Does this make sense or does this make sense or not?

[Wylie]

Hi folks,
I didn't get any feed back over in the Cafe forum with this so I thought I would give it a try over here. It gets better as you read into it.

I don't think this could be taken for any form of illusions of grandeur but I prefer to think of myself as a free thinker and idolize some people that have considered themselves the same.

Ben Franklin is one of them and he gave away one of his greatest inventions for the betterment of humanity.

What did he get for this but people in positions of the day that were among the highest ridiculing him and even the churches telling him that his lightening rods were a sacrilege as they shadowed man from the hand of god. My favorite point in Ben's argument was against the church as he replied by asking, do we expose ourselves to elements such as rain, snow or sleet by not clothing ourselves or building shelter to be closer to the hand of god.

Okay, I cut this up a little bit and may have even cut it down from its original whit but that is the basics.

Anyway, I have had an idea and it may not have the same merit, as lightening rods but it sure seems to make really good sense to me.

In the short time I have been toying with LEDs and becoming more aware of their many uses I have had questions coming to mind that may have entered many of yours as well. The cylindrical shape that most LEDs are produced in today for all different types of applications do not make the greatest use of space that is valued in many application these products are used for. I have seen that there are square bases on some of the LEDs produced but they still have the same dome as the other molds a great percentage of LEDs are made from. When you think about the space valued applications of these products such as fiber optics and others. Even non-space valued applications such as stadium picture screens it just seems as though a better shape would have come around by now at least for the lower viewing angled LEDs.

The shape that seems to make the best sense to me would be a hexagonal LED. Forget the bases like the round LEDs and just key the sides with a shape that makes a universal fit to other LEDs. With the super glues of today and the right circuit boards this really seems to make sense to me.

Does this make much sense to any of you or am I fooling myself.

?
Okay now its time for all of you to tell me that this is sacrilege and that I should be damned to hell forever.

Keeping it real,
Wylie

 

[monanza]

I saw your post in the other thread but was too tired to respond. This is a great idea.

Hexagonal LEDs would pack very nicely for larger arrays but the form factor should also be complemented with hexagonal dies. Furthermore the cylindrical domes do perform a lensatic function and need to be rethought for tight packing applications.

What you are suggesting is similar in a sense to what Fuji has done with CCD arrays. They use a hexagonal footprint for their cells to pack a higher cell density onto the chip.

Cheers.

 

[Wylie]

Monanza,

I understand what you mean about the optical properties of a completely hexagonal shape. I agree as I think a completely hexagonal domed LED would not really work that entirely well. The same goes for the dies for wider viewing angled LEDs but I was basically referring to lower viewing angles in the area of 15 to maybe 20 or 25 degrees.

As for the wider viewing angled LEDs the lens area could be 2 or 3mm closer to the die and completely illuminate the domed area of the lens like some LEDs are made now. On the other hand with the die closer to the lens area the lenses could take a smaller area just in front of the dies and still be round in shape for proper optical properties. This might allow for a narrower diameter also of maybe something like 4.5mm or 4.75mm for 5mm dies from round LEDs in the hexagonal shape. The hexagonal shape also could be brought to a half spherical or domed shape for optical properties quickly to help with wider viewing angles in hexagonal LEDs but I like the smaller lens area idea better myself. In either case the dies would have to be positioned as to have the anodes and cathodes in opposing corners of the hexagon shape but they should be real close to a nice fit. If implicated the domed lens portion of the hexagonal LEDs would most likely have to be lets say a more of a pointed lens then the round LEDs are now but I think this could be done with the same dies that are being used in round LEDs now. Both three and five millimeter LEDs could be taken into retrospect with this concept I figure.
I would be very interested in an LED engineer’s view of my ideas as I think it could work very well and in a lot of cases make for a much cleaner and painless applications of LEDs.

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Thanks for the feedback Monanza I just get these types of things running through my head and I like to get others opinions. Let me know what you think as I think I have a winning concept here.

Just keeping it real here,
Wylie

 

[Wylie]

Very interesting points Monanza,
I do know indexed or refractive lens materials have made my glasses a lot lighter and I see what you mean about maybe not needing any dome with these materials.
This may sound a little out there but maybe a mold for these materials using an electromagnetic field would set the indexed materials in the correct alignment for making awesome lens or maybe not. Oops, I think I’m scaring myself again.

Going into nano techs would probably lead to some really weird ideas from me so I will not even go there.
I was thinking the phosphorus was just sprayed into the cups but I can see how the non-uniformity of spaying would be tough to deal with that way too. Phosphorus wafer cutting is something new to me. I guess I should look that up and get informed.
Go figure, I was thinking a different mold could be made for the acrylics and just use the dies and contacts as used now to bring the new shape LEDs around. From what I know it may just work.

Thanks for your thoughts Monanza,

Wylie

 

[monanza]

Wylie,

I too would like to hear comments from lighting/LED/semiconductor design engineers.

From reading some of lumiled's material I understand that controlling the electrical path in the die is critical to achieving high output density. I think your idea has a very good chance of success at the die level.

I don't know much about nano-technology but it sounds like large scale LEDs will benefit greatly from nano-optics. Lenses do not really have to be round to provide focusing ability they can utilize index of refraction gradients to achieve the same effect. Furthermore the use of nano-reflectors should further improve the optical properties of large scale LEDs.

Last but not least I would be interested to know what kind of wafer cutting technology is used to discretize the individual LEDs during manufacture. This may (or may not) restrict the final shape of the die.

Cheers.

 

[Wylie]

Hey folks I got some answers on the hexagonal theory I was thinking of and it looks like it bombed!

These are emails from the assistant manager of Nichia here in the states.

Wylie,

My viewpoint is two fold (with summary)

A) Dense Mounting: Most companies try to avoid densely mounting LEDs as
the heat produced at the junction is very high. A densely mounted
cluster becomes a liability to its own life. In a sense you can
consider each LED as a candle, which is more light than heat. But bring
10+candles together and you compound the heat produced. It is the same
idea for electronic components.

B) Optical manipulation: Although some companies by strategy or
circumstance disdain the 5mm round package, it is very useful for a
majority of LED applications. It was even rather humorous that the
claim last year "round LEDs are dead in lighting!" The market expands
for 5mm (even in lighting) and allows other designs to thrive as well.
But why did the design end up as a cone? Most buyers wanted a conical
illumination output pattern. Even ovals exist but mainly for display
purposes.

Summary: Indeed a hexagonal structure allows for more densely populated
devices (but heat is a limiting factor). Another downside is, it is not
the best form for optical lenses. From a based point of view, it could
also be a novel way of designing circuit boards. And you can see an
attempt at hexagonal systems via www.norlux.com : they were trying to
make hexagonal die arrays (but didn't get very far) Die arrays are not
entirely workable.

With Best Regards,

James Creveling
Assistant Manager
Nichia America Corporation

I couldn’t help but try to pick his brain a little more so here is the next email I sent.

Hey thanks for the reply James. I never really run my LEDs all that hot
or over amp them too much but what you have said makes a lot of sense to
me. What I was thinking of could very well cut down on the longevity of
the LEDs.
Since I have you on the line has anybody been working with a two
stage acrylic process to create an inner lets say reflective cup or
culminator. I have been thinking the lens area could be done in the
first stage in a half sphere, and the second stage just below the die.
This housing could be of an acrylic with the same properties as Mylar,
at least the gold color would help with the red spectrums and others may
work for other colors as well.

Little did I know this was old news and his email clarified this for me.

Wylie,

We use a two stage process for white LEDs. Blue/Green/Red/Cyan are all
one stage. But as far as the materials, we can't say. Even the
technical agents like me are prohibited from knowing (let alone
discussing) the materials.

However, in general: choice of resin is very troublesome. You also
have to balance refractive index, glass transition temp, degradation,
expansion, temperature range, ability to transmit light, and many other
things. There are really great resins out there for some of the above,
but almost none for all of the above.

** Inner reflective cup - we use silver. Why use epoxy? You need a
conductor near the die to remove the heat. Silver & copper are the best
for both worlds.

With Best Regards,

James Creveling
Assistant Manager
Nichia America Corporation

So another day and another lesson learned but I always have to try to get my $0.02 in.

I was thinking of gold or a sort of zinc alloy really but then the
expense of production has be taken into account.
Yep, that's why you guys are making the big bucks!
Wylie Wiggins

 

[RossB]

LEDs are cylinders as manufactured, aren't they?

Cylinders naturally array themselves into a hexagon when forced into the most compact configuration, so the external shape of each individual LED wouldn't make much difference, would it?

Could they be reshaped? The shape of the actuator would have to be circular, since the energy is applied to a point, and so naturally falls off in a circular pattern. So, LED's are cylindrical by design. Besides which, making small glass hexagons would be more expensive than simple tubes.

Wylie, correct me if I'm wrong.

Happy New Year to the Forum.

RossB

 

[Wylie]

Hi Ross,
LEDs are cylinders as they are manufactured these days in most cases. Some LEDs have taken on other shapes like squares, triangles, rectangle and the square and rectangled based LEDs. Even the hexagonal LED shapes have been ventured by at least one company that I now know of.

I have seen this for myself and you are correct, tightly packed clusters of cylindrical LEDs do emit a hexagonal type pattern of transient light if I am right calling it this.

I am far from any type of electrical or LED engineer and I do not feel I would be in the right place to correct anyone. I am just toying with ideas and enjoy the feedback of others that have more knowledge in these areas then myself.

The term actuator for LEDs is new to me in the sense that the only actuators I have used in the past were fastener oriented. I might guess that this is the business end of the LEDs. From what I have picked up the business end deals with the filling of atomic sized holes in loosely molecularly bonded opposing poled semiconductors with mingling electrons from two naturally opposing poled semiconductors that creates a couple forms of an electrical discharge (heat and light) when electricity is applied against the natural poles of the semiconductors, these mingling electrons excite materials emitting photons of light? Wow, there I go scaring myself again

.I like this use of the word actuator as this is where the action is if I am correctly assuming this terminology?

I am with the thought that round dies (or actuator plates?) could be used with a hexagonal shaped LED. I am pretty sure that not all dies (or actuators) are round and they come in at least a few different shapes. I can understand that the application of the electrical charge to the near center of the die would be important as the electrons would work outward from the center seeking the least path of resistance. Most likely if the hexagonal shape were used for white or mixed color LEDs the corners of the dies would be less illuminated, but then again thinking about this I may be wrong.

One of the main perks I imagined with hexagonal LEDs would be the structural strength of clusters of them.

I would think if the cathodes and anodes were set in opposing corner of the hexagonal shape that measured 5mm from opposing corner to opposing corner these hexagonal LEDs would be able to pack together into a smaller space then a cylindrical LEDs that measure 5mm in diameter.

As for the heat generated by these LEDs I have to say I am a little more then skeptical when they are run at the correct current and voltage. I have made small arrays that are very close to the correct voltage and amperage and the heat was so minimal I feel it would really make no difference.

I do not know if the LEDs that are made today are molded by means of pouring or injected or just what is used to form the shapes that are made in. If were to guess from looking at them I would think that they are molded by an almost combination of the two, an open mold that is injected with whatever material is used through a syringe type device. If the hexagonal shape were implied here the greatest cost would be in the molds themselves. Every project has its initial costs and it would be up to the people with the money to decide if the difference in shape would be worth the cost of the molds.

As for myself I can see enough of an advantage to this shape to justify the cost and just like old Ben might have said I think I got something here.

Thanks for the feed back Ross, I just may be setting myself up to get schooled here but how else do we learn.

Wylie

 

[Wylie]

Wait a minute, I forgot the part about the vibration in the discharge of the electrical energy. Here I go pulling at strings again but from what gather the difference in the semiconductors materials creates a difference in the path of the electrons which makes different colors of light. Smaller orbits of electrons create a less visible light and larger orbits create more visible spectrums of light in different colors using different materials.

I think I am almost getting a grasp on this stuff but the metallurgy is beyond me at this point.