See if it helps refactoring with UNION:
SELECT
m.partId,
m.Revision_Id,
m.ReflowTemperatureSource_Revision_Id,
m.[MSLSource_Revision_id],
m.[BaseMaterialRevisionID],
m.[WaveTemperatureSource_Revision_ID],
m.[ShelfLifeRevisionID]
FROM ManufacturingData m
WHERE EXISTS (select 1 from #TempPC t where m.Revision_Id =t.RevisionID)
UNION
SELECT
m.partId,
m.Revision_Id,
m.ReflowTemperatureSource_Revision_Id,
m.[MSLSource_Revision_id],
m.[BaseMaterialRevisionID],
m.[WaveTemperatureSource_Revision_ID],
m.[ShelfLifeRevisionID]
FROM ManufacturingData m
WHERE EXISTS (select 1 from #TempPC t where m.ReflowTemperatureSource_Revision_Id=t.RevisionID)
UNION
SELECT
m.partId,
m.Revision_Id,
m.ReflowTemperatureSource_Revision_Id,
m.[MSLSource_Revision_id],
m.[BaseMaterialRevisionID],
m.[WaveTemperatureSource_Revision_ID],
m.[ShelfLifeRevisionID]
FROM ManufacturingData m
WHERE EXISTS (select 1 from #TempPC t where m.[MSLSource_Revision_id]=t.RevisionID)
UNION
SELECT
m.partId,
m.Revision_Id,
m.ReflowTemperatureSource_Revision_Id,
m.[MSLSource_Revision_id],
m.[BaseMaterialRevisionID],
m.[WaveTemperatureSource_Revision_ID],
m.[ShelfLifeRevisionID]
FROM ManufacturingData m
WHERE EXISTS (select 1 from #TempPC t where m.[BaseMaterialRevisionID]=t.RevisionID)
UNION
SELECT
m.partId,
m.Revision_Id,
m.ReflowTemperatureSource_Revision_Id,
m.[MSLSource_Revision_id],
m.[BaseMaterialRevisionID],
m.[WaveTemperatureSource_Revision_ID],
m.[ShelfLifeRevisionID]
FROM ManufacturingData m
WHERE EXISTS (select 1 from #TempPC t where m.[WaveTemperatureSource_Revision_ID]=t.RevisionID)
SELECT
m.partId,
m.Revision_Id,
m.ReflowTemperatureSource_Revision_Id,
m.[MSLSource_Revision_id],
m.[BaseMaterialRevisionID],
m.[WaveTemperatureSource_Revision_ID],
m.[ShelfLifeRevisionID]
FROM ManufacturingData m
WHERE EXISTS (select 1 from #TempPC t where m.[ShelfLifeRevisionID]=t.RevisionID);