Surface mounted piezoelectric devices for frequency control and selection - Standard outlines and terminal lead connections - Part 3: Metal enclosures (IEC 61837-3:2015); German version EN 61837-3:2015 / Note: DIN EN 61837-3 (2001-09) remains valid alo...
1Key Takeaways
This part of IEC 61837 deals with standard package dimensions and terminals for surface-mount devices (SMDs) used for frequency stabilization and selection in metal packages. It is based on IEC 61240, which standardizes design rules for package drawings of surface-mount devices.
2Expert Interpretation
An in-depth look at DIN EN 61837-3:2016-04, the standard for surface-mounted piezoelectric devices in metal housings, covers dimensional specifications, terminal connections, and geometric tolerance requirements for the design and manufacture of piezoelectric components for frequency control and selection.
Standard Overview and Technical Background
DIN EN 61837-3:2016-04 is an international standard adopted by the European Committee for Electrotechnical Standardization (CENELEC) on May 20, 2015. It standardizes the dimensions of metal housings for surface-mount piezoelectric devices. This standard replaces the 2001 version, with a transition period until May 20, 2018. The standard, developed by Working Group K642 of the German Committee for Electrical, Electronic and Information Technology (DKE), is based on IEC 61240:2012, Rules for the Preparation of Outline Drawings for Surface-Mount Devices.
Main technical changes
Compared with DIN EN 61837-3:2001-09, the 2016 edition has undergone important technical revisions:
| Changed items | 2001 edition specifications | 2016 edition new regulations | Technical impact |
|---|---|---|---|
| Drawing perspective requirements | Right view is optional | Four perspectives must be included: top view, front view, right view, bottom view | Improve the integrity of design documents |
| Height marking method | Use shell height | Use the overall height symbol G or G with a subscript number | The marking method is more accurate |
| Terminal spacing specifications | Not explicitly required | Center distance must be marked, the basic dimension e is 2.54n mm or 1.27n mm (when the shell size is <6mm) | Improve installation compatibility |
| Connection surface dimension marking | Use the minimum value | Use the maximum value | Simplify consumer use |
Metal shell configuration system
The standard adopts the SMS (Surface-Mounted, Special) special surface mount identification system, the structure includes:
| Components | Symbol Meaning | Example Description |
|---|---|---|
| A: Configuration Symbol | SMS (Special Surface Mount) | Fixed Marking |
| B: Lead Structure | L: Kinked Lead J: Kinked Lead No Marking: No Lead | Distinguish Connection Method |
| C: Number of Terminals | Digital Representation | E.g., 4 indicates 4 terminals |
| D: Serial Number | Two digits | 01-99 variant differentiation |
For identical housings with different heights (G) or lengths (F), use subscript numbers to differentiate, such as G1, G2, F1, F2, etc. For multiple spacing values, use e1-1, e1-2, etc.
Specific Enclosure Type Specifications
The standard details 37 metal enclosure types, which are mainly divided into two categories:
L-Lead Enclosures (SMS-L Series)
Metal enclosures using resistance welding technology, including 3-terminal (SMS-L3) and 4-terminal (SMS-L4) configurations:
- SMS-L4/01-03: LP1 maximum value increased from 1.2mm to 1.4mm
- SMS-L4/04-07: B1 maximum value increased from 9.5mm to 9.6mm, LP1 increased to 1.4mm
- SMS-L3 Series: Contains 27 variants (01-27) to cover different size requirements
J-Lead Enclosures (SMS-J Series)
Resistance-welded metal housing with plastic carrier:
- SMS-J4/01: 4-terminal J-lead configuration
- SMS-J2/01-02: Maximum B value increased from 4.7mm to 5.0mm, minimum K1 value reduced from 0.85mm to 0.6mm
Terminal Connection Specifications
Due to the special SMD design of the SMS housing, the standard does not prescribe a uniform terminal assignment; however, this requirement must be determined in consultation with the customer in the type specification. The connection surface dimensions have been redesigned from minimum to maximum, simplifying the choice for the consumer.
Metal cladding arrangements are provided as examples; specific portions of the connector can be reshaped under pressure, providing flexibility for different application scenarios.
Standard Implementation Recommendations
Design Phase Considerations
1. Drawing Specifications: Strictly adhere to the four-view requirements (top, front, right, and bottom) to ensure design document integrity
2. Dimensioning: Adopt a new height dimensioning system (G, G1, G2) to accurately reflect the total height rather than just the housing height
3. Terminal Spacing: Design according to the basic dimensional specifications of 2.54 mm or 1.27 mm to ensure compatibility with PCB layout
Manufacturing and Inspection Requirements
1. Tolerance Control: Refer to ISO 1101:2012 Geometric Product Specification to ensure tolerances on shape, orientation, position, and runout
2. Material Selection: The metal housing should be made of materials suitable for resistance welding to ensure connection reliability
3. Inspection standards: Establish acceptance criteria based on maximum values rather than minimum requirements
Transition implementation strategy
For products that have adopted the 2001 version of the standard, it is recommended:
1. Complete design updates before the end of the transition period on May 20, 2018
2. Gradually adjust dimensional parameters such as LP1 and B1 to the requirements of the new standard
3. Update the design document system and adopt new annotation and view specifications
Technology evolution trend analysis
DIN EN 61837-3:2016-04 reflects multiple development trends in surface mount piezoelectric device technology:
Improved standardization: The unified appearance annotation system and dimensional specifications improve the interchangeability of products from different manufacturers.
Manufacturing precision requirements: Stricter dimensional tolerances and view requirements reflect the need for component consistency in high-density electronic assembly.
Improved user-friendliness: The use of maximum value markings and more complete drawing information lowers the application threshold and selection difficulty.
This standard, together with related standards such as IEC 60122-3, IEC 60191-6, and the IEC 60368 series, constitutes a complete frequency control device standard system, providing a reliable technical foundation for high-precision electronic systems such as 5G communications and IoT devices.