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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4
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1answer
88 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
75 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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1answer
80 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
76 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 ...
4
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1answer
101 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
742 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
319 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 ...
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2answers
54 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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3answers
117 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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1answer
67 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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2answers
56 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
117 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
480 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 ...
3
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3answers
123 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
113 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
97 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 ...
2
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1answer
679 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
415 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 ...
2
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2answers
316 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
356 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 ...
1
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1answer
117 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 ...
0
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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 ...
4
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1answer
317 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) ...
14
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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 ...
0
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1answer
34 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
119 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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3answers
2k 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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0answers
350 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
709 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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1answer
372 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
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 ...
9
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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 ...
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2answers
131 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 ...
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1answer
104 views

Baking 0603 Components

I have a few 0603 LEDs that come with the instruction to bake them if they had the chance to draw moisture. What is the best way to do that? Can I leave them in the tape, so I don't lose the ...
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0answers
157 views

Vacuum dessication of MSL components?

The standard method of removing moisture from MSL-sensitive SMD components prior to reflow is to bake in an oven for 12 hours or more. Without baking, there is a possibility of popcorning, as the ...
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1answer
1k views

how to solder MEMS microphone to PCB at home? [closed]

I would like to experiment with audio applications using MEMS microphone. The problem is i cannot think of a way to solder these microphones on a pcb as PCB prototype manufacturers that i know won't ...
0
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1answer
99 views

DIY SMT Reflow 48LQFP

I am new to this forum. I am building a prototype board which uses a 48 pin LQFP 0.5mm pitch IC including other components. Included on the board I have 1206 SMT components and SOIC components. All ...
8
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1answer
923 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
724 views

Signs of overheated smd chip

I am developing a board that has a couple of small SMD chips. I have successfully made a couple of working boards. Unfortunately I found out that one of the chips in my original design is going to be ...
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3answers
572 views

Question after my first attempt with reflow soldering

I have a couple of questions, plus I'd invite any comments/feedback/suggestions to improve my results. I used solder paste Chipquik SMD291AX10 (Sn 63 / Pb 37) on the pads and also flux (Chipquik ...
4
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1answer
192 views

Do all/most SOIC chips whitstand the 235 degrees C for reflow soldering?

I want to try reflow soldering for several projects (small scale). For some of the components (e.g., resistors and ceramic capacitors), the datasheet does give specific information about maximum ...
3
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2answers
319 views

Low Melting Point solder paste reflow profile adviced

I've found a low temp solder paste with a melting point of 140°C. I want to use it with some SMD parts. I've looked for some reflow profiles and didn't found nothing with this low melting point. Can ...
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2answers
475 views

Potential pitfalls/caveats for developing a stencil for solder reflow

I'm developing a project that requires ICs that are in a QFN package, some have a slug on the bottom of the IC. Since these are QFNs, I'm not interested in hand soldering these; so I'm leaning toward ...
9
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1answer
1k 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 ...
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2answers
2k views

GPU reflow soldering profile

I've had my ENGTX480/2DI/1536MD5 GPU for 3 and half years now. Over the past 2 months it started causing trouble. At first, it started seldom displaying big zones with weird color, but simply ...
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2answers
535 views

Re-reflowing a populated PCB

I've printed, populated and baked a test PCB with most components that I needed. I left off a GPS chip and associated passives because the GPS chip itself costs more than the rest of the board, and I'...
2
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2answers
1k views

Consequences of not following reflow profile

I found many questions about how to perform reflow soldering, but my main concern is What are the consequences of not following the recommended reflow profile. Would there be any risk going the ...
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2answers
179 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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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 ...