About the manufacturing of PCBs (Printed Circuit Boards).

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45 views

Symmetry in routing

I'm moving a design to an 8"x6" panel, and got thinking as I drew the route layer(white). The cutouts on the right two boards will be routed out. The left cutout will stay with the frame. During ...
2
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1answer
49 views

From what pitch should I consider ENIG finish

My design (4-layer, FR4, 1.6mm) has a couple of ICs with 0.5mm pitch pads and some LEDs with 0.4mm pitch pads, very small LEDs. Should I consider ENIG (more expensive) or will HASL do the job? I read ...
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2answers
48 views

PCB design cost for 0.4mm pitch bga, 0.1mm drill hole, 4-layer routing using via-in-pad [on hold]

I am doing a development board for a IC with 36 WLCSP package. My PCB layout has 16 via over pads, minimum 0.1mm drill holes, 4-layers. I need to fabricate my PCB. And I could not find a exact pricing ...
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0answers
26 views

Convert Gerber files to scaled PNG's for A4 size paper

I need to export GERBER files to PNG's or PDF's so that I can print it on a A4 size paper and not loose the scaling, obviously to avoid mis fits of chips and components. I have gerbv installed on ...
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0answers
21 views

BOM/OPL parts help before PCB fab

I am completing my first official PCB project. I am outsourcing the PCB fab to Seeeed Studio. I was wondering if any of you might be able to shed some light on my issue. I am using their PCB ...
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5answers
1k views

Anything bad to place a via on a pad?

Once I mistakenly placed a via on 0603 pad and didn't have any problem on soldering. I am routing another board now and I could save some space by placing some vias (0.3mm) on a 0603 pad. I wonder if ...
2
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1answer
62 views

Understanding PCB layer stack-up shorthand notation [2:(1(2+345*67)*16):7]

I was given a PCB layer stackup specification like this: [2:(1(2+345*67)*16):7] For an 8 layer blind via setup. Could someone provide a reference to decode this ...
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1answer
73 views

Should PCBs be rinsed after being cleaned with IPA?

A lot of people recommend using 99% IPA to clean flux (and other stuff) off PCBs. I haven't been rinsing off boards after cleaning with IPA as to my knowledge it's not corrosive, but I'd like to hear ...
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1answer
196 views

Silk-screened 'buttons' on a touch-tone phone?

I've been taking apart a recent, standard touch tone phone with the aim for automated dialing via a separate MCU with transistors activating the contacts (Smirk. An assistive technologies project ...
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0answers
52 views

fiducials on a panel

have a little question about fiducials: My Layouter/My Boss likes to use 3 fiducials on the panelframe and one fiducial on each individual board in the panel. My job is to build the program for the ...
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0answers
61 views

What to look for in a CNC PCB router?

When shopping for CNC routers for milling PCBs, there are some specific tools and others that seem to be fit but are meant for other types of works (typically engraving wood or advertisement). For ...
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5answers
121 views

Correct way to define board outline?

I'm a student and am almost ready to have a PCB I designed fabricated, but I'm confused about how the board outline should be defined. Here's what I currently have: I also have a 20mil keepout ...
2
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2answers
297 views

Eagle - non solder mask defined (NSMD) pads

I am designing a PCB layout in Eagle and in the datasheet of my modul it is said that "Non solder mask defined (NSMD) type is recommended for the solder pads on the PCB". Does it mean that there will ...
4
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3answers
1k views

PCB opaque coating for anti reverse engineering?

Im trying to find a coating for my PCB in order to protect it from reverse engineering. I want it opaque, non-conductive and with a low thermal resistance. Basically I do not want that someone ...
1
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1answer
60 views

Should courtyard information be included in gerber files for manufacture?

I just used 4pcb's free DFM checker and it doesn't like the fact that the courtyard line widths on my board are 1.968mils (what Altium generated in the IPC component wizard). It's also complaining ...
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1answer
266 views

What is the black thing on the circuit [duplicate]

What is the black thing on the below circuit? Is it used to hide the IC (or other components) that is used on the circuit? What material is it?
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4answers
139 views

How to order a custom PCB

I need a tiny PCB for a tiny IC. Is this something I have to design in autocad? Do I have to go to a shop to print it for me? Ultimately I want to be able to flux solder the IC on the tiny board so ...
3
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1answer
114 views

LED module design considerations for an aluminium board

I need to design a LED module something similar to below. Could anyone who is experience tell me if there is any SW (or tools) to determine how to place the LEDs to have a good and evenly ...
0
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1answer
38 views

What is the recommended exposure time for presentisized positive photoresist board? [duplicate]

What is the recommended exposure time for presentisized positive photoresist board using UV light, fluorescent light, CFL bulb and (will it also work with LED light)? How do we also determine if the ...
0
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1answer
88 views

How multi layer PCB are connected

I've been watching videos how to make PCB at home and I understand the process. But none of them shows how 2 sides are connected, I see on some PCBs there are some circular end points, so it must be ...
0
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1answer
107 views

Twisted pair coil embedded on a PCB

Has anyone tried twisting very thin wires(of order 100 microns) and then sandwiching it in between 2 layers of a multilayer PCB? I have a problem of EMI and looks like twisted pair is the only ...
1
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1answer
74 views

Question about a dimension in this IC package drawing

this is the first time I'm making a PCB layout, so I'm not too familiar with datasheets. The picture below shows a diagram for an IC I'm using. The datasheet says all dimensions are in mm. However, ...
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2answers
93 views

What are the plated holes on this PCB for?

In the top left corner of this snapshot, you can see a bonafide test point, TP12. Slightly down and to the right of TP12 you can see an exposed copper pad, also likely a test point. What I am ...
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2answers
70 views

Inkjet Printers+lamp+unused pcb can It work? [closed]

So suppose I have design x Can I print design x inverted onto paper, shine a lamp on it above unused pcb and make a printed pcb? Sorry for my ignorance Cheers!
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1answer
63 views

Hole diameters in PCB software - finished or tool size?

Should I specify the diameter of holes on my PCB as before plating (tool size) or after plating (finished)? Michael Leonard says finished Olimex says tool sizes Pcbex says finished ... Thank you ...
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2answers
112 views

How to measure the PCB size?

Can somebody share me your methods measuring the PCB size in CAM Software ? In PCB house ,we always measure the size according to the centre of outline and get the final size of the unit board or ...
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1answer
122 views

PCB Open Via Issue

I am recently bump into a problem where we found a certain percentage fallout of the open via. This is my very first time seeing this kind of problem and don't really have an idea why. It comes back ...
0
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1answer
71 views

How to determine dielectric constant and loss tanget of a PCB board at a specific frequency?

I need to know dielectric constant (relative permittivity) and Tan loss of a FR4 board at 2.45 GHz. The specification of the manufacturer is as it is below: Dielectric Constant: Test method ...
2
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1answer
124 views

Is it bad to route a trace edge of a rectangular pad?

I got a quick friendly critic from someone in production for the below trace that I should not route the trace from the edge of a pad. What he said that it would create an extra force to the trace ...
1
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1answer
155 views

Ways of PCB Etching other than Photosensitive Spray or Toner Transfer

Toner Transfer is not an option for large quantity or quick production and in my area I could not find any photosensitive sprays. I tried with screen printing emulsion, but it does not stick with ...
6
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4answers
795 views

What is the purpose of holes on edge of the PCB?

Here is a photo of one of Texas Instrument's RF EVMs. Please pay attention to edge of the PCB that has multiple tiny holes. I marked 3 of them with a red circle on the photo. What is the ...
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2answers
240 views

Altium can't output NC drills file?

I'm about to send my gerber files to OSH park however I'm having trouble generating the drill file in Altium 14.3. The output file is some other format than the Excellon / NC Drills file that the fab ...
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3answers
272 views

What is the best way to plate VIAs?

My local hackerspace has a CNC machine. I can give them my Gerbers and they can print out the PCB. The machine does not plate VIAs. I need to do this after the CNC machine is finished. What is the ...
12
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1answer
503 views

How to select FR-4 board thickness

The PCB manufacturing house that I use says the board thickness between 0.4mm and 1.6mm are the same cost (I have 2 layer design). What is the benefit of having thinner or thicker board thickness for ...
9
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2answers
1k views

Mounting hole on a PCB

Here is a picture of 3 mounting holes on three different PCBs. The red one is what I prepared on Eagle CAD and used "hole" button on the left side menu , something like this: Do I need to use ...
6
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2answers
175 views

PCB Panelization tool/SW and adding test connections

I prepared 4 different PCB layouts on Eagle CAD and generated Gerber files. As I can see Eagle CAD doesn't have any option to panelization. Is there any free tool/program that can allow me to ...
3
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2answers
377 views

Why we need the PCB Panelised for assembly?

I have a PCB finished in invidividual size for customer but they gave me comment that it can't be used by their assembly vendor and ask me make the new batch for them, When we make the board in 2 up ...
3
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3answers
192 views

Does ferric chloride etchant “go bad” after some period of time?

I have some old circuit board etching solution (ferric chloride) that is unused but a few years old and has not been in a temperature controlled environment. It has been sitting, all but forgotten, ...
2
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1answer
130 views

PCB assembly cost per-board

I know this question might get closed because of being opinion depended but I couldn't find any answer from google or any other search, so I decided to ask it here. For clarity of question I want to ...
0
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1answer
306 views

Suggestions for in-house PCB/FPC lab? [closed]

We are a hardware startup based out of Greece, looking for in-house PCB/FPC fabing solutions/equipment. LPKF's ProtoLaser U3/S look great but they cost $140K and $70K (if I'm not mistaken) ...
4
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2answers
561 views

Gerber - is my understanding of solder mask layer (GTS / GBS) correct?

I've just had a PCB manufactured for me, but it seems like the solder mask is only applied to where the copper is. I'm trying to figure out if it's my fault or not. According to my understanding ...
2
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0answers
110 views

Is 3dBi PCB etched GSM/GPRS Antenna Possible?

Is it possible to design a GSM/GPRS antenna that has a gain of 3dBi? if not, what is the maximum gain possible with a PCB GSM/GPRS etched antenna? I'm thinking of a PCB sized 11cm long and 5cm width. ...
1
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1answer
93 views

Why should PCB design be mirrored before toner transfer?

I am currently designing a PCB to make with the toner transfer method for the first time. I was reading a guide that said to mirror the image before printing it to the paper. However it seems that the ...
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2answers
206 views

What Gerber file extension is used to specify PCIe edge connector plating?

I am designing a PCB in Eagle using the mini PCIe card format and am not sure how to specify finger plating the board edge connector to the PCB fabricator. These plating regions are specified in Eagle ...
0
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1answer
108 views

What fedex paper to use for toner transfer

I am very new to creating PCBs and I am planning to make my first one in the upcoming weeks. I noticed that all the instructions and tutorials called for using a laser printer which I do not have ...
2
votes
1answer
379 views

Any better alternative to produce PCB than UV etching

I hope this is an appropriate question to ask it here. I work for a small start up company that has a limited budget. We have UV box, etching tank, etc from manufacturer like Mega UK. Our problem ...
5
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4answers
467 views

Why did my homemade PCB turn out like this?

I did a first experiment with the UV-lamp + Transparency + Presensitized-Board method. Using a randomly drawn pattern, this was my (promising but unsatisfactory) result: What could typically be ...
3
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3answers
996 views

Solder Mask and Pad Area (SMD vs NSMD)

I have been trying to figure out the "right" way to size pads for surface mount components, and I have found some conflicting wisdom floating around the internets. Lets say I have this hypothetical ...
11
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4answers
765 views

PCB, pads with holes but with different nets on top and bottom sides

I need pads with holes in by PCB, but the top and bottom side of the pads need to have different nets i.e. the top and bottom sides must be isolated. Here is the picture Is this possible to fabricate ...
8
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2answers
1k views

What is the use of the golden like coat on this circuit?

The below PCB belongs to a wireless access point. Could anyone explain what are the golden-like part of the circuit that is indicated by the red circles(ish)? What material is it? What is the the ...