PCB material and copper weight basics in PCB Design - Real Business Scenario

Scenario Mode

👤 Your Role: You are a PCB design analyst at an electronics manufacturing company.

📋 Request: Your manager wants a report showing how different PCB materials and copper weights affect the cost and weight of PCBs produced last quarter.

📊 Data: You have data on PCB orders including material type, copper weight (in ounces), quantity, cost per unit, and weight per unit (grams).

🎯 Deliverable: Create a dashboard showing total cost and total weight by material and copper weight, with clear visualizations to help the manager decide on material choices.

Sample Data

OrderID	Material	CopperWeight_oz	Quantity	CostPerUnit_USD	WeightPerUnit_g
1001	FR4	1	500	2.50	15
1002	FR4	2	300	3.00	18
1003	Rogers	1	200	4.00	14
1004	Rogers	2	150	4.50	17
1005	Polyimide	1	400	3.50	13
1006	Polyimide	2	350	4.00	16
1007	FR4	1	600	2.45	15
1008	Rogers	2	100	4.60	17

1

Step 1: Create a new table grouping data by Material and CopperWeight_oz.

Group by Material, CopperWeight_oz; aggregate Quantity as SUM, CostPerUnit_USD as average, WeightPerUnit_g as average.

Expected Result

Table with rows for each Material and CopperWeight_oz combination showing total Quantity, average CostPerUnit_USD, and average WeightPerUnit_g.

2

Step 2: Calculate Total Cost for each group by multiplying Quantity by CostPerUnit_USD.

Add column TotalCost = Quantity * CostPerUnit_USD

Expected Result

New column TotalCost showing total cost per group, e.g. FR4 1oz: (500+600)*2.475 approx 2718.75 USD.

3

Step 3: Calculate Total Weight for each group by multiplying Quantity by WeightPerUnit_g.

Add column TotalWeight_g = Quantity * WeightPerUnit_g

Expected Result

New column TotalWeight_g showing total weight per group, e.g. FR4 1oz: (500+600)*15 = 16500 grams.

4

Step 4: Create a bar chart showing Total Cost by Material and CopperWeight_oz.

X-axis: Material, grouped by CopperWeight_oz; Y-axis: TotalCost; Use different colors for copper weights.

Expected Result

Bar chart clearly showing which material and copper weight combinations cost the most.

5

Step 5: Create a bar chart showing Total Weight by Material and CopperWeight_oz.

X-axis: Material, grouped by CopperWeight_oz; Y-axis: TotalWeight_g; Use different colors for copper weights.

Expected Result

Bar chart showing total weight distribution by material and copper weight.

6

Step 6: Add filters to the dashboard to select specific Materials or Copper Weights.

Add slicers or dropdown filters for Material and CopperWeight_oz.

Expected Result

User can filter charts to focus on specific materials or copper weights.

7

Step 7: Summarize key insights in a text box on the dashboard.

Write summary: 'FR4 with 1oz copper is the most ordered and cost-effective. Rogers material is more expensive but lighter.'

Expected Result

Clear summary text visible on dashboard for quick understanding.

Final Result

Dashboard: PCB Material and Copper Weight Analysis

Material | Copper Weight | Total Cost (USD) | Total Weight (g)
------------------------------------------------------------
FR4      | 1 oz          | 2718.75         | 16500
FR4      | 2 oz          | 900             | 5400
Rogers   | 1 oz          | 800             | 2800
Rogers   | 2 oz          | 1125            | 4250
Polyimide| 1 oz          | 1400            | 5200
Polyimide| 2 oz          | 1400            | 5600

[Bar charts show Total Cost and Total Weight by Material and Copper Weight]

Summary: FR4 with 1oz copper is the most ordered and cost-effective. Rogers is pricier but lighter.

✓FR4 material with 1 oz copper weight has the highest total quantity and total cost.

✓Rogers material is more expensive per unit but offers lighter PCB weight.

✓Polyimide material costs and weights are between FR4 and Rogers.

✓Copper weight increase from 1 oz to 2 oz raises both cost and weight significantly.

Bonus Challenge

Add a calculated measure to find cost per gram for each material and copper weight combination.

Show Hint

Divide TotalCost by TotalWeight_g to get cost per gram.

Practice

1. Which property of PCB material mainly affects the board's ability to withstand heat?

easy

A. Copper weight

B. Thermal resistance

C. Board thickness

D. Solder mask color

Solution

1. Step 1: Understand PCB material properties

   PCB materials are chosen for their ability to resist heat and mechanical stress.

2. Step 2: Identify the key property for heat resistance

   Thermal resistance measures how well the material withstands heat without damage.

3. Final Answer:

   Thermal resistance -> Option B

4. Quick Check:

   Heat resistance = Thermal resistance [OK]

Hint: Heat resistance relates to material's thermal resistance [OK]

Common Mistakes:

• Confusing copper weight with heat resistance
• Thinking board thickness controls heat tolerance
• Assuming solder mask color affects heat resistance

2. Which of the following correctly describes copper weight in PCB design?

easy

A. Thickness of copper layer measured in ounces per square foot

B. Color of the copper layer

C. Length of copper traces on the board

D. Weight of the entire PCB

Solution

1. Step 1: Define copper weight

   Copper weight refers to the thickness of the copper layer on the PCB, usually measured in ounces per square foot.

2. Step 2: Eliminate incorrect options

   Color, length of traces, and total PCB weight do not define copper weight.

3. Final Answer:

   Thickness of copper layer measured in ounces per square foot -> Option A

4. Quick Check:

   Copper weight = Thickness in oz/ft² [OK]

Hint: Copper weight means thickness in ounces per square foot [OK]

Common Mistakes:

• Confusing copper weight with PCB color
• Thinking copper weight is trace length
• Assuming copper weight is total board weight

3. If a PCB uses 2 oz copper weight instead of 1 oz, what is the main effect on current carrying capacity?

medium

A. It reduces the current carrying capacity by 25%

B. It halves the current carrying capacity

C. It has no effect on current carrying capacity

D. It doubles the current carrying capacity

Solution

1. Step 1: Understand copper weight impact

   Copper weight thickness directly affects how much current the PCB trace can safely carry.

2. Step 2: Compare 1 oz and 2 oz copper

   Doubling copper weight from 1 oz to 2 oz roughly doubles the cross-sectional area, thus doubling current capacity.

3. Final Answer:

   It doubles the current carrying capacity -> Option D

4. Quick Check:

   2 oz copper = double current capacity [OK]

Hint: Double copper weight roughly doubles current capacity [OK]

Common Mistakes:

• Assuming copper weight does not affect current
• Thinking current capacity halves with more copper
• Confusing copper weight with board thickness

4. A PCB designer wrote: "Using 0.5 oz copper weight will increase current capacity compared to 1 oz copper." What is wrong with this statement?

medium

A. 0.5 oz copper weight decreases current capacity compared to 1 oz

B. Copper weight does not affect current capacity

C. 0.5 oz copper weight is thicker than 1 oz

D. Current capacity depends only on board size

Solution

1. Step 1: Analyze copper weight values

   0.5 oz copper is thinner than 1 oz copper, so it carries less current.

2. Step 2: Identify the error in the statement

   The statement incorrectly claims 0.5 oz increases current capacity, which is false.

3. Final Answer:

   0.5 oz copper weight decreases current capacity compared to 1 oz -> Option A

4. Quick Check:

   Less copper = less current capacity [OK]

Hint: Less copper weight means less current capacity [OK]

Common Mistakes:

• Thinking thinner copper carries more current
• Ignoring copper weight effect on current
• Confusing copper weight with board size

5. A PCB project requires high durability and the ability to carry 3 times the current of a standard 1 oz copper PCB. Which combination is best?

hard

A. Use low thermal resistance material with 2 oz copper weight

B. Use standard material with 1 oz copper weight and thicker board

C. Use a high thermal resistance material with 3 oz copper weight

D. Use high thermal resistance material with 0.5 oz copper weight

Solution

1. Step 1: Identify durability requirement

   High durability means choosing a PCB material with high thermal resistance to withstand heat and stress.

2. Step 2: Calculate copper weight for current capacity

   To carry 3 times the current of 1 oz copper, use approximately 3 oz copper weight.

3. Step 3: Match material and copper weight

   Combining high thermal resistance material with 3 oz copper meets both durability and current needs.

4. Final Answer:

   Use a high thermal resistance material with 3 oz copper weight -> Option C

5. Quick Check:

   Durability + 3x current = High thermal resistance + 3 oz copper [OK]

Hint: Match high thermal resistance with needed copper weight [OK]

Common Mistakes:

• Ignoring material thermal resistance for durability
• Using too low copper weight for current needs
• Assuming thicker board replaces copper weight