Tape and Reel Packaging Compatibility for Feeders

A taped reel is the interface between the component supplier and the placement machine, and it is specified rather than chosen. The pitch, the pocket and the cover tape all have to match the feeder, and a reel that does not match feeds unreliably rather than not at all.

What the Standard Covers

The standard defines the reel diameter, the tape width, the pocket dimensions, the pitch and the cover tape peel force. Each of those has a range, and a reel that is inside the range on every item still has to be compatible with the specific feeder.

Compatibility is the practical requirement and the standard is the starting point. Our placement capability notes describe how a feed error appears in the placement data.

Pitch and Pocket Size

The pitch is the distance between pockets and it has to match the feeder index. A pitch that is correct and a pocket that is too deep allows the part to sit below the pickup plane, which the nozzle reads as a missing part.

A pocket that is too shallow is worse, because the part can sit proud of the tape and be displaced by the cover tape. Both faults produce intermittent rather than consistent failures.

The cover tape is peeled by the feeder, and the force it takes is specified by the standard. A force that is too high stalls the peel and one that is too low lets the tape lift in transit and release parts.

The force is measured on a sample with a defined peel angle and speed, and the result is compared with the range. A reel that measures inside the range and stalls in the feeder is usually a static or a humidity problem rather than a force problem. Our component selection notes describe the rest of the incoming checks.

The tape carries the part, and the act of peeling it generates charge. A carrier tape and a cover tape that are both insulative can leave the part charged after it is picked, which is a risk to the die rather than to the placement.

Conductive and dissipative tape materials are available, and the requirement is written for the component rather than for the assembly. A part with a low withstand voltage needs the dissipative tape.

A splice is a joint in the carrier tape, and it is made with a splice tape that is approved for the feeder. An unapproved splice is a hard stop in the machine and a potential loss of the parts around it.

The splice also creates a marker that the machine can be taught, so that the feeder is not left indexing against a joint. Teaching it is worth doing on a long run.

The reel is a moisture barrier only if it is inside a bag. A reel that has been opened and left on a rack is at the ambient humidity, and the parts inside it follow their own sensitivity rules.

Where the reel is stored in a dry cabinet, the cabinet conditions are recorded and the bag is not used as the control. Our board quality notes describe how the storage condition is verified for the assembly.

The receiving check covers the label and the part, the reel and the tape dimensions on a sample, and the peel force where the reels are being used on a feeder that is sensitive to it.

The check is short and it prevents the situation where a whole batch of reels is returned after the line has been stopping for a shift. Our first pass yield notes describe how the feed errors are counted.

Process Control and Verification

Where a value sits close to a process limit, the drawing should say so, since the shop can then open the process window rather than working to a nominal figure that carries no tolerance. A stack-up that is drawn rather than described removes most of the ambiguity from a quotation, and it lets the fabricator price the board against the dielectric and copper weights that will actually be used.

Where the requirement is not written down, the shop supplies its own default, and the default is chosen for the process rather than for the design. The measurements that matter are the repeatable ones: conductor width and spacing, annular ring, finished hole size, plating thickness and surface finish are all verifiable on a coupon that travels with the panel.

Running a first article through the same checks as the production panel confirms that the two agree, and that comparison is the cheapest form of process control available at prototype stage.

Is any reel that meets the standard usable? It is dimensionally usable and it still has to suit the feeder, so the feeder specification is checked as well.

Can a splice be used in production? It can where the splice tape is approved and the machine is taught to detect it.

What does gopcb provide for tape and reel? We provide incoming checks on the label, the reel and the tape dimensions, peel force measured where the feeder is sensitive, dissipative materials specified for sensitive parts, splices limited to approved tape and taught to the machine, and storage conditions recorded.

Checks Before Release

The checks that matter are the ones performed on the product rather than on a sample kept for the purpose, because a coupon that travels with the panel is the only evidence about that panel. Where a requirement can be measured, it should be measured at the point of manufacture and recorded against the board or the lot it applies to.

A parameter that is set once and never re verified drifts, and the drift is usually discovered by a defect rather than by the record. The tooling, the material and the profile form one system, and a change to any of them should be assessed against the other two before it is released.

Where the process window is narrow, the measurement resolution has to be better than the window, or the data cannot distinguish a good part from a marginal one.