Mounting hole placement in PCB Design - Dashboard Guide

Dashboard Mode - Mounting hole placement

Goal: Analyze Mounting Hole Placement for PCB Design

This dashboard helps engineers check the positions and sizes of mounting holes on a PCB to ensure proper fit and stability.

Sample Data: Mounting Hole Coordinates and Sizes

Hole ID	X Position (mm)	Y Position (mm)	Diameter (mm)
H1	10	10	3
H2	90	10	3
H3	90	50	3
H4	10	50	3
H5	50	30	4

Dashboard Components

• KPI Card: Total Number of Mounting Holes = 5
• KPI Card: Average Hole Diameter = 3.2 mm (Formula: AVERAGE(Diameter))
• Scatter Plot: Hole Positions (X vs Y) with point size representing Diameter
• Table: Detailed Hole Data with conditional formatting highlighting holes with diameter > 3 mm
• Calculated Measure: Max Distance Between Holes = 89.44 mm (calculated using distance formula between all hole pairs)

Layout

+----------------------+----------------------+
|  KPI: Total Holes    |  KPI: Avg Diameter    |
|       (5)            |       (3.2 mm)        |
+----------------------+----------------------+
|                      Scatter Plot (Hole Positions)             |
|                      (X vs Y, size = Diameter)                 |
+---------------------------------------------------------------+
|                      Table: Hole Details                       |
+---------------------------------------------------------------+
|                      KPI: Max Distance Between Holes          |
|                              (89.44 mm)                      |
+---------------------------------------------------------------+
    

Interactivity

User can filter holes by diameter range using a slider. Filtering updates:

• The scatter plot to show only holes within the selected diameter range.
• The table to list only filtered holes.
• KPI cards recalculate total holes and average diameter for the filtered set.
• Max distance recalculates based on filtered holes.

Self-Check Question

If you add a filter to show only holes with diameter greater than 3 mm, which holes remain and how do the KPIs update?

Answer: Hole H5 (4 mm) remains. Total holes = 1, Average diameter = 4 mm, Max distance = 0 mm (only one hole), scatter plot and table show only H5.

Key Result

Dashboard shows mounting hole count, average diameter, positions on PCB, and max distance between holes with interactive diameter filtering.

Practice

1. What is the main purpose of mounting holes on a PCB?

easy

A. To cool down the PCB components

B. To securely fix the PCB inside a device

C. To provide electrical connections

D. To increase the PCB size

Solution

1. Step 1: Understand mounting hole function

   Mounting holes are designed to hold the PCB in place inside a device.

2. Step 2: Differentiate from other PCB features

   Electrical connections and cooling are done by traces and heat sinks, not mounting holes.

3. Final Answer:

   To securely fix the PCB inside a device -> Option B

4. Quick Check:

   Mounting holes = Secure fixing [OK]

Hint: Mounting holes hold the board physically [OK]

Common Mistakes:

• Confusing mounting holes with electrical vias
• Thinking holes cool components
• Assuming holes increase PCB size

2. Which of the following is the correct way to specify a mounting hole position on a PCB?

easy

A. Using x and y coordinates on the board

B. Using the hole diameter only

C. Using the color of the hole

D. Using the number of pins

Solution

1. Step 1: Identify position parameters

   Mounting holes are placed by specifying their x and y coordinates on the PCB layout.

2. Step 2: Exclude irrelevant options

   Hole diameter defines size, color and pin count are unrelated to position.

3. Final Answer:

   Using x and y coordinates on the board -> Option A

4. Quick Check:

   Position = x,y coordinates [OK]

Hint: Positions need x and y coordinates [OK]

Common Mistakes:

• Confusing hole size with position
• Using color or pins to locate holes
• Ignoring coordinate system

3. Given a PCB with mounting holes at coordinates (10, 20), (50, 20), (10, 60), and (50, 60), what is the distance between the two holes at (10, 20) and (50, 20)?

medium

A. 30 units

B. 60 units

C. 50 units

D. 40 units

Solution

1. Step 1: Identify coordinates of the two holes

   The holes are at (10, 20) and (50, 20), so they share the same y-coordinate.

2. Step 2: Calculate horizontal distance

   Distance = |50 - 10| = 40 units since y is the same.

3. Final Answer:

   40 units -> Option D

4. Quick Check:

   Distance = 50 - 10 = 40 [OK]

Hint: Subtract x values when y is equal [OK]

Common Mistakes:

• Calculating vertical distance instead
• Adding coordinates instead of subtracting
• Mixing x and y values

4. A PCB designer placed mounting holes at (15, 25), (15, 75), (65, 25), but forgot one hole to complete the rectangle. Which coordinate should be added to complete the mounting hole placement?

medium

A. (65, 75)

B. (15, 50)

C. (40, 75)

D. (65, 50)

Solution

1. Step 1: Identify existing hole coordinates

   Holes are at (15, 25), (15, 75), and (65, 25). Two share x=15, two share y=25.

2. Step 2: Find missing corner to form rectangle

   The missing corner must have x=65 and y=75 to complete the rectangle.

3. Final Answer:

   (65, 75) -> Option A

4. Quick Check:

   Opposite corner = (65, 75) [OK]

Hint: Complete rectangle with missing opposite corner [OK]

Common Mistakes:

• Choosing midpoint instead of corner
• Mixing x and y values incorrectly
• Ignoring rectangle shape

5. You need to place four mounting holes on a PCB sized 100x80 units. The holes must be 5 units from each edge. What are the correct coordinates for the holes?

hard

A. (5, 0), (95, 0), (5, 80), (95, 80)

B. (0, 0), (100, 0), (0, 80), (100, 80)

C. (5, 5), (95, 5), (5, 75), (95, 75)

D. (10, 10), (90, 10), (10, 70), (90, 70)

Solution

1. Step 1: Calculate hole positions from edges

   Each hole is 5 units from left/right edges (x=5 and x=100-5=95) and top/bottom edges (y=5 and y=80-5=75).

2. Step 2: List all four corner coordinates

   Holes are at (5,5), (95,5), (5,75), and (95,75).

3. Final Answer:

   (5, 5), (95, 5), (5, 75), (95, 75) -> Option C

4. Quick Check:

   Edges minus 5 units = hole coords [OK]

Hint: Subtract 5 from edges for hole positions [OK]

Common Mistakes:

• Using 0 or full edge coordinates
• Adding 10 units instead of 5
• Mixing x and y values