Engineering design knowledge of RF shield [hardware]

1. The RF shielding cover mainly prevents electromagnetic interference (EMI) and shields the RF components and LCM on the PCB. 2. Divided into fixed type (directly soldered to PCB board with SMT) and detachable type (combined with structure and LCM or directly buckled on shielding_frame with protrusions on shielding_cover). 3. Mainly rely on solder joints or buckles to locate. 4. Design requirements: The flatness of the shielding_frame shielding frame is 0.13mm, sufficient strength, the thickness is 0.2mm, the height is 2mm, the distance from the edge of the PCB board is 0.75mm, and the inner edge of the frame is at least 0.8mm from the outer frame. Shieling_cover The thickness is 0.2mm; sometimes in order to dissipate heat and cool the components, small round holes can be added to the cover, the diameter is Φ1.0～Φ1.5mm, too large will lead to poor shielding effect. Shielding_can: Shielding LCM: All matching uses '0' matching, and the distance between the side of shielding_can and the side of the LCD viewing area is not more than 1.00mm. 5. Material application: The shielding frame generally uses Cu-C7521-H [general material], Cu-C7521-OH [soft material, for deep drawing] (Nickel-Nickel-Zinc Alloy, Nickel Silver) , Tu003d0.2,0,3mm; RF shielding cover generally uses stainless steel SUS304R-1/2H [bending processing], SUS304R-1/4H [for drawing], tu003d0.15, 0.2mm; tinned steel strip (tinplate Shielding_can can be used for welding on the PCB with nickel silver and tinplate, and it is recommended to use nickel silver; Reason: nickel silver is better in terms of welding, heat dissipation and steam. The height of the buckling convex point of the shielding cover is hu003d0.15-0.2mm, it will be loose when it is low, and it will be tight when it is high. 6. Design considerations. Problem 1: The tray where the shielding cover is placed has too much space, and it is easy to swing during placement, resulting in not being able to absorb. The material must be placed in the tray. There is about 1.0mm of moving space, which will cause the material to swing when it is too large. , Too small to take the material may not be taken up. Question 2: The size of the reclaiming point of the shielding cover should be appropriate. The reclaiming point should be in the middle of the material as much as possible. The size of the reclaiming point is preferably Φ6.0mm. The larger the reclaiming point, the higher the stability of the patch and the efficiency. Higher. 7. Material introduction: Copper-Nickel-Zinc Alloy. It is a kind of copper alloy sheet: Copper and its alloy are an indispensable material in the industry. Both pure copper and copper alloys containing different metal elements It has different characteristics to meet different needs. The users of copper sheet pay attention to the extreme consistency of tolerances, while the rods pay attention to roundness, concentricity and fast cutting. The above-mentioned materials are widely used in the electronics industry, as well as springs, motors, connectors, glasses, probes, etc. In the needle manufacturing industry, in addition to the general round sticks, the factory can also supply shaped sticks according to the needs of customers, reducing the user's processing volume.