The below figures show a simple computer chip package, such as a diode. Fine wires connect...
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
The below figures show a simple computer chip package, such as a diode. Fine wires connect the silicon die to metallic leads that are soldered to a circuit board. The entire unit is encapsulated in a polymeric compound such as epoxy. During operation, as electricity flows through the silicon unit, heat is generated throughout the package. The wires and encapsulant have different coefficients of thermal expansion, resulting in thermal stresses (uniform tension and compression) in the wires as the temperature fluctuates. Lead Wire Epoxy Diode The nominal stress due to thermal sources in the wire is given by ow (T) = Ew (de-aw) (T-To) where Ew is the modulus of elasticity of the wire; e, aw are the coefficients of thermal expansion of the encapsulant and wire, respectively; T is the package temperature in the vicinity of the wires, To is the starting ambient temperature. Wire Bond The design temperature range for this unit is expected to be from -70 °F to 130 °F, from a room temperature of 30°F. 130°F na -70°F The engineers are considering using aluminum (Al) or gold (Au) for the cylindrical wires. It is expected the necked-down bond area to the silicone die will be the source of fatigue failure, a cross section of which is shown below. The epoxy has a = 10 + 10-6/°F. Epoxy Ø 0.001 in Wire Solder R 0.00005 in Property E (ksi) ay (ksi) au (ksi) a (10-6/°F) of (ksi) b Figure A-15-7 Round shaft with shoulder fillet in tension. 00= F/A, where A = nd²/4. 2.6 2.2 K, 1.8 1.4 1.0 0 Al 104 14 21 13 17.8 -0.13 1.05 0,05 1.02 0.10 Au 1.2x10¹ 10 19 8 20.3 -0.12 Did 1.50 1.10 0.15 rid 0.20 0.25 0.30 a. Determine the maximum nominal stress experienced by the typical wire cross section for each material. b. Determine the maximum stress at the concentration point for each material. c. Assume the thermal cycling starts at room temperature then increases in temperature consistently cycles in a sinusoidal fashion within the temperature limits. Plot the stress series over time for each material at the critical location. d. Determine the fatigue life (N) of each material in this design. e. Which material is recommended considering fatigue life? recommended from a mechanical stress perspective? Is this the same material The below figures show a simple computer chip package, such as a diode. Fine wires connect the silicon die to metallic leads that are soldered to a circuit board. The entire unit is encapsulated in a polymeric compound such as epoxy. During operation, as electricity flows through the silicon unit, heat is generated throughout the package. The wires and encapsulant have different coefficients of thermal expansion, resulting in thermal stresses (uniform tension and compression) in the wires as the temperature fluctuates. Lead Wire Epoxy Diode The nominal stress due to thermal sources in the wire is given by ow (T) = Ew (de-aw) (T-To) where Ew is the modulus of elasticity of the wire; e, aw are the coefficients of thermal expansion of the encapsulant and wire, respectively; T is the package temperature in the vicinity of the wires, To is the starting ambient temperature. Wire Bond The design temperature range for this unit is expected to be from -70 °F to 130 °F, from a room temperature of 30°F. 130°F na -70°F The engineers are considering using aluminum (Al) or gold (Au) for the cylindrical wires. It is expected the necked-down bond area to the silicone die will be the source of fatigue failure, a cross section of which is shown below. The epoxy has a = 10 + 10-6/°F. Epoxy Ø 0.001 in Wire Solder R 0.00005 in Property E (ksi) ay (ksi) Tu (ksi) a (10-6/°F) of (ksi) b Figure A-15-7 Round shaft with shoulder fillet in tension. 00= F/A, where A = nd²/4. 2.6 2.2 K, 1.8 1.4 1.0 0 Al 104 14 21 13 17.8 -0.13 1.05 0,05 1.02 0.10 Au 1.2x10¹ 10 19 8 20.3 -0.12 Did 1.50 1.10 0.15 rid 0.20 0.25 0.30 a. Determine the maximum nominal stress experienced by the typical wire cross section for each material. b. Determine the maximum stress at the concentration point for each material. c. Assume the thermal cycling starts at room temperature then increases in temperature consistently cycles in a sinusoidal fashion within the temperature limits. Plot the stress series over time for each material at the critical location. d. Determine the fatigue life (N) of each material in this design. e. Which material is recommended considering fatigue life? recommended from a mechanical stress perspective? Is this the same material The below figures show a simple computer chip package, such as a diode. Fine wires connect the silicon die to metallic leads that are soldered to a circuit board. The entire unit is encapsulated in a polymeric compound such as epoxy. During operation, as electricity flows through the silicon unit, heat is generated throughout the package. The wires and encapsulant have different coefficients of thermal expansion, resulting in thermal stresses (uniform tension and compression) in the wires as the temperature fluctuates. Lead Wire Epoxy Diode The nominal stress due to thermal sources in the wire is given by ow (T) = Ew (de-aw) (T-To) where Ew is the modulus of elasticity of the wire; e, aw are the coefficients of thermal expansion of the encapsulant and wire, respectively; T is the package temperature in the vicinity of the wires, To is the starting ambient temperature. Wire Bond The design temperature range for this unit is expected to be from -70 °F to 130 °F, from a room temperature of 30°F. 130°F na -70°F The engineers are considering using aluminum (Al) or gold (Au) for the cylindrical wires. It is expected the necked-down bond area to the silicone die will be the source of fatigue failure, a cross section of which is shown below. The epoxy has a = 10 + 10-6/°F. Epoxy Ø 0.001 in Wire Solder R 0.00005 in Property E (ksi) ay (ksi) au (ksi) a (10-6/°F) of (ksi) b Figure A-15-7 Round shaft with shoulder fillet in tension. 00= F/A, where A = nd²/4. 2.6 2.2 K, 1.8 1.4 1.0 0 Al 104 14 21 13 17.8 -0.13 1.05 0,05 1.02 0.10 Au 1.2x10¹ 10 19 8 20.3 -0.12 Did 1.50 1.10 0.15 rid 0.20 0.25 0.30 a. Determine the maximum nominal stress experienced by the typical wire cross section for each material. b. Determine the maximum stress at the concentration point for each material. c. Assume the thermal cycling starts at room temperature then increases in temperature consistently cycles in a sinusoidal fashion within the temperature limits. Plot the stress series over time for each material at the critical location. d. Determine the fatigue life (N) of each material in this design. e. Which material is recommended considering fatigue life? recommended from a mechanical stress perspective? Is this the same material The below figures show a simple computer chip package, such as a diode. Fine wires connect the silicon die to metallic leads that are soldered to a circuit board. The entire unit is encapsulated in a polymeric compound such as epoxy. During operation, as electricity flows through the silicon unit, heat is generated throughout the package. The wires and encapsulant have different coefficients of thermal expansion, resulting in thermal stresses (uniform tension and compression) in the wires as the temperature fluctuates. Lead Wire Epoxy Diode The nominal stress due to thermal sources in the wire is given by ow (T) = Ew (de-aw) (T-To) where Ew is the modulus of elasticity of the wire; e, aw are the coefficients of thermal expansion of the encapsulant and wire, respectively; T is the package temperature in the vicinity of the wires, To is the starting ambient temperature. Wire Bond The design temperature range for this unit is expected to be from -70 °F to 130 °F, from a room temperature of 30°F. 130°F na -70°F The engineers are considering using aluminum (Al) or gold (Au) for the cylindrical wires. It is expected the necked-down bond area to the silicone die will be the source of fatigue failure, a cross section of which is shown below. The epoxy has a = 10 + 10-6/°F. Epoxy Ø 0.001 in Wire Solder R 0.00005 in Property E (ksi) ay (ksi) Tu (ksi) a (10-6/°F) of (ksi) b Figure A-15-7 Round shaft with shoulder fillet in tension. 00= F/A, where A = nd²/4. 2.6 2.2 K, 1.8 1.4 1.0 0 Al 104 14 21 13 17.8 -0.13 1.05 0,05 1.02 0.10 Au 1.2x10¹ 10 19 8 20.3 -0.12 Did 1.50 1.10 0.15 rid 0.20 0.25 0.30 a. Determine the maximum nominal stress experienced by the typical wire cross section for each material. b. Determine the maximum stress at the concentration point for each material. c. Assume the thermal cycling starts at room temperature then increases in temperature consistently cycles in a sinusoidal fashion within the temperature limits. Plot the stress series over time for each material at the critical location. d. Determine the fatigue life (N) of each material in this design. e. Which material is recommended considering fatigue life? recommended from a mechanical stress perspective? Is this the same material
Expert Answer:
Answer rating: 100% (QA)
The provided images showcase a computer chip package where fine wires connect the silicon die to metallic leads on a circuit board There are several parts to the problem and Ill address them step by s... View the full answer
Related Book For
Introduction to Operations Research
ISBN: 978-1259162985
10th edition
Authors: Frederick S. Hillier, Gerald J. Lieberman
Posted Date:
Students also viewed these mechanical engineering questions
-
A polyethylene tube (length L) has a cap which is held in place by a spring (with undeformed length L1 (a) What is the resulting force in the spring, Fk? (b) What is the resulting force in the tube,...
-
As programs become more complex, it becomes increasingly important to plan or "design" your code before writing it. Designing your code will help you organize its logic. It will also help you keep...
-
The accounting records of Pro Paint, Inc. include the following unadjusted balances at June 30: Accounts Receivable, $1,700; Supplies, $725; Salaries Payable, $0; Unearned Service Revenue, $900;...
-
Abdul Hassan, president of Floor Coverings Unlimited, has asked you to study the relationship between market price and the tons of rugs supplied by his competitor, Best Floor, Inc. He supplies you...
-
Gender in the Rock and Roll Hall of Fame From its founding through 2015, the Rock and Roll Hall of Fame has inducted 303 groups or individuals. Forty-seven of the inductees have been female or have...
-
A companys 5-year bonds are yielding 7.75% per year. Treasury bonds with the same maturity are yielding 5.2% per year, and the real risk-free rate (r*) is 2.3%. The average inflation premium is 2.5%;...
-
How do resource dependency theory and institutional theory inform our understanding of how organizations design their structures to manage external dependencies and institutional pressures ?
-
Bennett et al. (2003) measured the refractive index (RI) of a pane of glass at 49 di erent locations. She took a sample of 10 fragments at each location and determined the RI for each. The data from...
-
Mr. Ammar, a resident individual, owns a building in DHA Islamabad. On 1 October 2020, he rented out the building to Mr. Ali at an annual rent of Rs. 1,200,000. This amount included Rs. 15,000 per...
-
The data file mexican contains data collected in 2001 from the transactions of 754 Mexican sex workers. a. Using OLS, estimate the hedonic log-linear model with LNPRICE as the dependent variable and...
-
The annual average return of S&P 500 from 1950-2002 was calculated as 9.7% with the standard deviation of 15.5% A person, who is going to retire in 40 years, wants to invest in stocks. a. Assuming...
-
What is the most likely result of executing the following application? A. A deadlock is produced at runtime. B. A livelock is produced at runtime. C. The application completes successfully. D. The...
-
The first professional football player was W. W. Pudge Heffelfinger, a former All-American at Yale, who was working on a railroad in 1892 when he was paid $500 to play one game for the Allegheny...
-
Under a single-rate electricity tariff for households and small businesses in Australia, a flat usage rate is charged for "blocks" of electricity consumed. The rate for the first block is higher than...
-
Problem 7. Give an example of a function f (0,00) R that is in L((0, 1)) but not in L'((0, 0)). If you think that such function does not exist explain why.
-
Let (x) = x 2 - 9, g(x) = 2x, and h(x) = x - 3. Find each of the following. (((--) 2
-
You have been hired as an operations research consultant by a company to reevaluate the inventory policy for one of its products. The company currently uses the basic EOQ model. Under this model, the...
-
Freddie the newsboy runs a newstand. Because of a nearby financial services office, one of the newspapers he sells is the daily Financial Journal. He purchases copies of this newspaper from its...
-
The Metalco Company desires to blend a new alloy of 40 percent tin, 35 percent zinc, and 25 percent lead from several available alloys having the following properties: The objective is to determine...
-
Figure 4.11 shows the \(v_{x}(t)\) curves for a collision between two identical carts moving not on a low-friction track but rather on a rough surface, so that friction affects their motion. Are the...
-
(a) Classify and give examples of the kinds of processes that can change (i) the number of loaves of bread in a bakery, (ii) the number of Lego pieces inside a house, and (iii) the number of coins in...
-
Cite at least two possible choices of system in each of the following situations. For each choice, make a sketch showing the system boundary and state which objects (excluding air) are inside the...
Study smarter with the SolutionInn App