Abstract: Techniques related to laser lift-off masks are disclosed. In some embodiments, masking material is applied to a substrate that is attached to a plurality of semiconductor device sets. More specifically, the masking material is applied to one or more regions of the substrate between the semiconductor device sets. When the semiconductor device sets are embedded in a filling material, the masking material may be situated between the substrate and the filling material. Thus, transmitting light through the substrate toward the semiconductor device sets causes the substrate to become detached from the semiconductor device sets. However, the light is at least partially occluded by the masking material.

Abstract: LEDs are manufactured on a substrate layer and picked and placed using a pick-up tool (PUT) onto a target substrate. The PUT typically attaches to an LED via an elastomer layer deposited on a surface of the LED. A given batch of manufactured LEDs may contain operational LEDs as well as non-operational LEDs. In order to separate the operational and non-operational LEDs, the LEDs are placed on a unidirectional conductive film. A photo-curable polymer is deposited on a surface of each LED. A voltage difference is applied across the electrodes of each LED via the unidirectional conductive film, causing the operational LEDs to emit light and cure the photo-curable polymer to form an elastomer layer, while the polymer deposited on the non-operational LEDs will not cure. As such, the PUT will be able to pick up the operational LEDs, while being unable to pick up the non-operational LEDs.

Abstract: An online system determines a polygon representing a physical location associated with a content item and indexes edges of the polygon based on their positions along an axis of a map. The index is used to retrieve edges spanning a point on the axis representing a location of a client device associated with an online system user. The online system compares the positions of the point and retrieved edges on an axis perpendicular to the axis and determines whether the user is at the physical location based on the comparison. If the user is not at the physical location, a boundary surrounding the point is compared with boundaries surrounding the indexed edges to determine whether the user is within a threshold distance of the physical location. If the user is at or within the threshold distance of the physical location, the user is determined eligible to receive the content item.

Abstract: An online system identifies a conversion of an advertisement when a client device associated with an online system user is within a threshold distance of a physical location associated with the advertisement. The client device sends obfuscated information identifying the user associated with the client device and the location of the client device to an independent third party when the client device is within a threshold distance of the physical location associated with the advertisement. Using information from the client device, the third party requests information from the online system identifying one or more groups including the user. Based on information identifying groups including various online system users, the third party generates information identifying conversions associated with different groups. The online system may determine effectiveness of various advertisements using the information from the third party identifying conversions associated with different groups.

Abstract: Systems and methods are disclosed for electronic distribution of electronic content. The method may include receiving, from an advertiser or content provider, a request to transmit electronic content to a plurality of electronic devices of a desired subset of individuals. The electronic content may relate to a target location affiliated with the advertiser or content provider. The method also may include retrieving population density data for the target location and surrounding area, and correlating the subset of individuals with the population density. In addition, the method also may identifying a geographical zone extending from the target location to a perimeter location. The zone may have a size based on the population density correlated with the subset of individuals. The method may further include receiving an indication that the electronic device of a user has entered the geographical zone, and transmitting electronic content to the electronic device of the user.

Abstract: Embodiments relate to transferring dies or other electronic components from a carrier substrate to a target substrate of a device as part of chip assembly for the device. Bonding material is applied to selected dies on a carrier substrate by direct boning, or to corresponding die transfer locations on a target substrate. The carrier substrate is then brought into contact with the target substrate to transfer each of the selected dies to the carrier substrate. Dies can also be directly bonded to the target substrate even in the presence of other die in situ (e.g., from a previous bonding cycle), hence, enables more than one direct bond cycle to be carried out for a target substrate. As such, multi-color (RGB) display elements can be assembled in stages (e.g., separate bonding cycles) in a flexible manner to provide redundancy or to replace inoperative LED dies.

Abstract: A light emitting diode (LED) includes an elastomeric material that facilitates adhesive attachment with a pick-up head for pick and place manufacturing operations. The LED includes an epitaxial layer defining a mesa structure and a light emitting surface. The mesa structure includes an active layer to emit light, and the emitted light is reflected at the mesa structure toward a light emitting region of the light emitting surface and transmitted at the light emitting region. An elastomeric material is on a portion of the light emitting surface, such as the light emitting region or a passive region. At the light emitting region, the elastomeric material may be shaped as a lens that collimates light transmitted from the light emitting region, and also facilitates adhesion to the pick-up head. At the passive region, the elastomeric material facilitates adhesion to the pick-up head without interfering with light emitted from the light emitting region.

Abstract: A head-mounted display (HMD) presents viewable media to a user. The HMD includes a light source and an optical block. The light source includes a first sub-pixel mounted on a first set of microbumps at a first height from a substrate and emits light within a first optical band, and a second sub-pixel mounted on a second set of microbumps at a second height from the substrate that is different from the first height, and emits light over a second optical band that is different than the first optical band. The optical block receives the image light from the light source, and directs the image light to an eyebox, wherein the first height and the second height mitigates longitudinal chromatic aberration and field curvature in the optical block.

Abstract: A social networking system receives information describing locations associated with a plurality of its users. Based on information identifying each user and a location associated with each user, the social networking system generates and stores hash values. For example, the social networking system maintains various geo-tiles that each identify geographic areas and generates a hash value based on a user identifier and an identifier of a geo-tile including the location associated with the user. Based on the hash values and locations associated with one or more users, the online system determines a number of unique users associated with locations included in a geographic region. When determining the number of unique users, the online system accounts for a rate at which the online system updates location information associated with various users.

Abstract: A light emitting diode (LED) includes an elastomeric material that facilitates adhesive attachment with a pick-up head for pick and place manufacturing operations. The LED includes an epitaxial layer defining a mesa structure and a light emitting surface. The mesa structure includes an active layer to emit light, and the emitted light is reflected at the mesa structure toward a light emitting region of the light emitting surface and transmitted at the light emitting region. An elastomeric material is on a portion of the light emitting surface, such as the light emitting region or a passive region. At the light emitting region, the elastomeric material may be shaped as a lens that collimates light transmitted from the light emitting region, and also facilitates adhesion to the pick-up head. At the passive region, the elastomeric material facilitates adhesion to the pick-up head without interfering with light emitted from the light emitting region.

Abstract: A light emitting diode (LED) includes an elastomeric material that facilitates adhesive attachment with a pick-up head for pick and place manufacturing operations. The LED includes an epitaxial layer defining a mesa structure and a light emitting surface. The mesa structure includes an active layer to emit light, and the emitted light is reflected at the mesa structure toward a light emitting region of the light emitting surface and transmitted at the light emitting region. An elastomeric material is on a portion of the light emitting surface, such as the light emitting region or a passive region. At the light emitting region, the elastomeric material may be shaped as a lens that collimates light transmitted from the light emitting region, and also facilitates adhesion to the pick-up head. At the passive region, the elastomeric material facilitates adhesion to the pick-up head without interfering with light emitted from the light emitting region.

Abstract: A head-mounted display (HMD) presents viewable media to a user. The HMD includes a light source and an optical block. The light source includes a first sub-pixel mounted on a first set of microbumps at a first height from a substrate and emits light within a first optical band, and a second sub-pixel mounted on a second set of microbumps at a second height from the substrate that is different from the first height, and emits light over a second optical band that is different than the first optical band. The optical block receives the image light from the light source, and directs the image light to an eyebox, wherein the first height and the second height mitigates longitudinal chromatic aberration and field curvature in the optical block.

Abstract: Methods and apparatus for use in the manufacture of a display device including pixels. Each pixel includes a plurality of sub-pixels, each sub-pixel configured to provide light of a given wavelength. The method may include: performing, using a pick up tool (PUT), a first placement cycle comprising picking up first light emitting diode (LED) dies, and placing a first LED die on a substrate of the display device at a location corresponding to a sub-pixel the display device. The method further includes performing one or more subsequent placement cycles comprising picking up a second LED die, and placing the second LED die on the substrate of the display device at a second location corresponding to the sub-pixel of the display device. Multiple first and second LED dies may be picked and placed during each placement cycle to populate each pixel of the display device to provide redundancy of LED dies at each sub-pixel.

Abstract: Methods and apparatus for use in the manufacture of a display device including pixels. Each pixel includes a plurality of sub-pixels, each sub-pixel configured to provide light of a given wavelength. The method may include: performing, using a pick up tool (PUT), a first placement cycle comprising picking up first light emitting diode (LED) dies, and placing a first LED die on a substrate of the display device at a location corresponding to a sub-pixel the display device. The method further includes performing one or more subsequent placement cycles comprising picking up a second LED die, and placing the second LED die on the substrate of the display device at a second location corresponding to the sub-pixel of the display device. Multiple first and second LED dies may be picked and placed during each placement cycle to populate each pixel of the display device to provide redundancy of LED dies at each sub-pixel.

Abstract: A self-regenerating ion-exchange water softener has an inlet connectable to a source of softenable water under pressure, a resin chamber connected thereto, and an outlet connected to the resin chamber. A salt chamber is located above the resin chamber and contains a water-soluble salt for regenerating the resin. A chamber connection allows controlled downward flow of fluid from the salt chamber to the resin chamber. A first normally-open pressure-sensitive valve closes in response to increased water pressure in the resin chamber, and normally permits a downward fluid flow from the salt chamber to the resin chamber. A passageway permits pressurized water to flow upwardly from the resin chamber to a point above the high-water mark of the salt chamber to generate salt solution for contacting and regenerating the resin, and has a discharge control above the high-water mark.