Manufacturing constraints awareness in PCB Design - Real Business Scenario

Scenario Mode

👤 Your Role: You are a PCB design engineer working closely with the manufacturing team.

📋 Request: Your manager wants a report that highlights which PCB designs meet manufacturing constraints and which do not, so the team can focus on fixing the problematic designs before production.

📊 Data: You have a dataset of PCB designs with columns: Design ID, Layer Count, Minimum Trace Width (mm), Minimum Hole Diameter (mm), and whether each design meets the manufacturing constraints for these parameters.

🎯 Deliverable: Create a dashboard showing the count of designs that pass and fail manufacturing constraints, and a detailed table listing designs with issues.

Sample Data

Design ID	Layer Count	Min Trace Width (mm)	Min Hole Diameter (mm)	Meets Constraints
D001	4	0.15	0.3	Yes
D002	6	0.1	0.25	No
D003	2	0.2	0.35	Yes
D004	8	0.08	0.2	No
D005	4	0.18	0.3	Yes
D006	6	0.12	0.22	No
D007	2	0.16	0.3	Yes
D008	4	0.14	0.28	Yes

1

Step 1: Load the PCB design data into your BI tool.

Import the table with columns: Design ID, Layer Count, Min Trace Width (mm), Min Hole Diameter (mm), Meets Constraints.

Expected Result

Data table with 8 rows loaded.

2

Step 2: Create a calculated measure to count how many designs meet manufacturing constraints.

Count of designs where 'Meets Constraints' = 'Yes'.

Expected Result

Count = 5

3

Step 3: Create a calculated measure to count how many designs do not meet manufacturing constraints.

Count of designs where 'Meets Constraints' = 'No'.

Expected Result

Count = 3

4

Step 4: Build a bar chart showing counts of designs passing and failing constraints.

Axis: 'Meets Constraints' (Yes/No), Values: Count of Design ID.

Expected Result

Bar chart with two bars: Yes=5, No=3.

5

Step 5: Create a table visual listing all designs that do not meet constraints with their details.

Filter data where 'Meets Constraints' = 'No', show Design ID, Layer Count, Min Trace Width, Min Hole Diameter.

Expected Result

Table with 3 rows: D002, D004, D006 and their details.

6

Step 6: Add a summary card showing total number of designs.

Count of all Design IDs.

Expected Result

Total designs = 8

Final Result

Bar Chart

↓

Table: Designs Failing Constraints

↓

Summary

✓5 out of 8 PCB designs meet manufacturing constraints.

✓3 designs (D002, D004, D006) fail due to trace width or hole diameter being below limits.

✓Focus on fixing these 3 designs to avoid manufacturing issues.

Bonus Challenge

Create a new measure that calculates the percentage of designs meeting constraints out of total designs.

Show Hint

Divide the count of designs meeting constraints by total designs, then multiply by 100.

Practice

1. Which of the following is a common manufacturing constraint in PCB design?

easy

A. Color of the PCB silkscreen

B. Minimum trace width

C. Number of software licenses

D. Type of solder used

Solution

1. Step 1: Understand common PCB manufacturing constraints

   Manufacturing constraints include physical limits like trace width, spacing, and hole size.

2. Step 2: Identify the correct constraint from options

   Minimum trace width is a key constraint to ensure the PCB can be produced reliably.

3. Final Answer:

   Minimum trace width -> Option B

4. Quick Check:

   Manufacturing constraints = Minimum trace width [OK]

Hint: Think physical limits on PCB lines and holes [OK]

Common Mistakes:

• Confusing design preferences with manufacturing constraints
• Choosing cosmetic features like color
• Selecting unrelated options like software licenses

2. Which of these is the correct way to specify a minimum hole size constraint in a PCB design rule?

easy

A. MinHoleSize = 0.3mm

B. HoleSizeMin = 0.3mm

C. Min_Hole_Size = 0.3mm

D. MinimumHole = 0.3mm

Solution

1. Step 1: Recall standard naming conventions in PCB design rules

   Design tools often use concise, camel-case or Pascal-case names like MinHoleSize.

2. Step 2: Identify the exact syntax used for minimum hole size

   MinHoleSize = 0.3mm is the correct and common syntax for specifying this constraint.

3. Final Answer:

   MinHoleSize = 0.3mm -> Option A

4. Quick Check:

   Correct syntax = MinHoleSize = 0.3mm [OK]

Hint: Look for concise, standard naming without underscores [OK]

Common Mistakes:

• Using underscores instead of camel case
• Mixing words in unusual order
• Adding extra words not recognized by tools

3. Given a PCB design rule: MinTraceWidth = 0.15mm and a trace width of 0.1mm in the design, what will happen during manufacturing?

medium

A. The PCB will be manufactured without issues

B. The design software will ignore the rule

C. The trace width will automatically increase to 0.15mm

D. The trace may be too thin and cause manufacturing defects

Solution

1. Step 1: Compare trace width with minimum allowed

   The design trace width (0.1mm) is less than the minimum allowed (0.15mm).

2. Step 2: Understand manufacturing impact

   Traces thinner than minimum can cause defects like breaks or shorts during production.

3. Final Answer:

   The trace may be too thin and cause manufacturing defects -> Option D

4. Quick Check:

   Trace width below minimum = manufacturing risk [OK]

Hint: Check if design values meet or exceed minimum constraints [OK]

Common Mistakes:

• Assuming software fixes the trace width automatically
• Ignoring the importance of minimum trace width
• Thinking the rule is optional

4. A PCB design rule states MinSpacing = 0.2mm. The designer sets two traces 0.15mm apart. What is the error and how to fix it?

medium

A. Spacing too small; increase spacing to at least 0.2mm

B. No error; 0.15mm is acceptable spacing

C. Spacing too large; reduce spacing to 0.1mm

D. Rule syntax is wrong; change to Min_Spacing

Solution

1. Step 1: Identify the spacing violation

   The actual spacing (0.15mm) is less than the minimum required (0.2mm), causing a violation.

2. Step 2: Correct the spacing to meet the rule

   Increase the spacing between traces to at least 0.2mm to comply with manufacturing constraints.

3. Final Answer:

   Spacing too small; increase spacing to at least 0.2mm -> Option A

4. Quick Check:

   Spacing < minimum = increase spacing [OK]

Hint: Spacing must never be less than minimum rule [OK]

Common Mistakes:

• Thinking smaller spacing is better
• Ignoring rule syntax correctness
• Assuming no error if spacing is close

5. You must prepare a PCB design for a manufacturer who requires a minimum trace width of 0.2mm and minimum hole size of 0.4mm. Your design has traces at 0.15mm and holes at 0.35mm. What is the best approach to ensure manufacturability?

hard

A. Ignore the constraints since they are just recommendations

B. Submit the design as is and ask the manufacturer to adjust

C. Update the design to meet or exceed both minimums before submission

D. Increase only the hole size, leave trace width as is

Solution

1. Step 1: Compare design values with manufacturer constraints

   Trace width (0.15mm) and hole size (0.35mm) are both below required minimums (0.2mm and 0.4mm).

2. Step 2: Decide on corrective action

   To avoid production errors, update the design to meet or exceed both minimum constraints before sending to manufacturer.

3. Final Answer:

   Update the design to meet or exceed both minimums before submission -> Option C

4. Quick Check:

   Design meets constraints before submission = manufacturability [OK]

Hint: Always fix design to meet constraints before manufacturing [OK]

Common Mistakes:

• Relying on manufacturer to fix design errors
• Ignoring constraints thinking they are optional
• Fixing only one constraint and ignoring others