ADHESIVE JOINT SYSTEM FOR PRINTED CIRCUIT BOARDS

• US 20160381790A1
• Filed: 06/29/2015
• Published: 12/29/2016
• Est. Priority Date: 06/29/2015
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Andriy Pletenetskyy
• Inventors: Markovsky, Igor, Nikkhoo, Michael, Pletenetskyy, Andriy, Hurbi, Erin
• Granted Patent: US 10,187,977 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G06F 3/012 Head tracking input arrangements
• CPC Class Codes: G06T 19/006 Mixed reality object pose determination, tracking or camera calibration for mixed reality G06T7/00
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/0284 Details of three-dimensional rigid printed circuit boards H05K1/119 takes precedence; shaping of the substrate H05K3/0014
• CPC Class Codes: H05K 2201/068 wherein the coefficient of thermal expansion is important
• CPC Class Codes: H05K 2201/09081 Tongue or tail integrated in planar structure, e.g. obtained by cutting from the planar structure
• CPC Class Codes: H05K 2201/10969 Metallic case or integral heatsink of component electrically connected to a pad on PCB
• CPC Class Codes: H05K 2201/10984 Component carrying a connection agent, e.g. solder, adhesive
• CPC Class Codes: H05K 2203/0228 Cutting, sawing, milling or shearing
• CPC Class Codes: H05K 2203/068 Features of the lamination press or of the lamination process, e.g. using special separator sheets
• CPC Class Codes: H05K 3/0058 Laminating printed circuit boards onto other substrates, e.g. metallic substrates H05K1/0281 takes precedence
• CPC Class Codes: H05K 3/061 Etching masks
• CPC Class Codes: H05K 3/303 Surface mounted components, e.g. affixing before soldering, aligning means, spacing means H05K3/32 takes precedence
• CPC Class Codes: H05K 3/4688 Composite multilayer circuits, i.e. comprising insulating layers having different properties having a special base or central core H05K3/4602
• CPC Class Codes: H05K 5/0078 specially adapted for acceleration sensors, e.g. crash sensors, airbag sensors

Abstract

An adhesive joint system comprises a circuit board with a distal end and a proximal end mounted on a first side via a tongue and groove connection to a housing. An adhesive is positioned at least in the gap surrounding the tongue, and an electrical component mounted to the distal end on a second side of the circuit board that is opposite the first side. The respective coefficients of thermal expansion (CTE) of the tongue, adhesive, and the material defining the groove are related, such that as heat is applied to the tongue and groove connection, the adhesive is compressed within the gap.

Claims

1. An adhesive joint system, comprising:

a circuit board including a distal end and a proximal end mounted on a first side via a tongue and groove connection to a housing, the tongue and groove connection including a tongue and a groove and a gap between the tongue and the groove;

an adhesive positioned at least in the gap surrounding the tongue; and

an electrical component mounted to the distal end on a second side of the circuit board that is opposite the first side;

wherein respective coefficients of thermal expansion of the tongue, adhesive, and material defining the groove are related such that as heat is applied to the tongue and groove connection, the adhesive is compressed within the gap.

2. The adhesive joint system of claim 1, wherein

the electrical component is an inertial motion sensor.

3. The adhesive joint system of claim 2, wherein

the inertial motion sensor comprises one of a gyroscope and an accelerometer.

4. The adhesive joint system of claim 1, wherein

the tongue and groove connection is a first tongue and groove connection;

and

the housing is mounted on the first side via a plurality of tongue and groove connections including the first tongue and groove connection.

5. The adhesive joint system of claim 1, further comprising:

a flow channel that is contiguous with the groove and configured to accommodate adhesive that is bled out of the groove when the adhesive is compressed in the groove.

6. The adhesive joint system of claim 1, wherein

the coefficient of thermal expansion of the tongue is greater than the coefficient of thermal expansion of a material defining the groove, such that as heat is applied to the tongue and groove connection, the gap narrows, thereby compressing the adhesive in the gap.

7. The adhesive joint system of claim 1, wherein

the coefficient of thermal expansion of the tongue is less than the coefficient of thermal expansion of the material defining the groove, and the coefficient of thermal expansion of the adhesive is greater than that of the groove or the tongue, such that as heat is applied to the tongue and groove connection, the gap expands less than the adhesive expands, thereby compressing the adhesive in the gap.

8. The adhesive joint system of claim 1, wherein

the material defining the groove is in the circuit board, and the tongue extends from the housing into the groove.

9. The adhesive joint system of claim 8, wherein

the tongue is a pin coupled to the housing.

10. The adhesive joint system of claim 8, wherein

the tongue is formed integrally with the housing.

11. The adhesive joint system of claim 1, wherein

the material defining the groove is in the housing, and the tongue extends from the circuit board into the groove.

12. The adhesive joint system of claim 11, wherein

the tongue is a pin coupled to the circuit board.

13. The adhesive joint system of claim 11, wherein

the tongue is formed integrally with the circuit board.

14. A method for assembling an electronic device comprising an adhesive joint system, the method comprising:

forming a tongue;

forming a groove in a material defining the groove;

mounting a circuit board onto a housing, such that the tongue is disposed within the groove and an adhesive is disposed in a gap between the tongue and groove, thereby forming a tongue and groove connection on a proximal end on a first side of the circuit board; and

mounting at least an electronic component on a distal end on a second side of the circuit board that is opposite the first side;

wherein respective coefficients of thermal expansion of the tongue, adhesive, and material defining the groove are related such that as heat is applied to the tongue and groove connection, the adhesive is compressed within the gap.

15. The method of claim 14, further comprising:

configuring the coefficient of thermal expansion of the tongue to be greater than the coefficient of thermal expansion of a material defining the groove, such that as heat is applied to the tongue and groove connection, the gap narrows, thereby compressing the adhesive in the gap.

16. The method of claim 14, further comprising:

configuring the coefficient of thermal expansion of the tongue to be less than the coefficient of thermal expansion of the material defining the groove, and configuring the coefficient of thermal expansion of the adhesive to be greater than that of the groove or the tongue, such that as heat is applied to the tongue and groove connection, the gap expands less than the adhesive expands, thereby compressing the adhesive in the gap.

17. The method of claim 14, further comprising:

configuring a flow channel that is contiguous with the groove so as to accommodate adhesive that is bled out of the groove when the adhesive is compressed in the groove during a manufacturing process.

18. The method of claim 14, wherein

the material defining the groove is in the circuit board, and the tongue is formed to extend from the housing into the groove;

and

the tongue is a pin coupled to the housing or is formed integrally with the housing.

19. The method of claim 14, wherein

the material defining the groove is in the housing, and the tongue is formed to extend from the circuit board into the groove;

and

the tongue is a pin coupled to the circuit board or is formed integrally with the circuit board.

20. A head mounted computing device, comprising:

a housing;

an image production system coupled to the housing;

a position sensing system coupled to the housing;

a see-through holographic display coupled to the housing and configured to display holographic images output from the image production system at locations on the see-though holographic display which are calculated based on a position sensed by the position sensing system; and

wherein the position sensing system includes a circuit board; and

wherein the circuit board includes a distal end and a proximal end mounted on a first side via a tongue and groove connection to the housing, the tongue and groove connection including a tongue and a groove and a gap between the tongue and the groove;

wherein an adhesive is positioned at least in the gap surrounding the tongue; and

wherein an inertial motion sensor is mounted to the distal end on a second side of the circuit board that is opposite the first side; and

wherein respective coefficients of thermal expansion of the tongue, adhesive, and material defining the groove are related such that as heat is applied to the tongue and groove connection, the adhesive is compressed within the gap.