Plasma Impact on PI Roughness

摘要：

　　The standard pillar bump structure 1-3 is shown in Figure 2.Polyimide Re-passivation(PI)layer is widely used for pillar bump structure due to the increasingly stringent reliability requirements 4-5.PI layer serves as stress buffer layer which can enhance the structure reliability performance.And PI will be the direct surface contact material to FCBGA molding compound,so the PI surface roughness is a key factor to the adhesion between PI and molding compound.Lower surface roughness will cause delamination between PI and molding compound while higher surface roughness may cause flip chip process issue like backgrinding tape residue due to higher adhesion between PI and back-grinding tape 6-7.During the pillar bump process,the PI surface roughness is influenced by many plasma steps like gas and so on.In the present paper,plasma process parameters such as gas,process power and process time are studied in order to get the correlation between these process parameters and PI surface roughness result.This correlation can be used to further study the surface roughness with the assembly site required at the assembly process.As depicted in Figure 3,there are distinctions in the diffraction values of Selected Area Diffraction Pattern(SADP)in different process steps(PI Curing,O2 Descum,RF,Etch,Ar Descum).The influence of different gases plasma on PI surface roughness is quite significant,among which O2 plasma has more significant impact than others,which provides guidance for further research of PI surface roughness in FCBGA.

关键词： PI layer Plasma PI surface roughness Adhesion

作者: Qiang Cheng Liming Gao Li Zhang

作者单位: School of Materials Science and engineering Shanghai Jiao Tong University Shanghai,China Technical V.P.Jiangyin Changdian Advanced Packing Jiangyin,China

会议类型: 国际会议

会议名称: 第十九届国际电子封装技术会议(ICEPT 2018)

会议地点: 上海

会议语种:英文

页码: 860-862

在线出版日期: 2018-08-08（万方平台首次上网日期，不代表论文的发表时间）