Skip to main content
93 votes
Accepted

Why does a commercial PCB need this much rework?

This looks like it's due to a combination of bad engineering, bad management, and cheap labor. Circuits don't always perform as expected when first designed. Even experienced designers make mistakes ...
Olin Lathrop's user avatar
85 votes

Do dead weight 'components' exist?

Power your board from a 12V 7AH Sealed Lead Acid Battery. Then hot melt glue your board to the side of the battery. Similar to the ideas shown by @DaveTweed I have mounted prototype parts to a piece ...
Michael Karas's user avatar
73 votes

Do dead weight 'components' exist?

When prototyping, I often run into the same issue. What I usually do is find a sheet of suitable material that's larger than my board. It can be anything — wood, plexiglass, scrap PCB material, ...
Dave Tweed's user avatar
  • 174k
42 votes
Accepted

Why use kapton tape?

If you go through all the trouble to test and qualify something, like tape: check it doesn't unstick after a few years leaving glue everywhere, doesn't shrink, loosen, harden, or crack even if the ...
bobflux's user avatar
  • 78.9k
38 votes
Accepted

Connecting 10AWG wires to PCB

My general strategy for dealing with vibrating wires is to provide strain relief. I would consider adding holes in your PCB specifically for wire retention, like in the image below. You can use ...
Ocanath's user avatar
  • 2,231
37 votes

How to secure cables to a PCB

Zip ties are a good way to provide strain relief for cables attached to a PCB. You lay out a path for the cable on the PCB, and put adequately large holes on either side of this path for the zip tie. ...
Dave Tweed's user avatar
  • 174k
32 votes

Why use kapton tape?

On top of being a good adhesive, it's chemically inert, thermally stable, and does not off-gas when it gets hot.
KD9PDP's user avatar
  • 2,106
30 votes
Accepted

Hand soldering SMD 1206 components

You will likely find that 1206 are actually quite easy to hand solder. When you get used to SMD boards, you will find they are actually quite large. With a standard iron, I find it quite simple to ...
MCG's user avatar
  • 12k
28 votes
Accepted

How to remove this component from PCB

You need a lot more solder, so as to cover all the eight contacts and heat them to their melting point. Think "solder pool." Once you pull the component, then you can remove the solder pool using ...
TomServo's user avatar
  • 929
28 votes
Accepted

How can I remove the solder bridges?

With solder wick and a soldering iron. Flux will help
Davide Andrea's user avatar
25 votes
Accepted

Why are there no BGA chips with triangular tessellation of circular pads (a "hexagonal grid")?

Unless you use via-in-pad, which costs more, you need room to put routing vias in between the pads, like this
Daniel's user avatar
  • 6,188
25 votes

How to solder a stranded wire to a THT hole of a PCB as shock-resistant as possible

If the pcb is an automotive electronics solution, it should not only withstand slight shocks, it should also withstand vibrations and some harder shocks. So you should use only those connectors ...
Uwe's user avatar
  • 2,813
24 votes

What is the silver strip behind crystal in the PCB?

Here's a picture to help you understand better. The crystal's case can be soldered onto boards to secure them.
Jason Han's user avatar
  • 1,770
24 votes

SMD 0402 resistor flipped on its side

It's called "billboarding". The IPC standard is mute on the precise reason, but it notes that billboarding may occur during assembly. That condition is acceptable for all three IPC classes ...
vir's user avatar
  • 19.5k
23 votes

Keeping SMD parts in place while soldering with paste and heat

they suggested was that I use a stencil to apply my paste more evenly. In other words, they blew off my question. No, they didn't. They gave you correct advice. If you have a lot of solder on one ...
Olin Lathrop's user avatar
22 votes

Stompbox not working

Figure 1. Dry joints. Fix these first. Figure 2. Debug test points. Connect multimeter probe to GND for all voltage measurements. Confirm 9 V at (1). Connect the Mammoth GND to your amplifier ...
Transistor's user avatar
  • 177k
22 votes
Accepted

What are some reasons for hand painted dots on chips?

These are put there during assembly and test of the PCB and can mean anything the manufacturer wants to mark. Often such a dot is put on a microcontroller, when the firmware is successfully programmed ...
jusaca's user avatar
  • 9,609
20 votes
Accepted

Identify these wide ended tweezers

Looks like some wafer tweezer   These tweezers are especially designed for the handling of delicate and fragile silicon wafers, scintillation discs, glass slides, coverslips etc.
Huisman's user avatar
  • 10.7k
19 votes

How to secure cables to a PCB

Cable ties are great. Just put two through holes in the PCB away from the connector. There are also a variety of flat tie holders that can also facilitate zip ties. These can be pushed in or fastened ...
Voltage Spike's user avatar
  • 84.1k
18 votes

What is the silver strip behind crystal in the PCB?

I wish I could find an image of this, but that is a ground pad. When mounting larger crystals, like the one shown in Peter's answer, it is normal to bend the leads so the can is laid flat on the ...
Trevor_G's user avatar
  • 46.8k
18 votes
Accepted

Double-sided Assembly

You can find some good and relatively modern information in this document. WEIGHT LIMITS FOR DOUBLE SIDED REFLOW OF QFNS Sasha Smith, David Connell and Bev Christian Although their tests were for ...
Spehro Pefhany's user avatar
18 votes

Do dead weight 'components' exist?

Get some large nuts or bolts from a hardware store and glue them in. Not my invention, these have been seen inside commercial products to make them appear more robust.
Justme's user avatar
  • 154k
18 votes
Accepted

Soldering a thin spring steel wire to a PCB

We solder stainless steel from time to time. It needs more heat than I'm really happy bringing to a PCB, and the flux (we use a HCl flux, as you say) will quickly eat the tracks off the pcb if you ...
Jack B's user avatar
  • 12.2k
18 votes
Accepted

Solder SMD on through hole

For DIY project, no problem. If you manufactured a large quantity then you'd have to care about having a low number of defects which means taking care of all the details. But for one-off DIY projects, ...
bobflux's user avatar
  • 78.9k
18 votes
Accepted

Can extra long pads cause problems?

No, In fact there are different suggested footprints for hand soldering and for stencil applied paste soldering. https://forum.kicad.info/t/why-different-pcbnew-footprints-for-hand-soldering-smd-603-...
Miron's user avatar
  • 813
18 votes

Can extra long pads cause problems?

Short answer: in your case, there should be no problems. Longer answer: If you need impedance matching (high speed signals) the size/form of pads can have an influence on the signal quality. But as ...
kruemi's user avatar
  • 3,214
17 votes

How to solder a stranded wire to a THT hole of a PCB as shock-resistant as possible

A good way (but a bit late now...) is to have two holes for each wire, perhaps a half-inch apart - one large enough to pass the insulated wire, and the second of suitable size to pass the actual ...
Peter Bennett's user avatar
16 votes

Why did Axial Capacitors Fall Out of Use in the Industry?

Single-sided PCBs frequently required the use of wire links to bridge over other tracks on the board. With a suitable circuit layout, the use of axial capacitors (rather than radial) could be used to ...
Kaz's user avatar
  • 468
16 votes

How can I remove the solder bridges?

One of the best tips for this kind of stuff is BCM2, you can get it for most brands of soldering stations. If you don't have a soldering station, get the latest KSGER from aliexpress. As you can see ...
bobflux's user avatar
  • 78.9k

Only top scored, non community-wiki answers of a minimum length are eligible