IPC-A-600H-2010 中文版 印制板的可接受性 (1).pdf - 第100页
本节 涵 盖了印制板的 蚀 刻 、内 层 和 阻 抗 可 控 产品的可接受性要求。可接受的 蚀 刻 工 艺 必须保证产品上所有 多 余金 属 已 被 除 去 且 没 有 留 下 污染 的 痕 迹 。 如 果 过 度 蚀 刻 引起 金 属 抗 蚀 镀层 过大的 突 沿 而 产生 潜 在的 金 属镀 屑 ，或 者 造 成完 工的 导 体 宽度小 于规定的要求，则过 度 蚀 刻 是拒 收的理由。 如 果 蚀 刻 不足 而 造 成 产品上产生的…
This section covers acceptability requirements for printed board etching, innerlayers, and impedance controlled products. An acceptable
etching process must result in all residual metal being removed with no evidence of contamination remaining on the product.
Over etching is cause for rejection when potential slivers result from excessive overhang of metal resist plating or when the finished conduc-
tor widths are less than specification requirements.
Under etching is cause for rejection when spurious metal remains on the product to the extent that spacing between conductors is less than
specification requirements or if conductor width requirements are exceeded.
Conductor width is defined as the observable width of the copper conductor excluding organic or metallic resists unless otherwise specified.
The ‘‘Minimum Conductor Width’’ often specified on the procurement documentation or performance document is usually measured at the
base of the conductor and may not be the actual narrowest width of the conductor when observed in cross section or often when viewed from
the surface. An observation from the surface may not be adequate for acceptance of some products and etching processes. Where resistance
per unit length is a requirement, a measurement of the average width of the cross-sectional area may be necessary. Where impedance control
is required, a determination of the maximum conductor width may be important for the calculating impedance and a cross-section is often
required.
Considerable variation in etch configurations is possible due to different etchants, resists and plated metal thicknesses. The conductor width
may increase or decrease from the production artwork due to techniques used in processing during the imaging and developing operations.
To achieve the ‘‘Design Width of Conductor,’’ the production master artwork often has conductor width adjustments made during plotting.
The amount of adjustment of a conductor width on the ‘‘Production Master’’ may be 0.025 to 0.05 mm [0.001 to 0.0020 in]. Determination
of adjustment is made by experimentation and compensation for an increase or decrease of the conductor width during plating or etching.
The illustrations in 3.2.1 are intended as a guideline to illustrate some of the edge geometry conditions which may result from different pro-
cessing methods and illustrate the configurations of ‘‘Outgrowth,’’ ‘‘Undercut’’ and ‘‘Overhang.’’
3.2 CONDUCTIVE PATTERNS – GENERAL（导电图形 – 总则）
Introduction（引⾔）
91IPC-A-600H-2010 2010年4月
本节涵盖了印制板的蚀刻、内层和阻抗可控产品的可接受性要求。可接受的蚀刻工艺必须保证产品上所有多余金属已被除去且没
有留下污染的痕迹。
如果过度蚀刻引起金属抗蚀镀层过大的突沿而产生潜在的金属镀屑，或者造成完工的导体宽度小于规定的要求，则过度蚀刻是拒
收的理由。
如果蚀刻不足而造成产品上产生的金属残留物使导体之间的间距小于规定的要求，或者导体宽度超过了规定的要求，蚀刻不足也
是引起拒收的理由。
除非另有规定，导体宽度是指可观察到的铜导体宽度，但不包括有机的或金属的抗蚀层。采购文件或性能文件中规定的“最小导
体宽度”通常是在导体的基底处测量的，而不是按显微切片所观察到的或通常从表面所观察到的实际最窄宽度。从表面观察不能
作为一些产品和蚀刻工艺的验收依据。当导体的单位长度电阻有要求时，则可能有必要对导体横截面的平均宽度进行测量。当有
阻抗控制要求时，最大导体宽度的测定对计算阻抗可能很重要，同时往往要求对导体进行剖切。
由于蚀刻剂、抗蚀剂和金属镀层的厚度的不同，蚀刻后图形的变异可能相当大。同时在成像和显影操作过程中由于采用的工艺技
术的不同，也会使导体宽度可能比生产底片的宽度大或小。为了达到“导体设计宽度”，在光绘生产底版的过程中往往要调整导
体的宽度。对“生产底版”导体宽度的调整量可从0.025mm至0.05mm[0.000984in至0.0020in]。尺寸的调整通过电镀或蚀刻过程的
导体宽度增大或减小程度的实验而加以确定。
3.2.1节中的示意图用来表明不同的加工方法可能产生的几种导体边缘的几何形状，并图示了“镀层增宽”、“侧蚀”和“镀层突
沿”等不同外形。
3.2
CONDUCTIVE
PATTERNS – GENERAL（导电图形 – 总则）
Introduction（引⾔）
92 IPC-A-600H-20102010年4月
Definitions used in evaluating etched conditions (see IPC-T-50) include:
评价蚀刻状况时所用到的定义（见IPC-T-50）包括：
Outgrowth: The increase in conductor width at one side of the conductor, caused by plating buildup over that delineated by the production
master.
镀层增宽： 由于镀层堆积引起的导体一侧宽度增加，超过生产底版的绘制宽度。
Undercut: The distance on one edge of the conductor measured parallel to the printed board surface from the outer edge of the conductor,
including etch resists, to the maximum point indentation to the copper conductor.
侧蚀： 从导体一侧外边缘（包括抗蚀层）到同一侧铜导体的最大凹入点与板面平行的间隔距离。
Overhang: The sum of the outgrowth and undercut.
镀层突沿： 镀层增宽和侧蚀量的总和。
Design width of conductor: The width of a conductor as delineated or noted on the procurement documentation.
Notes: 1. The ‘‘Production Master’’ may be adjusted for process methods and the artwork conductor width may differ from the design
width.
2. Design width of conductor is most often stated as a minimum as measured at the base of the conductor. For impedance controlled
circuits, a ± tolerance may be placed on conductor width.
导体设计宽度： 采购文件上绘制的或标注的导体宽度。
注：1. “生产底版”可以按加工方法进行调整，而照相底版的导体宽度可以不同于导体设计宽度。
2. 导体设计宽度通常是指在导体底部测量所得的最小宽度。对于阻抗可控的线路，其导体宽度可设置正负公差要求。
Production Master: A 1:1 scale pattern which is used to produce one or more printed boards within the accuracy specified on the procure-
ment documentation.
⽣产底版： 用于生产一块或多块印制板的按1：1比例绘制的图形，精度在采购文件规定的范围以内。
Etch Factor: The ratio of the depth of etch to the amount of lateral etch.
蚀刻系数： 蚀刻深度与侧向蚀刻量之比。
3.2 CONDUCTIVE PATTERNS – GENERAL（导电图形 – 总则）
Introduction（引⾔）
93IPC-A-600H-2010 2010年4月