Altium Designer Documentation

Solder Mask Expansion

Modified by by Admin on Apr 11, 2017
All Contents

Rule category: Mask

Rule classification: Unary

Summary

The shape that is created on the solder mask layer at each pad and via site is the pad or via shape (or hole), expanded or contracted radially by the amount specified by this rule.

Constraints

Default constraints for the Solder Mask Expansion rule.

  • Expansion top - this constraint is used to specify the value applied to the initial pad/via shape (or hole) to obtain the final shape on the top solder mask layer.
  • Expansion bottom - this constraint is used to specify the value applied to the initial pad/via shape (or hole) to obtain the final shape on the bottom solder mask layer.
Use the  button to toggle between single, or separate expansions for the top and bottom sides of the board. When linked ( ), specify a value for the expansion in the Expansion top field. The Expansion bottom field will automatically inherit that same value. When unlinked ( ), you are free to specify different values for expansion, since the Expansion bottom field will become available to you for editing.
Enter a positive value to expand the mask, enter a negative value to contract it.
  • Solder Mask From The Hole Edge - use this constraint to determine the reference for the calculated mask expansion. When disabled, the perimeter of the object is used (the copper land edge for a pad or via). When enabled, the perimeter of the pad/via hole is used. For example, a 5mil Solder Mask Expansion applied to a 60mil diameter round pad will create a mask opening of 70mil (pad diameter + (2 x expansion)). If the reference is the hole edge, and the same pad had a hole diameter of 30mil, then the 70mil mask opening would be achieved by a 20mil expansion (hole diameter + (2 x expansion)).
The significance of the Solder Mask From The Hole Edge option is that when enabled, the Solder Mask opening will follow the shape of the pad or via hole. The mask is therefore independent of pad shape and size, and is scaled from both the hole size and shape. So for example, a pad/via with a square hole will create a square mask opening that matches the hole dimensions, plus the assigned expansion value. Also note that a pad or via's expansion mask opening size will track any changes in the hole size.

How Duplicate Rule Contentions are Resolved

All rules are resolved by the priority setting. The system goes through the rules from highest to lowest priority and picks the first one whose scope expression matches the object(s) being checked.

Rule Application

During output generation.

Tips

  1. Partial and complete tenting of pads and vias can be achieved by defining the appropriate value for the Expansion constraint:
    1. To partially tent a pad/via (covering the land area only) – if the expansion is from the land pattern perimeter, set the Expansion to a negative value that will close the mask right up to the pad/via hole. If the expansion is from the hole edge, simply set the Expansion to be 0.
    2. To completely tent a pad/via (covering the land and hole) – if the expansion is from the land pattern perimeter, set the Expansion to a negative value equal to, or greater than, the pad/via radius. If the expansion is from the hole edge, simply set the Expansion to be a negative value equal to, or greater than, the pad/via hole radius.
    3. To tent all pads/vias on a single layer, set the appropriate Expansion value and ensure that the scope of the rule (the Full Query) targets all pads/vias on the required layer.
    4. To completely tent all pads/vias in a design, in which varying pad/via sizes are defined, set the Expansion to a negative value equal to, or greater than, the largest pad/via radius.
  2. Solder mask expansion can be defined for pads and vias on an individual basis, in the associated properties dialog. Options are available to follow the expansion defined in the applicable design rule, or to override the rule and apply a specified expansion directly to the individual pad or via in question. Options are also available to force complete tenting of the pad/via on the top and/or bottom.
  3. Solder mask expansion can also be defined at the individual level for the following objects (through their associated properties dialogs): Track, Region, Fill, Arc. Options are available to follow the expansion defined in the applicable design rule, to override the rule and apply a specified expansion directly to the individual object in question, or to have no mask at all.

 

Found an issue with this document? Highlight the area, then use Ctrl+Enter to report it.

联系我们

联系原厂或当地办公室

You are reporting an issue with the following selected text
and/or image within the active document:
Altium Designer 免费试用
Altium Designer Free Trial
我们开始吧!首先,您或者您的公司已经在使用Altium Designer了吗?

如果您有任何需求,请点击这里联系获取当地办公室销售代表联系方式。.
Copyright © 2019 Altium Limited

既然您在使用Altium Designer,为何仍需要试用?

如果您有任何需求,请点击这里联系获取当地办公室销售代表联系方式。.
Copyright © 2019 Altium Limited

好的,实际上您无需下载一个试用版本。

点击下方按钮下载最新版本的Altium Designer安装包

下载Altium Designer 安装包

如果您有任何需求,请点击这里联系获取当地办公室销售代表联系方式。.
Copyright © 2019 Altium Limited

填写下方表格,获取Altium Designer最新报价。

点击[获取免费试用],并同意我们的隐私政策。您会接收到来自Altium的资讯,并允许其改变您的通知首选项。

如果您是Altium维保期内客户,您不需要下载试用版本。

如果您不是Altium维保客户,请填写下方表格免费试用。

点击[获取免费试用],并同意我们的隐私政策。您会接收到来自Altium的资讯,并允许其改变您的通知首选项。

您为何想要试用Altium Designer?

如果您有任何需求,请点击这里联系获取当地办公室销售代表联系方式。.
Copyright © 2019 Altium Limited

那您来对地方了!请填写下方表格申请试用吧。

点击[获取免费试用],并同意我们的隐私政策。您会接收到来自Altium的资讯,并允许其改变您的通知首选项。

听上去很棒!您知道我们为学生提供了特殊折扣么?欲知详情,请点击这里。.

同时,请填写下方表格申请免费试用吧。

点击[获取免费试用],并同意我们的隐私政策。您会接收到来自Altium的资讯,并允许其改变您的通知首选项。

好的,您可以下载免费的Altium Designer Viewer查看文档,有效期6个月。

请填写下方表格申请。

点击[获取免费试用],并同意我们的隐私政策。您会接收到来自Altium的资讯,并允许其改变您的通知首选项。

好棒!创作是一件超酷的事情,我们可以为您提供完美的设计软件。

Upverter是一个社区导向的交流平台,专为您这样的创客量身定做。

点击这里看看吧!

如果您有任何需求,请点击这里联系获取当地办公室销售代表联系方式。.
Copyright © 2019 Altium Limited

好的,您可以下载免费的Altium Designer Viewer查看文档,有效期6个月。

请填写下方表格申请。

点击[获取免费试用],并同意我们的隐私政策。您会接收到来自Altium的资讯,并允许其改变您的通知首选项。