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through hole questions

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So we all know through hole assembly hasn't been completely ... - Nov 17, 2014 by gregp  

#73096

through hole questions | 17 November, 2014

So we all know through hole assembly hasn't been completely eradicated. I am doing some research as to the types of through hole assembly that still remain. My questions are related to through hole requirements and past, current and future methodology for this type of assembly. Is your current level of through hole assembly more, less or the same as 5 years ago? If more or less, how much more or less (i.e. 10% less)? Are you OEM or CM? What method do you use for through hole assembly...fully automated, semi-automated (light guided hand assembly), manual (slide line)? If semi-automated or manual, what method do you use to trim the leads? Are your assemblies fully through hole or mixed technology or both? How many through hole components average per PCB (or panel)? What method do you see as the preferred method for the future and why? For example, if lot sizes are decreasing will you see more potential for semi-automatic guided assembly etc.? A lot of through hole assembly today consists of larger devices (connectors, transformers etc.). Do these present new challenges such as holding the components in place during soldering? Any and all feedback is appreciated. Thanks, Greg

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#73100

through hole questions | 17 November, 2014

this requires a huge answer.

Why do you ask?

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#73102

through hole questions | 18 November, 2014

Hi Adam, Good question. I know I am seeking a lot of details. Here's the deal. Five years ago I acquired the assets of Contact Systems. Since then I have been re-manufacturing the CS-400E machine which if you are not familiar with is a light guided system for through hole component insertion and features an automatic cut and clinch head under the PCB. I conceived of and partially developed a more modern machine to replace the Contact Systems CS-400E. The 400E was developed back in the days prior to SMT so although there is still a fair amount of through hole assembly I believe the requirements have probably changed. My questions are directed towards assisting me to find/confirm the best design for my new product as there is still time to mold it to the best possible overall solution. Even partial answers are ok...any feedback is greatly appreciated. Greg

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#73113

through hole questions | 19 November, 2014

Interesting, see we used to do a large amount of PTH but we have been able to convert most of those parts to SMT now. the majority of our PTH is connectors.

I am doing some research as to the types of through hole assembly that still remain.- This depends on what market is making what product, LED, connectors, resistors ect. can still be PTH but depends if the product is analogue or digital high volume/low volume.

My questions are related to through hole requirements and past, current and future methodology for this type of assembly. Is your current level of through hole assembly more, less or the same as 5 years ago? If more or less, how much more or less (i.e. 10% less)? - We have over 180 different products that we manufacture. Most of the power circuit were revised to SMT reducing our PTH an average of 80%

Are you OEM or CM?-OEM

What method do you use for through hole assembly...fully automated, semi-automated (light guided hand assembly), manual (slide line)?-We use work instruction guided manual slide line.

If semi-automated or manual, what method do you use to trim the leads? Are your assemblies fully through hole or mixed technology or both? We used to use a hand crank lead forming tool. but I don't think its been touched for 16 months now since we SMT'ed our parts.

How many through hole components average per PCB (or panel)? 3-15

What method do you see as the preferred method for the future and why? For example, if lot sizes are decreasing will you see more potential for semi-automatic guided assembly etc.? - Now a lot of our parts are fixed leads in the future we could look towards using an automatic placement machine.

A lot of through hole assembly today consists of larger devices (connectors, transformers etc.). Do these present new challenges such as holding the components in place during soldering?- Good thermal profiling with a wave machine can combat this, we solder with a wave machine or we use induction soldering irons.

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#73114

through hole questions | 19 November, 2014

Thank You Adam...this is the type of input I am looking for. To summarize, you are an OEM that has gone through the process to remove most through hole parts from your assemblies. Those that remain are primarily connectors which may not require lead trimming and could potentially be inserted automatically..I assume with a smt pick and place machine or odd form machine (but is it worth automating for only 3-15 parts per PCB/panel?). I would say your story is typical of many OEM's dependent upon the industry. For example many of our customers are servicing aerospace and defense industry and are building legacy through hole assemblies. It is forbidden to trim leads after soldering in these high reliability assemblies due to the possibility of fracturing the solder joints so Our machine is the perfect solution in this case.

Recently we have gotten some interest from the audio world as it is believed that through hole components produce better sound in amplifiers for instance. Neither of these applications are significant growth potential areas for my company. I am really seeking to replace slide lines with better guided assembly with cut and clinch capability and component dispensing.

Imagine a slide line with only one to three stations (for example) with the components for all of your assemblies on line in a JIT component delivery system. This would enable smaller lot sizes to be run with virtually no changeover time. It is possible these stations could also guide other assembly tasks such as screwed on heat sinks or battery clips etc. (virtually anything remaining in the assembly). Do you think a flexible system for this purpose would be received well by a company such as yours? Greg

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#73116

through hole questions | 19 November, 2014

your summary is pretty accurate! yeah our justification on the automatic system is long in the pipeline. we would need significant volume even then we could just bump the staff numbers.

I can see how you are having troubles with the legacy requirements. Though the only way forward if again you had the volume would be something like this https://www.youtube.com/watch?v=2sm_qdeconI Would be nice to see some high quality audio gear again, though its like the valve vs mosfet argument. Id be happy to see some since to it ;).

Currently our slide line system works with a sequential kanban taking components from the bins from right to left as we complete population of part type(due to factory outlay), I would look at some kind of vision system but our internal QA process has had us seen very little defects (missing/incorrect parts). Any parts that require heat sinks riveted are done by the part timers they take care of the little easy odd jobs.

P.S Millspec 2000 is outdated :P

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#73117

through hole questions | 19 November, 2014

Plenty of people don't like cut 'n clinch and might appreciate just having the cut part. We do a mix of OEM and CEM work, because of the low volumes special tooling for a product is often out of the question so that is one thing to consider. We use through hole components on many products, often these are switches, connectors, LED's and electrolytics but we also build 100% through hole assemblies, sometimes because they are audio products, but also to maintain the skills base or because they are simple enough that there is little to no benefit in going surface mount. Like many small companies we don't operate a slide line but I could see a place for a modern assembly aid taking the place of a basic workstation & jig. I would focus on making it simple to setup, modular in features with a low cost of entry. Perhaps if it started out somewhat resembling the Robotas Mascot and then you could add component prep/crop, crimping, verification... as extras so it appeals to as many people as possible.

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#73118

through hole questions | 19 November, 2014

Hi Spoilt...thanks for your reply. The latter part of your reply is a bit perplexing though. The CS-400E is easy to set up. There are two lights spots that indicate the insertion location. The component does not need to be prepped other than bent to the correct lead spacing. The component is presented by the dispenser and is inserted and automatically cut and clinched (with verification as an option). So compared to the Mascot it does the same and then more. What is it about the cut and clinch that makes the system less appealing as opposed to more appealing?

This is important and your opinions are extremely important to me so thanks again for your input.

Greg

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#73119

through hole questions | 19 November, 2014

Hi Adam...thanks for your follow up comments. The auto inserter in the video is a machine from a time gone by...But quite impressive. Those machines are good for higher volume where high flexibility may not be required. not sure if all of the components you are inserting on your slide line can be inserted on one machine though. Which brings up some interesting considerations. Because you still employ slide line strategy I assume your lot sizes are fairly large and each person on the line is inserting only a few components. This is fine if you have the luxury of larger lot sizes but when you need to build one off or even ten or 100 pieces the slide line can be a source or quality issues...do you agree? What are you average lot sizes?...and are your lot sizes large because your process would not be efficient for smaller lot sizes or are they large because you really need to produce large production runs of your products?

I am very interested in your reply...Greg

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#73129

through hole questions | 20 November, 2014

We process an average of 300 units per batch with spikes to 750, we can sustain about two to three people populating to maintain good quality/throughput. Part placement is broken up equally to reduce operator stress(usually a limit of 5 different part types before people begin to break). We also have post operator inspection and between stage operator inspection. Our lot sizes are based on a monthly average consumption trend. we have some minor inefficiencies in our lot sizes being so small sometimes, but continuous improvement and all.. gives us something to do.

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#73130

through hole questions | 20 November, 2014

gregp:

Our PTH process has not changed in many years. Our products are fairly simple as far as electronics goes and everything gets potted anyways.

~90% of everything we build is single sided TH with ~ 100 solder joints per board. Each board is ~ 2” x 2”. Boards are panelized 4 boards x 6 boards (24 board panel), approx. 8.5 “ by 12” panel dimension. Not many layers. The other 10% are mixed SMT/TH boards.As the company has gotten bigger we are the rare exception that has actually expanded our TH capabilities (though on a decline now as more gets outsourced to China).

We have a semi-automated process for building our boards. We have axial/radial and DIP machines to place the majority of our parts (~95%). Then they go through the hand load line for completion of assembly. The parts for the hand load line are formed and trimmed through a forming machine.

The majority of our products do not require connectors and the ones that do generally come from China.

Also we are OEM.

Hope this helps, Joe

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#73137

through hole questions | 21 November, 2014

I meant more from the programming perspective, make sure you make the most of what you can do with modern computing interfaces. Making configuring/creating jobs etc as accessible as possible to as wide an audience possible. As an example look at how easy it is to configure just about every imaginable parameter on a modern pick and place machine. Include handy things on the display like expected component marking, perhaps a way for users to report errors with the setup or the PCB or BOM. There can be any number of reasons people choose to dislike cut 'n clinch (I'm not saying they are valid): It looks nasty It can damage the component Its another mechanism to go wrong It needs tooling It makes rework/repair difficult (especially for those value tinkering audio types)

It is also much less common a sight to see I would suggest.

I have not used either a 400E or a Mascot, but I would suggest that at the Mascot end of the spectrum (largely guidance) it is possible these days to build something very affordable that you might even bolt to an existing bench, by contrast the CS400E is a huge hulking albeit capable beast.

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#73140

through hole questions | 21 November, 2014

Hi Adam, So with two to three people on the slide line, each only able to place five different components maximum, this means you generally don't exceed 10-15 through hole parts per assembly, correct? I am guessing these are mixed technology boards and the through hole stuff is done after SMT placement and reflow...or are you doing pin-in-paste? =Greg=

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#73142

through hole questions | 21 November, 2014

Hi J_Dub (Joe), Thanks for the input. Sounds like some fairly densely populated through hole assemblies. 100 solder joints per board is up to 50 parts per board (I know you may have DIP's so it could be less than 50). 24 boards in a panel x 50 parts could be 1200 parts per panel. So in this case automation makes sense for whatever you can automate. Can you tell me a bit more about what gets inserted manually? How many parts per board or panel and what types of parts? They are formed and trimmed prior to insertion...do they snap in? How are they kept in place when they go through the wave or do you use selective soldering for these parts? =Greg=

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#73143

through hole questions | 21 November, 2014

Hi Spoilt, Thanks again for the feedback. It is really an eye opener for me. What I fail to realize is that perception, whether right or wrong, plays a big role in whether or not someone might consider a process change.

Your first comment is really about ease of use (and therefore ease of implementation) and useful features. While the CS-400E falls in this category it is undeniable that it could use some updating and this is one of the areas I would focus on. BTW, there is an image of the component and markings on the display for the component being inserted on the CS-400E already but even this can be improved).

"It looks nasty It can damage the component Its another mechanism to go wrong It needs tooling It makes rework/repair difficult (especially for those value tinkering audio types)"--this is the perception part that interests me. As an original developer of the machine who has spent a lot of years dealing with customers who use the machine perhaps I am "a bit too close". The machine and especially the cut and clinch are extremely reliable and this has been proven over the machines 20 year history. In fact, I strongly believe the robustness of the machine was bad for Contact Systems because they lasted too long thereby negating the possibility of a replacement market.

As far as it being a huge hulking beast the Mascot is 16.5 sqft. and the CS-400E with rotary bin is 18 sqft.--basically a negligible difference. So, again, it is perception. Of course it's heavier as it needs to be with the moving parts and such, maybe this is what gives it the perception of being larger.

Your perception is most likely shared by others and it's great that you are honest with your input. Those who have used the machine love them and most of my customers have multiple machines some even 10 or more. It's the people that don't have the machines I am trying to to see if there would be interest.

For someone such as yourself you would like to see something more current looking, lighter weight, simpler looking etc.--like a mascot--but would you buy into a slide line looking thingy with component locating (i.e. light spots) with cut and clinch built in--that is the $64 question. The benefits of cut and clinch are many but if you don't want cut and clinch (or if it is not needed for the components you are inserting) then this is what I am wanting to know. =Greg=

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#73145

through hole questions | 21 November, 2014

On average there are about 3 parts per board that get hand placed (x24 is 72 parts per panel). One of these parts is a big 1W resistor that cannot fit on our axial machine. We also have a Zener Diode that needs to be hand placed because its leads are too hard to be cut by our axial machine, we will go through a 300$ pair of cutting blades every week with this part on the machine. The last part is a transistor that is to big for our radial machine.We have other various resistors that also get hand placed on different boards for one reason or another (i.e. to small, to big, hard leads, to fragile etc..)

All the transistors are trimmed on a very old GPD CF-10. All other parts are trimmed/formed on another very old GPD CF-8. These machines are more than twenty years old and have never failed beyond what some minor cleaning up can fix.

We have looked into selective soldering, but we have to many through hole parts to utilize it effectively. Our cycle time for selective solder would end up being around 18 minutes per panel which more than three times our current cycle time. All the machine placed parts are clinched but our boards go directly from the hand load line into the wave so we have no need to clinch our hand placed parts. The only defects we have ever seen from this is the Zener diode will pop out of place every great once in a while (easy fix for our low to medium volumes).

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#73148

through hole questions | 23 November, 2014

Hi J_Dub, thanks for the continued info...Of course selective soldering would be very time consuming for such a through hole assembly...but 18 minutes, wow...didn't realize selective soldering could take that long.

I would like to know the approximate lead diameters and lead material of the parts you insert by hand.

Seems like your process cannot necessarily be improved. How many different part numbers do you suppose you need to hand insert on all of the different assemblies combined? =Greg=

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