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#1
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Increasingly, components are more available in SMD form
than in leaded varieties. Now, I have not tried the following, it is a suggestion as I'm bogged down in other projects ... With a single-sided PCB, used as the earth plane, glue the SMD components down on the fibreglass side, allowing at least 1/4" either side of each component. This is to ensure that there is room for your soldering iron and allows for decreasing eyesight and wobbly fingers. When the glue is dried hard, then wire together using that pink stuff that does not need the enamel to be stripped before soldering. And I mean HARD! But be cautious over some glues that release when heated, such as cyanoacrylate super glues and the Brit Araldite. |
#2
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On Thu, 19 Jun 2014 16:24:46 +0100, gareth wrote:
Increasingly, components are more available in SMD form than in leaded varieties. Now, I have not tried the following, it is a suggestion as I'm bogged down in other projects ... With a single-sided PCB, used as the earth plane, glue the SMD components down on the fibreglass side, allowing at least 1/4" either side of each component. This is to ensure that there is room for your soldering iron and allows for decreasing eyesight and wobbly fingers. When the glue is dried hard, then wire together using that pink stuff that does not need the enamel to be stripped before soldering. And I mean HARD! But be cautious over some glues that release when heated, such as cyanoacrylate super glues and the Brit Araldite. Another way is to use perfboard with pads on one side every 0.1" (and no ground plane in between!). The other side can be bare, ground plane, more pads, or whatever is needed. 0805 and 1206 size components can be easily soldered between the pads, perhaps even 0603. Several components can be soldered to one pad, each going in its own direction; this is for where several components have a common connection. For ICs with 0.05" lead spacing, bend every other lead up and solder the remaining leads to pads. The bent-up leads are connected in the air. Sometimes, the circuit calls for adjacent leads to be connected together; if this is the case, it may be possible to alter the bending sequence to allow them to be soldered to the same pad. ICs with lead spacing closer than 0.05" are a pain to hand solder even on a correctly laid out PC board. And, of course, BGAs can't be hand soldered at all. An advantage over the OP is that you don't have to wait for glue to dry. I have personally used these techniques both in building home projects and breadboards for work. Sometimes using these methods with SMD parts is easier than using leaded parts. Don't use cyanoacrylate super glues on anything that will be heated; they give off nasty fumes. -- Jim Mueller To get my real email address, replace wrongname with dadoheadman. Then replace nospam with fastmail. Lastly, replace com with us. |
#3
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On Thu, 19 Jun 2014, Jim Mueller wrote:
On Thu, 19 Jun 2014 16:24:46 +0100, gareth wrote: Increasingly, components are more available in SMD form than in leaded varieties. Now, I have not tried the following, it is a suggestion as I'm bogged down in other projects ... With a single-sided PCB, used as the earth plane, glue the SMD components down on the fibreglass side, allowing at least 1/4" either side of each component. This is to ensure that there is room for your soldering iron and allows for decreasing eyesight and wobbly fingers. When the glue is dried hard, then wire together using that pink stuff that does not need the enamel to be stripped before soldering. And I mean HARD! But be cautious over some glues that release when heated, such as cyanoacrylate super glues and the Brit Araldite. Another way is to use perfboard with pads on one side every 0.1" (and no ground plane in between!). The other side can be bare, ground plane, more pads, or whatever is needed. 0805 and 1206 size components can be easily soldered between the pads, perhaps even 0603. Several components can be soldered to one pad, each going in its own direction; this is for where several components have a common connection. For ICs with 0.05" lead spacing, bend every other lead up and solder the remaining leads to pads. The bent-up leads are connected in the air. Sometimes, the circuit calls for adjacent leads to be connected together; if this is the case, it may be possible to alter the bending sequence to allow them to be soldered to the same pad. ICs with lead spacing closer than 0.05" are a pain to hand solder even on a correctly laid out PC board. And, of course, BGAs can't be hand soldered at all. An advantage over the OP is that you don't have to wait for glue to dry. I have personally used these techniques both in building home projects and breadboards for work. Sometimes using these methods with SMD parts is easier than using leaded parts. Don't use cyanoacrylate super glues on anything that will be heated; they give off nasty fumes. I seem to recall from early articles about surface mount the suggestion of using a dab of flux to hold the component in place. It was only to hold it until you actually had something soldered. That said, I really think a good magnifiying glass or microscope makes sense. I was trying to figure out something, and got out the jeweller's loupe, and it's amazing how much bigger everything is. That's not going to work for soldering, but getting good magnification that will stand on its own is bound to help a lot. And good lighting. Looking at that board with the loupe almost makes the idea of soldering surface mount within my capability. Michael |
#4
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"Michael Black" wrote in message
news:alpine.LNX.2.02.1406192357540.18018@darkstar. example.org... I seem to recall from early articles about surface mount the suggestion of using a dab of flux to hold the component in place. It was only to hold it until you actually had something soldered. Yes, but that presupposes a PCB is ready. |
#5
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"Brian Reay" wrote in message
... For SMD projects, rather than repairs, you can use a domestic oven to solder the boards. Ideally, get a small table top model (the type of thing student or caravaners use) but I did a test run in a full sized kitchen one. The key thing is to be able to get to 230C or so at least. But you're going off at a tangent, for my suggestion related to ugly construction and not going to the bother of getting PCBs made |
#6
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"Brian Reay" wrote in message
... For SMD projects, rather than repairs, you can use a domestic oven to solder the boards. Ideally, get a small table top model (the type of thing student or caravaners use) but I did a test run in a full sized kitchen one. The key thing is to be able to get to 230C or so at least. You need to plot a graph of the way the oven temp rises using a thermocouple (I borrowed one but they are cheap enough to buy). Basically you put the board it with all the components held in place by solder paste. Set the temp to about 200C and watch as it rises. When it gets to 100, turn oven off for 3 min, this is known as drying time and is to drive the solvent from the solder paste, them set temp to 250 or as high as you can if lower. Now watch carefully, as soon as the solder paste melts and flows to make the joints, turn off the oven and open the door. I've tried this a couple of times and the results are surprisingly good. No dry joints, no moved components. The graph will help you predict when things are about to 'happen' and the thermocouple is essential if your oven temp. gauge isn't accurate. Following on from your repeated childish sneer about vapourware and your inability to establish your own bona fides in respect of completed projects I suggest that what you type above really does take the biscuit in terms of confabulatory Walter Mittycism? |
#7
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On 6/20/2014 3:54 AM, Brian Reay wrote:
Michael Black wrote: I seem to recall from early articles about surface mount the suggestion of using a dab of flux to hold the component in place. It was only to hold it until you actually had something soldered. That said, I really think a good magnifiying glass or microscope makes sense. I was trying to figure out something, and got out the jeweller's loupe, and it's amazing how much bigger everything is. That's not going to work for soldering, but getting good magnification that will stand on its own is bound to help a lot. And good lighting. Looking at that board with the loupe almost makes the idea of soldering surface mount within my capability. Michael, For SMD projects, rather than repairs, you can use a domestic oven to solder the boards. Ideally, get a small table top model (the type of thing student or caravaners use) but I did a test run in a full sized kitchen one. The key thing is to be able to get to 230C or so at least. You need to plot a graph of the way the oven temp rises using a thermocouple (I borrowed one but they are cheap enough to buy). Basically you put the board it with all the components held in place by solder paste. Set the temp to about 200C and watch as it rises. When it gets to 100, turn oven off for 3 min, this is known as drying time and is to drive the solvent from the solder paste, them set temp to 250 or as high as you can if lower. Now watch carefully, as soon as the solder paste melts and flows to make the joints, turn off the oven and open the door. I've tried this a couple of times and the results are surprisingly good. No dry joints, no moved components. The graph will help you predict when things are about to 'happen' and the thermocouple is essential if your oven temp. gauge isn't accurate. Brian, I hadn't heard of using a domestic oven like this. It sounds like an interesting idea. But wouldn't it be a bit hard on the components? I wouldn't think many would like being heated his hot. The commercial assembly lines I've seen use robot soldering irons instead of heating the entire board. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
#8
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In message , Jerry Stuckle
writes On 6/20/2014 3:54 AM, Brian Reay wrote: Michael Black wrote: I seem to recall from early articles about surface mount the suggestion of using a dab of flux to hold the component in place. It was only to hold it until you actually had something soldered. That said, I really think a good magnifiying glass or microscope makes sense. I was trying to figure out something, and got out the jeweller's loupe, and it's amazing how much bigger everything is. That's not going to work for soldering, but getting good magnification that will stand on its own is bound to help a lot. And good lighting. Looking at that board with the loupe almost makes the idea of soldering surface mount within my capability. Michael, For SMD projects, rather than repairs, you can use a domestic oven to solder the boards. Ideally, get a small table top model (the type of thing student or caravaners use) but I did a test run in a full sized kitchen one. The key thing is to be able to get to 230C or so at least. You need to plot a graph of the way the oven temp rises using a thermocouple (I borrowed one but they are cheap enough to buy). Basically you put the board it with all the components held in place by solder paste. Set the temp to about 200C and watch as it rises. When it gets to 100, turn oven off for 3 min, this is known as drying time and is to drive the solvent from the solder paste, them set temp to 250 or as high as you can if lower. Now watch carefully, as soon as the solder paste melts and flows to make the joints, turn off the oven and open the door. I've tried this a couple of times and the results are surprisingly good. No dry joints, no moved components. The graph will help you predict when things are about to 'happen' and the thermocouple is essential if your oven temp. gauge isn't accurate. Brian, I hadn't heard of using a domestic oven like this. It sounds like an interesting idea. But wouldn't it be a bit hard on the components? I wouldn't think many would like being heated his hot. The commercial assembly lines I've seen use robot soldering irons instead of heating the entire board. Don't they often use a blast of hot air? -- Ian |
#9
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On 6/20/2014 7:45 AM, Ian Jackson wrote:
In message , Jerry Stuckle writes On 6/20/2014 3:54 AM, Brian Reay wrote: Michael Black wrote: I seem to recall from early articles about surface mount the suggestion of using a dab of flux to hold the component in place. It was only to hold it until you actually had something soldered. That said, I really think a good magnifiying glass or microscope makes sense. I was trying to figure out something, and got out the jeweller's loupe, and it's amazing how much bigger everything is. That's not going to work for soldering, but getting good magnification that will stand on its own is bound to help a lot. And good lighting. Looking at that board with the loupe almost makes the idea of soldering surface mount within my capability. Michael, For SMD projects, rather than repairs, you can use a domestic oven to solder the boards. Ideally, get a small table top model (the type of thing student or caravaners use) but I did a test run in a full sized kitchen one. The key thing is to be able to get to 230C or so at least. You need to plot a graph of the way the oven temp rises using a thermocouple (I borrowed one but they are cheap enough to buy). Basically you put the board it with all the components held in place by solder paste. Set the temp to about 200C and watch as it rises. When it gets to 100, turn oven off for 3 min, this is known as drying time and is to drive the solvent from the solder paste, them set temp to 250 or as high as you can if lower. Now watch carefully, as soon as the solder paste melts and flows to make the joints, turn off the oven and open the door. I've tried this a couple of times and the results are surprisingly good. No dry joints, no moved components. The graph will help you predict when things are about to 'happen' and the thermocouple is essential if your oven temp. gauge isn't accurate. Brian, I hadn't heard of using a domestic oven like this. It sounds like an interesting idea. But wouldn't it be a bit hard on the components? I wouldn't think many would like being heated his hot. The commercial assembly lines I've seen use robot soldering irons instead of heating the entire board. Don't they often use a blast of hot air? No, the ones I've seen actually have a hot tip. A quick touch is all it needs; in operation it looks like a sewing machine. The biggest advantage is the connection gets hot, but the part doesn't, due to the short contact time. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
#10
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![]() I hadn't heard of using a domestic oven like this. It sounds like an interesting idea. But wouldn't it be a bit hard on the components? I wouldn't think many would like being heated his hot. The commercial assembly lines I've seen use robot soldering irons instead of heating the entire board. I ahve never heard of a line usiung robot soldering irons!! It would be far too slow. Lines normally use either wave soldering or IR reflow. Jeff |
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