Hur man eliminerar och minskar fel i ytmonteringstekniken

Tillverkningsprocess-, hanterings- och tryckt kretsmontering (PCA) -testning kan utsätta paketet för mycket mekanisk stress som kan orsaka fel . när nätmatrispaket blir större blir det allt svårare att ställa in säkerhetsnivåer för dessa steg .}}
For many years, packages have been characterized using a monotonic bending point test method, which is described in IPC/JEDEC-9702 Monotonic Flexural Characterization of Horizontal Interconnects on a Board. This test method describes the fracture strength of horizontal interconnects on a printed circuit board under bending loads. However, this test method does not determine the maximum Tillåten spänning .
One of the challenges of the manufacturing process and assembly process, especially for lead-free PCAs, is that the stress on the solder joint cannot be measured directly. The most widely used metric to describe the risk of an interconnect component is the tension on the printed circuit board adjacent to the component, which is described in IPC/JEDEC-9704 Strain Testing Guide for Printed Wiring Brädor .
Several years ago, Intel recognized this problem and began to develop a different test strategy to reproduce the worst-case bending conditions that occur in the field. Other companies such as Hewlett-Packard also realized the benefits of other test methods and began to consider similar ideas as Intel. The method has gained interest as more chip manufacturers and customers realize the value of determining the strain limit to minimize mechanically induced failures during Tillverkning, hantering och testning .
När användningen av blyfria enheter har expanderat har användarintresse också ökat; Många användare står inför kvalitetsproblem .
As interest has increased, IPC has felt the need to help other companies develop test methods that can ensure that BGAs are not damaged during manufacturing and testing. This work has been completed by the IPC 6-10d SMT Attachment Reliability Test Methods Working Group and the JEDEC JC-14.1 Packaged Device Reliability Test Methods Subcommittee.
The test method specifies eight contact points arranged in a circular array. The PCA with a BGA mounted in the center of the printed circuit board is mounted with the component facing down on the support pins and the load applied to the back of the BGA. The strain gages are placed adjacent to the component according to the recommended gage layout of IPC/JEDEC -9704.
PCA är böjd för de relevanta spänningsnivåerna och omfattningen av skador orsakade av böjning till dessa spänningsnivåer bestäms genom felanalys . Spänningsnivån vid vilken ingen skada inträffar bestäms av ett iterativt tillvägagångssätt och är spänningsgränsen .}