阅读说明：本技术 一种bga焊接小圆pad的pcb制作方法 (PCB manufacturing method for welding small circular PAD through BGA ) 是由 文国堂 贺波 于 2019-11-15 设计创作，主要内容包括：本发明属于PCB加工技术领域,提供一种BGA焊接小圆PAD的PCB制作方法,包括以下关键控制点：A、设计时通过蚀刻因子计算好损失量,在原设计的基础上补偿损失宽度；B、沉铜前将基铜通过微蚀药水减铜至6—9um；C、电镀孔铜厚度控制在16-18um；面铜控制在27—30.5mil；D、蚀刻因子需控制在4-10。本发明实现了设计前补偿值的精准化、铜厚的最优控制、蚀刻因子的有效控制,可满足高精度BGA焊接小圆PAD的PCB制作的需求。(The invention belongs to the technical field of PCB processing, and provides a PCB manufacturing method for welding a small circular PAD by a BGA, which comprises the following key control points: A. calculating the loss amount through an etching factor during design, and compensating the loss width on the basis of the original design; B. reducing the copper content of the base copper to 6-9 um by using a micro-etching liquid medicine before copper deposition; C. controlling the thickness of the copper in the electroplating hole to be 16-18 um; controlling the surface copper to be 27-30.5 mil; D. the etching factor needs to be controlled to be 4-10. The method realizes the precision of the compensation value before design, the optimal control of the copper thickness and the effective control of the etching factor, and can meet the requirement of PCB manufacture of high-precision BGA welding small circular PAD.)

1. A PCB manufacturing method for welding a small circular PAD by a BGA is characterized by comprising the following key control points:

A. calculating the loss amount through an etching factor during design, and compensating the loss width on the basis of the original design;

B. reducing the copper content of the base copper to 6-9 um by using a micro-etching liquid medicine before copper deposition;

C. controlling the thickness of the copper in the electroplating hole to be 16-18 um; controlling the surface copper to be 27-30.5 mil;

D. the etching factor needs to be controlled to be 4-10.

2. The method of claim 1, wherein in step A, the loss width is 0.8-2.5 mil.

3. The method of claim 2, wherein in step A, the loss width is 1.5 mil.

4. The method of claim 1, wherein in step B, the base copper is reduced to 7-8um by micro-etching solution before the copper deposition.

5. The method as claimed in claim 1, wherein in the step C, the plating operation speed is controlled to be 1.4-1.5 m/min, the plating time is controlled to be 45-48min, and the current density is controlled to be 30-40 ASF.

6. The method of claim 1, wherein in step D, the etching pressure is controlled to 1.5-2.0kg/cm for reaching the etching factor²。

Technical Field

The invention belongs to the technical field of PCB processing, and particularly relates to a PCB manufacturing method for welding a small circular PAD by a BGA.

Background

Along with the multifunctionality development of electronic products, the PCB is widely applied to the fields of scientific and technological electronic products and the like, the integration level of the BGA chip is continuously improved, the requirement on the packaging of an integrated circuit is stricter, the function is increased along with the improvement, and the size is smaller, so that the BGA welding PAD designed on a PCB circuit carrier is smaller and smaller, and the precision is higher and higher.

The diameter of the BGA of the conventional PCB with the mechanically drilled through hole is generally designed to be larger than 8mil, and due to the improvement of product functions and refinement, the BGA welding PAD of part of high-end products is designed to be smaller and smaller (the diameter is not less than 6mil and not more than 8 mil) and more precise. In order to meet the customer requirements, improve the competitiveness in the market and continue upgrading the process.

Disclosure of Invention

In view of this, the invention provides a method for manufacturing a PCB by BGA soldering of a small circular PAD, which realizes the precision of a compensation value before design, the optimal control of copper thickness, and the effective control of an etching factor, and can meet the requirement of high-precision PCB manufacturing by BGA soldering of a small circular PAD.

The technical scheme of the invention is as follows:

a PCB manufacturing method for welding a small circular PAD by a BGA is characterized by comprising the following key control points:

A. calculating the loss amount through an etching factor during design, and compensating the loss width on the basis of the original design;

B. reducing the copper content of the base copper to 6-9 um by using a micro-etching solution before copper deposition, wherein the thickness of the copper material in the prior art is HOZ;

C. controlling the thickness of the copper in the electroplating hole to be 16-18 um; controlling the surface copper to be 27-30.5 mil;

D. the etching factor is controlled to 4-10, wherein the etching factor = etching line thickness/[ (resist width-narrowest line width)/2 ]

Further, in the step A, the loss width is 0.8-2.5 mil.

Further, in the step A, the loss width is 1.5 mil.

Further, in the step B, the copper of the base copper is reduced to 7-8um by micro-etching liquid before copper deposition.

Furthermore, in the step C, the electroplating operation speed is controlled to be 1.4-1.5 m/min, the electroplating time is controlled to be 45-48min, and the current density is controlled to be 30-40 ASF.

Further, in the step D, in order to reach the etching factor, the etching pressure is controlled to be 1.5-2.0kg/cm²。

According to the invention, through the control of the compensation of the BGA before-manufacture design, the uniform control of the thickness of the base copper before copper deposition and electroplating, the control of the thickness of the copper of the electroplating surface after copper deposition, and the control of the pressure, the speed and the etching factor in the etching process, the precision of the compensation value before design, the optimal control of the thickness of the copper and the effective control of the etching factor are realized, and the requirement of PCB manufacture of a high-precision BGA welding small circular PAD can be met.

By the processing method, the following economic benefit indexes can be realized:

the method can effectively improve the whole process design capacity, can meet the requirements of more customer orders, obtain considerable order areas, and predict and increase stable order areas by about 500 square meters per month, wherein the order structures are high-end products, and the economic benefit which can be predicted to be brought is 10 ten thousand yuan per month by calculating according to the profit of 200 yuan per square meter.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.