一种带热沉结构的100Gbps高速差分BGA一体化封装外壳  

A 100 Gbps High-Speed Differential BGA Integrated Package Shell with Heat Sink Structure

作　　者：金浓 左汉平 周扬帆 乔志壮 Jin Nong;Zuo Hanping;Zhou Yangfan;Qiao Zhizhuang(The 13^(th) Research Institute,CETC,Shijiazhuang 050051,China)

机构地区：[1]中国电子科技集团公司第十三研究所,石家庄050051

出　　处：《微纳电子技术》2024年第8期16-24,共9页Micronanoelectronic Technology

摘　　要：为满足高速芯片对高密度封装、高速传输性能、高散热以及高可靠性的综合要求,基于低温共烧陶瓷(LTCC),研究了一款带热沉结构的高速差分球栅阵列(BGA)一体化封装外壳。该BGA外壳集成了20路高速信号传输通路,具有高密度和高集成的特点。分析了高速传输路径中水平转垂直结构时节距改变引入的失配问题,采用了分叉结构处过渡优化布线方案。通过对键合丝进行阻抗匹配设计,降低了键合指端头尺寸较小时键合丝引入的电感-电容效应,实现单个通路射频(RF)性能在DC~67 GHz满足回波损耗≤-12 dB,可支持单通道100 Gbps PAM4信号传输。通过设置通腔结构焊接钼铜热沉,使芯片与热沉直接接触,并将热沉与BGA焊盘置于不同侧,可在不影响二级装配的同时满足大功率芯片散热需求,解决了LTCC陶瓷散热不足的问题。采用下沉式封口区,在实现气密性封装的同时避免盖板与焊球干涉。To meet the comprehensive requirements of high-density packaging,high-speed transmission performance,high heat dissipation,and high reliability for high-speed chips,a highspeed differential ball grid array(BGA)integrated package shell with heat sink structure based on low temperature co-fired ceramic(LTCC)was studied.The BGA shell integrates 20 highspeed signal transmission paths with the characteristics of high density and high integration.The mismatch problem caused by pitch changes during the horizontal to vertical structure transition in high-speed transmission paths was analyzed,and a transition optimization wiring scheme was adopted at the bifurcation structure.Through the impedance matching design for the bonding wire,the inductance-capacitance effect introduced by the bonding wire is reduced when the size of the bonding finger end is small,and a single channel radio frequency(RF)performance with return loss≤-12 dB at DC-67 GHz is achieved,supporting single channel 100 Gbps PAM4 signal transmission.By setting the through cavity structure to weld molybdenum copper heat sink,the chip was in direct contact with the heat sink,and the heat sink was positioned on different sides with the BGA solder pad,which could meet the heat dissipation demands of highpower chips without affecting the secondary assembly,and solved the problem of insufficient heat dissipation in LTCC ceramics.A sunken sealing area was adopted to realize airtight package and avoid the interference between the cover plate and solder balls.

关 键 词：高速差分 球栅阵列(BGA)封装 散热 气密性 低温共烧陶瓷(LTCC) 一体化封装 

分 类 号：TN405.97[电子电信—微电子学与固体电子学]