8 ms·
What does that mean?
by raldi 5y ago
What does that mean?
- db48x 5y ago“Isotropic” means that something is the same in all directions, and “anisotropic” means that it _isn’t_ the same in all directions. In this case, the tape conducts electricity between its top and bottom surfaces, but not along its length.
- an1sotropy 5y agowell said.
- teruakohatu 5y agoYou could (in theory) put the tape over a circuit board and place components on tape and the circuit would function. It would not short circuit because it only conducts on the z-axis (up and down) not between things on the surface.
- heavyset_go 5y agoI take it the tape would go in the middle between the circuit board and components?
- Brian_K_White 5y ago"I take it the tape would go in the middle between the circuit board and components?" Let me see... "place the tape on a circuit board and place components on the tape"
- heavyset_go 5y agoThanks, without your constructive comment I would've never known that I was asking a dumb question.
- anonymousiam 5y agoPerfect for easily removable/replaceable surface mount components (as long as there is no G/shock requirement), but even that could be mitigated with a pressure plate over the components.
- mrfusion 5y agoI don’t quite get how that’s useful.
- pvarangot 5y agoYou can place BGA components on a board without soldering, which for BGA requires an oven, a hotplate or a heat gun. Also ribbon cables without a housing.
- addaon 5y agoBesides an occasional process improvement over soldering, this can be applied in cases where soldering cannot, for example with very heat-sensitive components such as OLEDs.
- a9h74j 5y agoPerhaps also on stress-sensitive components such as high-stability voltage references.
- Brian_K_White 5y agoIt's useful in certain special circumstances where it's useful. It's probably not useful to you or most people. It's just a very exotic and strange thing that does make some things possible which would otherwise be difficult or impractical some other way. It can do essentially the same job as a zebra strip, with the following differendes: Zebra strips are typically very thick blocks of silicone rubber. This is very thin tape. Zebra are generally not adhesive. They're usually just a chunk of rubber that conducts electricity in two dimensions and insulates in one dimension, but the 3-part sandwich of pcb+zebra+part must be held in place mechanically (metal frames around lcd screens). This is double-sided adhesive tape. Zebra conduct in two directions and insulate in one. They are useful in only one dimnsion. You can take a line of contacts and lay a zebra strip across them. The line can be curved or straight but it's sill essentially a single dimension which is along the line. IE the row of contacts could be say radiating lines and you could lay a zebra in a circle to cross tbose. What you can't have is a grid of dots or any other random arrangement of contacts, just a line. This tape however insulates in two dimensions and only conducts in only one dimension. It's like a tiny carpet of vertical conductors all insulated from each other. You can lay an inch square sheet of it right over a footprint of any random arrangement of contacts, and it conducts an exact image vertically up from each contact, but does not short between the contacts. Some uses for that could be prototyping where you want to test components temporarily and conveniently without soldering. You just stick the components to the pcb with the magic tape and they actually work. More likely uses are to connect things where soldering would be difficult or impossible. For instance connecting displays or ribbons to pcbs where the part may be glass with no metal to solder to, or delicate plastic film that would be destroyed by heat, etc. You can do that with zebra strips now, but this would allow packing in a whole lot more contacts into a smaller space. Or allow sticking components directly onto materials they can't be soldered to. Like sticking a chip directly onto the back of a glass display with no ribbon and no pcb.
- myself248 5y agoImagine a tiled surface, where the tiles are conductive but the grout is not. So you have islands of conductive material which don't connect to each other. If you shrink that very small, and make it flexible and sticky, it's useful: Suppose you have a glass LCD panel, like the kind used in clocks and watches. The traces are indium-tin-oxide (ITO), on the glass. This is fiendishly difficult to connect to, it doesn't take solder well, etc. And you want to connect it to some flexible ribbon cable which will carry the signals to the control board. But how to do that? With Z-tape! By laying a strip of the tape over the ITO traces on the glass, and then smushing the flexible cable to it, the conductive spots in the tape now connect the cable traces to the ITO traces, without shorting them to each other.
- blt 5y agoThis is a great answer. I guess the "tiles" are so small that there's no way they could bridge even the tiniest IC packages?
- cwillu 5y agoThe article has several pictures in which you can see that conductive grains in the tape are relatively sparse in the tape, such that any given grain isn't in contact with any other grains.
- aidenn0 5y agoAnisotropic -> not equal in all directions (isotropic would be equal in all directions). In this case, the tape is insulating in the X and Y direction (directions parallel to the adhesive "plane") but conductive in the Z direction (perpendicular to the adhesive "plane"). I put plane in quotes because the tape need not be applied to a flat surface.
- Salgat 5y agoDirectly above and below a point on the tape conduct to each other (along the thickness), and no where else.