Analysis of the cause of bronze without a gradient hole.Double Layer Flex PCB Board Solution_Shenzhen StarLight Industrial Development Co., Ltd.

Analysis of the cause of bronze without a gradient hole.Double Layer Flex PCB Board Solution

source:Other information release time:2023-06-16 Hits: Popular:PCB Assembly company: Share:

　　1. The tin light agent deep plating (positioning) has poor ability to call tin bad;

　　2. PTH abnormalities, not sinking copper in the hole;

　　3. Poor deep -plating ability of copper plating.

　　In actual production, it is not uncommon for gradually thinning holes. The reason is that there is an obstacle to the electroplated copper sedimentary obstruction on the electrical substrate (a copper or thick copper layer) on the conductive substrate. The following analysis is based on the generation and prevention of this blocking layer.

　　During the sequencing line of a copper or thick copper or thick copper, the ink that the PCB board surface is not gathered to aggregate ink is dissolved in the development liquid. At this time, if the subsequent pressure is washing (water -washed water), it is not enough to rinse the residue of the PCB board and the ink -containing polymer in the pores, then the remaining ink polymer compounds will be adhered on the wall of the hole to form a layer of layer The thinner plating layer, the more the cleaning effect is, the worse the cleaning effect, the greater the chance of the resistance of the plating layer, especially the small hole. (Multi -level water washing in the development section is just a process of constantly diluting the residue, the purpose is to dilute the residue as much as possible).

　　It is understood that after the high -molecular anti -adhesive obstruction coating is the culprit that leads to the thinning of the copper layer in the pores, the focus of the problem is concentrated in the cleaning effect in the hole to remove the anti -adhesive obstruction layer. The right medicine can be cured.

　　In addition, the premise of dealing with realistic problems is to face up to and respect the existing production conditions of customers, such as: lines and welds, dry membranes and wet membranes with sharing lights, and water washing flows are restricted by environmental protection.

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