to that spread. Pocket depth is a range rather than a value, and the cover tape peel force changes with temperature and humidity. For parts that are sensitive to height, the feeder should be dedicated to the product and the reels should come from one supplier and one tape class, which is also the basis of feeder setup control.

Changeover Routine and Recheck Interval

Pick height belongs on the changeover checklist beside the nozzle check and the peel force check. The practical check is a first pickup at the start of the run, viewed on the placement camera or under the microscope, plus a vacuum reading taken on the first panel of the batch.

Between scheduled checks, the error count per feeder is the best early warning. Errors that start at the same point in every reel usually point at the tape, while errors that begin right after a nozzle change point at the height. The two are easy to confuse, so the record should show which event came first. Where the part is heavy, also confirm the contact force after any teach.

FAQ

Can one pick height serve every feeder on the line? No. The value depends on the feeder plate, the tape class and the nozzle, so it has to be treated as a setup item for each position. A shared number works only where the feeders, the tape and the nozzle are identical, and that is rarely true across a full product.

Why do pickup errors appear only at the end of a reel? The tape at the end of a reel has seen more tension and more handling, and its pocket can sit differently in the channel. That is a tape and feeder issue rather than a height issue, but the height setting decides how much of that variation the process can absorb.

Should pick height be rechecked after a nozzle change? Always, because tip length is part of the height calculation. Recheck on the same feeder and the same tape so that the result can be attributed, and record the vacuum reading so that the next change has something to compare against.