Questions tagged [reflow]

Reflow soldering is a type of soldering where solder paste is applied to the pads, after which the components are placed on top and then it is baked in an oven.

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1answer
66 views

How to solder large smd components on a PCB with 2oz copper

I’ve got a large inductor that needs to be soldered to my board. The pads are hidden underneath the component so hand soldering is not an option. The data sheet says to reflow at 260c for 40 seconds ...
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1answer
412 views

Do 0402 chip component need solder mask web between the pads?

In my board, all 0402 parts are using gang solder mask. The pad to pad distance is 10 mils. Is there any risk of solder short? Do I need to suggest applying solder mask web between the pads for all ...
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2answers
126 views

Reflow Soldering at home

I’m trying to solder my TSSOP-16 chip to the DIP adapter. I’m planning to apply solder paste to the adapter’s pads, put the chip on the adapter and then use my kitchen oven to melt solder paste and ...
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5answers
6k views

Using a home oven for solder paste

I'm doing a project and I have a PCB which needs surface mount components attaching to it. One component has already been attached, and I have some 138deg solder paste in a syringe. This is possibly ...
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8answers
2k views

Assembly of PCBs containing a mix of SMT and thru-hole parts?

I have a batch of beta PCBs which we have to assemble in our lab. We have an APS manual pick-and-place machine and a tabletop reflow oven so I thought assembly tomorrow would be easy and straight ...
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2answers
81 views

Solder bridging when reflowing QFP

Today I attempted to reflow solder a board using a solder paste mask and a hot air station but for a QFP chip, I got a of solder bridging. This has generally been my experience with trying to solder ...
4
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1answer
90 views

Small DFN chips come out twisted from the oven

This is a 2 x 2 mm chip with 12 no lead contact points. Half of the time I get it out of the reflow oven, it's twisted like in the image below. I am using a stencil in order to lay the paste down and ...
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1answer
81 views

Can a castellated PCB/module have electrolytic capacitors in it?

We're designing a small module (3in x 3in) that will have castellations on the edges for connection. I just watched a video on castellation PCB design. The video talked about the module going thru ...
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3answers
19k views

Questions about reflowing solder on a motherboard

One of my laptop's DIMMs is dead and working with less than my usual 8GB of RAM is brutal. Multiple sources suggest reflowing the board. I quite frequently tinker with/hack my electronics, but I've ...
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1answer
89 views

Causes of burning solder paste

I’ve recently acquired a modified T962A reflow oven and have been experimenting with profiles. I’ve had to really ramp up the peak temperature and time at peak temperature to even have any chance at ...
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2answers
77 views

Reflow soldering, pin longer than pad?

I was designing the footprint for this FPC connector: Datasheet The recommended land pattern is shown here: The issue I encountered is that the pins on one side protrude outside of the pad: I ...
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6answers
3k views

SMT solder reflow temperature profile

I have read many website and forums about DIY reflow ovens for SMT soldering. I have also seen many solder profiles as specified by the solder manufacturers, component manufacturers, and other self-...
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1answer
109 views

When I rework an SMD capacitor or resistor, it will sometimes stick to the soldering tip. Does this high temp then destroy it?

When I rework 0402 capacitors, then often stick to the tip of the soldering iron. My iron is set at 350. I then discard the cap because I am worried the sustained temp for a few seconds has destroyed ...
5
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1answer
777 views

Do SMD resistors have to be reflowed black side up, or is black side down okay?

I reflow my own boards in a toaster oven. When I drop my resistors off the paper tape, I always flip them over to black side up before I place them. Should I bother if it doesn't really matter?
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2answers
405 views

Burned PCB with reflow soldering

I made a homemade reflow oven and used it for the first time to solder a board. As you can see in the image below, I botched the job and burned the solder connections (not surprisingly, the board does ...
9
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1answer
2k views

Soldering BGA components DIY

If I understood correctly, current BGA components contain solder balls under the package. Do I still need additional solder paste to put on the board, or the amount of solder on the component contacts ...
0
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2answers
61 views

reflow oven issues with RO4003 PCB

Im trying to reflow some RF pcbs in a legit reflow oven. The PCBs material is "Rogers RO4003 305 Um" and 3 layer. (Its a very thin pcb) If temperature is high enough to reflow the paste, the pcb ...
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4answers
534 views

Do any SMT components require hand soldering due to heat limitations?

It has been claimed on another board that some SMT components cannot be used in an automated production line (i.e. reflow or wave soldering) because they cannot withstand the heat/temperature. Hand ...
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3answers
122 views

Makeshift SMT Station. Any suggestions? [closed]

I am trying to do some surface mount soldering for my project and have hit a few snags. My hot air gun works perfectly fine for most of the PCBs I am making but one type in particular is problematic....
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2answers
57 views

Alternatives to Large Transformer or PSU for Driving DC Heater

I have a 3D printer heated bed, instead of 3d printing I want to use it for reflow soldering. The bed is intended to operate at 70c, using 12v or 24v. It can be wired in series or parallel depending ...
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1answer
70 views

How to prevent a low duty cycle load from flickering lights

This is a follow up question to this: Alternatives to Large Transformer or PSU for Driving DC Heater I've hooked up 120v AC to a zero crossing SSR and a 3.2 ohm resistive load. To get my desired ...
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1answer
124 views

Transitioning to lead-free reflow and soldering

I have recently been thinking about moving to a lead-free process for my production and though I've been reading up, I was hoping someone more knowledgable than me would be able to point me in the ...
6
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1answer
509 views

Rule of thumb for surface tension when placing components on the secondary side of a board

I've been working on my first multi-layer PCB design, and have been placing a variety of components on the secondary side of the board (mostly decoupling capacitors and QFN ICs). However, some of ...
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3answers
5k views

Soldering heatsink pad on bottom of IC

I am attempting to make a board for the tlc5951 24-channel led driver to drive an 8x8 rgb led array. I have made what I think is a good eagle library for the sop-38 package, but I am not sure what to ...
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3answers
3k views

Reflow oven vs even hot plate

I've recently been searching for a simple, easy yet cheap way to reflow SMDs on a PCB board as I have never tried it before and always wanted to create a small and compact circuit. I then found a ...
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3answers
140 views

SMD solder failure due to probing? How to solve it?

I was visually inspecting a board that had functional problems, and I have noticed a strange pattern in the pads surrounding the IC. Upon electrical inspection, there are two pads that are shorted ...
3
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1answer
121 views

LEDs lighting up while being baked inside a reflow oven

This is a board with 80 3535 LEDs on it just after completing the reflow cycle in my home-made reflow oven. Why are the bottom corner LEDs lit up? Rather, how is this happening?
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1answer
108 views

exploding cartridge heater

I bought this cartridge heater for my reflow oven. Since this was rated for 220VAC I connected it to my mains through an SSR which is in turn controlled by the reflow oven firmware. The firmware goes ...
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1answer
799 views

Should I spray some flux on my board before putting it in the reflow oven?

I am using Tin-Lead solderpaste to make my prototype circuits. This is the exact solder paste: ALPHA OM-5100 (https://alphaassembly.com/Products/Solder-Paste/OM-5100)     ...
10
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1answer
461 views

Can you program a surface mount IC with flash memory and then reflow solder them?

I know that many chips, such as the ATMEGA328P-AU list flash storage lifetimes at certain temperatures, but they usually cap out at 100° C. I know that, ideally, one should include leads on their ...
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2answers
377 views

Baking SMD integrated circuits for prolong time

I recieved samples of AD7175-2 and AD5684R with an instruction: If these samples are to be subjected to solder reflow or high temperature process, they must be baked for 24 hours at 125°C prior ...
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0answers
386 views

FR-4 discoloring in reflow oven

Is it normal for exposed (no solder mask) FR-4 to blacken during reflow? We're using a fairly ordinary profile with a max at 233C, about 5 minutes total and only about 60 seconds above 200C. I ...
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2answers
28k views

Any drawbacks to “low temp” lead-free solder paste?

I am about to try my first "reflow skillet" soldering job, and as I look at the available types of solder paste I see there are lead-free pastes with much lower melting temperatures than others. For ...
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1answer
2k views

Difference between infrared heating tube coatings?

I'm converting a toaster oven to a SMD reflow oven and have found the thermal momentum of the resistive elements to be a problem (standard dark-grey type). So I've been searching online for some ...
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2answers
135 views

Probe testing LFCSP components with a multimeter

If I reflow a LFCSP IC such as an ADV7180 I probably won't be able to see any solder bridges or unsoldered pads because the pads are under the chip. Can I safely test for bridges by using a multimeter ...
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1answer
125 views

Second Reflow with BGA

For a DIY project BGA reflow soldering is really expensive to get it done by commercial means. I approached a university which allowed me to avail the help of their staff but they said they would only ...
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3answers
4k views

Is it safe to repeat reflow soldering?

I have a board that is partially reflow soldered with a QFN and a couple of 0603 capacitors and resistors. I wanted to test functionality with this stage before I go ahead and place the other ...
4
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1answer
353 views

How to bake MSL components for DIY reflow?

I'm intending to reflow solder some components from Analog Devices. Since they are an LFCSP package, hand-soldering is not possible. They arrived with a warning that they are moisture sensitive (MSL3) ...
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1answer
37 views

S-PFQP-G80 package

I am having some troubles soldering a S-PFQP-G80 package since I get solder bridges between pins after putting it into the reflow oven and I was wondering it would make sense to decrease the pad ...
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1answer
129 views

Solder paste for stencil

I'm going to solder a small pcb with reflow process and I'd like to use a stencil for that because the components are too tiny for hand soldering iron. The pcb has a QFN32 (0.5mm pitch and exposed pad)...
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1answer
2k views

PCB Reflow in oven, will solder melt before VRM's, caps etc get damaged?

From Wikipedia: Alloys commonly used for electrical soldering are 60/40 Sn-Pb, which melts at 188 °C (370 °F), and 63/37 Sn-Pb used principally in electrical/electronic work. 63/37 is a eutectic ...
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2answers
1k views

Will “hot plate” reflow soldering work without a solder resist coating?

With a successful through-hole design under my belt I am now ready to try fabricating a board that uses surface-mount components. I have been reading about this, and have gathered that the DIY crowd ...
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1answer
407 views

What's the min space between exposed via pad to exposed component pad during reflow?

In my opinion, the solder will not run into the via as long as there is a reliable soldermask web between them. Is that right? As I know, PCB manufacturers change gerbers all the time to make the ...
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2answers
727 views

Why do the Sparkfun and Adafruit Eagle libraries use smaller footprints than the manufacturer's recommended land pattern?

I'm comparing two datasheets from Micron and Infineon to the Sparkfun and Adafruit footprints for TSSOP-28 Both the footprints use an SMD pad size of 1.0x0.3 mm, while the manufacturers recommend ...
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3answers
1k views

What's a good plastic for self-cutting solder paste stencils on a laser?

I've tried making my own solder paste stencil using 4 mil polyester (for overhead projection slides) on a 45W Epilog laser cutter at the local TechShop maker space. I could not "cut" the stencil ...
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2answers
1k views

In order to avoid solder bridges during reflow, What is the minimum pad-to-pad spacing?

With regard to DFM, I am wondering if there is no risk of solder bridge during reflow as long as there is a soldermask web between the pads? Soldermask clearance(2 mils*2) + soldermask web(4 mils) = 8 ...
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3answers
2k views

Solder paste not wetting at all

I have an issue with solder paste, I would like to know its origin so I can fix the problem and solder by components properly. I use a lead free Sn42/Bi57.6/Ag0.4 solder paste, manufactured by ...
8
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1answer
999 views

Solder paste stencil application

I am trying to do reflow soldering with a stencil for the first time. I have done some reflow soldering before, but every time I manually applied the paste using a small syringe + needle. These ...
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2answers
7k views

DIY BGA soldering feasability

BGA seems to be somewhat of a showstopper for the diy community, especially with the newer more powerful parts being almost exclusively bga. I know it can be done with the skillet/toaster oven method,...
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2answers
134 views

What situation does it make sense to mod a toaster oven instead of just buying a reflow oven?

I have seen kits like this online http://whizoo.com/reflowoven to modify a toaster oven to use as a reflow oven, but they seem like a significant amount more work and lower quality than just buying ...