Today, talk about the processing flow of FR-4 epoxy board. The following is the introduction of the processing flow of FR-4 epoxy board by Suzhou Huayan Fuji New Material Co., Ltd.
FR-4 epoxy glass cloth laminate product surface preparation and treatment
1. After the copper surface is patterned and etched to form a circuit, try to reduce the treatment and contact of the PTFE surface. The operator should wear clean gloves and place an interlayer film on each board for transfer to the next procedure.
2. The etched PTFE surface has sufficient roughness for bonding. It is recommended to treat the surface of PTFE in order to provide sufficient adhesion in areas where the sheet has been etched or where the uncovered laminate will be bonded. The chemical components used in the pth preparation process can also be used for surface treatment. Plasma etching or sodium-containing chemicals are recommended, such as FluroEtch® by Acton, TetraEtch® by Gore, and Bond-Prep® by APC. Specific processing technology is provided by the supplier.
3. Copper surface treatment should ensure the bonding strength. The brown copper monoxide circuit treatment will strengthen the surface shape to facilitate chemical bonding using TacBond adhesive. This process requires a cleaner to remove residue and dispose of oil. Next, a fine copper etch is performed to form a uniform rough surface area. The brown oxide needle crystals stabilize the adhesive layer during the lamination process. As with any chemical process, adequate cleaning after each step is necessary. Salt residues can inhibit adhesion. The flushing should be monitored and the PH value should be kept below 8.5. Dry layer by layer and ensure that the surface is not contaminated with oil or the like on your hands.
Overlay and Lamination
Recommended bonding (pressing or pressing) temperature: 425 ° F (220 ° C)
1. Bake the board at 250ºF (100 ℃) to eliminate moisture. The plies are stored in a tightly controlled environment and used within 24 hours.
2. A pressure field should be used between the tool plate and each electrolytic plate so that the pressure in the control plate can be evenly distributed. High voltage areas present in the board and in the circuit board to be filled will be absorbed by the field. The field can also unify the temperature from the outside to the center. Thus, a uniform thickness between the control board and the control board is formed.
3. The board must consist of a thin layer of TAC BOND provided by the supplier. Care should be taken to prevent contamination when cutting thin layers and stacking. Depending on circuit design and filling requirements, 1 to 3 sheets of adhesive thin layer are required. The areas to be filled and the dielectric requirements are used to calculate the requirements for 0.0015 "(38 microns) thin plates. It is recommended to use clean stainless steel or aluminum mirror plates between the laminates.
4. To assist lamination, perform vacuum treatment for 20 minutes before heating. The vacuum is maintained throughout the cycle. Extracting air will help ensure that the circuit is packaged.
5. Placing thermocouples in the peripheral area of the center plate can determine the temperature monitoring and the appropriate period.
6. The plate can be installed on a cold or preheated press platen to start. If the pressure field is not used for compensation, the thermal rise and circulation will be different. Importing heat into the package is not critical, but it should be controlled as much as possible to reduce the gap between the periphery and the center area. Generally, the heat rate is between 12-20ºF / min (6-9 ℃ / min) to 425ºF (220 ℃).
7. Once installed in the press, the pressure can be applied immediately. The pressure will also vary with the size of the control board. Should be controlled within the range of 100-200psi (7-14bar).
8. Maintain the hot pressing temperature at 425ºF (230 ℃) for at least 15 minutes. The temperature must not exceed 450ºF (235 ℃).
9. During the lamination process, minimize the time in the unpressed state (such as the time from the hot press to the cold press). Maintain the pressure until the pressure is below 200ºF (100 ℃).
Welcome to choose Suzhou Huayan Fuji New Materials Co., Ltd. The above process of FR-4 epoxy board is organized by Suzhou Huayan Fuji New Materials Co., Ltd.