An Improved MENSCH™ Microcomputer

[barnacle]

Hint: start by mounting the processor. It's going to be the hardest to solder, so the more room you have around it, the better.

Neil

[BigDumbDinosaur]

Martin_H wrote:

DHL just dropped off a package from PCBWay...

I wish board houses would offer matte finishes instead of that glossy solder mask that seems to be “in fashion.”  The glare from the solder mask has always given me trouble during assembly—sometimes I have trouble distinguishing the pads from the rest of the board. 

[SKO]

Quote:

I wish board houses would offer matte finishes instead of that glossy solder mask that seems to be “in fashion.”

A tip, especially for people in Europe: Aisler will let you choose any color of solder mask, as long as your choice is "green", but it's a beautiful dark-green matte finish.

Unfortunately, I am afraid most hobbyists will find their prices and turnaround times not to be competitive with the Chinese. For me this is less of an issue, as I live in Germany, and shipping from their factory is 2.00 euros and takes two business days. They have been my go-to PCB manufacturer for a while now.

[Martin_H]

barnacle wrote:

Hint: start by mounting the processor. It's going to be the hardest to solder, so the more room you have around it, the better.

I agree. Unfortunately, it's on backorder without an ETA. If I do anything it will be the power supply components, and the decoupling caps on the top half of the board. That would leave lots of room for soldering the w65c265.

Update: I looked at my order confirmation from Mouser and the estimated shipment date was "Will Advise**" and the footnote read "** We will contact you with an estimated shipment date."

I also purchased a regular w65c816 which shipped from inventory as one of my SBC's can take either it or a w65c02. So, I will get my fix of 16-bit goodness until it ships.

[Martin_H]

The Mouser order arrived yesterday. They did a good job packing the parts, although over packing them in some cases. But no update on the w65c265 shipment date. What annoys me is that the W65C265QBX is in stock! I'm half tempted to buy some Chip Quik and take matters into my own hands.

I almost finished the learn to SMD solder kit when I pinched an 0805 0.1uF cap wrong. I heard a plink and it disappeared in an instant. I looked around my workbench and the floor, but it is clear the shop goblins got it. The kit only included the exact number of parts to build it, which is honestly annoying. I cleaned the flux, and the PCB almost looks respectable.

For my Mouser order I ordered extras of every SMD part because if you have extras, you never lose a part. It's well established that shop goblins are only attracted to irreplaceable parts.

[barnacle]

Martin_H wrote:

It's well established that shop goblins are only attracted to irreplaceable parts.

And you're wondering where your w65c265 is?

Neil

[Martin_H]

One month of the w65c265 being backordered with no word from Mouser.

I have heard that people are having supply issues with SMT AVR chips and are ordering cheap Arduino boards to desolder the IC.

[J64C]

BigDumbDinosaur wrote:

Martin_H wrote:

DHL just dropped off a package from PCBWay...

I wish board houses would offer matte finishes instead of that glossy solder mask that seems to be “in fashion.”  The glare from the solder mask has always given me trouble during assembly—sometimes I have trouble distinguishing the pads from the rest of the board. 

They do. Or PCBWay does anyway. Matte black and matte green.

[Martin_H]

Mouser shipped my backordered w65c265!

[Martin_H]

The w65c265 arrived and I decided to try soldering it to the PCB. Three sides went well, unfortunately one of the long sides did not. I solder bridged some pins and used to much pressure with the desoldering braid when cleaning them up. This pushed several pins sideways bridging them between pads. Ouch! In retrospect the QFP 100 pins are finer pitch than the QFP 44 and not as stiff. So greater care is required.

I am not sure how to correct this mistake. But the most important thing is to no make it worse trying to fix it.

I heated one of the bent pins and tried slight sideways pressure. It removed the bridge, but the pin is still slightly skewed. But there are more to correct.

I am thinking that using the dull side of an exacto blade between pins and nudging them while heated may work.

Any other suggestions?

[plasmo]

A closeup picture please.
QFP100 has relatively generous spacing, so it is possible to get a fine tweezer between pins and straighten out a pin while heating it. You do need a fine tweezer and hand-free magnification while straightening out the pin. Be sure to flux the affected area. Nudge with a fine Xacto blade should also work although I’ve always used a fine pair tweezer successfully. Good luck,
Bill
PS, skewed pins do not matter as long as they are well soldered to pads without shorts. I have a batch of QFP100 that were mangled during removal, I straightened pins as best as I can and soldered them with some pins skewed. They pretty much all worked.

[Martin_H]

Attached is a picture. The row of pins at the bottom has six pins which are straddling pads.

[plasmo]

It can definitely fixed by grabbing each misaligned lead with fine tweezer and heat the pad while shifting the lead over the pad. It does require a steady hand and some practice, but definitely fixable. I see your QFP100 footprint has generous pad size so it is fairly easy to heat the pad and shift the misaligned lead.
Bill

[barnacle]

I'd agree with Bill there. Lots of flux should keep the solder where you want it - I've moved to the gloopy stuff though it's a pain to clean sometimes. Might work better with hot air than a soldering iron; fine tip irons are often much cooler than advertised at the very tip (and have a habit of wetting with the solder part way up the pointy bit where it's hotter).

Neil

[AndrewP]

Martin_H wrote:

Attached is a picture. The row of pins at the bottom has six pins which are straddling pads.

So... soldering PLCCs without checking if the pins are bent first is skill of mine.

I don't really have the motor skills to fix individual pins one the board but I'm going to second Plasmo in that a fine pair of tweezers should do it. Don't be afraid to add more solder and lots flux - you can always unbridge pins with desolder braid and even more flux.

Cleaning afterwards is easy if you can invest in an ultra sonic cleaner. A hardware shop up the road from me had a decently big one for cleaning tools, carburettors and such. It wasn't nearly as expensive as some of the devices I've seen on electronics sales sites and its exactly the same thing. Plus it's big enough to fit some good sized PCBs.

I just fill it with 99% isopropyl alcohol which I then reuse - although I top it up with a bit more unused every time. I find it gets gunky before evaporation becomes a problem and a 5L lasts me about 2 years. A five minute runs takes a horribly flux burnt board and turns it into something that looks like its clean off the production line.

However, if like me, you're not up to fixing the pins in situ then I'd suggest getting a hot plate and then take the whole IC back off again. Just remember to re-tin all the pads and add more flux before dropping the board and IC back on the hotplate.