Method of packaging and assembling micro-fluidic device

• US 6,821,819 B1
• Filed: 02/20/2003
• Issued: 11/23/2004
• Est. Priority Date: 02/21/2001
• Status: Active Grant

• Current Assignee: National Technology & Engineering Solutions Of Sandia LLC (Honeywell International Inc.)
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Giunta, Rachel K., Emerson, John A., Zamora, David Lee, Peterson, Kenneth A., Galambos, Paul C., Watson, Robert D., Benavides, Gilbert L.
• Primary Examiner(s): Parekh, Nitin
• Application Number:
  US10/370,543
• Time in Patent Office: 642 Days
• Field of Search: 438/122, 438/125, 438/123, 438/124, 438/127, 438/48, 438/54, 438/55, 438/121, 257/714, 257/715, 257/712, 257/713, 361/764
• US Class Current: 438/122
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 23/473 by flowing liquids H01L23/4332, H01L23/4338 take precedence
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01025 Manganese [Mn]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/04941 : TiN
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/10161 : with a rectangular active surface
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15173 : in a single layer of the multilayer substrate
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: Y10T 137/87153 : Plural noncommunicating flow paths
• CPC Class Codes: Y10T 137/87249 : Multiple inlet with multiple outlet

Abstract

A new architecture for packaging surface micromachined electro-microfluidic devices is presented. This architecture relies on two scales of packaging to bring fluid to the device scale (picoliters) from the macro-scale (microliters). The architecture emulates and utilizes electronics packaging technology. The larger package consists of a circuit board with embedded fluidic channels and standard fluidic connectors (e.g. Fluidic Printed Wiring Board). The embedded channels connect to the smaller package, an Electro-Microfluidic Dual-Inline-Package (EMDIP) that takes fluid to the microfluidic integrated circuit (MIC). The fluidic connection is made to the back of the MIC through Bosch-etched holes that take fluid to surface micromachined channels on the front of the MIC. Electrical connection is made to bond pads on the front of the MIC.

Claims

1. A method of manufacturing a package for housing an electro-microfluidic device, comprising:

(a) providing a substantially planar substrate having an upper surface, an opposing lower surface, and a first fluidic channel disposed within;

(b) applying a first adhesive layer to the upper surface; and

(c) match drilling a first hole in both the first layer of adhesive and the substrate, to a depth sufficient to create a first fluidic opening into the first fluidic channel;

wherein the method further comprises;

(d) providing a strip of adhesive tape, wherein the tape comprises an adhesive film covered by a protective liner;

(e) cutting the tape into a shape that approximately matches the footprint of the electro-microfluidic device;

(f) removing the protective liner, thereby exposing the adhesive film; and

(g) positioning the exposed film above the upper surface of the substrate, overlapping at least part of the fluidic channel, prior to applying the film to the substrate.

2. The method of claim 1, further comprising laser drilling the first hole.

3. The method of claim 1, wherein the first adhesive layer comprises VHB™

pressure-sensitive acrylic adhesive transfer tape, having a thickness between about 0.05 mm and 0.25 mm.

4. The method of claim 1, further comprising applying about 15 psi of pressure during the step of adhering the first adhesive layer to the substrate.

5. The method of claim 1, further comprising baking the first adhesive layer at a temperature between 60 and 70 C for approximately 1 hour, after adhering the adhesive layer to the substrate.

6. The method of claim 1, further comprising attaching a plurality of electrical leads, arranged in a standardized DIP geometry, to the substrate.

7. The method of claim 1, further comprising fabricating the substrate by using a material additive process selected from the group consisting of rapid prototyping with built-up plastic layers, thermal spray metal deposition, cold spray deposition, Laser Engineered Net Shape (LENS™

) directed metal deposition, casting, molding, injection molding of a moldable material, cold-isostatic processing, hot isostatic processing, sintering, and lamination.

9. The method of claim 1, wherein the substrate comprises a thermoplastic material.

8. The method of 7, further comprising embedding an electrical lead frame within the substrate during the additive material step.

10. A method of manufacturing a package for housing an electro-microfluidic device, comprising:

(a) providing a substantially planar substrate having an upper surface, an opposing lower surface, and a first fluidic channel disposed within;

(b) applying a first adhesive layer to the upper surface; and

(c) match drilling a first hole in both the first layer of adhesive and the substrate, to a depth sufficient to create a first fluidic opening into the first fluidic channel;

wherein the method further comprises fabricating a plurality of tapered fluidic channels arranged in a fan-out pattern in the substrate.

11. The method of claim 10, further comprising molding the substrate from a moldable plastic.

12. The method of claim 10, further comprising fabricating the substrate by using a ceramic fabrication process selected from the group consisting of slip casting, machining of a green ceramic body followed by sintering, rapid forging, cold-isostatic pressing followed by hot-isostatic pressing, and uniaxial pressing followed by sintering.

13. The method of claim 10, further comprising fabricating the substrate by using a low-temperature or a high-temperature cofired ceramic multilayered process.

14. The method of claim 13, wherein the cofired ceramic multilayered process comprises:

(a) providing multiple layers of a ceramic-based material, the layers having individualized patterns cutout through their thickness, the patterns corresponding to sequential planar slices through the substrate, the slices being oriented substantially parallel to the planar surface of the substrate;

(b) stacking and registering the layers to form an assembly; and

(c) baking and firing the assembly, whereby the stacked layers are cofired and laminated together to form a unitized and monolithic substrate comprising a fluidic channel disposed therein.

15. The method of claim 10, further comprising fabricating the substrate by creating a plurality of open trenches in the substrate'"'"'s lower surface.

16. The method of claim 15, wherein creating the open trenches comprises using a material removal process selected from the group consisting of milling with a miniature milling tool, laser milling, chemical etching, and milling with an abrasive jet spray.

17. The method of claim 15, further comprising molding the open trenches.

18. The method of claim 15, further comprising adhering a second adhesive layer to the lower surface of the substrate.

19. The method of claim 18, further comprising defining the fan-out pattern in the second layer of adhesive film prior to adhering the second layer to the substrate, wherein the cutout pattern corresponds to the outline of the open side of the trench;

and further wherein the step of adhering the second layer of adhesive film comprises aligning the cutout pattern to substantially match said trench outline.

20. A method of manufacturing a package for housing an electro-microfluidic device, comprising:

(a) providing a substantially planar substrate having an upper surface, an opposing lower surface;

a first fluidic channel disposed inside of the substrate, having a first fluidic opening disposed on the upper surface, and having a second fluidic opening disposed on the lower surface of the substrate; and

a first adhesive layer adhered to the upper surface, having a first hole disposed through the layer, the first hole being substantially aligned with the first fluidic opening;

(b) providing a substantially planar base having an upper base surface;

a lower base surface;

a second fluidic channel;

a third fluidic opening of the second fluidic channel disposed on the upper base surface; and

means for electrically interconnecting the base to an external fixture;

(c) positioning the substrate above the base so that the second fluidic opening aligns with the third fluidic opening; and

(d) attaching the lower surface of the substrate to the upper surface of the base.

21. The method of claim 20, wherein the substrate is attached to the base by using a second adhesive layer disposed in-between the substrate and base.

22. The method of claim 20, wherein step (d) further comprises applying heat and pressure to the mating surfaces.

23. The method of claim 20, further comprising attaching to the base a plurality of electrical leads arranged in a standardized DIP arrangement.

24. A method of packaging an electro-microfluidic device, comprising:

(a) providing a substantially planar substrate having an upper surface, an opposing lower surface;

a first fluidic channel disposed inside of the substrate, having a first fluidic opening disposed on the upper surface, and having a second fluidic opening disposed on the lower surface of the substrate; and

having a first adhesive layer bonded to the upper surface, the layer having a hole disposed through the layer, the hole being substantially aligned with the first fluidic opening;

(b) providing an electro-microfluidic device, having a fluidic access port disposed on the bottom surface of the device;

(c) aligning the fluidic access port on the device with hole in the first adhesive layer;

(d) adhering the electro-microfluidic device to the substrate by applying pressure to the first adhesive layer; and

(f) making an electrical interconnection between the device and the substrate.

25. The method of claim 24, further comprising using a flip-chip optical bonding jig to position, align, and join the electro-microfluidic device to the substrate.

26. The method of claim 24, further comprising creating a vacuum inside of the fluidic channel, thereby applying a force to the electro-microfluidic device during the adhering step.

27. The method of claim 24, further comprising wire bonding the device to the substrate.

28. The method of claim 24, further comprising encapsulating the electrical interconnection with a polymeric material.

29. The method of claim 24, further comprising attaching a cover lid to the substrate.

30. The method of claim 24, further comprising attaching an electrical lead to the upper surface of the substrate with an adhesive film.

31. The method of claim 30, further comprising encapsulating the device, electrical lead, and substrate in a moldable plastic material.

32. A method of packaging an electro-microfluidic device, comprising:

(a) providing a package comprising a substrate mechanically joined, and fluidically coupled to, a base;

wherein the substrate comprises an upper surface comprising a first fluidic opening;

(b) providing an electro-microfluidic device, having a fluidic access port disposed on the bottom surface of the device;

(c) positioning and aligning the device with the substrate so that the first fluidic opening of the substrate aligns with the fluidic access port of the device;

(d) joining the electro-microfluidic device to the substrate by applying pressure to an adhesive layer disposed in-between the device and the substrate; and

(e) making an electrical interconnection between the device and the base.

33. The method of claim 32, wherein the electro-microfluidic device is aligned and joined to the substrate prior to the step of joining the substrate to the base.

34. The method of claim 32, further comprising making a solder-bumped electrical joint.

35. The method of claim 32, further comprising releasing any MEMS elements in the electro-microfluidic device after joining the device to the substrate.

36. The method of claim 35, further comprising releasing the MEMS elements by flowing etchant fluid through the fluidic channel disposed within the substrate, and into the fluidic access port on the electro-microfluidic device, thereby exposing the unreleased MEMS elements to the etchant fluid.

37. The method of claim 36, wherein the etchant fluid comprises a dry plasma gas etchant.

38. A method of assembling an electro-microfluidic device on to a fluidic printed wiring board, comprising:

(a) providing a fluidic printed wiring board comprising an upper surface comprising a first fluidic opening;

(b) providing an electro-microfluidic device comprising a fluidic access port disposed on the bottom surface of the device;

(c) positioning and aligning the device with the fluidic printed wiring board so that the first fluidic opening of the fluidic printed wiring board aligns with the fluidic access port of the device; and

(d) mechanically attaching, electrically interconnecting, and fluidically coupling the electro-microfluidic device to the fluidic printed wiring board;

wherein the method further comprises;

e) flip-chip bonding the electro-microfluidic device to the fluidic printed wiring board with a bumped interconnection, wherein the bump comprises a solder bump or a conductive polymer bump.

39. The method of claim 38, further comprising underfilling the bumped electrical interconnection with an organic material.

40. A method of assembling an electro-microfluidic device on to a fluidic printed wiring board, comprising:

(a) providing a fluidic printed wiring board comprising an upper surface comprising a first fluidic opening;

(b) providing an electro-microfluidic device comprising a fluidic access port disposed on the bottom surface of the device;

(c) positioning and aligning the device with the fluidic printed wiring board so that the first fluidic opening of the fluidic printed wiring board aligns with the fluidic access port of the device; and

(d) mechanically attaching, electrically interconnecting, and fluidically coupling the electro-microfluidic device to the fluidic printed wiring board;

wherein the method further comprises;

(e) wirebonding the electro-microfluidic device to the fluidic printed wiring board.

41. The method of claim 40, further comprising encapsulating the wire-bonded interconnection in an organic material.

42. The method of claim 40, further comprising:

(a) providing an adhesive layer bonded to the upper surface of the fluidic printed wiring board, having a hole disposed through the layer, the hole being aligned with the first fluidic opening on the board;

(b) aligning the hole in the adhesive layer with the fluidic access port on the device;

(c) joining the electro-microfluidic device to the board by applying pressure to the device; and

(d) wirebonding the electro-microfluidic device to the fluidic printed wiring board.