5G precision circuit board back drilling hole depth control method

Abstract

The invention relates to a 5G precision circuit board back drilling hole depth control method. The method comprises the following steps: (1) forming a first drilling hole in a laminated circuit board; (2) performing hole metallization processing on each first drilling hole to change the first drilling hole into a plated-through hole, two plated-through holes in the edge of the circuit board being a board edge test hole E and a board edge test hole F respectively; (3) secondary drilling is carried out on another plated-through hole in the edge of the circuit board to form a verification hole G, and the diameter of the secondary drilling is larger than that of the plated-through hole; (4) detecting the conduction state between the verification hole G and the board edge test hole E and / or the board edge test hole F; and (5) when the conduction state is qualified, recording the depth of the secondary drilling at the moment, and performing secondary drilling on the required position of the back drilling hole D in the center of the circuit board at the same depth to obtain the back drilling hole D meeting the depth requirement. Compared with the prior art, the method has the advantages that the circuit board structure is prevented from being damaged, time is saved, and the detection accuracy is high.

Description

technical field [0001] The invention relates to the field of circuit board detection, in particular to a method for controlling the depth of back-drilled holes on a 5G precision circuit board. Background technique [0002] With the opening of the 5G cycle, a series of changes in downstream industries such as base station construction, smart phone upgrades, cloud computing, and the increase in the complexity of automotive electronics have promoted the upgrading of the circuit board (PCB) industry. There are big deficiencies, for example, conventional 4G and below communication circuit boards are mainly insulated by layers or conducted through metal holes during processing. [0003] On the other hand, 5G circuit boards need to control back-drilling or multiple pressing and back-drilling, that is, to conduct depth-controlled drilling again after all processes are completed to ensure communication quality; the actual inter-layer accuracy is tested by designing layer alignment A...

AI Technical Summary

Problems solved by technology

[0004] The processing method of the existing PCB circuit board back drilling: a. Provide the PCB, and the PCB is provided with a positioning hole, and use the positioning hole to position the PCB with a drill and perform a drill; b. After drilling a drill The PCB is subjected to hole metallization treatment, and after the treatment, the PCB is patterned by using the principle of dry film sealing and exposure; c, pattern plating is performed on the PCB after the outer layer pattern is formed, and the final required pattern is formed by alkaline etching after pattern plating. d. On the basis of one drill, import the back-drilling program for back-drilling positioning, and use a drill to back-drill the electroplated holes that need to be back-drilled; e. Wash the back-drilled holes after back-drilling to remove the back-drilling Drilling cuttings remaining in the drill hole; f. The back-drilling effect is verified through physical destructive tests, and there are the following defects:

[0005] 1. Each layer that requires back-drilling needs to be confirmed by making a slice; 2. It takes a lot of time for professional personnel to participate in the confirmation of slicing. Until it is OK; 3. The accuracy of back drilling control depth is relatively high, so if there is a deviation in the thickness of the laminated board, the control depth of back drilling is not easy to control, and multiple back drilling is required (upper board - back drilling - lower Board - take the board to the laboratory to make slices to confirm) physical damage to confirm the effect of back drilling; 4. Multiple physical damages will lead to PCB scratches and scrapping and waste too much time, affecting the progress and delivery of the product

Images