我做过的几个项目ESD解决问题的方法.docx

我做过的几个项目ESD解决问题的方法.docx

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我做过的几个项目ESD解决问题的方法

Case1．S888－/S888ESDproblemimprovement

ForS888-V00,therearesomeESDproblemsasfollow,

1.Themobilewilllosecommunicationandsearchnetworkagainwhendischargingtoarrowkeyanddatakeyatair>6KVincommunicationstate,

2.Themobilewilllosecommunicationandsearchnetworkagainwhendischargingtosidekeyandcameradecorationringatair>5KVincommunicationstatewithmobiledownwards,

3.Themobilewillpowerofforlostnetworkwhenreleasingstaticfromtheheadsetspeakeratair>5KVinmobilewithheadsetstate.

4.ThePAwilldestroywhendischargingtothecameradecorationringatair>5KV.

Fortheseproblems,thesolutionsareasfollow,

Problem1improvement:

MakethemetaldomeandMMIGNDwellconnectedwithtwopoints,andkeeptheresistancebetweenmetaldomeandtheGNDunder2ohm,

Afterimprovement,itisOKforESDatair10KVonthearrowkeyanddatakey.

Problem2improvement:

（1）ScratchtheNBSCANtestpointwhichisjustunderthemetaldome.

（2）Adda10nfcapacitorontheNBSCANtestpoint.

（3）Changetheformersparsemetaldomewithdensemetaldome.

Afterimprovement,itisOKforESDatair10KVonthepositionofsidekeyandcameradecorationring.

Problem3improvement:

（1）AddTVSESDAVLC6V1-1M2ontheHSGND,itisOKforESDatair10KV.

（2）Add10nfcapacitorontheHSGND,itisOKforESDatair10KV.

Afterimprovement,itisOKforESDatair10KVwhenreleasingstaticfromtheheadsetspeaker.

Problem4improvement:

Useisolatedtapetocovertheantennawhichisnearthegapofthecameradecorationring

Afterimprovement,itisOKforESDatair10KVwhendischargingtothecameradecorationring.

1.1.keyPADPROBLEM

◆Description

Whendischargingtoarrowkeyanddatakeyatair>6KVincommunicationstate,themobilewilllosecommunicationandsearchnetworkagain.

◆Problemanalysis

AtfirstthemetaldomeisconnectedwiththeGNDbyonepointandtheresistancebetweenthemetaldomeandtheGNDisbiggerthan2ohm,whendischargingtoarrowkeyanddatakeyatair7KVincommunicationstatus,themobilewilllosenetworkandsearchnetworkagain.

OnlyonepointformetaldometoconnectwithGND,theresistancebetweenmetaldomeandGNDisbiggerthan2ohm

◆Improvement

WhenkeeptheresistancebetweenmetaldomeandtheGNDunder2ohm,itwillnotlosenetworkagainatair10KV,soitisadvisedtokeepthemetaldomeconnectedwiththeGNDbytwopointandkeeptheresistancebetweenthemunder2ohm.

UsetwopointstomakemetaldomeconnectwiththeGNDwellandkeeptheresistancebetweenthemunder2ohm.

Afterimprovement,itisOKforESDatair10KVonthearrowkeyanddatakey.

1.2.sidekeyandcameradecorationringPROBLEM

◆Description

Whendischargingtosidekeyandcameradecorationringatair>5KVincommunicationstatewithmobiledownwards,themobilewilllosecommunicationandsearchnetworkagain.

◆Problemanalysis

AstheNBSCANtestpointisjustunderthemetaldomeandverysensitivetoESD,whenmobiledownwards,theNBSCANtestpointiseasilyaffectedbycouplingelectricfieldformedbetweenworkbenchandtheMMI.Whendischargingtosidekeyandcameradecorationringatair>5KVincommunicationstatewithmobiledownwards,themobilewilllosecommunicationandsearchnetworkagain.

TheNBSCANtestpointisverysensitivetoESD.

◆Improvement

Densemetaldome

Sparsemetaldome

Changetheformersparsemetaldomewithdensemetaldome

（1）ScratchtheNBSCANtestpointwhichisjustunderthemetaldome,itisOKforESDatair10KVonthepositionofsidekeyandcameradecorationring

（2）Adda10nfcapacitorontheNBSCANtestpoint,itisOKforESDatair10KVonthepositionofsidekeyandcameradecorationring

（3）Changetheformersparsemetaldomewithdensemetaldome,itisOKforESDatair10KVonthepositionofsidekeyandcameradecorationring

.

1.3.releasingSTATICPROBLEM

◆Description

Themobilewillpowerofforlostnetworkwhenreleasingstaticfromtheheadsetspeakeratair>5KVinmobilewithheadsetstate.

◆Problemanalysis

AstheC50110nfcapacitorontheHSGNDisnotmounted,whenreleasingstaticfromtheheadsetspeaker,themobilewillpowerofforlostnetwork.

AsNMC501,whenreleasingstaticfromtheheadsetspeaker,themobilewillpowerofforlostnetwork.

◆Improvement

（1）AddTVSESDAVLC6V1-1M2ontheHSGND,itisOKforESDatair10KV.

（2）Add10nfcapacitorontheHSGND,itisOKforESDatair10KV.

Afterimprovement,itisOKforESDatair10KVwhenreleasingstaticfromtheheadsetspeaker.

1.4.PADESTROYPROBLEM

◆Description

ThePAwilldestroywhendischargingtothecameradecorationringatair>5KV.

◆Problemanalysis

Asantennaisverynearfromthecameradecorationring,whendischargingtothegapofthering,ESDwilleasilyreleaseto