Manufacturing file review in PCB Design - Cell-by-Cell Formula Trace

Sample Data

This table lists manufacturing files for a PCB project, showing file names, types, review status, and error counts.

Cell	Value
A1	File Name
B1	File Type
C1	Status
D1	Errors
A2	board_top.gbr
B2	Gerber
C2	Checked
D2	0
A3	board_bottom.gbr
B3	Gerber
C3	Checked
D3	1
A4	drill_file.drl
B4	Drill
C4	Pending
D4	0
A5	assembly_instructions.pdf
B5	Document
C5	Checked
D5	0

Formula Trace

=COUNTIF(C2:C5, "Checked")

Step 1: C2:C5 values = ["Checked", "Checked", "Pending", "Checked"]

Step 2: Check each cell if value equals "Checked"

Step 3: Count TRUE values

Cell Reference Map

    A               B           C           D
1 | File Name      | File Type | Status    | Errors
2 | board_top.gbr | Gerber    | Checked   | 0
3 | board_bottom.gbr | Gerber  | Checked   | 1
4 | drill_file.drl | Drill     | Pending   | 0
5 | assembly_instructions.pdf | Document | Checked | 0

Formula references cells C2 to C5 for Status values.

The formula counts how many files have the status 'Checked' in the Status column (C2:C5).

Result

    A               B           C           D
1 | File Name      | File Type | Status    | Errors
2 | board_top.gbr | Gerber    | Checked   | 0
3 | board_bottom.gbr | Gerber  | Checked   | 1
4 | drill_file.drl | Drill     | Pending   | 0
5 | assembly_instructions.pdf | Document | Checked | 0

Result cell (e.g., E1): 3

The formula result is 3, showing three files have been reviewed and marked as 'Checked'.

Sheet Trace Quiz - 3 Questions

How many files have the status 'Checked' according to the formula?

A 3

B 2

C 4

D 1

Key Result

COUNTIF(range, criteria) counts how many cells in the range meet the criteria.

Practice

1. What is the main purpose of a manufacturing file review in PCB design?

easy

A. To prevent costly errors during PCB production

B. To design new PCB layouts

C. To write software for PCB testing

D. To order components for assembly

Solution

1. Step 1: Understand the role of manufacturing file review

   Manufacturing file review checks files like Gerber and drill files before production.

2. Step 2: Identify the main goal

   The goal is to catch errors early to avoid costly mistakes in production.

3. Final Answer:

   To prevent costly errors during PCB production -> Option A

4. Quick Check:

   Manufacturing file review = prevent errors [OK]

Hint: Focus on error prevention in production files [OK]

Common Mistakes:

• Confusing design with review process
• Thinking review is for ordering parts
• Mixing software testing with file review

2. Which file type is NOT typically checked during a PCB manufacturing file review?

easy

A. Source code files

B. Drill files

C. Component placement files

D. Gerber files

Solution

1. Step 1: List common files reviewed

   Gerber, drill, and component placement files are standard in manufacturing review.

2. Step 2: Identify the odd file out

   Source code files relate to software, not PCB manufacturing files.

3. Final Answer:

   Source code files -> Option A

4. Quick Check:

   Manufacturing review excludes software files [OK]

Hint: Remember manufacturing files are physical layout files [OK]

Common Mistakes:

• Including software files in manufacturing review
• Confusing component files with source code
• Assuming all project files are reviewed

3. Given a BI dashboard showing counts of errors found in Gerber, drill, and component files, which visualization best helps identify the file type with most errors?

medium

A. Table listing file names only

B. Line chart showing error counts over time

C. Scatter plot of file sizes vs error counts

D. Pie chart showing error counts by file type

Solution

1. Step 1: Understand the goal of visualization

   The goal is to identify which file type has the most errors.

2. Step 2: Choose visualization type

   A pie chart clearly shows proportions of errors by file type, making comparison easy.

3. Final Answer:

   Pie chart showing error counts by file type -> Option D

4. Quick Check:

   Pie chart = compare parts of whole [OK]

Hint: Use pie charts to compare parts of a whole quickly [OK]

Common Mistakes:

• Using line charts for categorical comparison
• Choosing tables without summary
• Scatter plots confuse error focus

4. A BI report shows zero errors in drill files, but the drill file was not uploaded. What is the likely issue?

medium

A. The report is correctly showing zero errors

B. The drill file was missing, causing no data to check

C. The drill file has no errors by default

D. The BI tool automatically fixes missing files

Solution

1. Step 1: Analyze the zero error count

   Zero errors can mean no errors or no data to check.

2. Step 2: Consider missing file impact

   If the drill file was not uploaded, the BI tool has no data to analyze, so it shows zero errors incorrectly.

3. Final Answer:

   The drill file was missing, causing no data to check -> Option B

4. Quick Check:

   Missing file = no data, not zero errors [OK]

Hint: Check if files are uploaded before trusting zero errors [OK]

Common Mistakes:

• Assuming zero means no errors
• Believing BI tools fix missing data automatically
• Ignoring file upload status

5. You want to create a BI report that highlights PCB manufacturing errors by file type and severity. Which approach best combines these two aspects for clear decision-making?

hard

A. Display a line chart of errors over time without file type distinction

B. List all errors in a long table sorted by file name

C. Use a stacked bar chart with file types on X-axis and error counts stacked by severity

D. Show a pie chart of total errors without severity details

Solution

1. Step 1: Identify key data dimensions

   We need to show errors by file type and severity together.

2. Step 2: Select visualization that combines categories and subcategories

   A stacked bar chart groups errors by file type and stacks severity levels, making it easy to compare both.

3. Final Answer:

   Use a stacked bar chart with file types on X-axis and error counts stacked by severity -> Option C

4. Quick Check:

   Stacked bar = compare categories + subcategories [OK]

Hint: Stacked bars show parts of categories clearly [OK]

Common Mistakes:

• Using tables that are hard to scan
• Ignoring severity in summary charts
• Choosing charts that miss key comparisons