Electronics > Beginners
Chip making process
srce:
--- Quote from: ZeroResistance on October 16, 2018, 09:53:43 am ---So lets say I send my design to the mask maker and he sends me back a 1mm2 size mask or reticule and for each of the layers.
Or does the mask maker make a grid of the whole design based on what the foundry silicon wafer size is, and and then gives me that for all the layers And then this is submitted to the foundry right? and then they expose the whole wafer at one go and you get he desired number of chips from that wafer.
This would be the process wouldn't it?
--- End quote ---
For an MPW - you don't have anything to do with masks or reticles. You wont even get to see them. You'll create a GDS file containing the design - send that off - and you'll get dies back in the post. You don't really need to understand anything about the manufacturing process (aside from the purpose of each layer in the GDS file of course :P)
Generally, IC designers just talk about masks, and don't really care about the distinction. The only time you care, is if your die size is limited by the reticle size, but you shouldn't be anywhere near that.
srce:
--- Quote from: ZeroResistance on October 16, 2018, 04:58:30 am ---We need to remember that those prices are for untested / unpackaged chips and how to handle unpackaged chips would be another topic of discussion, hope someone puts in more info regarding this.
--- End quote ---
You will get the dies from Europractice in a little tray like this:
You can just forward that to the packaging house, without even opening it. But if you do, because you'll obviously want a look :P, don't worry, too much, they'll probably survive even if you fiddle with them with tweezers (you can get proper tools). Just don't forget the ESD structures on your IO pads!
Europractice can do packaging - I personally use: http://www.icproto.com/ in the USA. You need to send them a bonding diagram showing how the bond pads should be bonded to the package pins:
And give them some other details like diameter of the bond wires, what metal to use and of course what package you want, and a logo / marking. It will take them about a week (with postage) to do it. A couple of dies may be damaged in the setup process.
You may want to split it in to two lots for packaging, in case you make a mistake in your bonding diagram or they get lost in the post!
You'll need to design the test procedure yourself!
Wimberleytech:
--- Quote ---I remember in the late 1970s, 4-inch (100mm) wafers were still being exposed with whole-die methods using equipment from Perkin-Elmer.
--- End quote ---
4" single mask (per layer) were common into the 80's.
--I think you meant "whole-wafer" btw.
Wimberleytech:
In the old days, a reticle was made first from the database. Using the reticle, a mask was made. In these photos, you see a retical, the mask that was made from the reticle, and the wafer that was made from the mask (obviously, only one layer is represented).
Somewhere around here, I have a reticle used for a modern step-and-repeat system, but I cannot find it |O
--- End quote ---
--- End quote ---
--- End quote ---
Ahaa...here is the reticle
--- End quote ---
The die is stepped on this redical (5x5) and the 8" wafer is made by stepping this reticle
ZeroResistance:
--- Quote from: srce on October 16, 2018, 01:57:39 pm ---You will get the dies from Europractice in a little tray like this:
--- End quote ---
Whats the problem in soldering the die directly to a pcb? are the bond pads too small that they can't be soldered directly to the board, similar to a LGA package? And then pour epoxy on it similar to a COB package. Like many chinese items have.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version