Selective component bonding technique

Patent metadata

Field	Value
Publication number	US-2016004029-A1
Application number	US-201414322054-A
Country	US
Kind code	A1
Filing date	Jul 2, 2014
Priority date	Jul 2, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

A method of selectively bonding a component to a substrate prevents glue displacement onto neighboring components. The method entails shortening a section of the perimeter of a mount wall so that the foot of the mount wall contacts the glue without causing substantial displacement. A cure step hardens and holds the shortened foot of the mount wall in a stationary position, while providing a partial bond. Meanwhile the rest of the mount wall that is not located near contact pads on the substrate has a tall foot that extends to the surface of the substrate and is bonded in the usual way. By modifying the component, it is not necessary to modify either the chemistry of the epoxy or the epoxy dispense operation.

First claim

1 . A method of selectively bonding a component to a substrate, the method comprising:
fabricating a customized device mount attachable to the component, the customized device mount having a mount wall that includes a tall foot and a short foot, a length difference between the tall foot and the short foot designed to substantially match a selected height of a narrow glue line; dispensing epoxy onto a top surface of the substrate to form a narrow glue line, the narrow glue line having a top surface spaced apart from the substrate at the selected height; aligning the mount wall to the narrow glue line; adhering the mount wall to the substrate so that a lower surface of the short foot contacts the top surface of the narrow glue line; and curing the glue lines.

2 . The method of claim 1 wherein the substrate is a printed circuit board (PCB).

3 . The method of claim 1 wherein the component is an optical lens assembly.

4 . The method of claim 1 wherein the curing further comprises baking the substrate together with the customized device mount in place.

5 . The method of claim 1 wherein the curing further comprises heating to a temperature within the range of about 50-150 C.

6 . The method of claim 1 wherein the curing further comprises heating for a time interval within a range of about 0.1-3.0 hours.

7 . The method of claim 1 wherein the curing further comprises localized heating.

8 . The method of claim 1 wherein the curing causes the glue lines to harden, forming at least a semi-rigid joint between the short foot and the substrate.

9 . The method of claim 1 wherein the adhering further comprises placing the tall foot in contact with a narrow glue line segment and applying pressure to the customized device mount until the tall foot is in contact with the top surface of the substrate.

10 . The method of claim 9 wherein, in response to applying pressure to the customized device mount, the narrow glue line segment spreads to form a wide glue line segment that is at least 25% wider than the narrow glue line segment.

11 . The method of claim 1 , further comprising roughening a lower surface of the mount wall to enhance adhesion to the substrate.

12 . The method of claim 1 wherein the narrow glue line height is within a range of about 50-150 μm.

13 . The method of claim 1 wherein the narrow glue line width is within a range of about 300-500 μm.

14 . A lens assembly comprising:
an optical lens element; a lens barrel surrounding the lens element; a lens mount surrounding the lens barrel; and a device mount supportably attached to the lens mount, the device mount having a customized mount wall that includes a tall foot and a short foot, there being a selected length difference between the tall foot and the short foot.

15 . The lens assembly of claim 14 wherein the customized mount wall has a rectangular perimeter, the tall foot encompassing three sides of the rectangular perimeter and the short foot encompassing one side of the rectangular perimeter.

16 . The lens assembly of claim 14 wherein the customized mount wall has a rectangular perimeter, a first pair of parallel sides of the rectangular perimeter each having a tall foot, and a second pair of parallel sides of the rectangular perimeter each having a short foot.

17 . The lens assembly of claim 14 wherein the customized mount wall has a circular perimeter of which a selected arc, having an associated radial angle less than 180 degrees, has a short foot, and the remaining circular perimeter has a tall foot.

18 . The lens assembly of claim 14 wherein the short foot contacts a glue line having a selected height within a range of about 50-150 μm, without substantially displacing the glue line.

19 . A device mount, comprising:
a central mount portion attachable to a device; and a perimeter wall having an uneven footprint, a standard section of the perimeter wall having a tall foot, and a customized section of the perimeter wall having a short foot, there being a selected length difference distinguishing the short foot from the tall foot.

20 . The device mount of claim 16 wherein a length of the customized section of the perimeter wall having the short foot is no greater than 50% of the total perimeter wall.

21 . The method of claim 1 wherein the substrate is a laminate substrate.

Assignees

• St Microelectronics Pte Ltd

Inventors

• Tun Tin

Classifications

• G02B7/02

  for lenses {(supports for magnifying lenses G02B25/002)} · CPC title

• G02B7/025 Primary

  using glue · CPC title

• B32B2307/412

  Transparent · CPC title

• B32B37/06

  characterised by the heating method · CPC title

• B32B2037/1253

  curable adhesive · CPC title