Mounting Instruction for DP3 Power Module
AN6046
Introduction
This application note describes general concepts, guidelines, and recommendations for the procedures and specifications related to heatsink installation, Printed Circuit Board (PCB) mounting, and unmounting for the Microchip Dual Pack 3 (DP3) power module. This document does not address all possible applications or conditions that may be encountered by end users.
This document is not part of any warranty agreement from the supplier. We strongly recommends that users perform comprehensive electromechanical evaluations to ensure suitability for their specific application.
DP3 Power Module Overview
The DP3 power module features press-fit pin technology, enabling solderless PCB mounting via a press-fit insertion process. This ensures low-resistance, stable electrical contact. The press-fit pins are tin-electroplated T2 copper with a nominal width of 1.2 mm.
Note: During installation, the press-fit pin is forcibly inserted into the PCB hole. This action deforms the pin, resulting in a tight interference fit and reliable electrical contact between the interfaces.
The following figures show the press-fit pin description and insertion.
Figure 1. Press-fit Pin Description
Figure 2. Press-fit Pin Insertion
Electrostatic Discharge (ESD) Handling
Always observe Electrostatic Discharge (ESD) safety precautions when handling ESD-sensitive components, such as IGBT modules. Ensure proper installation and maintain workplace ESD safety compliance to prevent latent or severe damage that may result from excessive static electricity discharge during handling.
The following figure shows the ESD caution symbol.
Figure 3. ESD Caution Symbol
PCB Mounting and Dismounting Instructions
This section describes the detailed information on PCB requirements, as well as instructions for mounting and dismounting the PCB.
1.1. PCB Requirements
The recommended PCB specifications for the DP3 power module with press-fit pins, as provided in this section, are based on experimental validation using standard FR4 material with copper base metallization and tin-plated holes, in accordance with IEC 60352-5. If alternative technologies, design parameters, materials, or metallization thicknesses are considered, end users are advised to perform appropriate qualification and evaluation to ensure compatibility For optimal electrical contact between the press-fit pins and PCB holes, the PCB should be designed according to the specifications as given in the below figure and table. Deviation from these recommendations may result in reduced contact reliability or mechanical issues during PCB mounting.
Figure 1-1. Recommended PCB Design Structure
Table 1-1. Recommended PCB Design Specifications
| PCB Feature | Min. | Typ. | Max. | Unit |
| Drill hole diameter | 1.12 | 1.15 | — | mm |
| Copper thickness in hole | 25 | — | 50 | µm |
| Hole tin metalization | 4 | — | 15 | µm |
| Final hole diameter | 0.94 | — | 1.09 | mm |
| Copper thickness of conductors | 35 | 70–105 | 400 | µm |
1.2. PCB Mounting Process
The DP3 power module is mounted onto the PCB by inserting the module’s press-fit pins into the designated PCB holes. This connection is established through a press-fit process, which can be performed using either a manual lever press or an automated press machine. Automated presses should provide adjustable speed, displacement, and force control to ensure consistent contact quality and repeatability.
The following figure shows the recommended stacking arrangement, including a sample work holder and press plate tool, for the PCB press-fit pin insertion process. Ensure that all interfaces are vertically aligned and parallel to prevent damage or issues such as bent pins, tilted PCBs, or loose connections during mounting.
Figure 1-2. Recommended Stacking Arrangement
Maintain a minimum clearance of 5 mm from the center of each press-fit pin to adjacent components on the PCB. This spacing must also be considered when designing user-developed press tools and when positioning components on the PCB.
After aligning the PCB and module in the work holder, apply a constant force and speed to insert the pins into the PCB holes. Continue pressing until the PCB contacts the mounting guide or footing on the module. Always verify the planarity between the PCB and the module.
The following figure shows the example of press-fit insertion process.
Figure 1-3. Example of Press-fit Insertion Process
The following table lists the recommended press-fit pin insertion parameters. These parameters ensure sufficient force and displacement speed to establish reliable contact between interfaces, based on the specified materials and structure, without damaging the PCB. If alternative parameters, materials, or structures are used, end users should perform their own evaluations.
Table 1-2. Recommended Press-fit Pin Insertion Parameters
| Parameter | Min. | Typ. | Max. | Unit |
| Drill hole diameter | 1.15 | mm | ||
| Press-fit pin insertion speed | 25 | mm/min | ||
| Copper thicknesss in hole | 25 | — | 50 | µm |
| Press-fit pin insertion force per pin | — | 110 | — | N |
1.3. PCB Dismounting Process
If the PCB needs to be replaced, dismounting can be performed on processed units. A dismounted PCB can be reused and remounted onto the module up to three times. However, a module that has been dismounted should not be reused with the press-fit method, as the pins may be deformed after the initial mounting. If remounting the PCB onto the module is required, soldering the pins to the new board is necessary to ensure a reliable and stable connection.
The dismounting process can be performed using a manual lever press or a mechanized press machine. The upper press-out tool, developed by the end user, must be designed according to the PCB layout to apply pressure only to the press-fit pins and avoid damaging other components.
To dismount, place the module with the mounted PCB onto the work holder, ensuring the board is fully supported by the tooling ledge. Apply force to the pins to release the contact between interfaces and separate the module from the PCB. The module will descend into the work holder, and the PCB will be completely detached.
The following figure shows the dismounting process using a sample work holder and press plate tooling.
Figure 1-4. Example of Press-fit Extraction Process
The following table lists the recommended press-fit pin extraction parameters.
Table 1-3. Recommended Press-fit Pin Extraction Parameters
| Parameter | Min. | Typ. | Max. | Unit |
| Extraction speed | 12 | mm/min | ||
| Press-fit pin extraction force per pin | 40 | — | — | N |
Fastening the PCB to the Module
Additional fasteners are used to secure the PCB to the module. These fasteners help maintain connection integrity by minimizing tension between the PCB and the press-fit pins. Using additional fasteners also reduces the risk of external strain affecting the pins during subsequent processes.
2.1. Fastener Recommendations
The DP3 power module includes a PCB footing and screw guide structure with an internal hole diameter of 2.1 ± 0.1 mm. This design supports the use of self-tapping screws with a recommended diameter of 2.25 mm to 2.45 mm. Select a screw length between 4 mm and 10 mm, based on the thickness of the PCB and the weight of the mounted assembly.
The following figures shows the mounting hole dimension, recommended screw dimension, and the PCB footing structure respectively.
Figure 2-1. Mounting Hole Dimension
Figure 2-2. Recommended Screw Dimension
Figure 2-3. PCB Footing/Screw Guide Location
2.2. Fastening Screw Insertion
The upper part of the screw holes is designed to guide and support the PCB during mounting. This area cannot withstand excessive forces during self-tapping screw insertion. Always ensure vertical alignment of the screw to the hole and use the correct screw diameter. Misalignment or incorrect screw size can cause damage to the module and negatively impact the quality of the press-fit pin and PCB contact.
The recommended mounting torque is approximately 0.4–0.5 Nm. Manual screw tightening is preferred to minimize the risk of damage. If automated tools are used, select electronically controlled drivers with slow rotation speed. End users should assess and validate the chosen method to ensure safe and reliable installation.
The following figures show the properly aligned mounting screw, misaligned mounting screw, and possible mechanical damage due to misaligned screw or incorrect screw diameter.
Figure 2-4. Properly Aligned Mounting Screw
Figure 2-5. Misaligned Mounting Screw
Figure 2-6. Possible Mechanical Damage
Heatsink Mounting Assembly
Temperature regulation is essential to ensure optimal functionality of power modules, particularly during high-power switching operations, which can generate significant heat due to power loss. To maintain the module within its allowable operating temperature range, use a heatsink to dissipate excess heat.
3.1. Heatsink Requirements
The condition of the materials at the heatsink-to-baseplate interface is critical during mounting, as it directly affects heat dissipation. Ensure that all contact surfaces are free from contamination, foreign materials, and corrosion. The mounting surface of the heatsink should have a surface roughness of less than 10 μm and a flatness of less than 30 μm.
Verify that the heatsink is rigid and can withstand subsequent processes without twisting or distortion. Defects in the heatsink can increase contact thermal resistance and introduce additional stress to the module, potentially leading to thermal or electrical failure.
3.2. Thermal Conductive Paste (TCP) Application
Applying TCP during mounting fills gaps between the baseplate and the heatsink, which are caused by surface irregularities. Proper application of TCP significantly improves heat dissipation efficiency and reduces the thermal resistance of the module during operation.
To achieve optimal thermal dissipation and ensure uniform and reproducible thermal layers, apply TCP using a stencil screen printing process. This method allows for precise control and adjustment of TCP distribution for each module. The recommended thermal paste thickness is typically between 50 μm and 100 μm.
The following figure shows the stencil screen printing process. In this process, the unit is placed on a work holder, the stencil screen is positioned on top of the module, and TCP is applied using a manual metal squeegee.
Figure 3-1. Stencil Screen Printing Process
3.3. Mounting Screw and Tightening Requirement
The DP3 power module requires four DIN M5 screws for heatsink mounting. When selecting screws and washers, ensure that the resulting clearance and creepage distances between the power terminals and the nearest screw head or washer comply with applicable standards. Evaluate these distances during the development phase.
Follow the below steps for heatsink mounting procedure and bolt tightening sequence:
- Position the Module
a. Place the power module, with thermal conductive paste applied, onto the heatsink. - Initial Screw Placement
a. Insert all four M5 screws.
b. Tighten each screw to 0.5 Nm in the following diagonal sequence: 1 – 2 – 3 – 4, see Figure 3-2. - Intermediate Tightening
a. Tighten each screw to 2 Nm, following the same sequence: 1 – 2 – 3 – 4. - Final Tightening
a. Tighten each screw to the specified final torque, again in the sequence: 1 – 2 – 3 – 4.
b. See the product datasheet for the maximum allowable torque. - Torque Verification (Recommended)
a. Use a torque-controlled screwdriver for all tightening steps.
b. If possible, re-tighten all screws to the final torque in the same sequence (1 – 2 – 3 – 4) after three hours.
The following figure shows the tightening sequence to mount the module to the heatsink.
Figure 3-2. Tightening Sequence to Mount the Module to the Heatsink
Connection Pull and Push Forces for DP3 Module
The DP3 power module must be mounted to ensure that pull forces applied to the power terminals are minimized. Excessive pull or push forces can damage the terminals or compromise the reliability of the electrical connection.
The following figure shows the maximum allowable pull and push forces at the power terminals during the screw-in operation.
Figure 4-1. Maximum Pull and Push Forces for DP3 Module
Assembling Busbars to Power Terminals
Mount the busbars onto the power module and secure them to the power terminals using M6 screws with M6 flat washers. Select the screw length based on the combined thickness of the busbar and washers. Ensure that the effective thread engagement does not exceed a maximum depth of 10 mm in the module. See product datasheet for the maximum allowable torque.
To minimize switching over voltages, place decoupling capacitors as close as possible to the VBUS and 0/VBUS power terminals.
When installing isolated spacers, set their height (X) to be approximately 0.5 mm lower than the height (Y) of the power terminals. This pre-tensions the power terminals and prevents permanent force in the Fz+ direction (see Figure 4-1 and Figure 5-1). Ensure that the busbars are at the same height as the power connectors. See the following figure and the product datasheet for an example of proper assembly.
For heavy components such as electrolytic or polypropylene capacitors located near the power module, use isolated spacers to support their weight. The weight of these components should be borne by the spacers, not by the power module. Add additional isolated spacers as needed to prevent issues caused by vibration and shock.
Figure 5-1. Example of DP3 Assembly
Conclusion
This application note provides key recommendations for mounting the DP3 power module.
Following these guidelines will help minimize mechanical stress on the busbar, PCB, and power module, supporting long-term system operation. Adhering to the specified heatsink mounting instructions is also critical to achieving the lowest possible thermal resistance from the power chips to the cooler. Implementing these procedures is essential to ensure optimal system reliability.
Revision History
The revision history describes the changes that were implemented in the document. The changes are listed by revision, starting with the most current publication.
| Revision | Date | Description |
| A | 07/2025 | Initial revision |
Microchip Information
Trademarks
The “Microchip” name and logo, the “M” logo, and other names, logos, and brands are registered and unregistered trademarks of Microchip Technology Incorporated or its affiliates and/or subsidiaries in the United States and/or other countries (“Microchip Trademarks”). Information regarding Microchip Trademarks can be found at https://www.microchip.com/en-us/about/legalinformation/microchip-trademarks.
ISBN: 979-8-3371-1627-3
Legal Notice
This publication and the information herein may be used only with Microchip products, including to design, test, and integrate Microchip products with your application. Use of this information in any other manner violates these terms. Information regarding device applications is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. Contact your local Microchip sales office for additional support or, obtain additional support at www.microchip.com/en-us/support/design-help/client-support-services.
THIS INFORMATION IS PROVIDED BY MICROCHIP “AS IS”. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY, AND FITNESS FOR A PARTICULAR PURPOSE, OR WARRANTIES RELATED TO ITS CONDITION, QUALITY, OR PERFORMANCE. IN NO EVENT WILL MICROCHIP BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, INCIDENTAL, OR CONSEQUENTIAL LOSS, DAMAGE, COST, OR EXPENSE OF ANY KIND WHATSOEVER RELATED TO THE INFORMATION OR ITS USE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS BEEN ADVISED OF THE POSSIBILITY OR THE DAMAGES ARE FORESEEABLE. TO THE FULLEST EXTENT ALLOWED BY LAW, MICROCHIP’S TOTAL LIABILITY ON ALL CLAIMS IN ANY WAY RELATED TO THE INFORMATION OR ITS USE WILL NOT EXCEED THE AMOUNT OF FEES, IF ANY, THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THE INFORMATION.
Use of Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights unless otherwise stated.
Microchip Devices Code Protection Feature
Note the following details of the code protection feature on Microchip products:
- Microchip products meet the specifications contained in their particular Microchip Data Sheet.
- Microchip believes that its family of products is secure when used in the intended manner, within operating specifications, and under normal conditions.
- Microchip values and aggressively protects its intellectual property rights. Attempts to breach the code protection features of Microchip products are strictly prohibited and may violate the Digital Millennium Copyright Act.
- Neither Microchip nor any other semiconductor manufacturer can guarantee the security of its code. Code protection does not mean that we are guaranteeing the product is “unbreakable”. Code protection is constantly evolving. Microchip is committed to continuously improving the code protection features of our products.
Application Note
© 2025 Microchip Technology Inc. and its subsidiaries
DS00006046A – 16
Documents / Resources
 |
MICROCHIP AN6046 DP3 Power Module [pdf] Instruction Manual AN6046 DP3 Power Module, AN6046, DP3 Power Module, Power Module, Module |