"How to?" indeed!

[Cozzer]

Bought this set of mini-drill bits a couple of weeks ago...0.3mm up to 1.2mm.

I'm sure that some of 'em will come in very handy, especially when I figure out how to open the case!
No sign of hinges as such, so could it be a sliding top? If it is, it's a bloody good fit!
I've been "at it" for 30 minutes now, and I'm none the wiser!

 

[Cozzer]

Ye Gods! How difficult can it be?!

 

[paulrbarnard]

Ye Gods! How difficult can it be?!

View attachment 166720

Show off

 

[rob1693]

I got this set to try for £8.99, hopefully they're better than the parkside forstner bit set I got

 

[clogs]

cobalt drills should have the cobalt in the material not on the outside.....
set of even cheapie cobalt drills like that would be over £50......
I pay €1,50 for a 2.5mm cabalt drill made in Austria.....
let us know how u get on pls......

 

[nickds1]

Bought this set of mini-drill bits a couple of weeks ago...0.3mm up to 1.2mm.

View attachment 166715

I'm sure that some of 'em will come in very handy, especially when I figure out how to open the case!
No sign of hinges as such, so could it be a sliding top? If it is, it's a bloody good fit!
I've been "at it" for 30 minutes now, and I'm none the wiser!

These are either solid tungsten carbide or TC tipped drills for drilling holes and vias in newly manufactured PCBs. They tend to be in very small sizes only and are quite brittle. Looking at the markings, I think that these are USA-made, rather than European.

In PCB plants, the CNC machines get through a LOT of these as the fibreglass (typically FR4) boards are harsh on the drills and the used & resharpened ones often appear pretty cheaply on the s/h market. Once they get too short, they're flogged off. Parkside are obviously buying them in bulk.

Bit of trivia: I have PCBs made by these sort of places - it's dirt cheap nowadays. A typical board may have several hundred holes that need drilling. You get charged more per board if you use drill sizes that aren't in the standard rack as the CNC machine has to be specially set up just for you. A key rule of PCB design is to use standard hole & via sizes. Actually, if you can, standard everything: board material & thickness, hole & via sizes, copper thickness, minimum track separation (feature size), conformal layer colour, surface finish (HASL, ENIG...) etc.

I've had the solid TC drills below (from Kemmer Präzision) for maybe 20 years. They're brilliant. I'm not sure if the Parkside ones are solid carbide, but you might be lucky. New, these are about 5 euros each. You can still buy these ex-CNC, e.g. Fifty Carbide Drills - 25 Sizes from #80 to #56 - .0135 to .046" 1/8"

The smallest in the photo are #84 0.0115" or 0.2921mm

 

[rob1693]

cobalt drills should have the cobalt in the material not on the outside.....
set of even cheapie cobalt drills like that would be over £50......
I pay €1,50 for a 2.5mm cabalt drill made in Austria.....
let us know how u get on pls......

I'll let you know when I give them a try

 

[Just4Fun]

A key rule of PCB design is to use standard hole & via sizes.

What is a via in this context?

 

[Sachakins]

Probably var, for various sizes, via likely the auto-correct spell checker.

 

[graham88]

What is a via in this context?

It's just the holes drilled on solder points to connect different layers in a mutli layer PCB.

 

[Cozzer]

Amazing info from nickds1!
I tell you, the combined knowledge on this forum is astounding!
Had to smile about his Kemmer Präzision drills story, about having them for 20 years....I confess my first thought was "Why? Couldn't you open the box either?"!

 

[nickds1]

Probably var, for various sizes, via likely the auto-correct spell checker.

A PCB via is a hole that connects a signal between two surfaces - the hole is typically very tiny and chemically plated to be conductive - they are essentially wires that carry signals between layers.

Because vias are typically small, they can't carry much current, so if you need heavier currents you simply put a whole load of vias together, 10, 20, whatever you need. Layout tools generally include calculators that let you know the current carrying capacity of different types and sizes of vias in differing environmental conditions.

In the simplest case of a double sided PCB, all vias will go from one side to the other (we'd say "top to bottom"), but in the case of a 4 layer PCB having two internal layers, a via could go from 1-2,1-3,1-4,2-3,2-4 or 3-4.

A via that is completely internal, e.g 2-3 in the 4 layer example, is not visible from the top or bottom and is thus referred to as a "buried via". A via that goes from an external to an internal layer, e.g. 1-3, is known as a "blind via".

PCBs are actually quite complex things to get right. At really high frequencies, e.g. for. PC motherboards that run in the GHz range, the length of a signal trace is critical as, believe it or not, signal propagation is close to the speed of light so tiny inconsistencies in trace lengths can cause horrendously difficult timing issues, i.e. bugs. We're talking timing sensitivity in the nS range. Industrial PCB board layout programs will actually make sure that traces that are timing sensitive are exactly the length they need to be by inserting tiny wiggles and using other tricks. This obviously gets more complex where signals move between layers too, as via length also has to factored in. With fast digital signalling, the divide between the digital and analogue domains becomes blurred - digital signals are just a special case of analogue. The traces on the PCB then start acting as transmission lines, and that's another world again.

PCB layout is mainly science but has a lot of art involved. It's a highly skilled job and although most electronic engineers can maybe layout a simple PCB that works fine, a specialist at work is a joy to behold.

Commercially, layout is a distinct bit of the DFM (design for manufacturing) process.

 

[John Brown]

A PCB via is a hole that connects a signal between two surfaces - the hole is very tiny and chemically plated to be conductive - they are essentially wires that carry signals between layers.

In the simplest case of a double sided PCB, all vias will go from one side to the other (we'd say "top to bottom"), but in the case of a 4 layer PCB having two internal layers, a via could go from 1-2,1-3,1-4,2-3,2-4 or 3-4.

A via that is completely internal, e.g 2-3 in the 4 layer example, is not visible from the top or bottom and is thus referred to as a "blind via". A via that goes from an external to an internal layer, e.g. 3-4, is known as a "half blind via".

PCBs are actually quite complex things to get right. At really high frequencies, e.g. for. PC motherboard that run in the GHz range, the length of a signal trace is critical as, believe it or not, even though signal propagation is close to the speed of light, tiny inconsistencies in trace lengths can cause horrendously difficult timing issues, i.e. bugs. Industrial PCB board layout programs will actually make sure that traces that are timing sensitive are exactly the length they need to be by inserting tiny wiggles and using other tricks. This obviously gets more complex where signals move between layers too, as via length also has to factored in.

PCB layout is mainly science but has a lot of art involved. It's a highly skilled job and although most electronic engineers can layout a simple PCB that works fine, a specialist at work is a joy to behold.

Commercially, layout is a distinct bit of the DFM (design for manufacturing) process.

Which is why I never attempted any PCB layouts for anything faster than about 12mHz. That high frequency stuff is like black magic...

Incidentally, I bought a couple of those micro-drill sets from Lidl. I may never use them, but nothing beats the lovely smug feeling of having exactly the right tool for some arcane job. I had a set of PCB drills decades ago, but nearly all them got broken, by me, over the years.

 

[Sideways]

Very, very crudely, "1nS per foot" .....

 

[nickds1]

Very, very crudely, "1nS per foot" .....

That's the speed of light in free space (vacuum), not the speed of propagation of a signal in a wire.

The speed of light in free space (a vacuum), c, is very close to 300,000,000 m/s, i.e. 30cm/nS or about 11.8"/nS.

Real-world signal propagation speed occurs relative to c, and is defined in terms of relative permittivity, or dielectric constant known as "Er". For the FR4 material used in most common PCB boards, Er ranges from 3.8 to 4.8, depending on the glass weave style, thickness, resin content, and copper foil roughness etc.

The speed of signal propagation in a wire is c/sqrt(Er) where Er is the dielectric constant for the surrounding material.

Therefore, on an FR4 PCB, in 1nS a signal will travel between 13.7 and 15.4cm, i.e. between 5.4 and 6in.

Teflon (PTFE) has an Er of 2.1 (or thereabouts), which means that in 1nS, a signal propagates about 20.7cm.

For comparison, BS6231/Tri-rated cable has a PVC covering with an Er of around 3.2, so in 1nS a signal travels about 16.8cm, i.e. Teflon is FAR superior to PVC as an insulator or substrate at high frequencies.

The Er values for PCB substrates and wire insulation are extremely important at high frequencies where timing is important, so material choice is a critical part of the design process.

 

[Fergie 307]

Too work well, and minimise breakage these tiny drills have to be run very fast, so dremel or similar in a stand rather than your pillar drill.

 

[John Brown]

The runout in my pillar drill would break them straight away! I'll bear the high speed thing in mind, though, won't use the eggbeater.

 

[throbscottle]

You can get these micro drills from AliExpress much cheaper and in a wide range of sizes. My collection now runs from 0.3mm to a whopping 3.17mm. You need to run them at upwards of 10,000 RPM. The tiny ones should in theory be run around 100k RPM. I've built a PCB drill that runs at 30k RPM, which is still slow but at least it's feasible without involving gearing.
You need to mount them in a micro drill ideally fitted in a stand anyway. At least collet choice is easy, the shanks are all 3.17mm. They break devilishly easily. I've got boxes just of the sizes I break most...

 

[throbscottle]

Oh, there are dill speed / feed calculators online if you look.

 

[Sachakins]

A PCB via is a hole that connects a signal between two surfaces - the hole is typically very tiny and chemically plated to be conductive - they are essentially wires that carry signals between layers.

Because vias are typically small, they can't carry much current, so if you need heavier currents you simply put a whole load of vias together, 10, 20, whatever you need. Layout tools generally include calculators that let you know the current carrying capacity of different types and sizes of vias in differing environmental conditions.

In the simplest case of a double sided PCB, all vias will go from one side to the other (we'd say "top to bottom"), but in the case of a 4 layer PCB having two internal layers, a via could go from 1-2,1-3,1-4,2-3,2-4 or 3-4.

A via that is completely internal, e.g 2-3 in the 4 layer example, is not visible from the top or bottom and is thus referred to as a "buried via". A via that goes from an external to an internal layer, e.g. 1-3, is known as a "blind via".

PCBs are actually quite complex things to get right. At really high frequencies, e.g. for. PC motherboards that run in the GHz range, the length of a signal trace is critical as, believe it or not, signal propagation is close to the speed of light so tiny inconsistencies in trace lengths can cause horrendously difficult timing issues, i.e. bugs. We're talking timing sensitivity in the nS range. Industrial PCB board layout programs will actually make sure that traces that are timing sensitive are exactly the length they need to be by inserting tiny wiggles and using other tricks. This obviously gets more complex where signals move between layers too, as via length also has to factored in. With fast digital signalling, the divide between the digital and analogue domains becomes blurred - digital signals are just a special case of analogue. The traces on the PCB then start acting as transmission lines, and that's another world again.

PCB layout is mainly science but has a lot of art involved. It's a highly skilled job and although most electronic engineers can maybe layout a simple PCB that works fine, a specialist at work is a joy to behold.

Commercially, layout is a distinct bit of the DFM (design for manufacturing) process.

Well, that's me told.
But thanks, now I've learned something new, which is always a benefit