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46 I-CONNECT007 MAGAZINE I MARCH 2026 Automated Optical Alignment and Pinless Layup Process The optical alignment process is like manual layup, but faster and more accurate, with automated checks to ensure correct material order and orien- tation. A typical process includes: 1. Place the lower lamination plate on the layup table and begin layup as usual up to the first separator plate. 2. After placing the first separator plate, place the untooled copper foil (this foil will be out- side layer n). 3. Place the untooled prepreg (all prepreg be- tween layers n–2 and n–1). 4. Align prepreg using two perpendicular laser layup lines (Figure 4). 5. Continue placing material up to layer (core) 1 and 2, then activate the welding head. 6. Place the welded package along the two perpendicular laser lines. The welded package consists of layers 2 to n–1 with prepreg welded in place between the layers. 7. Place untooled prepreg (between layers 1 and 2). 8. Place the untooled copper foil (this will be layer 1). 9. Place the next separator plate and repeat for the entire book. The inner layers must first be prepared with the corresponding fiducial targets on the top and bottom sides for optical align- ment (Figure 4). The prepreg does not require holes or punching. The inner layers must include weld coupons etched in the reserve zones (Figure 5). These coupons can be placed along the panel edges or inside the image area, if necessary. The use of fiducial targets aligned through CCD cameras and image process- ing becomes the critical alignment step. This re- duces manufacturing and maintenance by eliminat- ing the cost of pins, bushings, and tool separator plates from the lamination process. The weld coupons replace the old drilled or punched registration holes. Coupon designs vary, but typical sizes range from 6–10 mm wide by 15–40 mm long, with copper clearances as recom- mended by the equipment supplier. All include solid copper decals (Figure 6). Each supplier pro- vides additional process details based on years of field experience. H A P PY'S T EC H TA L K # 47 Figure 4: a) Tolerances associated with pinning systems; b) Stackup plates with welded panel, foil, and laser lines used as a guide. Figure 5: Various induction welding heads and registration coupon.