Manufacturing file review in PCB Design - Real Business Scenario

Scenario Mode

👤 Your Role: You are a quality analyst in a printed circuit board (PCB) manufacturing company.

📋 Request: Your manager wants you to review the manufacturing files to identify any discrepancies in layer counts, drill sizes, and material specifications before production starts.

📊 Data: You have a dataset containing PCB job IDs, layer counts, drill hole sizes, material types, and file approval status.

🎯 Deliverable: Create a report that highlights any files with mismatched layer counts, drill sizes outside the allowed range, or incorrect material types. Include a summary dashboard showing the count of approved and rejected files.

Sample Data

Job ID	Layer Count	Expected Layers	Drill Size (mm)	Allowed Drill Range (mm)	Material Type	Expected Material	Approval Status
PCB001	6	6	0.8	0.6 - 1.0	FR4	FR4	Approved
PCB002	4	6	1.2	0.6 - 1.0	FR4	FR4	Rejected
PCB003	8	8	0.5	0.6 - 1.0	Polyimide	Polyimide	Approved
PCB004	6	6	0.7	0.6 - 1.0	FR4	FR4	Approved
PCB005	6	6	1.1	0.6 - 1.0	FR4	FR4	Rejected
PCB006	4	4	0.9	0.6 - 1.0	FR4	FR4	Approved
PCB007	6	6	0.6	0.6 - 1.0	FR4	FR4	Approved
PCB008	8	8	1.3	0.6 - 1.0	Polyimide	Polyimide	Rejected

1

Step 1: Create a new column 'Layer Mismatch' to check if 'Layer Count' matches 'Expected Layers'.

Layer Mismatch = IF([Layer Count] <> [Expected Layers], "Mismatch", "Match")

Expected Result

Row with PCB002 shows 'Mismatch', others show 'Match' accordingly.

2

Step 2: Create a new column 'Drill Size Valid' to check if 'Drill Size (mm)' is within 'Allowed Drill Range (mm)'.

Drill Size Valid = IF(AND([Drill Size (mm)] >= 0.6, [Drill Size (mm)] <= 1.0), "Valid", "Invalid")

Expected Result

PCB002, PCB003, PCB005, and PCB008 show 'Invalid' drill sizes.

3

Step 3: Create a new column 'Material Mismatch' to check if 'Material Type' matches 'Expected Material'.

Material Mismatch = IF([Material Type] <> [Expected Material], "Mismatch", "Match")

Expected Result

All rows show 'Match' since materials are correct.

4

Step 4: Filter the dataset to show only rows where 'Layer Mismatch' = 'Mismatch' OR 'Drill Size Valid' = 'Invalid' OR 'Material Mismatch' = 'Mismatch'.

Filter condition: Layer Mismatch = 'Mismatch' OR Drill Size Valid = 'Invalid' OR Material Mismatch = 'Mismatch'

Expected Result

Filtered rows: PCB002, PCB003, PCB005, PCB008.

5

Step 5: Create a summary dashboard showing count of files by 'Approval Status'.

Count Approved = COUNTROWS(FILTER(Table, [Approval Status] = "Approved")) Count Rejected = COUNTROWS(FILTER(Table, [Approval Status] = "Rejected"))

Expected Result

Approved: 5 files, Rejected: 3 files.

Final Result

Manufacturing File Review Dashboard
-----------------------------------
| Approval Status | Count          |
|-----------------|----------------|
| Approved        | 5              |
| Rejected        | 3              |

Files with Issues:
Job ID | Layer Mismatch | Drill Size Valid | Material Mismatch
-------------------------------------------------------------
PCB002 | Mismatch       | Invalid          | Match
PCB003 | Match          | Invalid          | Match
PCB005 | Match          | Invalid          | Match
PCB008 | Match          | Invalid          | Match

✓Four files have issues: PCB002 has wrong layer count and invalid drill size.

✓PCB003, PCB005 and PCB008 have drill sizes outside the allowed range.

✓All materials match expected specifications.

✓Five files are approved, three are rejected due to these discrepancies.

Bonus Challenge

Create a visual heatmap showing the frequency of each type of discrepancy across all files.

Show Hint

Use conditional formatting or color coding in your BI tool to highlight mismatches in layers, drill sizes, and materials.

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