Little knowledge of circuit boards you haven't seen

Basic knowledge of circuit boards that you haven't seen 2020-06-06 16:48:00 1. How many types of printed circuits are divided into substrates and conductive patterns used? a. According to the substrate used: rigid, flexible, rigid-flexible; b. According to the conductive pattern: single-sided, double-sided, multi-layer. 2. What are the two main methods for the classification of printed circuit manufacturing processes? What are the advantages of each? a. Additive method: avoid a large amount of copper etching and reduce the cost. Simplifies the PCB copy board production process and improves production efficiency. Able to achieve flush wires and flush surfaces. Improve the reliability of metallized holes. b. Subtractive method: The process is mature, stable and reliable. 3. How many types of additive processes are used in printed circuit manufacturing? Write down the process separately? a. Full additive method: drilling, imaging, viscosity increasing treatment (negative phase), electroless copper plating, resist removal. b. Semi-additive method: drilling, catalytic treatment and viscosity increasing treatment, electroless copper plating, imaging (electroplating resist), pattern copper electroplating (negative phase), resist removal, differential etching. c. Partial addition method: imaging (anti-etching), etching copper (normal phase), removing the resist layer, coating the entire plate with electroplating resist, drilling, electroless copper plating in the hole, and removing electroplating resist. 4. What are the types of printed circuits in the subtractive process? Write down the process flow of full-board plating and pattern plating. a. Non-perforated plated printed boards, perforated plated printed boards, perforated plated printed boards and surface mounted printed boards. b. Full board plating (masking method): blanking, drilling, hole metallization, full board plating thickening, surface treatment, photomasking dry film, making positive phase conductor patterns, etching, removing Film, plug electroplating, shape processing, inspection, printing solder mask, hot air leveling, screen printing marking symbols, finished products. c. PCB copy board graphic electroplating (bare copper clad solder mask): blanking of double-sided copper clad laminates, punching positioning holes, CNC drilling, inspection, deburring, electroless thin copper plating, electroplating thin copper, inspection, brushing, Filming (or screen printing), exposure and development (or curing), inspection and revision, pattern copper plating, pattern tin-lead alloy plating, film removal (or removal of printing material), inspection and revision, etching, lead-back tin, continuity and disconnection test , Cleaning, solder mask graphics, plug nickel/gold plating, plug tape, hot air leveling, cleaning, screen printing marking symbols, shape processing, cleaning and drying, inspection, packaging, finished products. 5. What types of electroplating technology can be divided into? a. Conventional hole electroplating technology, direct electroplating technology, conductive adhesive technology. 6. What are the main features of flexible printed boards? What are the base materials? a. It can be bent and folded to reduce the volume; light weight, good wiring consistency and high reliability. 7. Briefly describe the main features and uses of rigid-flexible printed boards? a. The rigid and flexible parts are connected into a whole, eliminating the need for connectors, reliable connection, weight reduction, and miniaturization of assembly. PCB copy boards are mainly used in medical electronic equipment, computers and their peripherals, communication equipment, aerospace equipment, and national defense and military equipment.