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电镀锡或锡合金质量要求内容

2023-03-07 来源:步旅网
目

1.电镀工艺或外购件鉴定要求

7777788888

............................................................................................................................................. 7

1.1总则.................................................................................................................................................................................. 1.2工艺设计要求.................................................................................................................................................................. 1.3工艺鉴定程序.................................................................................................................................................................. 1.4试验及试样要求.............................................................................................................................................................. 1.4.1 试样要求 ...................................................................................................................................................................... 1.4.2 试验项目及试样数量 .................................................................................................................................................. 1.5试验方法及质量指标...................................................................................................................................................... 1.5.1 外观 .............................................................................................................................................................................. 1.5.2 镀层成份 ...................................................................................................................................................................... 1.5.3 镀层厚度 ......................................................................................................................................................................

1.5.4 结合强度 ...................................................................................................................................................................... 91.5.5 耐蚀性 .......................................................................................................................................................................... 91.5.6 可焊性及润湿性测试 .................................................................................................................................................. 91.6鉴定状态的保持............................................................................................................................................................ 132.电镀批生产中产品质量控制要求2.1

................................................................................................................................... 13

镀前表面质量要求 .................................................................................................................................................... 13

2.2镀后包装要求 ............................................................................................................................................................ 132.3电镀零件质量要求 .................................................................................................................................................... 132.3.1.外观........................................................................................................................................................................ 132.3.2.镀层厚度................................................................................................................................................................ 142.3.3.2.3.4.2.3.5.

结合强度................................................................................................................................................................ 14耐蚀性.................................................................................................................................................................... 14可焊性及润湿性.................................................................................................................................................... 14

3.参考文献........................................................................................................................................................................... 14

表目录

表1 鉴定试验项目及试样数量

............................................................................................................................................ 8

图目录

图1.功放基板上功率管器件开槽焊接位置图纸位置示例图2.功率管开槽详细设计信息示例

.............................................................................................. 5

.................................................................................................................................. 5

.............................................................................................. 6

图3.功放基板上功率管器件凸台焊接位置图纸位置示例图4.功率管凸台详细设计信息示例

.................................................................................................................................. 6

图5.外观要求图.................................................................................................................................................................. 8图6.润湿性测试钢网设计要求图7.润湿性测试锡膏印刷要求

........................................................................................................................................ 10 ........................................................................................................................................ 10

............................................................................................................................ 11

图8.润湿性测试后铺展直径测试方法图9.润湿性满足要求功放基板图10.润湿性满足要求功放基板图11.润湿性不满足要求功放基板

........................................................................................................................................ 11 ........................................................................................................................................ 12 .................................................................................................................................... 12

图12.润湿性不满足要求功放基板 .................................................................................................................................... 13

错误!未找到引用源。

围:

本规规定了在铜、铝基体表面电镀纯锡(或锡合金)和在钢基材表面电镀

“高温锡”的工艺要求及其质量要求。

本规适用于华为技术各种产品(包括定制加工件、外购件)上的电镀锡和电镀“高温锡”的工艺鉴定或产品鉴定、

以及电镀批生产中的质量控制和检验。

本规所要求的电镀层只适用于一般环境,其目的主要是保证表面的可焊性。本规不适用于马口铁(镀锡钢板)材料的检验。

简介:

锡电镀层、“高温锡”层均属于功能性镀层,其目的主要是增加材料表面的可焊性,“高温锡”镀层可以承受更高的焊接温度。本规根据华为产品的具体要求而规定了镀层的种类(不允许含铅镀层)、镀层应该达到的各项性能指标。本规分两部分,第一部分“工艺鉴定要求”规定了电镀加工商必须保证的技术管理、工艺设施及产品质量水平要求,用作对电镀商进行技术资格认证和电镀首样的质量鉴定,是华为对电镀工艺和电镀件进行质量鉴定的依据;第二部分规定了正常批生产条件下电镀零件的质量要求,是电镀生产方控制批生产镀层质量的标准依据,也是产品验收的质量依据。本规也可作为电镀零件或产品设计、产品采购的依据。华为公司对来料的质量检验方法可参考本规执行。

关键词:

电镀,锡,高温锡

引用文件:

下列文件中的条款通过本规的引用而成为本规的条款。凡是注日期的引用文件,其随后所有的修改单(不包括勘误的容)或修订版均不适用于本规,然而,鼓励根据本规达成协议的各方研究是否可使用这些文件的最新版本。凡是不注日期的引用文件,其最新版本适用于本规。

序号1 2 3 4

文件编号IEC 60068-2-11 ISO 1463 ISO 3497 DKBA2332

基本环境试验程序金属和氧化物覆盖层金属覆盖层厚度测量华为采购物料环保规

文件名称

.第2部分:试验.试验Ka:盐雾覆盖层厚度的测定X射线光谱方法

显微法

等效标准GB 2423.17 ASTM B117 GB 6462 GB/T 16921

术语和定义:

术语

高温锡平均厚度生产批外购件

定义

一种特殊的锡合金电镀层,其主要特点是可以在高达生镀层金属的熔化、起皮、起泡等现象。

在规定区域进行5至10次厚度测量的算术平均值。

指同一天在相同条件下处理的、材料和形状相似的零件的总和

指业界已成熟、商品化的、由一级供应商直接采购的功能零部件。包括紧固件、屏蔽材料、防尘网、铰链、拉手把手、绝缘材料、橡胶、电子元器件保护固定座、脚垫、地脚、电缆辅料(包括热缩套管、编织网、防水胶带、接插件螺钉、焊锡等)等。

晶须标准胶带功放基板功率管开槽

从锡金属晶粒上因应力作用而生长出来的一种细长锡丝

指能够满足在镀层上的粘附强度不低于(10±1)/25mm的、不会有胶转移到镀层上的(无残胶)单面胶带,其宽度不低于20mm。指用于散热的金属块,如图

1所示。

0.05mm,

260℃的焊接温度下不发

指功放基板上的方形开槽,开槽深度精度要求一般在图纸上注明为是用于与功率管器件的焊接的位置,计如图2所示。

图纸标识如图1所示,功率管开槽详细设

功率管凸台

指功放基板上的方形凸台,凸台高度精度要求一般在图纸上注明为0.05mm,是用于与功率管器件的焊接的位置,图纸标识如图1所示,功率管凸台详细设

术语

计如图4所示。

功放基板关键焊接位置

定义

指功放基板的焊接面(功率管开槽或凸台对应的面,如图1所示)大平面(在同一平面上,不包含在不在同一平面上的沟槽)及功率管开槽或凸台表面的位置

焊接面

功率管开槽

图1.功放基板上功率管器件开槽焊接位置图纸位置示例

类型一功率管开槽设计

类型二功率管开槽设计

图2.功率管开槽详细设计信息示例

焊接面

功率管凸台

图3.功放基板上功率管器件凸台焊接位置图纸位置示例

图4.功率管凸台详细设计信息示例

1. 电镀工艺或外购件鉴定要求

1.1 总则

本规要求的电镀层包括纯锡和“高温锡”。不允许镀层中含有铅、镉等不符合环保要求的物质或其它杂质。镀层的光泽不限制(以半光亮或无光镀层为最佳),但必须能够证明其镀层不会产生晶须。

电镀生产者的工艺设备、工艺流程、质量保证措施应在其主要的工艺文件中加以说明。生产者的工艺质量必须满足第1节的要求。

有锡或锡合金镀层要求的外购件的认证及首样鉴定应参照第

1节的要求进行。

1.2 工艺设计要求

按本规要求进行的电镀工艺,均需要铜或镍底镀层。生产者应保持并遵守经华为技术正式批准的工艺和检验文件。

1.3 工艺鉴定程序

被鉴定的工厂必须完成以下全部试验工作,这些试验必须在零件批生产所用的条件下完成:

试样加工表面处理

(注1)(注2)

试样检查及测试

提供试验报告(注3)及试验后的试样、以及一组新的试样给华为技术以便复验。

注1:鉴定用试样可由华为技术完成并提供给被鉴定工厂。注2:所有试样必须同时进行处理。

注3:试验报告的发出者必须是华为技术认可的试验室或机构。

(试样数量参见表1)

1.4 试验及试样要求1.4.1 试样要求

1) 挂镀工艺

材料:根据生产要求选择铜、铝或钢尺寸:25×100×0.3 ~4 (mm) 表面粗糙度:Ra ≤ 1μm

表面处理:根据生产要求进行镀锡、或者

“高温锡”

2) 非挂镀工艺

材料:根据生产要求选择铜或铝合金

尺寸:依工艺设备特点选择适当形状和大小的试样表面粗糙度:Ra ≤ 1 μm表面处理:镀锡

3) 外购件试样要求

每一种型号的外购件均按表1的要求直接抽取规定数量的采购状态成品作为试验样品。的镀锡或锡合金部分单独取下作为试验样品。本文所提到的试样表面均是指锡镀层表面。

必要时,可以将外购件上

1.4.2 试验项目及试样数量

表1给出了镀锡工艺或外购件鉴定所需的试验项目和试样数量要求。

表1 鉴定试验项目及试样数量

试验项目

外观

铅、镉、汞含量及镀层成份镀层厚度结合强度耐蚀性可焊性

试样数量(件)

所有试样1 3 3 3 3

1.5 试验方法及质量指标1.5.1 外观

所有试样均进行目视外观检查。

锡镀层为银白色或略带浅黄色;镀层光泽可以是亚光型或光亮型;且镀层结晶均匀、细致、平滑。挂镀件允许在隐蔽部位有轻微的夹具印。

允许因基体材质不均和表面加工状态不同而表现出的轻微的颜色或光泽不均匀现象。

不允许有斑点、黑点、烧焦、粗糙、针孔、麻点、裂纹、分层、起泡、起皮、脱落、晶状镀层、局部无镀层等缺陷。

镀锡衬底由于烘烤氧化导致的发黄和发黑,在不影响可焊性的前提下,衬底侧面发黄或发黑不做要求,衬底正面及背面允许发黄或轻微发黑,具体要求为:允许距离衬底边缘下图所示。

10mm围发黄;允许距离衬底边缘

1mm围发黑;如

a)合格

图5.外观要求图

b)不合格

1.5.2 镀层成份

在一件试样上进行镀层成份检测。要求镀层中不能含有铅、要求。同时纯锡镀层中锡的含量不能低于99%。

镉、汞、六价铬等有害物质,符合Q/DKBA 3002 的

1.5.3 镀层厚度

纯锡镀层用X射线荧光光谱测厚仪在三个试样上进行厚度检测,测厚法(参见GB 6462)检测。“高温锡”镀层采用金相测厚法(参见

检测方法参考ISO 3497,必要时也可采用金相

ISO 1463)检测

1、对功放基板:

对纯锡镀层,在每一试样上镀层除背面、孔壁、深度大于直径或开口宽度的部分不规定厚度外,关键焊接位置镀层厚度要求为:

(1)对纯铜基材(Cu基材/Cu/Sn或Cu基材/Ni/Sn)铜镀层:最薄处不低于4μm;镍镀层:电镀镍最薄处不低于5μm,或化学镍最薄处不低于3μm;锡镀层:平均厚度为8~12μm,最薄处大于6μm。

(2)对铝基材(Al基材/Cu/Sn或Al基材/Ni/Sn)

铜镀层:最薄处不低于10μm;镍镀层:电镀镍最薄处不低于厚度为8~12μm,最薄处大于6μm。

2、对其他结构件:

在每一试样上镀层平均厚度要求为:镍或铜底镀层不低于“高温锡”镀层要求平均总厚度至少50μm。

5μm,或化学镍最薄处不低于3μm;锡镀层:平均

4μm、锡或锡合金镀层为8 - 12μm 。

1.5.4 结合强度

在三件试样上进行结合强度试验。

对纯锡镀层:将试样放在恒温箱中,使其在

220℃下保持

15min,然后自然冷却。然后在镀层上贴紧标准胶带,

5min

5min后迅速拉扯胶带,要求镀层无剥落、起皮或起泡现象。

对“高温锡”镀层:将试样放在260℃的烘箱保温15min 后,然后自然冷却。然后在镀层上贴紧标准胶带,后迅速拉扯胶带,要求镀层无剥落、起皮或起泡现象。

若外购件上含有不耐高温部分时,其上的镀锡部分必须单独取下进行本试验。试验中注意:必须从恒温箱达到规定温度值开始计时,恒温箱的温度波动不能超过±5℃。

1.5.5 耐蚀性

在三件试样上进行耐蚀性试验。按IEC 60068-2-11方法进行迹象。

24h 的中性盐雾试验。试验后,在试样表面不能出现任何黑色、绿色、红色腐蚀

1.5.6 可焊性及润湿性测试

1.一般要求

在三件试样上进行可焊性试验。方法和要求如下:

(1)锡炉中的焊料及其温度:采用普通锡铅焊料,温度维持在235℃±5 ℃之;

(2)用不锈钢刮板刮去熔融焊料表面上的氧化层、残渣以及助焊剂燃烧后的残留物,立即将样件垂直浸入锡炉,浸入深度≥10mm;

(3)在熔融焊料停留时间约5秒后,从熔融焊料中取出样件并在空气中冷却固化。

(4)冷却后即用10倍放大镜检查样件表面的润湿性,在检测前可使用酒精等物质清洗掉焊剂残留物。(5)质量要求:每一个浸入熔融焊料的焊端表面被焊料润湿连续、良好,其上的焊料覆盖面积比≥95%,焊料润湿可以是不规则外形,其针孔、不润湿和缩锡缺陷的总面积低于5%,且分散分布。具体要求可参见《IPC/EIA/JEDEC J-STD-002》标准。

2.功放基板可焊性测试要求及方法:

在三件试样上关键焊接位置进行可焊性试验及溶蚀性试验,方法和要求如下:(1)测试材料及设备要求:

1)焊锡丝焊料成分要求:对于有铅测试,成分要求为Sn60/Pb40或Sn63/Pb37,采用ROL0型;2)加热设备为热板炉(2)测试前准备要求:

在进行可焊性测试前,首先对试样进行蒸汽老化,老化条件为在饱和蒸汽条件下老化8小时。详细要求可参见《IPC/EIA/JEDEC J-STD-002A》标准。

(3)可焊性测试方法及步骤:

1)测试目的:

本测试是为模拟衬底板回流焊接过程中实际的焊接性能。2)测试步骤:

a)将衬底板放在热板炉上加热,要求衬底焊接面的温度达到

210±5℃(温度越低测试条件越恶劣);

b)在关键焊接位置加锡(焊锡丝),锡量以铺满关键焊接位置为准,焊锡熔化后加热时间为1min;c)然后将样品从加热台平移到冷却台冷却固化;

d)冷却后即用10倍放大镜检查样件表面的润湿性,在检测前需要使用酒精等物质清洗掉焊剂残留物。

e)评估标准

合格标准:每一个测试位置暴露出底层的非润湿基材或金属化层部分的表面积≤5%可焊端子的表面积。拒收标准:所有测试位置中只要有一个暴露出底层的非润湿基材或金属化层部分的表面积≥5%可焊端子的表面积。

(4)耐熔蚀测试方法及步骤1)测试目的:

:

本测试是为测定由于如下原因造成可焊性损失的敏感度:

a)非可焊性基材上的金属镀层的溶解(表现为润湿性下降或缩锡);b)来自基材的杂质累积(表现为缩锡)。2)测试步骤:

a)将衬底板放在热板炉上加热,要求衬底板焊接面上温度为220±5℃(温度越高测试条件越恶劣);b)在关键焊接位置加锡(焊锡丝),锡量以铺满关键焊接位置为准,焊锡熔化后加热时间为8min;c)然后将样品从加热台平移到冷却台冷却固化;

d)冷却后即用10倍放大镜检查样件表面的润湿性,在检测前需要使用酒精等物质清洗掉焊剂残留物。e)评估标准

合格标准:每一个测试位置暴露出底层的非润湿基材或金属化层部分的表面积≤5%可焊端子的表面积。拒收标准:所有测试位置中只要有一个暴露出底层的非润湿基材或金属化层部分的表面积≥5%可焊端子的表面积。

3.功放基板润湿性测试要求及方法:

在三件试样上关键焊接位置进行润湿性试验,方法和要求如下:(1)测试材料及设备要求:

1)锡膏要求:对于有铅测试,锡膏成分要求为型,锡粉目数为-325/+500。

2)印锡小钢网:钢网厚度

Sn60/Pb40、Sn63/Pb37或者Sn62/Pb36/Ag2。锡膏采用ROL0

0.2mm,圆孔直径6.5mm,孔间距10mm。如下图所示:

图6.润湿性测试钢网设计要求

3)加热设备为热板炉:热板炉温度设置为(2)润湿性测试方法及步骤:

220度。

1)测试目的:

本测试是为模拟衬底板回流焊接过程中实际的润湿性能。2)测试步骤:

a)首先在衬底上的关键焊接位置使用钢网印刷锡膏,锡膏厚度为

0.2mm~0.3mm,如下图所示;

图7.润湿性测试锡膏印刷要求

b)然后将衬底板放在热板炉上加热,从锡膏熔化开始计时,在锡膏熔化中冷却固化;

c)冷却后测量锡膏的铺展直径及润湿情况。

90s后将衬底移开热板炉加热区在空气

d)评估标准

合格标准:6.5mm≤润湿铺展直径≤11mm 拒收标准:所有测试的位置润湿铺展直径<6.5mm或>11mm。

图8.润湿性测试后铺展直径测试方法

图9.润湿性满足要求功放基板

图10.润湿性满足要求功放基板

图11.润湿性不满足要求功放基板

图12.润湿性不满足要求功放基板

1.6 鉴定状态的保持

经过华为技术鉴定的工艺,在未得到华为技术的同意之前,不能改变任何可影响性能质量的工艺参数,否则将重新进行鉴定.。

2. 电镀批生产中产品质量控制要求

2.1 镀前表面质量要求

应无严重油污、金属屑、油漆油墨层以及锈蚀和氧化皮等;

零件表面应无毛刺、裂纹、压坑等因操作不良而导致的人为损伤;表面划伤不能超出对零件平面度的要求;焊接件应无针孔、焊料剩余物和溶渣等。

2.2 镀后包装要求

需要焊接的零件必须在电镀完成后立即进行密封包装。

密封包装形式可以用PE塑料袋抽真空密封、也可以放干燥剂密封,或者采用其它等效方法。不允许使用袋”或PVC膜。

“气泡

2.3 电镀零件质量要求2.3.1. 外观

所有零件都应进行目视外观检查。

镀层为银白色或略带浅黄色,且镀层结晶均匀、细致、平滑。挂镀件允许在隐蔽部位有轻微夹具印。

允许因基体材质不均和表面加工状态不同而表现出的轻微的不均匀颜色或光泽;允许高温检验后的零件表面有轻微变黄色。

不允许有斑点、黑点、烧焦、粗糙、针孔、麻点、裂纹、分层、起泡、起皮、脱落、晶状镀层、局部无镀层(在盲孔、通孔深处及技术文件有规定的除外)等缺陷。

2.3.2. 镀层厚度

厚度检查在零件上进行;每生产批零件至少检测5 件。用X射线荧光光谱测厚仪在零件上进行厚度检测。检测方法参考

GB/T 16921 。

1、对功放基板:

对纯锡镀层,在每一试样上镀层除背面、孔壁、深度大于直径或开口宽度的部分不规定厚度外,关键焊接位置镀层厚度要求为:

(1)对纯铜基材(Cu基材/Cu/Sn或Cu基材/Ni/Sn)

铜镀层:最薄处不低于4μm;镍镀层:电镀镍最薄处不低于5μm,或化学镍最薄处不低于3μm;锡镀层:平均厚度为8~12μm,最薄处大于6μm。

(2)对铝基材(Al基材/Cu/Sn或Al基材/Ni/Sn)铜镀层:最薄处不低于10μm;镍镀层:电镀镍最薄处不低于平均厚度为8~12μm,最薄处大于6μm。

2、对其他结构件:凡能被直径为20 mm

的球接触到的区域,镍或铜底层应不低于

5μm,或化学镍最薄处不低于

3μm;锡镀层:

4μm ;锡或锡合金镀层为8~12μm ;

凡直径为20 mm 的球不能接触到的区域,其厚度不作要求。规定厚度。

对带螺纹的零件,应优先保证螺纹尺寸。“高温锡”镀层总厚度不低于50μm。

孔壁、以及深度大于直径或开口宽度的部分不

2.3.3. 结合强度

所有零件都需进行检查。

将试样放在恒温箱中,电镀纯锡零件需在

220℃下保持15min,电镀“高温锡”的零件需在260℃度的烘箱保温

5min后迅速拉扯掉胶带,要求镀层无剥落、起皮或起泡现象。

15min,然后自然冷却。然后在镀层上贴紧标准胶带,

2.3.4. 耐蚀性

镀“高温锡”的零件每生产批均需要进行本项检测,至少在三件试样或零件上进行耐蚀性试验。

按IEC 60068-2-11方法进行24小时的中性盐雾试验。试验后,在试样表面不能出现任何黑色、绿色、红色腐蚀迹象。

2.3.5. 可焊性及润湿性

可焊性检测在样件上进行,样件必须是与该批零件相同的基材并同时进行相同的表面处理;每生产批零件至少检测1 件。

试验应在电镀24h 以后、1月之进行。检验方法和要求见1.5.6节。

3. 参考文献

制定本规参考的文献,但没有直接引用里面的容

序号

1 2 3 4 5 6 7 8 9 10 11

文献编号或出处

GB 5270 GB 12599 GB/T 17461 HB 5046 HB 5049 JB 2836 QJ 457 QJ/Z 55 SJ 1276

SJ 42

ISC/QU-01-01-05/W35

金属覆盖层金属覆盖层

文献名称

金属基体上的金属覆盖层(电沉积层和化学沉积层)附着强度试验方法

锡电镀层技术规和试验方法锡-铅合金电镀层

锡镀层质量检验

铅锡合金镀层质量检验

电工产品的电镀层和化学覆盖层锡镀层技术条件锡镀层生产说明书

金属镀层和化学处理层质量检验技术要求

金属镀层和化学处理层的分类、特性、应用围和标记元器件可焊性检验操作指导书

TABLE OF CONTENTS

1APPRAISAL REQUIREMENTS FOR ELECTROPLATING PROCESS OR PURCHASED EQUIPMENT 1.11.21.31.41.4.1.1.4.2.1.51.5.1.1.5.2.1.5.3.1.5.4.1.5.5.1.5.6.1.6

...... 21

GENERAL PRINCIPLE.................................................................................................................................................. 21REQUIREMENTS FOR PROCESS DESIGN...................................................................................................................... 21PROCEDURE OF PROCESS APPRAISAL ........................................................................................................................ 21REQUIREMENTS FOR TESTS AND SAMPLES................................................................................................................. 21Requirements for Samples ...................................................................................................................................... 21Test Items and Quantity of Samples ....................................................................................................................... 22TEST METHODS AND QUALITY INDEXES .................................................................................................................... 22Appearance ............................................................................................................................................................ 22Elements of Coating ............................................................................................................................................... 23Thickness of Coating .............................................................................................................................................. 23Binding Strength ..................................................................................................................................................... 23Corrosion Resistance ............................................................................................................................................. 24Solderability and Wettability .................................................................................................................................. 24RETENTION OF APPRAISAL STATUS............................................................................................................................ 28

28

2REQUIREMENTS FOR QUALITY CONTROL DURING ELECTROPLATING BATCH PRODUCTION ......

2.1REQUIREMENTS FOR SURFACE QUALITY BEFORE ELECTROPLATING....................................................................... 282.2PACKAGE REQUIREMENTS FOR ELECTROPLATED PARTS.......................................................................................... 292.3QUALITY REQUIREMENTS FOR ELECTROPLATED PARTS........................................................................................... 292.3.1.Appearance ............................................................................................................................................................ 292.3.2.Thickness of Coating .............................................................................................................................................. 292.3.3.Binding Strength ..................................................................................................................................................... 302.3.4.Corrosion Resistance ............................................................................................................................................. 302.3.5.Solderability and Wettability .................................................................................................................................. 303REFERENCE DOCUMENT

.......................................................................................................................................... 30

LIST OFTABLES

TABLE 1 TEST ITEMS AND QUANTITY OF SAMPLES

........................................................................................... 22

LIST OF FIGURES

FIGURE 1.FIGURE 2.FIGURE 3.FIGURE 4.FIGURE 5.FIGURE 6.FIGURE 7.FIGURE 8.FIGURE 9.

EXAMPLES OF SOLDERING POSITIONS OF THE PA SLOTS ON THE HEAT-SINK ................. EXAMPLES OF DETAILED DESIGN OF THE PA SLOT .................................................................... EXAMPLES OF SOLDERING PROTRUDEDABLE POSITIONS FOR PA ON THE HEAT-SINK 20

EXAMPLES OF DETAILED DESIGN OF THE PROTRUDEDABLE POSITION FOR PA OF THE

HEAT-SINK .................................................................................................................................................. 20REQUIREMENTS FOR THE APPEARANCE

......................................................................................... 23

........................................... 26

26271919

REQUIREMENTS FOR STENCIL DURING WETTABILITY TESTING

REQUIREMENTS FOR SOLDER PASTE DURING WETTABILITY TESTING .............................. MEASURING SPREADING DIAMETER AFTER WETTABILITY TESTING .................................. PA BASE BOARD MEETING THE REQUIREMENTS FOR WETTABILITY

................................... 27................................... 27

2828

FIGURE 10.PA BASE BOARD MEETING THE REQUIREMENTS FOR WETTABILITY

FIGURE 11.PA BASE BOARD NOT MEETING THE REQUIREMENTS FOR WETTABILITY ......................... FIGURE 12.PA BASE BOARD NOT MEETING THE REQUIREMENTS FOR WETTABILITY .........................

错误!未找到引用源。

Scope

This document stipulates the process requirements and quality requirement for electroplating pure tin and tin alloy on the surface of such matrixes as copper and aluminum, and for electroplating high-temperature tin on steel.

The technical specifications herein are applicable to the design of electroplating tin and high-temperature tin on the surface of Huawei’s various products (including custom-made products and purchased equipment), appraisal of

the electroplating process or electroplated products, and quality control & inspection for electroplating batch production.

The electroplated coating herein is only suitable to a general environment with a view to ensuring the solderability

of surface. The technical specifications herein are not applicable to the parts made of tinplate (tin plated steel sheet).

Brief Introduction

The pure tin and high-temperature tin electroplated coating is a functional coating, which is mainly intended to enhance the solderability of the material surface. The high-temperature tin can support higher weld temperature.

The technical specifications herein stipulate the variety of coatings (a lead-bearing electroplated coating is not allowed) and the required performance indexes for each coating. The technical specifications comprise two parts. Part I “Appraisal Requirements for Electroplating Process or Purchased Equipment” stipulates the requirements for the electroplating manufacturer’s technological management, process equipment, and product quality. It is used to certify the electroplating manufacturer’s technical qualification and appraise its electroplating samples. Generally, it is the criteria of quality appraisal for the tin electroplating process and electroplated products. Part II “Requiremenfor Quality Control During Electroplating Batch Production” stipulates the quality requirements for the electroplated parts under the normal batch production conditions. Generally, it is the manufacturer's criteria of quality control for electroplating batch production, as well as the quality criteria for product inspection. The technical specifications

herein can also serve as the criteria for the design of electroplated parts/products and the procurement of electroplated products. Huawei can inspect the quality of the incoming materials in compliance with the technical specifications herein.

Keywords

Electroplating, Tin, High-temperature

Normative references

The following normative documents contain provisions which, through reference in this text, constitute provisions of the specifications. For dated references, subsequent amendments, excluding corrections, to, or revisions of, any of these publications do not apply. However, parties to agreements based on this specification are encouraged to

investigate the possibility of applying the most recent editions of the normative documents. For undated references, the latest edition of the normative document referred to applies.

No. Document No. Document Title

Equivalent Standard

GB 2423.17 ASTM B117 GB 6462

1 IEC 60068-2-11

Basic environmental testing procedures. Part 2 : Tests. Test Ka: Salt mist

Metallic and oxide coatings – Measurement of coating thickness – Microscopical method Metallic coatings - Measurement of coating thickness - X-ray spectrometric methods

2 ISO 1463

3 ISO 3497 GB/T 16921

4 DKBA2332

Environmental Regulations For the Purchase of Materials

Term & Definition

Term

High-temperature tin

Definition

A special tin alloy electroplating coat, which can not meltbe bubble on weld temperature of 260

、peel and

Average thickness The arithmetic mean value of the thickness that is measured for five to ten times in the specified area

Batch

The sum of the parts with the similar materials and shape that are processed in the same conditions on the same day

The purchased products or components that are not designed or produced by Huawei

A long and thin tin silk that grows from the tin metal grains due to the stress effect

Single-faced tape (residue-free) whose adhesion strength is not less than (101)/25 mm and whose width is not less than 20 mm. ±Metal block for dissipating heat, as shown in

Purchased equipment

Tin whisker

Standard tape

PA base board

错误!未找到引用

源。.

Power tube slot

Square slot on the PA base board where the power tube components are soldered, as shown in See 错误!未找到引用源。power tube slot.

Polarizing key of power tube

Square polarizing key on the PA base board where the power tube components are soldered, as shown in 错误!未找到引用源。The precision of slot depth is marked as 0.05 mm on the drawing. See 错误!未找到引用源。polarizing keys of the power tube.

Key soldering position of the PA

base board

The large plane (grooves in the same plane rather than grooves in different planes) of solder side (the same as the slot or polarizing keys of the power tube) of the PA base board and position inside the power tube or on the surface of the polarizing key.

for the detailed design of the

错误!未找到引用源。.

The precision of slot depth is marked as 0.05 mm on the drawing.

for the detailed design inside the

.

soldering face

Slots for PA

Figure 1.

Examples of soldering positions of the PA slots on the heat-sink

Type 1 slots for PA

Type 2 slots for PA

Figure 2.

Examples of detailed design of the PA slot

soldering face

the protrudedable position for PA

Figure 3.

Examples of soldering protrudedable positions for PA on the heat-sink

Figure 4. Examples of detailed design of the protrudedable position for PA of the heat-sink

1 Appraisal Requirements for Electroplating Process or Purchased Equipment

1.1 General Principle

As required by the technical specifications, the tin and high-temperature tin electroplated coating must be pure tin and must not contain any environmental unfriendly mater (for example, lead and cadmium) or other impurity. The coating luster is not restricted (preferably, the coating is semi-glossy or lusterless). However, it must be certified that the coating will not generate any tin whisker.

The electroplating manufacturer’s processing equipment, process flow, and quality assurance measures should be described in its main process documents. The producer’s process quality should come up to the requirements as stipulated in Section 1.

If the purchased equipment has a tin or tin alloy coating, certification and sample appraisal should be performed in accordance with Section 1.

1.2 Requirements for Process Design

As required by the technical specifications herein, copper or nickel coat must be present as the bottom. The manufacturer should abide by the process documents and inspection documents approved by Huawei officially.

1.3 Procedure of Process Appraisal

The factory to be appraised should complete all the following tests upon condition that the parts are produced in batches.

Sample processing (Note 1) Surface treatment (Note 2) Sample inspection and test

The factory should provide the test report (see Note 3), tested samples, and a group of new samples to Huawei for the purpose of reinspection (For details, see Table 1).

Note 1: The test pieces can be arranged and provided by Huawei for the factory. Note 2: All samples must be processed at a time.

Note 3: The test report must be released by a laboratory or institution recognized by Huawei.

1.4 Requirements for Tests and Samples 1.4.1. Requirements for Samples

1) Rack Plating Material: copper Size: 25

、aluminum or steel.

100 ×× 0.3 to 4 (mm)

≤ 1 μm

Surface roughness: Ra

Surface treatment: electroplating tin or high-temperature

2) Non-Rack Plating

Material: copper or aluminum alloy.

Size: The shape and size of the samples should be suited to the process equipment and process features. Surface roughness: Ra

≤ 1 μm

Surface treatment: electroplating tin

3) Requirements for Sample of Purchased Equipment

For each model of purchased equipment, a specified number of purchased products should be sampled, as described in Table 1. If necessary, the tin or tin alloy electroplating parts in the purchased equipment can be sampled separately. The sample surface herein refers to the surface of the tin coating.

1.4.2. Test Items and Quantity of Samples

Table 1 describes the required test items and quantity of samples.

Table 1 Test items and quantity of samples

Test Item

Appearance

Content of lead, cadmium, and mercury, and elements of the coating Thickness of coating Binding strength Corrosion resistance

Quantity of Samples

All samples 1

3 3 3 3

Solderability

1.5 Test Methods and Quality Indexes 1.5.1. Appearance

All samples should undergo appearance inspection.

The pure tin coating should be silvery white or a little pale yellow. The coating can be semi-glossy or glossy. The coating crystallization should be even, tiny, and smooth. A rack plated product allows tiny clamp marks in the hidden parts.

Considering the unevenness of materials and difference in the status of surface finishing, slight uneven colors or luster is allowed.

The following defects are not allowed: spot, macula, scorch, roughness, delamination, bubble, peeling, fall-off, crystallized coating, and no coating locally.

pinhole, pock, crackle,

Without affecting solderability, yellowness and blackness due to baking oxidation are not specified at the sides of the tin-plated base materials and are allowable at the front and rear surfaces. To be specific, it is allowable if yellowness within 10 mm away from the edge of the base materials and blackness within 1 mm away from the edge of the base materials, as shown in 错误!未找到引用源。.

a)allowed

Figure 5.

b)not allowed

Requirements for the appearance

1.5.2. Elements of Coating

Assay the elements of the coating in one sample. The coating should not contain any harmful matter (for

example, lead, cadmium, mercury, and sexavalent chrome), and should comply with Q/DKBA3002. In additionally, the content of tin in the pure tin electroplated coating should be not lower than 99%.

1.5.3. Thickness of Coating

Measure the thickness of coatings in three samples by using x-ray fluorescence. For details on the measurement method, refer to GB/T 16921. If necessary, you can also measure the coating thickness through metallography (for details, refer to GB 6462). Measure the thickness of high-temperature tin coating thickness also through metallography (for details, refer to GB 6462)

For each sample of tin electroplating, the average coating thickness should be as follows: Bottom copper coating: at least 4 Tin coating, or nickel coating at least 3um, tin coating 8 to 12 μm1. Coat of the PA base board:

For samples coated with pure tin, the coat thickness is not specified on the rear side, the inner walls of the holes, or the parts whose depth is greater than the diameter or the opening width. The requirements for coat thickness of key soldering positions are as follows:

For pure copper base materials (Cu base materials /Cu/Sn or Cu base materials /Ni/Sn) 4 μm at least for copper coat; 5 μm at least for nickel coat (or 3 at least for tin coat with the average thickness of 8–12 μmFor aluminum base materials (Al base materials /Cu/Sn or Al base materials /Ni/Sn) 10 μm at least for copper coat; 5 μm at least for nickel coat (or 3 μm at least for tin coat with the average thickness of 8–12 μm.2. Coats of other components:

The average coat thickness of each sample should meet the following requirements: 4 μm at least for nickel or copper coat; 8–12 μm for tin or tin alloy coat.For high-temperature tin is more than 50um.

μm at least for electroless nickel coat); 6 μm at least for electroless nickel coat); 6

μm.

1.5.4. Binding Strength

Test the binding strength for three samples.

For tin coating, heat the sample in a thermostat in a temperature of 220C for 15min, and then cool the sample naturally. Paste the standard adhesive tape on the sample, than tear it down 5min later. Inspect the coating, and ensure that no fall-off, peeling, or bubble occurs.

For high-temperature tin coating, heat the sample in a thermostat in a temperature of less than 260

15min, and then cool the sample naturally. Paste the standard adhesive tape on the sample, than tear it down 5min later. Inspect the coating, and ensure that no fall-off, peeling, or bubble occurs.

If the purchased product has a heat-sensitive part, remove the tin-plated part separately for the binding strength test.

C for

Caution: the test time start when the thermostat reach the requirement value, and the fluctuate of the temperature of the thermostat is not allowed beyond 5C.

1.5.5. Corrosion Resistance

Conduct the corrosion-resistance test in three samples.

Conduct a 24-hour neutral salt spray test (NSS test) by using the IEC 60068-2-11 method. After the test, ensure that no black、green or red corrosion occurs in the surface of the sample.

1.5.6. Solderability and Wettability

1. General Requirements

Test the solderability on three samples. The following describes the test method and requirements. (1) Use common tin/lead (SnPb) solder and maintain the temperature of the solder pot at 235

C±5°C.

(2) Scrape off the oxide layer, residues and the burned flux from the surface of the molten solder with a stainless steel spatula. Then immerse the sample into the solder pot vertically to a depth of equal to or greater than 10 mm.

(3) Dip in the molten solder for five seconds, take the sample out, and solidify them by air cooling. (4) Remove the flux residues by using detergents such as alcohol, and then use a 10X magnifier to check the wettability of the sample surfaces.

(5) Quality requirements: The surfaces of the portion which is immersed in the molten solder shall exhibit a continuous solder coating with a minimum coverage of 95%. The solder coating can be irregular, of which the pin holes, nonwetting or dewetting must not exceed 5% of the total area and must be evenly distributed. See the IPC/EIA/JEDEC J-STD-002 for detailed requirements. 2. Solderability Test Requirements and Method of the PA Base Board

Test the solderability and corrosion of the key soldering positions on three samples. (1) Materials and device: Requirements for solder wires: The leaded solder wires shall conform to Sn60/Pb40 or Sn63/Pb37

type ROL0. Heating stove

(2) Preparation before testing

Before the solderability test, perform steam aging on the samples by exposing the samples to saturated vapor for eight hours. See the IPC/EIA/JEDEC J-STD-002A for detailed requirements. (3) Methods and procedures for solderability testing Purpose:

Test the actual soldering performance of a heat-sink by simulating a reflow process. Procedures:

°

and

Heat the heat-sink on a heating stove with the temperature of the 210

C±5°C at the soldering side (the °

lower the temperature is, the worse the solderability test conditions become).

Cover the key soldering positions with tin (or tin wires). Heat one minute after the soldering tin melts. Move the sample horizontally from the heating table to the cooling table for cooling and solidification. Remove the flux residues by using detergents such as alcohol, and then use a 10X magnifier to check the

wettability of the sample surfaces. Evaluation criteria

Acceptance criterion: The surface area of nonwettable base materials or metallization of the base material of each test position is less than or equal to 5% of the total area of the solderable terminals.

Rejection criterion: The surface area of nonwettable base materials or metallization of the base material of each test position is more than or equal to 5% of the total area of the solderable terminals. (4) Methods and procedures for melted corrosion resistance testing 1) Purpose:

Test the susceptibility to loss of solderability in the following conditions:

Dissolution of the metal coat over unsolderable base materials (as indicated by loss of wetting dewetting)

Accumulation of impurities from the base materials (as indicated by dewetting) 2) Procedures:

Heat the heat-sink on a heating stove with the temperature of the 210

C±5°C at the soldering side (the °

lower the temperature is, the worse the solderability test conditions become).

Cover the key soldering positions with tin (or tin wires). Heat one minute after the soldering tin melts. Move the specimens horizontally from the heating table to the cooling table for cooling and solidification.. Remove the flux residues by using detergents such as alcohol, and then use a 10X magnifier to check the

wettability of the sample surfaces. Evaluation criteria

Acceptance criterion: The surface area of nonwettable base materials or metallization of the base material of each test position is less than or equal to 5% of the total area of the solderable terminals.

Rejection criterion: The surface area of nonwettable base materials or metallization of the base material of each test position is more than or equal to 5% of the total area of the solderable terminals. 3. Wettability Test Method and Requirements of the Heat-sink Test the wettability of key soldering positions. (1) Materials and device:

Requirements for solder paste: The leaded solder paste shall conform to Sn60/Pb40, Sn63/Pb37 Sn62/Pb36/Ag2, and ROL0 type and shall have a mesh size of -325/+500.

Printed tin stencil: 0.2 mm in thickness, with holes of 6.5 mm across, and 10 mm as the distance between holes, as shown in Figure 6.

or or Figure 6. Requirements for stencil during wettability testing

C.

°

Heating stove: Temperature of the heating stove is set as 220(2) Methods and procedures for wettability testing 1) Purpose:

Test the actual wettability performance of the heat-sink by simulating the reflow process. 2) Procedures:

Use the stencil to place solder paste onto key soldering positions of the heat-sink. The solder paste is 0.2 mm to 0.3 mm thick, as shown in Figure 7.

Figure 7. Requirements for solder paste during wettability testing

Heat the heat-sink on the heating stove. Remove the heat-sink from the heating stove 90s after the solder paste melts, and solidify the plate by air cooling.

Measure the spreading diameter and wetting condition of the solder paste. Evaluation criteria

Acceptance criterion: 6.5 mm

≤ spreading diameter of positions under test

≤ 11 mm

Rejection criterion: spreading diameter of positions under test < 6.5 mm or spreading diameter of positions under test > 11 mm.

Figure 8. Measuring spreading diameter after wettability testing

Figure 9. PA base board meeting the requirements for wettability

Figure 10. PA base board meeting the requirements for wettability

Figure 11. PA base board not meeting the requirements for wettability

Figure 12. PA base board not meeting the requirements for wettability

1.6 Retention of Appraisal Status

Without prior consent of Huawei, do not modify the process parameters of any process appraised by Huawei, which may affect its performance quality. Otherwise, the process has to be appraised again.

2 Requirements for Quality Control During Electroplating Batch Production

2.1 Requirements for Surface Quality Before Electroplating

No serious oil stain, metal particles, paint ink lay, rust, or oxide skin is allowed.

Various misoperations-caused damages (burr, crackle, or indentation) are not allowed in the surface of every part. The superficial scratch should not exceed the range allowed by the flatness requirements. There should b no pinhole, welding remains or sprue on the surface of the weldment.

2.2 Package Requirements for Electroplated Parts

After the electroplating process is complete, the part to be welded should be sealed immediately.

The sealed package can be a vacuumized PE plastic bag (with drying agent if necessary) or equivalent. A bubbled bag or PVC film is not allowed.

2.3 Quality Requirements for Electroplated Parts 2.3.1. Appearance

All parts should undergo appearance inspection.

The pure tin coating should be silvery white or a little pale yellow. The coating crystallization should be even, tiny, and smooth.

A rack plated product allows tiny clamp marks in the hidden parts.

Considering the unevenness of materials and difference in the status of surface finishing, slight uneven colors or luster is allowed. If a part undergoes the high-temperature test, its surface can be a little yellow.

The following defects are not allowed: spot, macula, scorch, roughness, pinhole, pock, crackle, delamination, bubble, peeling, fall-off, crystallized coating, and no coating locally (except in a blind hole, deep position of a through hole, or other positions as stipulated by the related technical document).

2.3.2. Thickness of Coating

Thickness measurement is made in the parts. Among every batch of parts, at least five parts should be measured.

Measure the thickness of coatings in the parts by using x-ray fluorescence. measurement method, refer to GB/T 16921. 1. Coat of the PA base board:

For samples coated with pure tin, the coat thickness is not specified on the rear side, the inner walls of the holes, or the parts whose depth is greater than the diameter or the opening width. The requirements for coat thickness of key soldering positions are as follows:

For pure copper base materials (Cu base materials /Cu/Sn or Cu base materials /Ni/Sn) 4 μm at least for copper coat; 5 μm at least for nickel coat (or 3 at least for tin coat with the average thickness of 8–12 μmFor aluminum base materials (Al base materials /Cu/Sn or Al base materials /Ni/Sn) 10 μm at least for copper coat; 5 μm at least for nickel coat (or 3 μm at least for tin coat with the average thickness of 8–12 μm.2. Coats of other components:

4 μm at least for nickel or copper coat and 8~12um for the tin and tin alloy coat while the diameter of the square larger than 10mm.

There is no requirement of thickness while the diameter of the square smaller than 10mm. For the parts with screw thread, the dimension should be assured first. For high-temperature tin is more than 50um.

electroless nickel coat); 6 μm at least for

μm at least for electroless nickel coat); 6

For details on the

2.3.3. Binding Strength

All parts should be tested.

For tin coating, heat the sample in a thermostat in a temperature of 220C for 15min, and then cool the sample naturally. Paste the standard adhesive tape on the sample, than tear it down 5min later. Inspect the coating, and ensure that no fall-off, peeling, or bubble occurs.

For high-temperature tin coating, heat the sample in a thermostat in a temperature of less than 260

15min, and then cool the sample naturally. Paste the standard adhesive tape on the sample, than tear it down 5min later. Inspect the coating, and ensure that no fall-off, peeling, or bubble occurs.

C for

2.3.4. Corrosion Resistance

Conduct the corrosion-resistance test in three samples.

Conduct a 24-hour neutral salt spray test (NSS test) by using the IEC 60068-2-11 method. After the test, ensure that no black、green or red corrosion occurs in the surface of the sample.

2.3.5. Solderability and Wettability

The solderability test is conducted in a sample. The sample must have the same matrix material as the parts of this batch. Among every batch of parts, at least one sample should be tested.

The solderability test should be conducted within one month after 24 hours have passed upon completion of the electroplating.

For details on the test method and requirements, see section 1.5.6.

3 Reference Document

The following table lists the reference documents for the technical specifications, but no clauses are directly cited from these reference documents.

No.

1

Document No.

GB 5270

Document Title

Metallic coatings on metallic substrates chemically deposited coatings testing adhesion

– Electrodeposited and

– Review of methods available for

2 GB 12599 Metallic Coatings - Electroplated Coating of Tin-Specification and Test Methods

3 4 5 6

GB/T 17461 HB 5046 HB 5049 JB 2836

Metallic Coating - Electroplated Coating of Tin-lead alloys Quality Inspection for Electrodeposited Tin Coatings Quality Inspection for Tin-Lead Alloy Electroplated Coating Electroplated Coating and Chemical Coating of Electrotechnical

Products

Technical Conditions for Tin Electroplated Coatings Production Specifications for Tin Electroplated Coating Technical Requirements for Quality Inspection of Metallic Coatings and Chemically Treated Layers

7 8 9

QJ 457 QJ/Z 55 SJ 1276

10 SJ 42

Classification, Properties, Field of Applications, and Marking of Metallic Coatings and Chemically Treated layers Operation Guide to Inspection of Component

11 ISC/QU-01-01-05/W35

solderability

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