Slide 1: VA package handling and assembly in inverters (conventional Hall)
APPLICATION NOTE VA package handling and assembly in inverters (conventional Hall) Revision 1.0 – January 2024 Advanced Customer Solutions
Slide 2: VA package handling and assembly in inverters
Application Note VA package handling and assembly in inverters 1. Scope 2. Sensor design and handling for THT assembly 3. Sensor design and handling for SMT assembly 4. Vibration robustness and plastic holder 2 VA package handling and assembly in inverters (conventional Hall) - 39011000002401 – rev
Slide 3: 1. Scope
Application Note 1. Scope Inverter main architectures Melexis current sensors come in two different packages, which allow for two different architectures when designing inverter modules: • VA package: The busbar is placed within a magnetic C-shape core and the sensor is placed in the core gap. The m
Slide 4: 1. Scope
Application Note 1. Scope Melexis current sensors in VA package Typical inverter application requires that the current sensor body is assembled vertical on a defined height above the PCB in order to fit into the notch of the C-core. • VA package of Melexis current sensors is a straight leads (18mm l
Slide 5: VA package handling and assembly in inverters
Application Note VA package handling and assembly in inverters 1. Scope 2. Sensor design and handling for THT assembly 3. Sensor design and handling for SMT assembly 4. Vibration robustness and plastic holder 5 VA package handling and assembly in inverters (conventional Hall) - 39011000002401 – rev
Slide 6: 2. Sensor design and handling for THT assembly
Application Note 2. Sensor design and handling for THT assembly Radial tape handling There are two delivery forms for current sensors in VA package: • Radial tape on reel (*-CR): According to standard IEC 60286-2/EIA-481 and intended for automatic handling. • Bulk (*-BU): The leads might be slightly
Slide 7: 2. Sensor design and handling for THT assembly
Application Note 2. Sensor design and handling for THT assembly Reference flow for panel level soldering In case of TH assembly of sensor, lead length trimming should be made as a first step of PCB insertion process: Insert onto PCB via Cut from tape Hold IC by gripper (camera alignment Soldering (d
Slide 8: 2. Sensor design and handling for THT assembly
Application Note 2. Sensor design and handling for THT assembly PCB landpattern for VA straight leads Minimum hole size can be calculated using IPC-2222, 9.2.2 Plated-Through Holes. The minimum pad size can be calculated using IPC-2221, 9.1.1 Land requirements. Both dimensions depend on technologica
Slide 9: VA package handling and assembly in inverters
Application Note VA package handling and assembly in inverters 1. Scope 2. Sensor design and handling for THT assembly 3. Sensor design and handling for SMT assembly 4. Vibration robustness and plastic holder 9 VA package handling and assembly in inverters (conventional Hall) - 39011000002401 – rev
Slide 10: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly T-shapes for SMT soldering There are two different reverse T-shapes, each one with a different pitch: • Reverse T-shape 1.27mm Because of the asymmetrical nature of the pins, the orientation of the part is guaranteed both during transpo
Slide 11: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Lead forming for customer requirements – sensor position vs PCB and core The dimensions and tolerances of the reverse T-shape lead forming should meet customer designed sensor position versus the PCB after soldering (height) and versus
Slide 12: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Reverse T-shape options at Melexis For different inverter designs, Melexis is producing 3 reverse T-shaped sensor variants STD2, STD3 and STD4. STD4 has the lowest sensor height and therefore the best vibration robustness. Refer to the
Slide 13: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Lead SMT solderability design considerations • Soldering of reverse T-shaped sensor by SMD reflow shall meet J-STD-001 and IPC-A-610 requirement. If it is a part of the common PCB with the switching circuitry, sensor solder paste type a
Slide 14: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Definition of coplanarity and impact on the application JESD22-B108 defines a methodology for measuring the coplanarity of SMD (Surface Mount Devices) using three pins to define a seating plane. Coplanarity is mostly defined by the bend
Slide 15: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Worst cases by bending angle variation – STD4 example The worst cases for both tilting and soldering depend on the resulting pin angle to seating plane. Lead bending angle (ϴ) shall be ≥ 90°for proper contact to printed solder paste Ф =
Slide 16: Worst case vertical tilt – STD4 example
Application Note 3. Sensor design and handling for SMT assembly Worst case vertical tilt – STD4 example Tilting is defined by the maximum angle to seating plane (Ф) and the IC height (H). The gap in the core (A) should be designed to accommodate for the maximum tilting of the device when the sensor
Slide 17: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Homogeneity inside core airgap Homogeneity zone can be defined as the volume where the magnetic field does not change by more than 2% b c Dimension Value [um] a Core Core a 700 b 1800 c 790 Simulation results Note: 2% is a proposed valu
Slide 18: Worst case for pin contact to solder paste – STD4 example
Application Note 3. Sensor design and handling for SMT assembly Worst case for pin contact to solder paste – STD4 example Soldering quality (reflow process on printed solder paste) is defined by lead bending angle (ϴ) and lead length (S). IPC-A-610H 8.3.5.4 requires that effective soldering is appli
Slide 19: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Lead forming for robust soldering to PCB Soldering quality (reflow process on printed solder paste) is defined by lead bending angle (ϴ) and solderable lead length (L). IPC-A-610H requires effective soldering is applied at least to 75%
Slide 20: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Pin side bending limits to control pin side overhang in NSMD pad IPC-A-610H 8.3.5.1 defines the maximum side overhang (A) as 25% of the lead width (W) for class 3 PCBAs. Parameter ‘A’ can be used to calculate the minimum solder pad widt
Slide 21: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly PCB solder pad design recommendations Dim. Meaning Reverse T-shape Reverse T-shape Reverse T- PCB solder pad design: Non-solder mask defined (NSMD) 1.27 STD4 1.27 STD2/3 shape 2.54 PCB finish: OSP, ENIG recommended SPW Solder Pad Width
Slide 22: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Melexis lead forming process control by automatic optical inspection of dimensions Coplanarity cannot be measured directly, but the two main dimensions defining it (bending radius and pin length) are checked during AOI (Automatic Optica
Slide 23: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Reel and tape handling risks Reverse T-shape options are delivered in TOR (Tape On Reel) with deep pockets. EIA-481 standard does not foresee sensitive devices in deep pockets and the empty pocket leader might not be long enough for saf
Slide 24: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Protection of reel during tape-on-feeder installation The role of the empty pocket leader (at the beginning of the tape for PnP) is to avoid component stress risk during manual manipulation of loading the tape into the feeder unit of th
Slide 25: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Device pickup from embossed tape Gripper Embossed tape pocket IC Example of embossed tape on reel with pockets Example of nozzle gripper accessing pocket The embossed tape on reel for SIP in SMD shape is custom made. Contact Melexis for
Slide 26: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Placement of SIP packages in SMD shape onto PCB by gripper Placement force < 1N Gripper Exceeding the placement force might lead to extra bending of the leads and springback effect. Hold pressure < 3N/sq. mm Exceeding the hold pressure
Slide 27: 3. Sensor design and handling for SMT assembly
Application Note 3. Sensor design and handling for SMT assembly Known issues when soldering SIP in SMD shape Cut burr Risk of lead stepping on solder mask Risk of conflict with cut burr (if bending is out of spec) If SMD solder pads are used, there is a risk that the lead steps on If the solder pad
Slide 28: VA package handling and assembly in inverters
Application Note VA package handling and assembly in inverters 1. Scope 2. Sensor design and handling for THT assembly 3. Sensor design and handling for SMT assembly 4. Vibration robustness and plastic holder 28 VA package handling and assembly in inverters (conventional Hall) - 39011000002401 – rev
Slide 29: 4. Vibration robustness and plastic holder
Application Note 4. Vibration robustness and plastic holder Vibration in inverter applications Vibration robustness also depends on the inverter module position in the powertrain of a car. The vibration experimented by the inverter can be divided in three main components: X, Y and Z. From the IC poi
Slide 30: 4. Vibration robustness and plastic holder
Application Note 4. Vibration robustness and plastic holder IC vibration robustness Inverter assembly is a subject of vibration test with a specific frequency/amplitude/time profile. Melexis applies FEA simulations of soldered sensor reference model to establish natural (self-resonance) frequency in
Slide 31: 4. Vibration robustness and plastic holder
Application Note 4. Vibration robustness and plastic holder Plastic holder The Plastic holder shall prevent (absorb) fatigue stress on the IC pins which is applied during vibration testing. Melexis does not have the core competency for design and manufacturing of plastic holders. However, some best
Slide 32: Annex I: List of Abbreviations
Application Note Annex I: List of Abbreviations AOI: Automatic Optical Inspection SM: Solder Mask ENIG: Electroless Nickel Immersion Gold SMD: Surface Mount Device FEA: Finite Element Analysis SMT: Surface Mount Technology IC: Integrated Circuit SOIC: Small Outline Integrated Circuit NSMD: Non-Surfa
Slide 33: Annex II: List of Standards
Application Note Annex II: List of Standards JESD22-B108 Coplanarity Test for Surface-Mount Semiconductor Devices J-STD-033 Handling, Packing, Shipping and Use of Moisture/Reflow Sensitive Surface Mount Devices IPC-A-610 Acceptability of Electronic Assemblies IPC-2221 Generic Standard on Printed Boa
Slide 34: Annex III: List of Related Application Notes
Application Note Annex III: List of Related Application Notes For the latest revision of this document and related Application Notes, visit www.melexis.com/ic-handling-and-assembly Guidelines for leadforming of SIP Hall sensors Guidelines for positioning and fixation of PCB-less devices Guidelines f
Slide 35: The content of this document is believed to be correct and accurate. However, the
The content of this document is believed to be correct and accurate. However, the content of this document is furnished "as is" for informational use only and no representation, nor warranty is provided by Melexis about its accuracy, nor about the results of its implementation. Melexis assumes no re