UL rohs flexible pcb
The substrate material can be divided into four classes, namely ul-94 V0 class, ul-94 V1 class, ul-94 V2 class and HB class, according to the grade of burning property of the board specified by UL standard (UL94, UL746E, etc.).Generally speaking, the copper clad plate with flame retardant HB grade is detected according to UL standard, which is called non-flame retardant board (commonly known as HB board).The copper clad laminates that meet the combustion requirements of the vertical-combustion method in UL standard (the best grade of flame retardant property is grade ul-94 V0) are called flame retardant boards (commonly known as V0 boards).
PWB is used in electrical and electronic products and in many ways. Products are manufactured all over the world and sold to the United States, so PWB is required to be UL certified.UL standards are often used in the United States to ensure product safety.As a result, when many products enter the United States, customs officers carry out UL safety certification checks.Similarly, UL standards are needed for interregional communication.Ul-746a is a testing method for the electrical, mechanical and physical aspects of polymer materials.Ul-746a is associated with ul-746e and 746B
UL- underwriter laboratories inc.Established in the United States, the company has been engaged in safety assessment and certification of related materials, tools, mechanical and electrical products, equipment construction, methods and systems for more than 100 years.Testing laboratories have been set up in 71 countries, with clients in 92 countries.Over the past few years, UL has worked to improve its service and set up a customer service department (known as ul-cap) with a professional administrative service agency, which has customer service specialists who provide assistance in the areas of customer expertise, technical projects and non-technical aspects.
In addition, ul-746b is used for long-term performance testing. For this kind of long-term thermal aging test, it is usually fixed at fixed time and fixed temperature.UL746E is used for testing of industrial boards, printed circuit substrates, coated and uncoated metal laminates, such as FR4, CEM-3, etc.UL94 is used for flammability test, this standard test method is 94v-0, 1,2 (vertical combustion), 94HB (horizontal combustion), 94vtm-0, 1,2 (vertical combustion of thin materials).UL769 is the standard used for PWB testing of printed circuit boards.Ul-769f is the test standard for flexible material interconnection structure PWB.
FPC soft board is the simplest structure of flexible circuit board, mainly used to connect with other circuit boards
FPC software board is generally divided into single-layer board, double-layer board, multi-layer board, double panel and so on.
FPC single layer flexible board structure: this structure of flexible board is the simplest structure flexible board.Usually base material + transparent adhesive + copper foil is a set of bought raw materials, protective film + transparent adhesive is another bought raw materials.First, the copper foil is etched to get the required circuit, and the protective film is drilled to expose the corresponding pad.After cleaning, use the rolling method to combine the two.The solder plate is then partially electrically plated or tin exposed for protection.In this way, the board is ready.Generally, it is necessary to press the corresponding small circuit board.There are also resistance soldering layer printed directly on copper foil without protective film, which will be cheaper, but the mechanical strength of the circuit board will become worse.Unless the strength requirements are not high but the price needs to be as low as possible, it is best to apply the method of protective film.