Leveling agent and preparation method thereof

Abstract

The invention relates to the field of circuit boards, and particularly discloses a leveling agent and a preparation method thereof. The leveling agent is prepared from the following raw materials in parts by weight: 15-30 parts of a nitrogen heterocyclic polymer, 75-100 parts of water, 1-2.5 parts of a preservative and 3-10 parts of a wetting agent; and the nitrogen-containing heterocyclic ring polymer is selected from one or more of poly 1-hydroxyl 2 (1-pyridyl) butyl acetate, poly 1-hydroxyl 4 (4 (6-methyl) pyridyl) 4 amino amyl acetate, poly 3-carbonyl 4 (1-pyridyl) amyl ether and poly 1, 2-dihydroxyl (4 (2-hydroxyl) pyridyl) 5 amino hexyl acetate. The preparation method comprises the following steps: weighing the nitrogen-containing heterocyclic ring polymer and water, mixing and stirring to prepare a mixed solution; and weighing the preservative and the wetting agent, adding the preservative and the wetting agent into the mixed solution, and stirring to obtain the finished product leveling agent. And meanwhile, the method has the advantages that the copper filling speed is high, the surface copper thickness is low, filling is basically free of gaps, the appearance state is good, and through-blind co-plating can be performed.

Description

technical field [0001] The application relates to the field of circuit boards, more specifically, it relates to a leveling agent and a preparation method thereof. Background technique [0002] Electroplating copper has important applications in the electronics industry, especially in the manufacture of printed circuit boards and semiconductors; there are wirings on each layer of the printed circuit board multilayer board, and the circuit connection between layers is through metallization holes; the existing metallization of holes is achieved by copper plating. In the electroplating process, due to the limitation of electric field distribution, the current density in the holes tends to be unevenly distributed, so that the current density in the holes is large, and the holes in the holes , Especially the current density in the middle of the hole is small, which easily causes the thickness of the copper coating at the hole to be much larger than the thickness of the coating in ...

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Problems solved by technology

[0004] In the hole filling technology, when the reaction condensate of amines and glycidyl ether or the quaternary ammonium derivative of the condensate are used as a leveling agent, it has the advantages of good board surface appearance and basically no pores in blind hole filling, but copper filling The speed is slower and requires a thicker surface copper coating, generally 20-25 μm, which is not easy to prepare fine lines; and when the reactant of imidazole and other compounds and polyepoxides containing ether bonds is used as a leveling agent, it has the ability to fill blind holes. The advantages of fast copper speed and thin surface copper. Generally, the surface copper thickness is 12-15 microns. However, during the copper plating process, it is easy to cause holes to be filled and the appearance of the board to be rough. When co-plating through blind holes, the corners of the through holes are easy to The phenomenon of "shoulder reduction"

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