ICT夹具故障处理

Troubleshooting, repairing, and maintaining fixtures夹具的故障解决，修理和维护This chapter contain information about troubleshooting fixtures for the most common problems encountered. Repair procedures follow troubleshooting tactics. This chapter also describes the recommended maintenance procedures to keep your fixtures operating properly over their full lifetime.此章包括了在夹具上遇到的大多数普通的问题的解决。

在故障发现之后就是修理过程。

本章也描述了推荐的维护程序，以保持夹具在整个使用过程中工作顺利。

14.1 TROUBLESHOOTIING AND REPAIRING YOUR FIXTURES发现夹具问题并修理夹具The information presented here will help you solve most fixture problems whether they occur when the fixture first built or after the fixture has been in use for some time. First the problem is listed in the section heading, followed by possible causes and ways to fix the problem.在这里介绍的情况将帮助你解决大多数的夹具问题，不论是在第一次做夹具的时候还是夹具已经使用了一段时间。

首先问题在每段开头列出了问题，接着是可能的原因，以及解决问题的方法。

14.1.1 The Board Does Not Sit Flat On The Gasket主板在垫圈上不能平放1.This can be caused by components or component leads on the bottom side of the circuit board contacting spacers, gasket material, or the support plate itself. To fix this, youcan move the spacers or gasket material, trim the leads, or cut a relief slot into the support plate.这可能是由于在电路板底边的元件或元件引脚接触到了隔板，衬垫材料，或者是支撑板本身。

为了解决它，你可以移动隔板或衬垫材料，修整引脚，或在支撑板上切割一个减压槽。

2. This can also be caused by uneven placement of probe; that is , more probes on one side of the board than the other. This can be especially true when connectors or high density components are probed. You can fix the problem by putting low force probes in these high probe density areas. Fixturing software takes probe density into consideration on the HP SimPlate Express fixture and recommends the use of low force probes in high density areas. However , the s oftware doesn’t know probe locations on an HP SimPlate fixture; therefore, you will have to determine when and where to use low force probes. If the problem persists, you can also add HP PreLoaded Springs near the problem area as explained in chapter 8.这也可能是由于探针的不平整的放置，也就是说，在主板上一边的探针比另一边的多。

当连接器或者高密度的元件被探测的时候尤其可能发生。

你可以在那些高密度的探针区域放置低压力的探针来解决问题。

夹具软件在HP SimPlate Express夹具上考虑到探针密度，推荐在高密度区域使用低压力探针。

但是，软件不知道在一个HP SimPlate夹具上的探针排列。

因此，你不得不决定何时何地使用低压力探针。

如果这个问题还存在，你也可以象在第8章说的那样在问题区域增加HP PreLoaded弹簧。

3. Another cause could be lack of vacuum pressure orair-flow capacity. See chapter 11 for these requirements.另一个原因可能是缺乏真空压力或气流容量。

查看11章解决问题。

4. Improper positioning or not enough spacers can also cause this problem. To fix it, add more spacers to the low areas of the circuit board. Also, be sure that the spacers are notplaced so that they interfere with components or component leads.不恰当的放置或没有足够的空间间隔也可能导致这个问题。

为解决它，在电路板的底部区域增加更多的隔板。

同时，确定那些隔板并没有放置在影响元件或元件引脚的地方。

5. Excess gasket material under the circuit board can also cause this problem. Only 3.2 millimeters (0.125 in.) of gasket material should underlap the board.在线路板下有过多的垫圈材料也会导致这个问题。

只能有3.2毫米（0.125英寸）的垫圈材料能从板底露出。

14.1.2The Board Will Not Pull Down Far Enough电路板下拉不充分1.This can be caused by insufficient vacuum pressure orair-flow capacity. Be sure that your vacuum system meets therequirements specified in chapter 11.这可能由真空压力或者气流容量不够引起。

确保你的真空系统达到了11章需要的标准。

2.This can also be caused by a vacuum leak due to a worn orimproperly installed circuit board gasket or HP SpringSeal. The leak is usually very noisy and can be located byrunning your fingers around the edge of the board andsupport plate after vacuum is applied. You will be able toeither feel the suction or hear a change in the noise madeby the leak when your fingers contact the leak area. Torepair these kinds of problems, refer to chapter 8.这可能的原因是，由于用旧的或不正确安放的电路板垫圈或HP弹簧封口导致的真空泄漏。

泄漏经常噪声很大。

在真空加上后，可以通过将你的手指在板和支撑板的周围移动来确定泄漏的位置。

当你的手指接触到泄漏区域的时候，你将能感受到由于泄漏产生的吸力或听到声音的改变。

要修理这些问题，参考第8章。

3.An obstruction on the underside of the support plate orbetween the board and support plate can also cause thisproblem.在支撑板的下面有堵塞物或在支撑板和电路板间有堵塞物也可能导致这个问题。

4.Tooling pins binding on either the support plate or thecircuit board can also cause this problem by not allowing the board or the support plate to travel down far enough to seal properly. Using a small tri-square, inspect the fixture for bent or crooked (non-vertical) tooling pins, andstraighten or replace them as necessary. If you muststraighten tooling pins, be sure to bend them at the base, not in the middle.在支撑板或者电路板上装订的加工插脚，由于不允许电路板和支撑板下压足够深来吻合完全，也可能导致这个问题。

使用小的曲尺检查夹具上的弯曲或扭曲的加工插脚，必要时弄直它或替换它。

如果你必须弄直加工插脚，要在他们的基部弯曲，不要在中间弯曲。