Multi-keypress require diodes?

[zixzixzix]

I want too use multi-keypress……but i got a ghosting key problem. May be add diodes is the only way too solved it? But what the positon should the diodes be installed? It should toward the row ?or the column?

[DavidMenting]

Pointing from the the row towards the column in series with the switch (before or after doesn't matter). I usually connect the anode to the row and the cathode to the switch.