Analysis on the material characteristics and process of SMT steel mesh wipe paper
Material classification and technical parameters Currently, mainstream SMT steel mesh wipe paper consists of three basic materials: plain-woven spun lace non-woven fabric, mesh composite material and UFP microfiber material. Taking the most widely used plain weave material as an example, it uses a composite process of 55% refined wood pulp and 45% high-density polyester fiber. Laboratory test data shows that this ratio can achieve a liquid absorption rate of 2.3ml/s while maintaining the durability index of 200 wipe cycles. It is particularly important to note that the polyester component uses polyethylene terephthalate (PET) raw material, and its molecular chain structure imparts excellent chemical stability to the material.
Composite structural engineering design The double-sided composite structure design fully considers the special needs of the SMT process:
1. Polyester functional surface: adopts a three-dimensional weaving process similar to a microporous filter membrane, with a pore density of 3800 holes/cm². This structure not only achieves a 96% oil-fouling retention rate, but also has a tensile strength of 28N/cm², which can withstand the working pressure of pneumatic wipe equipment common in electronics factories. Comparative tests from a well-known patch machine manufacturer showed that using this surface for steel mesh cleaning can reduce the residual solder paste to 0.12 mg/cm².
2. Wood pulp contact surface: Through nanoscale fiber refinement treatment, the surface roughness is controlled below Ra0.8μm. This precision design is equivalent to forming a buffer protective layer on the surface of the steel mesh. In Foxconn's practical application case, this material reduces the micro-scratch rate of the steel mesh by 73%.
Intelligent identification and operation specifications To ensure the best performance of the wipe paper, it is recommended to use the double recognition method: – Tactile identification method: The wood pulp surface has a velvet-like 3D three-dimensional touch (coefficient of friction 0.15), while the polyester surface has silk-like smooth properties (coefficient of friction 0.08) – Optical detection method: When observing the material at 45 degrees, the polyester surface will produce about 12% of the diffuse reflectivity of light, which is derived from its surface microprism structure.
Scientific use of six-step method 1. Material pre-inspection: unfold the wipe paper to check the structural integrity between layers 2. Direction determination: Confirm the direction mark of the wipe paper machine 3. Precise liquid application: Use a special spray gun to atomize isopropanol to spray the polyester surface at a pressure of 0.25MPa to form a uniform micro-liquid film 4. Pressure control: It is recommended to use a contact pressure of 0.6-0.8kg/cm² 5. Movement trajectory: Wipe along the diagonal direction of the steel mesh opening, which can improve the cleaning efficiency by 18%. 6. Replacement standard: When the material has obvious fluffy fibers or the thickness is reduced by 30%. Replacement standard: If the material has obvious fluffy fibers or the thickness is reduced by 30%.
Industry cognitive upgrade Traditional cognitive misunderstandings believe that the double-sided functions of wipe paper are equivalent, but the ASTM F3189-17 standard clearly states that mixed contact surfaces will lead to accelerated tension loss of steel mesh (about 0.8N/cm per month).
