Why design review catches errors before fabrication in PCB Design - Formula Trace Breakdown

Sample Data

This data shows the steps in PCB design process and where errors are caught before fabrication.

Cell	Value
A1	Step
B1	Action
C1	Error Found
D1	Reason
A2	1
B2	Initial schematic design
C2	No
D2	Designer creates initial circuit
A3	2
B3	Design review meeting
C3	Yes
D3	Multiple eyes catch mistakes
A4	3
B4	Update design after review
C4	No
D4	Corrections applied
A5	4
B5	Final check before fabrication
C5	Yes
D5	Verification prevents costly errors

Formula Trace

IF(AND(B3="Design review meeting", C3="Yes"), "Error caught", "No error")

Step 1: B3 = "Design review meeting"

Step 2: C3 = "Yes"

Step 3: AND(B3="Design review meeting", C3="Yes")

Step 4: IF(TRUE, "Error caught", "No error")

Cell Reference Map

    A       B                     C         D
1 | Step | Action               | Error Found | Reason
2 | 1    | Initial schematic    | No          | Designer creates initial circuit
3 | 2    | Design review meeting| Yes         | Multiple eyes catch mistakes
4 | 3    | Update design        | No          | Corrections applied
5 | 4    | Final check          | Yes         | Verification prevents costly errors

References: B3 and C3 are used in the formula to check if error was caught during design review.

The formula checks cells B3 and C3 to determine if the design review meeting caught an error.

Result

    A       B                     C         D
1 | Step | Action               | Error Found | Reason
2 | 1    | Initial schematic    | No          | Designer creates initial circuit
3 | 2    | Design review meeting| Yes         | Multiple eyes catch mistakes
4 | 3    | Update design        | No          | Corrections applied
5 | 4    | Final check          | Yes         | Verification prevents costly errors

Result in E3: Error caught

The formula result 'Error caught' appears in cell E3, indicating the design review meeting step found an error.

Sheet Trace Quiz - 3 Questions

What does the formula check in cell B3?

A If the design is updated

B If an error was found

C If the step is 'Design review meeting'

D If fabrication is complete

Key Result

IF(condition, value_if_true, value_if_false) returns different text based on logical test.

Practice

1. Why is a design review important before PCB fabrication?

easy

A. It eliminates the need for testing after fabrication.

B. It speeds up the manufacturing process directly.

C. It reduces the number of components needed.

D. It helps find errors early to avoid costly mistakes.

Solution

1. Step 1: Understand the purpose of design review

   Design review is done to catch errors before the PCB is made.

2. Step 2: Identify the benefit of early error detection

   Finding errors early prevents costly mistakes and rework later.

3. Final Answer:

   It helps find errors early to avoid costly mistakes. -> Option D

4. Quick Check:

   Early error detection = It helps find errors early to avoid costly mistakes. [OK]

Hint: Design review = find errors early to save cost [OK]

Common Mistakes:

• Thinking design review speeds manufacturing directly
• Believing it reduces components needed
• Assuming it removes need for testing

2. Which of the following is the correct step in a PCB design review process?

easy

A. Checking component placement and routing carefully

B. Ignoring schematic errors until after fabrication

C. Skipping the review if the design looks simple

D. Starting fabrication before review completion

Solution

1. Step 1: Identify correct review steps

   Design review includes checking component placement and routing.

2. Step 2: Eliminate incorrect options

   Ignoring errors, skipping review, or starting fabrication early are wrong.

3. Final Answer:

   Checking component placement and routing carefully -> Option A

4. Quick Check:

   Review step = Checking component placement and routing carefully [OK]

Hint: Review = check placement and routing carefully [OK]

Common Mistakes:

• Ignoring errors until fabrication
• Skipping review for simple designs
• Starting fabrication too early

3. During a design review, a PCB schematic shows a missing connection between two components. What is the likely outcome if this error is not caught before fabrication?

medium

A. The PCB will function perfectly without issues.

B. The PCB will fail or behave unpredictably.

C. The fabrication cost will decrease.

D. The error will fix itself during manufacturing.

Solution

1. Step 1: Understand impact of missing connection

   A missing connection means the circuit is incomplete and won't work properly.

2. Step 2: Predict outcome if error is not fixed

   The PCB will fail or behave unpredictably, causing problems.

3. Final Answer:

   The PCB will fail or behave unpredictably. -> Option B

4. Quick Check:

   Missing connection = PCB failure [OK]

Hint: Missing connection causes failure [OK]

Common Mistakes:

• Assuming PCB works fine without all connections
• Thinking fabrication cost decreases due to errors
• Believing errors fix themselves automatically

4. A design review checklist missed verifying the power supply connections. After fabrication, the PCB does not power on. What is the best way to fix this issue?

medium

A. Ignore the problem and use the PCB as is.

B. Add extra components on the existing PCB to fix power.

C. Redesign the PCB to correct the power connections and fabricate again.

D. Change the software to compensate for power issues.

Solution

1. Step 1: Identify the cause of power failure

   Power supply connections were not verified, causing no power.

2. Step 2: Determine correct fix

   Redesigning and refabricating the PCB to fix power is necessary.

3. Final Answer:

   Redesign the PCB to correct the power connections and fabricate again. -> Option C

4. Quick Check:

   Fix power by redesign and refabrication [OK]

Hint: Fix power issues by redesigning PCB [OK]

Common Mistakes:

• Ignoring the problem
• Trying to fix power with extra components
• Changing software instead of hardware

5. A PCB design review process includes schematic check, layout verification, and design rule check (DRC). If the DRC flags a clearance violation, what should be the next step to ensure fabrication success?

hard

A. Adjust the layout to fix the clearance violation before fabrication.

B. Remove components to avoid the violation.

C. Proceed with fabrication and fix errors later.

D. Ignore the violation if it looks minor.

Solution

1. Step 1: Understand what a clearance violation means

   Clearance violation means components or traces are too close, risking shorts or failures.

2. Step 2: Decide the correct action

   Adjusting the layout to fix the violation before fabrication prevents costly errors.

3. Final Answer:

   Adjust the layout to fix the clearance violation before fabrication. -> Option A

4. Quick Check:

   Fix clearance violation by layout adjustment [OK]

Hint: Fix DRC errors before fabrication [OK]

Common Mistakes:

• Ignoring minor violations
• Fabricating with known errors
• Removing components unnecessarily