What are the effects of the forming method of the carrier tape on its performance?

1、 Dimensional accuracy (tolerance of cavity length, width, and depth)
Punching forming (paper tape)
Mold punching, no material stretching, highest dimensional accuracy, extremely small tolerance, good cavity consistency; But it can only create thin holes and cannot create deep cavities.
Advantage: 0201/0402 small resistance capacitance high-speed tape without jamming.
Hot pressing molding (mainly PS)
The sheet metal is subjected to heat extrusion and stretching, and the shallow cavity accuracy is still acceptable. The deeper the cavity, the more uneven the wall thickness, and the depth tolerance is too large. It is prone to shrinkage and deformation after heating.
Shortcoming: Deep cavity components are prone to material bouncing and jamming.
Vacuum vacuum forming (PET/PC)
Negative pressure adsorption stretching, excellent shallow cavity accuracy, thinning of deep cavity sidewall thickness, slightly larger mouth size; The inner wall of the positive suction cavity is flat, and the accuracy is better than that of the reverse suction.
Advantage: Only vacuum forming can achieve irregular and stepped cavities.
2、 Uniformity of wall thickness
Punching: The original thickness of the substrate remains unchanged, and the wall thickness of the entire hole is completely consistent.
Hot pressing: The bottom of the mold cavity is thick, and the side walls are pulled thin. The greater the depth difference, the greater the wall thickness drop.
Blister: The thinner the corners and side walls of the cavity, the more obvious it becomes, especially for large PC carriers.
Impact: Uneven wall thickness → fluctuation of anti-static resistance, inconsistent carrying tape toughness, unstable adhesion of cover tape.
3、 Heat resistance and shrinkage performance
Punched paper tape: Non thermoforming processing, unchanged physical properties of raw materials, minimal thermal shrinkage.
Hot pressed PS: High temperature compression results in high internal stress, and SMT environments experience significant thermal shrinkage, making them prone to warping.
Vacuum formed PET/PC: Mature temperature control for molding, lower internal stress than hot pressing, low high and low temperature shrinkage rate, suitable for vehicle mounted and high-temperature processes.
4、 Physical toughness, bending resistance
Punching: The original paper has a complete structure and stable toughness.
Hot pressing: PS is prone to brittle cracking and fracture at low temperatures due to stress concentration caused by extrusion.
Blister: PC/PET is uniformly stretched, with the best toughness and bending resistance. It is not easy to break when repeatedly taken and placed in deep cavities.
5、 Anti static stability
Punching: The anti-static coating on the substrate has no tensile damage, and the resistance value is uniform and stable.
Hot pressing: Squeezing and stretching cause uneven thickness of the anti-static layer, resulting in local resistance drift.
Blister: Stretching will slightly alter the conductive coating, and the anti-static performance of the deep cavity sidewall is slightly lower than that of the bottom surface; Permanent anti-static PET is least affected.
6、 Depth of cavity and ability to shape
Punching: ≤ 1mm shallow flat hole, cannot have irregular shapes or step grooves.
Hot pressing: ≤ 3mm conventional cavity, difficult to make complex and irregular shapes.
Blister: Suitable for depths ranging from 0.5 to 15mm, it can be molded into steps, irregular shapes, and eccentric cavities.
7、 Adhesive performance of sealing tape (heat sealing of cover tape)
Punching: The carrier plane is flat, the heat sealing performance is optimal, and it is not easy to leak materials.
Hot pressing: The edge of the carrier tape is slightly uneven, and the consistency of the edge sealing is average.
Blister: The edge flatness of deep cavity products is slightly poor, and the sealing temperature and pressure need to be adjusted.