1. A substrate for supporting and electrically connecting to a semiconductor dice, the substrate including a first surface supporting the semiconductor die and a second surface opposite the first surface, the second surface including portions defining a planar surface and a patterned area recessed within the planar surface, the substrate comprising:
a first pattern on the first surface of the substrate, the first pattern aligning with the patterned area, the first pattern comprising:
an etched portion within a footprint of the aligned patterned area; and
an unetched portion surrounding the etched portion, the first pattern reducing a mechanical stress generated by the patterned area on the semiconductor dice during a molding process.
2. A substrate as recited in claim 1, wherein the patterned area includes a contact finger for forming an external electrical connection.
3. A substrate as recited in claim 2, wherein the etched portion of the first pattern includes a pair of straight edges, a distance between the straight edges being approximately equal to a width of the contact finger, and a length of the straight edges being approximately equal to a length of the contact finger.
4. A substrate as recited in claim 2, wherein the etched portion of the first pattern includes two pair of etched sections, each pair of etched sections including straight sections inclined toward each other from a middle of the etched portion to top and bottom edges of the etched portion along a length of the etched portion.
5. A substrate as recited in claim 1, the substrate including:
a core having a first surface and a second surface opposite the first surface;
a first conductive layer formed on the first surface of the core, the first pattern being formed in the first conductive layer; and
a second conductive layer formed on the second surface of the core, the second conductive layer including the patterned area.
6. A substrate as recited in claim 1, wherein the first pattern has a thickness of between 10 \u03bcm to 24 \u03bcm.
7. A rigid wave pattern formed on a first surface of a substrate, the substrate capable of supporting and electrically connecting to a semiconductor dice, a second surface of the substrate opposite the first surface including one or more contact fingers for making one or more external electrical connections, the rigid wave pattern comprising:
one or more etched portions on the first surface, an etched portion of the one or more etched portions overlying a contact finger of the one or more contact fingers on the second surface; and
an unetched portion surrounding the one or more etched portions, the rigid wave pattern for reducing a mechanical stress generated by the contact finger on the semiconductor dice during a molding process.
8. A rigid wave pattern as recited in claim 7, wherein the etched portion of the rigid wave pattern includes a pair of straight edges, a distance between the straight edges being approximately equal to a width of the contact finger, and a length of the straight edges being approximately equal to a length of the contact finger.
9. A rigid wave pattern as recited in claim 7, wherein the one or more etched portions of the first surface includes two pair of etched sections, each pair of etched sections including straight sections inclined toward each other from a middle of the etched portion to top and bottom edges of the etched portion along a length of the etched portion.
10. A rigid wave pattern as recited in claim 7, the substrate including:
a core having a first surface and a second surface opposite the first surface;
a first conductive layer formed on the first surface of the core, the rigid wave pattern being formed in the first conductive layer; and
a second conductive layer formed on the second surface of the core, the one or more contact fingers being formed in the second conductive layer.
11. A rigid wave pattern as recited in claim 7, wherein the unetched portion of the rigid wave pattern is rectangular in shape.
12. A semiconductor die package, comprising:
a semiconductor dice;
a substrate including a first surface capable of supporting the semiconductor dice, the substrate including a first pattern formed in the first surface of the substrate and the substrate including a second surface having portions defining a plane, the second surface including a patterned area recessed into the plane, the first pattern including:
an etched portion aligned with and overlying the patterned area, and
an unetched portion surrounding the etched portion, the first pattern for reducing a mechanical stress generated by the patterned area on the semiconductor dice during a molding process; and
a molding compound for encapsulating the semiconductor dice and the substrate.
13. A semiconductor die package as recited in claim 12, wherein the semiconductor die package is a land grid array package.
14. A semiconductor die package as recited in claim 12, wherein the semiconductor die package is capable of use in a compact flash memory module.
15. A substrate for supporting and electrically connecting to a semiconductor dice, the substrate including a first surface and a second surface opposite the first surface, the second surface including portions defining a planar surface and a patterned area recessed within the planar surface, the substrate comprising:
a first pattern on the first surface of the substrate, the first pattern being formed of metal and comprising:
a removed portion removed from the metal; and
a portion surrounding the removed portion, the first pattern reducing a mechanical stress generated by the patterned area on the semiconductor dice during a molding process.
16. A substrate as recited in claim 15, wherein the patterned area includes a contact finger for forming an external electrical connection.
17. A substrate as recited in claim 16, wherein the etched portion of the first pattern includes a pair of straight edges, a distance between the straight edges being approximately equal to a width of the contact finger, and a length of the straight edges being approximately equal to a length of the contact finger.
18. A substrate as recited in claim 16, wherein the etched portion of the first pattern includes two pair of etched sections, each pair of etched sections including straight sections inclined toward each other from a middle of the etched portion to top and bottom edges of the etched portion along a length of the etched portion.
19. A substrate as recited in claim 15, the substrate including:
a core having a first surface and a second surface opposite the first surface;
a first conductive layer formed on the first surface of the core, the first pattern being formed in the first conductive layer; and
a second conductive layer formed on the second surface of the core, the second conductive layer including the patterned area.
20. A semiconductor die package, comprising:
a semiconductor dice;
a substrate including a first surface capable of supporting the semiconductor dice, the substrate including a first pattern formed in the first surface of the substrate and the substrate including a second surface having portions defining a plane, the second surface including a patterned area recessed into the plane, the first pattern being formed of metal and including:
an etched portion, and
an unetched portion surrounding the etched portion, the first pattern for reducing a mechanical stress generated by the patterned area on the semiconductor dice during a molding process; and
a molding compound for encapsulating the semiconductor dice and the substrate.
21. A semiconductor die package as recited in claim 20, wherein the semiconductor die package is a land grid array package.
22. A semiconductor die package as recited in claim 20, wherein the semiconductor die package is capable of use in a compact flash memory module.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A system for stress-rupture testing of materials in a high-temperature liquid salt environment, the system comprising:
a vertically elongated vessel having an upper end and a lower end, the vessel comprising one or more gas ports for maintaining a controlled inert gas environment within the vessel;
a first pull rod positioned within the vessel and extending downwardly from or through the upper end of the vessel, the first pull rod having a first specimen grip at a lower end of the first pull rod, the first specimen grip adapted to grip an upper end of a test specimen having a tubular gage portion for containing a salt;
a second pull rod positioned within the vessel below the first pull rod, the second pull rod having a second specimen grip at an upper end of the second pull rod, the second specimen grip adapted to grip a lower end of the test specimen;
a thermal break positioned within the vessel and coupled to a lower end of the second pull rod, the thermal break comprising a fixture coupled to a lower end of the second pull rod and a thermally insulating spacer supported by the fixture below the second pull rod; and
a third pull rod having an upper end spaced below the lower end of the second pull rod and spaced within the thermal break fixture, the upper end of the third pull rod being supported by the thermally insulating spacer such that the third pull rod is thermally decoupled from the second pull rod by the thermally insulating spacer, the third pull rod having a lower end that extends through a lower end of the vessel and is adapted to be coupled to a loading source for applying a load to the test specimen via the second and third pull rods and the thermal break.
2. The system of claim 1, further comprising a load cell coupled to the third pull rod within the vessel below the thermal break, the load cell being thermally protected by the thermal break and configured to measure the load applied to the test specimen via the third pull rod.
3. The system of claim 1, further comprising a furnace positioned around an upper portion of the vessel for maintaining the test specimen at a desired temperature that is sufficient to cause a salt within the test specimen to be in the liquid phase.
4. The system of claim 1, wherein the thermal break fixture comprises a metallic tubular body having an upper end secured to the second pull rod and a lower end forming an inner ledge that supports a lower surface of the thermally insulating spacer.
5. The system of claim 4, wherein the thermally insulating spacer comprises a ceramic disk and the upper end of the third pull rod comprises a flared head that contacts an upper surface of the ceramic disk and is spaced apart from the fixture and the second pull rod.
6. The system of claim 1, wherein the vessel comprises a lower opening through which the third pull rod extends, there being a gap between the third pull rod and the lower opening such that inert process gas from within the vessel is allowed to exit the vessel through the gap.
7. The system of claim 1, further comprising a cooling coil coupled to the third pull rod within the vessel below the thermal break.
8. The system of claim 1, wherein the system is capable of applying a stress load to the test specimen while the test specimen is maintained at a temperature greater than 700\xb0 C.
9. The system of claim 1, wherein the salt comprises 27LiF\u2014BeF2 or KF\u2014ZrF4.
10. A test specimen for stress-rupture testing in a high-temperature liquid salt environment, the test specimen comprising:
a first end portion having a first engagement portion for connecting to a stress-rupture testing system;
a second end portion having a second engagement portion for connecting to the stress-rupture testing system;
a narrowed gage portion between the first and second end portions; and
an inner void extending through the first end portion and through the gage portion;
wherein the gage portion has a substantially cylindrical outer surface defining an outer diameter and the inner void is substantially cylindrical within the gage portion such that the gage portion has a substantially cylindrical inner surface defining an inner diameter and the gage portion has a substantially constant wall thickness between the inner diameter and the outer diameter;
wherein the inner void is configured to receive a salt in solid form such that when the test specimen is subjected to high temperatures, the salt melts to form molten salt that completely fills the portion of the void that is within the gage portion; and
wherein a ratio AiV of the gage portion is at least about 20, wherein Ai is the inner surface area of the gage portion and V is the volume of material in the gage portion between the inner surface of the gage portion and the outer surface of the gage portion, in units of square inches divided by cubic inches.
11. The test specimen of claim 10, wherein the ratio AiV of the gage portion is at most about 32.
12. The test specimen of claim 10, wherein the inner diameter is in a range of from about 0.41 inches (about 10.41 mm) to about 0.44 inches (about 11.18 mm).
13. The test specimen of claim 10, further comprising a basin ring that is attached around the test specimen below the gage portion and configured to catch liquid salt that escapes from inside the test specimen when the test specimen ruptures or leaks during stress-rupture testing.
14. A method of stress-rupture testing of a selected material in a high-temperature liquid salt environment, the method comprising:
placing a solid salt ingot within an inner void of a test specimen of the selected material and sealing the void closed;
mounting the test specimen, with the salt ingot enclosed, in a load train within a vessel of a stress-rupture testing system;
filling the vessel with an inert gas;
heating the test specimen, while mounted in the load train within the vessel filled with inert gas, such that the salt ingot melts within the void and the resulting molten salt contacts an entire inner surface of a gage portion of the test specimen;
applying a load to the gage portion of the test specimen while the test specimen is mounted in the load train within the vessel filled with inert gas and the salt is molten, and measuring the applied load until the gage portion of the test specimen fails.
15. The method of claim 14, wherein the method further comprises continuously feeding the inert gas into the vessel while the load is applied and allowing the inert gas to escape from the vessel through a gap between the load train and a lower end of the vessel.
16. The method of claim 14, wherein heating the test specimen comprising heating the test specimen to a temperature that is at least 100 degrees C. greater than the melting temperature of the salt.
17. The method of claim 14, wherein measuring the applied load is performed at least in part by a load cell mounted within the load train positioned within the vessel.
18. The method of claim 14, wherein placing the solid salt ingot within an inner void of a test specimen comprises:
placing a mold within a vacuum chamber;
creating an inert gas environment within the vacuum chamber around the mold;
heating the mold within the vacuum chamber in the inert environment to remove impurities from the mold;
after removing impurities from the mold, placing a salt into the mold and closing the mold in an inert environment;
heating the mold to melt the salt and remove voids and impurities from the salt;
cooling the mold to solidify the salt into the salt ingot with impurities removed; and
transferring the salt ingot from the mold into a test specimen in an inert environment.
19. The method of claim 18, wherein creating an inert gas environment within the vacuum chamber comprises drawing a vacuum on the vacuum chamber and feeding an inert gas into the vacuum chamber to purge ambient air from the vacuum chamber.
20. The method of claim 18, wherein the method further comprises:
placing a funnel and a mold housing within a vacuum chamber along with the mold;
heating the mold, funnel, and mold housing within the vacuum chamber in the inert environment to remove impurities from the mold, funnel, and mold housing;
transporting the mold and funnel sealed within the mold housing from the vacuum chamber to a salt-filling chamber having an inert environment;
using the funnel to place the salt into the mold in the salt-filling chamber; and
transporting the salt-filled mold sealed within the mold housing from the salt-filling chamber to a vacuum chamber.