Surface-Mount Technology (SMT) refers to the way components are mounted on a PCB: SMDs (Surface-Mounted Devices) have pins or contacts which lay on top of the PCB's pads, without the need for holes in the PCB.

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78 views

Red light therapy LED spotlight

What's the easiest way to mount a bunch of surface mount LEDs into an array or spotlight? There are a bunch of very interesting new papers on red light therapy for a variety of conditions. I want to ...
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42 views

Looking for a device the size of a small watch, that takes a touch as input, waits for touch*60 seconds, then vibrates [closed]

I'm trying to get in to strengthening and flexibility, and it's very common to have instructions like: use the muscle for 90 seconds, or hold the pose for 2 minutes. There are interval timers, but ...
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1answer
41 views

Minimum voltage rating for output capacitor for use with LTC3525-5 boost voltage regulator

I'm (still) selecting parts to build a 3 to 5V boost DC-DC converter using the LTC3525-5. The board I'm planing to build is based on the typical application shown in page 11 of the aforementioned ...
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1answer
195 views

SMD Removal Process

I'm practicing my SMD soldering skills and done my research on how to remove SMD devices from a PCB motherboard and brought a T8280 PREHEATING STATION and 852D SMD station. I understand you have to ...
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328 views

LTC3525 datasheet states that capacitors must be X5R or X7R, not Y5V. Why?

I'm selecting parts to build a 3 to 5V boost DC-DC converter using the LTC3525-5. The board I'm planing to build is based on the typical application shown in page 11 of the aforementioned datasheet, ...
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64 views

Surface mount capacitor marking

In general... 1206 resistors have their value marked on them. Why don't 1206 capacitors have their values marked? The only reason I can guess is that marking them would somehow change their ...
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2answers
59 views

Is airbath + air gun reflow appropriate for low-volume commercial production?

I understand there are a number of ways of reflowing individual SMT boards. I've seen small temperature profile ovens, hotplates, skillets, airbaths, and hot air guns used. I'm trying to determine ...
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71 views

SMD component identification

I need help regarding identification of an SMD component , the package is SOT223 package. I checked many code books but couldnt find the marked number. ...
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57 views

SMD Code Parts BE P04 & AE P04

I'm looking to find out what these parts are on a PLC controller. Both are SOT-89 packages. The AE P04 I suspect maybe something to do with a constant current circuit for +24vDC for a 4-20mA loop ...
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2answers
112 views

What is a good lab surface to hot-air rework on?

I have been scouring the internet for information regarding what would be a good surface to do hot air rework on. Right now, my lab, if you want to call it that, is a wooden bench with cardboard ...
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3answers
85 views

How to connect 1.5mm SMT alternating pins to 0.1" pin header?

I have a toy I'm trying to rehabilitate - the microcontroller was fried and I'm attempting to replace it with an Arduino. It looks like the connections were at a SMT pin-pitch (1.5mm spacing). To ...
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46 views

10GHz Regime Differential to Single Ended Conversion

I'm looking for a board mount (IC) solution that will take the differential output of something like ONET1191 @10GHz and convert it to 50 or even 75 Ohm single ended. I've looked through various ...
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3answers
144 views

How can I “print” traces on the back of a ceramic package?

I have a project I'm working on that is so tightly packed that I'm totally out of room. I could save the whole thing by slapping a bunch of surface mount LEDs (30 of them) on the back of a ...
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44 views

Pb-free reflow soldering of thick packages on PCB

We have a PCB board with approx. 600 SMT components (various IC, passive components, etc.). This board is to be assembled by our manufacturing house and they do use a reflow oven to solder our ...
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1answer
74 views

SMD component clearance limitations and guidelines?

I'm laying out a fairly compact PCB (first SMD design of this degree) and am concerned about how close some of my SMD components are getting. I've been unable to find any guidelines or advice online ...
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51 views

How can I adapt a 8-WFDFN Exposed Pad to a breadboard?

I got a few of these:http://www.digikey.com/product-detail/en/DRV8837DSGR/296-34806-2-ND/3471184 without looking close enough at the package type. Is there an adapter for this so I can fit it on to a ...
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69 views

Fiber-coupled diode laser in an SMD package?

Does anyone manufacture a fiber-coupled diode laser in an SMD package? Something like this, but smaller.
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108 views

SMD capacitors for a guitar distortion pedal

I'm trying to build a guitar distortion pedal. Alright, a bit about the motivation behind this project : It's my friend's birthday in a couple of days and I wanted to get him a distortion pedal cause ...
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48 views

Identify part number of a surface mount device

I have a commercial data logger to gather data from a heat flux sensor. The sensor puts out a signal in the microvolt-range. This signal is amplified before it gets logged. I think that I've located ...
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1answer
77 views

DIY SMD - options for covering exposed vias?

I printed a PCB + got a kapton stencil made for a project I'm working on. One of the components is a BGA chip, and has vias close to the bga pads. The vias on the board don't have solder mask on them, ...
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2answers
124 views

1N4004 SMD replacment [closed]

Please help me, how do I find the corresponding equaivalent of 1N4004 Diode. Also as not everything is available in local market here in India, I would appreciate, if there are some well known ...
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464 views

Is it possible to attach leads to surface mount component?

I ordered an op amp to experiment with. I knew this was a surface mount component when I ordered it. I assumed that I would be able to somehow attach leads to it, so I could use it on my breadboard. ...
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274 views

How does power dissipation for surface mount components work?

I know that with usual through hole components we can attach heatsinks etc. But how does it work with surface mount components? Is having a copper plate around the component the way to go? How do we ...
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1answer
114 views

Why are SMD Diodes different Packages than Resistors and Capacitors?

I was looking for SMD Schottky Diodes on Digikey, and they all come in weird packages like SOD-123. There were some that were 1206 or 0805, but they seem fairly rare. Why is this? The only difference ...
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158 views

KiCad : How can I create a footprint with thermal vias?

I have a SMD chip that gets pretty warm when operating and I want to try and design a footprint that allows more ventilation and extra copper to keep it in range. Does anyone know of a tutorial that ...
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150 views

Soldering guidelines for freezer applications?

I'd like to do a home project where I take temperatures inside of my freezer and inside liquids. Liquid-compatibility aside, I'm mostly curious about whether or not anyone can recommend some best ...
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132 views

What standard governs the dimensions of SMT chip resistors and capacitors?

I am aware of the JEDEC registered outlines, which define the standard mechanical dimensions and tolerances for a wide variety of solid-state packages. However, these standards do not appear to cover ...
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487 views

Soldering underside pads of Teensy 3.1

I have to place this Teensy 3.1 on a PCB, I am planning to make the PCB such that it has headers on which the whole Teensy will fit. Essentially, it is similar to making a shield like we make for ...
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2answers
177 views

Rule of Thumb for PCB pad sizes of SMD devices?

I am trying to make a PCB for the first time and am concerned about the sizes of the soldering pads over the actual dimensions that I should realize on the board. That is, with the following diagram: ...
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65 views

Standard for right angle SMD LED?

I'm trying to specify a SMD LED which has "right angle" mounting, ie edge mounted, with the light going parallel to the horizontal PCB. I need a RGB version (tri-color). Example. As usual, there ...
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3answers
452 views

0402 Land Pattern

I'm working on the second iteration of a board which uses quite a lot of 0402 caps for decoupling around processors. On the first version of the board I had complaints from the subcontractor that ...
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1answer
164 views

LM348 replacable by LM358

I want to give SMD soldering a try and therefore I was looking for some useful circuit (no LED-blink-crap) I could build more or less easily. So I found a nice DIY function generator here. It uses ...
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45 views

Physical stability of different surface mount footprints

While looking for rotary switches to use as user inputs to a processor, I came across these three footprints: I'm considering using a surface-mount part for board layout considerations, but ...
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105 views

Identify and replace a resistor [closed]

My APC UPS stopped working. I have had it for many years and it was serviced once by APC while in warranty and never opened again. Now since it is not in warranty anymore I opened it and saw two ...
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1answer
72 views

Building a SMT footprint for a MSOP

I'm putting together a board and it's requiring a footprint for a 16 lead Plastic MSOP. Usually I try to dig around and find a manufactures recommended footprint and try to stick with that. I figure ...
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2answers
105 views

How to find a datasheet for a part that doesn't exist on the manufacturer's website?

While bored recently, I decided to take apart a few old pieces of electronic equipment and attempt to reverse-engineer them. I've been doing pretty well, but I've come to an IC that I can identify ...
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2answers
667 views

Help identifying pwm controller “67A”

I am repairing a battery charger that uses two power supplies. TH20594 (couldn't find any info on that either) controls the primary PSU, while the mysterious chip controls the bootstrap/standby supply ...
2
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1answer
154 views

Are thermal reliefs on SMD pads beneficial when reflow soldering?

I know that thermal reliefs have benefits when hand-soldering through-hole components. For some high-frequency or high-current components, I understand why it's a good idea not to use thermal ...
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2answers
83 views

differences between different footprint surface mount RLC components

This is my first question here and I am new to board level digital design(I have years of experience on programming development boards though). So here is my question, what are the differences ...
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4answers
890 views

How can I indicate pin 1 on a SMT package footprint without silkscreen

Sometimes when I order PCBs from a board house, I omit the bottom silkscreen for budgetary reasons. When I place surface-mount chips on the bottom of the board, I then end up with a footprint that ...
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1answer
215 views

Thermal calculation for a D2PAK with a SMT Heatsink

I am trying to calculate the junction temperature of a D2PAK FET that is dissipating 5W. The junction-to-case thermal resistance is 0.4 C/W. The junction-to-ambient (PCB mounted, steady state) ...
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1answer
132 views

PCB component with abbreviation SR1

I have a laptop battery pack with a fried component (visually fried) that has the appearance of a large surface mount resistor (only 2 connectors). It has the PCB abbreviation next to it of "SR1" ...
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2answers
155 views

Easiest way to solder connections to all the legs on a surface-mount chip?

Recently, I went through the process of soldering wires onto the legs of a TQFP chip (~0.8mm pitch) which has already been mounted on a PCB. This is a project where I am doing some modifications to ...
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50 views

BGA reflow and RTV

I am having trouble with a board at work that we need to replace a BGA on but near the part is a section covered in DOW Corning 3140 RTV. We are using and Air-Vac DRS25 for this process. when we run a ...
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1answer
201 views

How to identify value of a surface mounted fuse

I have a PCB from a WIFI router and there is a lot of little surface mount components. I am looking for fuses, some of them might actually be them. My question is how do I identyfy them and find out ...
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42 views

Wire wound inductors naming

I see some SMT wire wound inductors are named like 3R3 or 4R5, much like a resistor, why so? I expected them to be like 4H5.
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95 views

How to bypass or replace a defective SMD switch?

I have a wireless keyboard with a defective on/off switch. The switch has a little play, and it's closing the circuit only when it is almost pushed to the extreme position for on. If 0 represents the ...
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2answers
442 views

What does WFQFN stand for?

I saw this as a package type for an attiny microcontroller in the digikey catalog. I'm pretty sure that "QFN" stands for Quad Flat No leads. However, I'm not sure what prefixed "WF" means. Is there a ...
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1answer
480 views

Definitive land pattern for 0603 SMD capacitors?

So, I am trying to figure out what pad size to use for 0603 (imperial) SMD capacitors. The datasheet for the particular capacitors I plan to use provides part dimensions but does not recommend a land ...
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1answer
119 views

Pick and place machine + AAA battery holder?

Say I design a two-sided PCB. I want the bottom side to have just a 2xAAA battery holder. Could a pick and place machine handle this or is it out of the question? What happens when the top side is ...