Method of manufacturing variable reflectance mirror reflective element for exterior mirror assembly

A method of making a variable reflectance exterior mirror reflective element suitable for use in a vehicular exterior rearview mirror assembly, said method comprising:

• providing a front substrate and a rear substrate, wherein the front substrate has a first surface and a second surface, and wherein the rear substrate has a third surface and a fourth surface;
• wherein providing a front substrate and a rear substrate comprises providing a front glass substrate and a rear glass substrate;
• disposing a transparent electrically conductive layer at the second surface of the front substrate;
• disposing a perimeter layer at the second surface of the front substrate proximate a perimeter edge of the front substrate, wherein the perimeter layer comprises an electrically conductive reflective perimeter layer;
• disposing a mirror reflector at the third surface of the rear substrate, wherein the mirror reflector comprises a stack of thin films comprising at least two thin films, and wherein the stack of thin films comprises at least one metal thin film;
• wherein a first thin film of the stack of thin films comprises a material that has a specific resistivity of less than 1×10−3 ohm·cm, and wherein a second thin film of the stack of thin films comprises a material that has a specific resistivity of less than 1×10−3 ohm·cm;
• establishing, via laser ablation, a light-transmitting window through the mirror reflector;
• joining and spacing the front substrate and the rear substrate via a perimeter seal, the perimeter seal establishing an interpane cavity between the third surface of the rear substrate and the second surface of the front substrate that is bounded by the perimeter seal;
• after the front substrate is joined with the rear substrate, disposing an electrochromic medium in the interpane cavity established between the third surface of the rear substrate and the second surface of the front substrate and bounded by the perimeter seal;
• wherein, with the front substrate joined with the rear substrate, the perimeter layer conceals the perimeter seal from view through the front substrate;
• wherein, with the front substrate joined with the rear substrate, no part of the rear substrate extends beyond any part of the front substrate;
• wherein, with the front substrate joined with the rear substrate and with the electrochromic medium disposed in the interpane cavity, light that reflects off of the mirror reflector and passes through the electrochromic medium and out through the front substrate is non-spectrally selective when no voltage is applied to the electrochromic medium;
• wherein, with the front substrate joined with the rear substrate, at least a portion of the mirror reflector extends under the perimeter seal and towards a perimeter edge of the rear substrate;
• making an electrical connection to the portion of the mirror reflector outboard of the perimeter seal;
• disposing a display proximate the fourth surface of the rear substrate of the variable reflectance exterior mirror reflective element at the light-transmitting window through the mirror reflector, wherein the display comprises at least one light emitting diode;
• wherein the display is configured to be operated responsive to a blind spot detector of a vehicle equipped with an exterior rearview mirror assembly that incorporates the variable reflectance exterior mirror reflective element;
• and
• wherein the at least one light emitting diode, when activated responsive to the blind spot detector of the equipped vehicle, emits light that passes through the light-transmitting window through the mirror reflector for viewing through the front substrate of the variable reflectance exterior mirror reflective element.

A method of making a variable reflectance exterior mirror reflective element suitable for use in a vehicular exterior rearview mirror assembly, said method comprising:

• providing a front substrate and a rear substrate, wherein the front substrate has a first surface and a second surface, and wherein the rear substrate has a third surface and a fourth surface;
• disposing a transparent electrically conductive layer at the second surface of the front substrate;
• disposing a perimeter layer at the second surface of the front substrate proximate a perimeter edge of the front substrate, wherein the perimeter layer comprises an electrically conductive reflective perimeter layer;
• disposing a mirror reflector at the third surface of the rear substrate, wherein the mirror reflector comprises a stack of thin films comprising at least two thin films, and wherein the stack of thin films comprises at least one metal thin film;
• wherein a first thin film of the stack of thin films comprises a material that has a specific resistivity of less than 1×10−3 ohm·cm, and wherein a second thin film of the stack of thin films comprises a material that has a specific resistivity of less than 1×10−3 ohm·cm;
• establishing, via laser ablation, a light-transmitting window through the mirror reflector;
• joining and spacing the front substrate and the rear substrate via a perimeter seal, the perimeter seal establishing an interpane cavity between the third surface of the rear substrate and the second surface of the front substrate that is bounded by the perimeter seal;
• after the front substrate is joined with the rear substrate, disposing an electrochromic medium in the interpane cavity established between the third surface of the rear substrate and the second surface of the front substrate and bounded by the perimeter seal;
• wherein, with the front substrate joined with the rear substrate, the perimeter layer conceals the perimeter seal from view through the front substrate;
• wherein, with the front substrate joined with the rear substrate, the perimeter seal is at least partially visible through the rear substrate;
• wherein, with the front substrate joined with the rear substrate, no part of the rear substrate extends beyond any part of the front substrate;
• wherein, with the front substrate joined with the rear substrate and with the electrochromic medium disposed in the interpane cavity, light that reflects off of the mirror reflector and passes through the electrochromic medium and out through the front substrate is non-spectrally selective when no voltage is applied to the electrochromic medium;
• wherein, with the front substrate joined with the rear substrate, at least a portion of the mirror reflector extends under the perimeter seal and towards a perimeter edge of the rear substrate;
• making an electrical connection to the portion of the mirror reflector outboard of the perimeter seal;
• wherein making the electrical connection comprises disposing a conductive epoxy at the portion of the mirror reflector outboard of the perimeter seal;
• disposing a display proximate the fourth surface of the rear substrate of the variable reflectance exterior mirror reflective element at the light-transmitting window through the mirror reflector, wherein the display comprises at least one light emitting diode;
• wherein the display is configured to be operated responsive to a blind spot detector of a vehicle equipped with an exterior rearview mirror assembly that incorporates the variable reflectance exterior mirror reflective element;
• and
• wherein the at least one light emitting diode, when activated responsive to the blind spot detector of the equipped vehicle, emits light that passes through the light-transmitting window through the mirror reflector for viewing through the front substrate of the variable reflectance exterior mirror reflective element.