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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Surface Mount vs. PTH Components For Production
I'm a hobbyist who has developed a product which uses ~20 PTH components. The device is essentially an Arduino UNO with some extra driver ICs and LEDs. I have had quite a lot of positive feedback on ...
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1answer
98 views
Why UPS for sensitive SMD development?
My friend suggests me UPS for SMD development. I already have a a surge protector over all devices. He recommended the UPS that transmit all energy through its battery and he recommend to find some ...
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3answers
100 views
How to design contact pins for testing SMD board? Only optical inspection possible testing technique?
The point 6.56 and the Teensy's testing are examples about testing, also the pictures below. Now suppose you want to do a SMD board to the size of fingerprint or smaller. The earlier video mentioned ...
4
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2answers
116 views
How to etch finely-packed SMD boards?
I have tested HCl+peroxide etching with the light/transparent for SMD but it is very easy to get lines broken -- even though I had blue liquid and a proper etching equipment that I could monitor. I am ...
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1answer
99 views
Soldering smallest SMD components such as 0402 with Microscope?
I need to use as small components as possible but I need to do everything by hand. My plan is to use OSH Park for the production of the board. The answers did not focus on whether they used microscope ...
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1answer
73 views
Help identifying/selecting SMD MOSFET
I am repairing an IP camera that has a blown transistor in the power supply section. The transistor looks like a SOT23 transistor, but it has 6 pins (how is that package called, anyway?), 4 of them ...
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2answers
78 views
SMDs for Breadboards
I'm looking at building an inductive charger (based on the design at http://people.oregonstate.edu/~watersal/documents/uhc_awaters.pdf), and there are a few components they use that are ...
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1answer
8 views
Is it possible to use a non-Leonardo board to act as a keyboard or other device?
I have been seeing lots of reports about the brand new Leonardo and it's capabilities, cheapness, and most popular, it's USB features. However, I look down at the ol' Arduino Uno and sigh. I don't ...
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3answers
80 views
Identifying SMT element 331K
I am trying to repair a remote from a car lock. The symptoms are that a red led is lit longer than usual after button press and no respond from car lock. It works sometimes. The battery and ...
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2answers
24 views
How can I use my SMD Arduino to program a separate DIP ATmega328?
I have an arduino with a surface mounted (SMD) microcontroller:
I know how to use a DIP arduino as a programmer for a DIP ATmega328. It's easy --you just pop your microcontroller in the holder.
...
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1answer
38 views
Regulated power supply from thermostat to zigbee module
I have a thermostat that outputs a DC power supply for a communication daughter board. When I read it with the voltmeter, it reads ~3.9v, but the zigbee module that I want to use requires 3.3v ...
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1answer
71 views
PCB has strange looking pads, how do I solder them without impacting nearby surface mount components?
I've recently brought the px4fmu and px4ui boards. The px4io requires me to solder a power socket and headers onto it.
However there are surface mount components very close to the holes/pads. Also ...
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3answers
131 views
2 × 20 pin SMT to DIP adapter?
I want to adapt a 40 pin SMD (0.5mm pitch) for usage on a breadboard. Are there any adapters available that I can use together with a simple soldering iron?
Already I found the SchmartBoard adapters, ...
4
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1answer
93 views
Moisture sensitivity for SMD LEDs
I was adding some small components to a Digikey order, just because I couldn't stand to pay the shipping costs for the single item I really needed. I just received my order to find that the SMD LEDs ...
8
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2answers
457 views
SMD package size chart
Is there a scale drawing of SMD package sizes as a design aid? This could be useful in schematic/layout stages of a project in when deciding to trade off size vs. cost.
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83 views
Issues with going to small passives
I'm going to be working on my second major design where size is the number 1 goal. What are the theoretical issues going with 0201 or less for resistors/capacitors, besides soldering difficulties?
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1answer
250 views
A good technique for removing 50-pin SMD CF/MD card slot with Hot air
I have a piece of equipment that has a CF/MD card on it. Somebody tried to force the card in and broke 2 pins off. I managed to replace the two pins temporarily, but it was kind of a hack job, but it ...
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2answers
76 views
Is Rja in parallel with an external heatsink?
I have done heat sinking before, but now I'm trying to do it on SMT chips which is a bit more difficult. Anyway, I'm wondering whether the resistance between junction and ambient, Rja, is in parallel ...
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5answers
188 views
Is it possible to solder or otherwise connect to this camera chip by hand?
[Disclaimer: I'm a beginner.] I ordered this OV7740 camera chip from Digikey without really researching it, thinking maybe I could connect to it with a microcontroller. (I have only Arduino at this ...
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3answers
312 views
SOT-223 Thermal Pad and Vias
I am using a LDO with a SOT-223 footprint and since it might get hot, I wanted to make a nice thermal pad under it to dissipate that heat.
I googled and I only found thermal pads, but i wanted some ...
8
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1answer
239 views
What are the advantages of larger SMD pads at the ends of a SOIC land pattern?
I was looking at this NXP TSSOP8 footprint and was wondering why the end pads were 0.600 mm, and the non-end pads were 0.450 mm.
What advantages does this have?
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1answer
338 views
Is there a good replacement for stripboard in the surface mount world?
More and more components I want to use are only available in surface mount packages.
I can either get a big collection of adapter boards for all flavors of SOIC/WFBGA/QDERP to 100 mil pin spacing, ...
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2answers
377 views
Soldering leads/pins to SMD/SMT for solderless breadboard prototyping?
Background:
I just began with electronics and I'm looking to build a 12v to 5v converter circuit. My plan is to use a Murata 78SR-5 to power either an Arduino or Rasberry Pi. I'm studying electronic ...
6
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3answers
279 views
What is this adhesive tape that comes in some parts?
I think this is a Mylar tape, but why they come with it? I guess its so to make the Pick and Place machine job easier?
And why is so common to find them holding cables inside some laptops? Just ...
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1answer
86 views
SMD Trimpot specs - some cite in K/M and others in uH
Was searching for SMD trimpots at a popular online component site, and noticed that the search results were showing trimpots (s.a. from Bourns) some of whose 1-line specs read like they were variable ...
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249 views
Soldering 0.5mm pitch ICs using stencil and reflow oven
I'm new to SMD soldering, and tried to assemble a couple of boards, using a reflow oven.
I 'm using a stencil (Kapton - mylar) and so far it worked fine except for the LQFP48 devices (pitch 0.5mm). In ...
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1answer
164 views
Tips for constructing small PCBs with only one SOIC
So I'm going to repackage this breakout module for simple SPI with a bus-powered LED light strip. It seems expensive and unnecessary for advanced SMT assembly equipment and since its a small PCB with ...
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5answers
587 views
PCB-less prototyping with surface mount components (like DFN)
I'm expecting some interesting comments and answers on this one, mainly because I'm probably just insane for even considering / asking this.
One component I want to prototype with is the MCP73123 ...
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2answers
240 views
Using SMD capacitor as a decoupling capacitor
I'm trying to figure out if one SMD capacitor is the same as a through hole decoupling capacitor. With the through hole capacitor the positive current is on one side of the capacitor and the negative ...
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5answers
245 views
Covering PCB Pads
I have a PCB that was poorly designed and there is a ground pad that is too close to a signal pad. As a result, the signal pad on the surface mount component will short to ground. I was looking to use ...
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2answers
172 views
Any website resource to find diode/transistor replacement from through-hole to SMD footprint?
I always having this problem when trying to convert my prototype design (which usually built using normal discrete through-hole electronic components) to surface-mount (SMD) version for size-shrinking ...
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2answers
238 views
How to split Analog and Digital GND planes for a TQFN device
This question is in reference to Mixed signal PCB layout for PSoC.
If I am using a microcontroller which has separate analog and digital supply inputs and GNDs, what should do with the grounds?
...
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4answers
838 views
vias directly on SMD pads?
I was looking at an example board schematic provided by TI and I noticed something rather curious: vias were placed directly on SMD pads. Is this a normal/acceptable practice to follow? Or is it ...
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1answer
124 views
Mylar Paste Stencils - Paste Mask File Conversion
I want to cut some cheap mylar stencils from mylar for quickly assembling some fine pitch SMT designs. I have access to a laser cutter for this purpose. The laser cutter accepts various file types... ...
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1answer
204 views
What causes components to “jump” during reflow soldering?
I've been using a hot plate technique (with a PID controller / thermocouple / SSR setup) to get into making SMD boards. I had an interesting experience earlier today, and I was hoping some more ...
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3answers
2k views
Polarity of unmarked smt electrolytic capacitor
I have a kit with three capacitors, described in the parts list as "10uF 25V SMD 1206" and shown on the circuit diagram as polarised (an open rectangle and a filled one). Seen through the transparent ...
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2answers
99 views
How do I properly size the components for an RC filter?
Background
I'm filtering low-speed signals from some 5V automotive sensors. That is, their signal is within 0-5V and less than 1kHz. As such, I have selected a 1.3Kohm 1% resistor and a 0.1uF C0G ...
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1answer
194 views
SMD ceramic capacitors producing ticking sound?
I've soldered a couple of SMD capacitors to pads which were not intended to host them. As a result there's a bit of space between the PCB and the capacitors. I have a signal on the capacitors as shown ...
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2k views
Detect damaged SMD capacitors
How can I easily find damaged SMD capacitors without removing them from the PCB? I want to repair my laptop's graphics card (ATI Mobility Radeon x300). I have done a visual inspection of the board and ...
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2answers
566 views
Reliability and failure mode of MLCC (chip capacitors)
Recently I've been preparing to manufacture a product which exclusively uses MLCC capacitors across the board. It integrates an onboard buck converter which uses them, and MLCC are also used for local ...
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2answers
188 views
Cheap high speed oscillator [closed]
What is the fastest oscillator I can build for less than $1 in parts ?
Further specifications:
SMT only
Pricing for Quantity 1000
Stable frequency
Sine wave preferable
I don't care too much what ...
12
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4answers
394 views
What is the best way to short adjacent SMD pads?
Which of the three ways shown above would be the best way to short two adjacent SMD pads together, and why? These are TSSOP pads and the assembly process will be lead-free reflow, if that matters. ...
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2answers
269 views
How well do reflowed connectors self align?
I am thinking of using some Hirose DF40 PCB stacking connectors to stack together a bunch of PCBs. Each pair of PCBs would be connected by two connectors for mechanical stability.
These connectors ...
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3answers
496 views
Repairing broken trace on commercial board
A friend has a USB flash drive on which the SMD USB connector broke off. When it broke, it pulled the pad traces off the board with the solder. We are trying to think of a way to reconnect the ...
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1answer
288 views
How are SMD thermal pads handled in Kicad's eeschema?
I'm using Kicad to do a board with a MSOP-PowerPad which has a metal pad underneath the chip that should be soldered to the board. How are these thermal pads usually represented in eeschema?
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2answers
720 views
supercap-powered RTC?
I'm designing a ATmega-based microcontroller test board. One of the features I want to include is a Real Time Clock with a Maxim DS1307 IC. Instead of including a traditional coin cell battery backup, ...
6
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1answer
3k views
Safe temperature for desoldering SMD components w/ hot-air rework gun?
What is a reasonably safe temperature to use for desoldering SMD components using a hot-air rework gun? I have a new-to-me rework station from Xytronic and the documentation clearly assumes you know ...
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4answers
960 views
Can you stack SMD resistors in parallel to reduce power dissipation per resistor?
I sent my PCB a couple of days ago for fabrication but just realized a terrible error:
I need to send 70mA to an IR LED with a 5V supply so I would need a resistor of about 70ohm, which means the ...
6
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4answers
326 views
Is soldering SMD capacitors directly to TO-220 regulator pins a good idea?
A while ago I read here that it's a good idea to have ceramic capacitors on the input and output pins of 78xx regulators and to put \$10 \mbox{ } \mu F\$ on the input and \$1 \mbox{ } \mu F\$ on the ...
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3answers
541 views
Breadboard/veroboard and SMT
By now, through-hole components have almost completely disappeared from consumer devices and also professional PCBs.
But what is the alternative to build breadboard-veroboard for SMT technology? ...
