VICOR Maxi DC Converter User Guide
- June 12, 2024
- VICOR
Table of Contents
Maxi DC Converter
Product Information
The Surface-Mount Socketing System (SurfMate) is a connector
system designed for use with pin-compatible Maxi, Mini, and Micro
Family DC-DC Converters and Configurable Power Supplies. It allows
circuit-board designers and assemblers to surface mount
high-density DC-DC converters with current ratings up to 50A.
The SurfMate system consists of a pair of surface-mounted
headers that contain sockets to accept the input and output pins of
the module. It is compatible with any thickness PCB and does not
increase the module mounting height above the board. The SurfMate
system is available for all three standard module sizes: Maxi,
Mini, and Micro (full, half, and quarter bricks).
This unique interconnect scheme combines the flexibility of
component power designs with the manufacturing efficiency of
surface-mount assembly.
Printed Circuit Board Design and Solder Guidelines
Recommended PCB layout drawings for SurfMates are provided on
the Vicor website. All unspecified PCB dimensional tolerances
comply with ANSI/IPC-D-300 for Class B boards. DXF versions of the
PCB outlines are available in the Accessories section of the Vicor
website.
Recommended PCB Construction: The SurfMate system is capable of
very high current-carrying capacity. It is recommended to use a
multilayer PCB with three-ounce copper and internal power and
ground planes. Consult the drawings for the recommended size and
quantity of via holes for carrying current to the internal
planes.
The smaller solder mask keep-out areas are circular and are
located on each pad, for the solder joint between the PCB and the
SurfMate. The remainder of the pad has a covering of solder mask.
The solder paste is dispensed in a rectangular area covering the
soldering area and part of the solder mask area. During soldering,
the paste will migrate away from the solder mask area to the
soldering area, providing ample volume for quality solder
joints.
Each pad features a non-plated through hole in the center to
provide a venting function. It is normal for the solder joint to
have a slight void centered on this through hole.
Solder Paste: Solder paste thickness requirements will vary
depending on whether the board pads are flush or elevated from the
laminate.
Flush-Mounted Pads: For boards with flush-mounted pads, a
minimum of 0.010in [0.254mm] solder paste should be used. The
preferred thickness is between 0.012in [0.305mm] and 0.016in
[0.406mm].
Placement: SurfMate locating pins will engage in the
corresponding PCB holes with a light push of the SurfMate into the
solder paste. The SurfMate should not be taped or adhered in place.
The surface tension of the solder during reflow will center the
SurfMate parts on the PCB, resulting in accurate positioning.
Standoffs: Mounting standoffs are required for SurfMate
applications. The location for standoff holes is shown on the PCB
layout. A selection chart of recommended standoff kits is provided
in this section.
15. Surface-Mount Socketing System (SurfMate)
Design Guide & Applications Manual
Maxi, Mini, Micro Family DC-DC Converters and Configurable Power Supplies
SurfMate is a surface-mount connector system for use with pin-compatible Maxi,
Mini, Micro Family converters and input / front-end modules. For the first
time, circuit-board designers and assemblers have the ability to surface mount
high-density DC-DC converters having current ratings up to 50A. (Table 15.1)
SurfMate utilizes a pair of surface-mounted headers that contain sockets to
accept the input and output pins of the module. (Table 15.2) The SurfMate
header assembly is compatible with any thickness PC board, does not increase
the module mounting height above the board, and is available for all three
standard module size: Maxi, Mini and Micro (full, half and quarter bricks).
SurfMates are available packaged in standard recyclable JEDEC-style trays for
use with automated pick-and-place equipment and are compatible with standard
reflow solder operations. After reflow, the modules are simply inserted into
the SurfMates. Any secondary soldering operation used for through-hole sockets
or pins can now be entirely eliminated reducing manufacturing time and
eliminating dual processes.
This unique interconnect scheme combines the inherent flexibility of component
power designs with the manufacturing efficiency of surface-mount assembly.
Printed Circuit Board Design and Solder Guidelines for the SurfMate Socketing
System
Recommended PCB layout drawings for SurfMates are provided on the Vicor
website. All unspecified PCB dimensional tolerances comply with ANSI/IPC-D-300
for Class “B” boards. DXF versions of the PCB outlines are available in the
Accesorries section of the Vicor website.
Recommended PCB Construction: The SurfMate system is capable of very high
current-carrying capacity. We therefore recommend a multilayer PCB with three-
ounce copper and internal power and ground planes. Consult the drawings for
the recommended size and quantity of via holes for carrying current to the
internal planes.
Solder Mask and Pad: Two solder mask keep-out areas are recommended. The
larger area encompasses the complete pad area at either end. It ensures the
proper height of the three-ounce solder pads to the surrounding laminate. This
provides for the optimum gap between the SurfMate and the PCB 0.0042in
±0.0004in [0,106mm ±0,010mm], minimizing the solder paste thickness required
for quality solder joints. Without this solder mask keep-out area, the gap may
widen, (see “Flush-Mounted Pads”), requiring thicker solder paste to fill the
larger gap.
The smaller solder mask keep-out areas are circular and are located on each
pad, for the solder joint between the PCB and the SurfMate. The remainder of
the pad has a covering of solder mask. The solder paste is dispensed in a
rectangular area covering the soldering area and part of the solder mask area.
During soldering, the paste will migrate away from the solder mask area to the
soldering area, providing ample volume for quality solder joints.
Each pad features a non-plated through hole in the center of the pad to
provide a venting function. It is normal for the solder joint to have a slight
void centered on this through hole.
Solder Paste: Solder paste thickness requirements will vary depending on
whether the board pads are flush or elevated from the laminate.
Elevated Pads (preferred): The ideal height for elevated pads is 0.0042in [
0,106 mm] ±10%. This can be achieved by using a three-ounce copper surface
layer. With this height, a minimum solder paste thickness of 0.006in should be
used. Thicker stencils of between 0.008in [0,203mm] and 0.012in [0,305mm] are
preferred.
Flush-Mounted Pads: For boards with flush-mounted pads a minimum of 0.010in
[0,254mm] solder paste should be used. Preferred thickness is between 0.012in
[0,305mm] and 0.016in [0,406mm].
Placement: SurfMate locating pins will engage in the corresponding PCB holes
with a light push of the SurfMate into the solder paste. The SurfMate should
not be taped or adhered in place. The surface tension of the solder during
reflow will center the SurfMate parts on the PCB, resulting in accurate
positioning.
Equipment and Solder: Soldering of SurfMates should be done using either an
infrared or convection oven reflow process. Solder type Sn63Pb37, or
equivalent, with a eutectic temperature of 361°F [183°C] should be used.
Higher temperature solder is not recommended.
Standoffs: Mounting standoffs are required for SurfMate applications. The
location for standoff holes is shown on the PCB layout. A selection chart of
recommended standoff kits is provided in this section.
Module Pins: SurfMates must be used with modules with the “S” or “F” pin
style.
Module Insertion / Extraction: Sockets and modules are rated for up to five
insertions and extractions before requiring replacement. When installing a
module, lightly place it into position so that all pins are properly aligned
over each socket. Then apply even pressure by uniformly tightening each of the
mounting screws through the mounting slots on the baseplate into the pcb
mounted standoffs. For module removal, Vicor highly recommends the use of our
Module Exchange Tool in order to ensure that the sockets are not damaged
during the module removal process. Removing the module at an angle should be
avoided as this can damage the sockets.
Maxi, Mini, Micro Design Guide Page 73 of 87
Downloaded from Arrow.com.
Rev 5.7 05/2023
15. Surface-Mount Socketing System (SurfMate)
Design Guide & Applications Manual
Maxi, Mini, Micro Family DC-DC Converters and Configurable Power Supplies
Board Thickness
All
Mounting Style
Surface Mount
SurfMate: Surface-Mount Sockets
Full Brick (Maxi)
Half Brick (Mini)
Input Output
Five Sets
Input Output
Five Sets
22100 22101 16017 22100 22102 16021
Quarter Brick (Micro)
Input Output
Five Sets
22103 22104 16025
Pin Style
S, F
Parameter Compatibility
Module Pin Style
Mechanical Contact Normal Force Number of Mating Cycles Module Engagement
Force Module Disengagement Force Electrical
Current Rating
Low-Level Contact Resistance 0.080in [2,03mm] dia socket (LLCR) Low-Level
Contact Resistance 0.150in [3,81mm] dia socket (LLCR) Low-Level Contact
Resistance 0.180in [4,57mm] dia sockets (LLCR) Thermal Max Socket Temperature
Temperature Rise Environmental
Shock and Vibration
Specification Value
F S
100g EOL min 5 max [d] 32lbs per connector set max 32lbs per connector set max
50A Maxi [a], Mini; 25A Micro (Based on 248°F [120°C] max socket temp & 86°F
[30°C] max temperature rise of contact)
400 max
300 max
200 max
Reference
Short RoHS pins Short ModuMate pins
GR-1217-CORE, R5-23 Exception to GR-1217-CORE which specifies 25 mating cycle
GR-1217-CORE, R5-31,32 GR-1217-CORE, R5-31,32
Gold plating standards and accepted industry standards such as IICIT, EIA,
Bellcore guidelines GR-1217-CORE, 6.2.1
GR-1217-CORE, 6.2.1
GR-1217-CORE, 6.2.1
248°F [120°C] max 86°F [30°C] max
Max continuous-use temperature for gold plating
GR-1217-CORE [b] EIA-364-70A [c]
SurfMate products are tested in random vibration environments to best simulate the broad spectrum of frequencies and amplitudes that may be encountered in typical applications. Actual system resonant frequencies will depend on PCB construction and mounting details. For critical or unusual shock and vibration environments, the performance of the system should be independently verified.
Table 15.1 — SurfMate specifications and materials
[a] For 80A operation with Maxi, contact Applications Engineering. [b]
GR-1217-CORE issue 1, November 1995 Generic requirements for separable
electrical connectors used in telecommunications hardware.
A module of NEBSFR, FR-2063 [c] ANSI/EIA-364 American National Standards
Institute / Electronic Industries Association (Electronic Components,
Assemblies & Materials Association) [d] The module and socket must be replaced
after five mating cycles.
Maxi, Mini, Micro Design Guide Page 74 of 87
Downloaded from Arrow.com.
Rev 5.7 05/2023
15. Surface-Mount Socketing System (SurfMate)
Design Guide & Applications Manual
Maxi, Mini, Micro Family DC-DC Converters and Configurable Power Supplies
Materials Headers Material: Vectra E150i LCP Flammability Thermal Stability (short term) Thermal Stability (long term)
Ratings
Liquid Crystal Polymer UL94 V-0/5VA 500°F [260°C] 392°F [200°C]
Solder Cap Material
Plating
260 cartridge brass (70Cu, 30Zn)
100in min Cu, followed by 50 100in min low stress sulfamate-based
electrolytic nickel, followed by 20in min soft gold
Sockets Material
Plating
Brush Wellman Alloy #25 C17200 deep draw quality or equiv. 0.010in thick
Woods nickel strike followed by 50in min low stress sulfamate-based
electrolytic nickel, followed by 20in min hard gold, followed by 10in min soft
gold
Table 15.2 — SurfMate specifications and materials
SurfMates
Figure 15.1 — SurfMates; five-pair sets
Package Five-Pair Sets
Maxi 16017
Mini 16021
Individual Part Numbers Input
22100
22100
Output
22101
22102
Table 15.2 — SurfMate specifications and materials
Figure 15.2 — SurfMates; individual part numbers
Micro 16025
22103 22104
Notes Inputs and outputs for five modules
Sold only in multiples of 35 Maxi, Mini or 40 Micro Shipped in JEDEC trays
Maxi, Mini, Micro Design Guide Page 75 of 87
Downloaded from Arrow.com.
Rev 5.7 05/2023
15. Surface-Mount Socketing System (SurfMate)
Design Guide & Applications Manual
Maxi, Mini, Micro Family DC-DC Converters and Configurable Power Supplies
Module Exchange Tool
Used in facilitating the proper extraction of modules from InMate or SurfMate sockets. Removal without using the Exchange Tool may cause damage to the sockets.
Description Maxi Exchange Tool Mini Exchange Tool Micro Exchange Tool
Part Number 22827 22828 22829
22827
22829
22828
Standoff Kits for SurfMate Mounted Modules
Figure 15.3 — Slotted baseplate; height above board with standoff
Figure 15.4 — Through-hole or threaded baseplate; height above board with standoff
Heat Sinks
Module Kit #
100 Piece Kit
Slotted Baseplate
Through Hole
20178
20188
Threaded
20179
20189
Through-Hole Baseplate
Through Hole
20176
20186
Threaded
20177
20187
No Heat Sink
20184
20186
Threaded Baseplate
Through Hole
20176
20186
Threaded
N/A
N/A
No Heat Sink
20184
20186
Table 15.4 — Standoff kits for SurfMate mounted modules: part numbering and packaging; module kits contain enough standoffs and screws for one module. 100 piece kits contain standoffs only.
Standoff Kits for SurfMate-Mounted Modules
Board Thickness
Mounting Options
Slotted Baseplate
Through-Hole Baseplate
Nominal [Min / Max] All
Mounting Style
Surface Mount
Through-Hole Heat Sink
Kit-20178
Bag-20188
Threaded Heat Sink
Kit-20179
Bag-20189
Through-Hole Heat Sink
Kit-20176
Bag-20186
Threaded Heat Sink
Kit-20177
Bag-20187
Kits include six (6) standoffs and screws. Mini and Micro modules require a minimum of four (4) standoffs. Bags of one hundred (100) do not include screws; #4-40 thread hardware required.
Threaded Baseplate
Through-Hole Heat Sink
Kit-20176
Bag-20186
Maxi, Mini, Micro Design Guide Page 76 of 87
Downloaded from Arrow.com.
Rev 5.7 05/2023