Application
Specification
PRE:
APP:
114-1114
See Yun Jaan
Leong See Fan
DCR No.
15 Jul 08
Rev C
D20080715001838_438039
SO(Small Outline) DIMM (Dual-In Memory Module) Sockets,
144 Positions with 0.8mm Centerline Spacing
All numerical values are in metric units. Dimensions are in millimeters. Unless otherwise
specified, dimensions have a tolerance of ±0.13 and angles have a tolerance of ±1°. Figures
and illustrations are for identification only and are not drawn to scale.
1.
INTRODUCTION
This specification covers the requirements for application of AMP SO (Small Outline) DIMM (Dual
In-Line Memory Module) 144-position sockets with 0.8 centerline spacing onto PC (printed circuit)
boards.
These surface mount sockets are available in either SDRAM (Synchronous Dynamic Random
Access Memory) or SGRAM (Synchronous Graphics Random Access Memory) configurations
designed for 3.3V systems.
The SDRAM sockets are available with 2.1 (low profile), 3.3 (standard), or 3.7 (high profile) card
slot height.
The SGRAM sockets are available with 3.7 (high profile) or 8.0 (ultra-high profile) card slot height.
The sockets may be placed on the PC board by hand or by automatic application tooling (typically
vacuum pick and place). The sockets are supplied in soft tray form for manual placement, hard tray
form for automatic machine placement, and tape-and-reel form for high-speed automatic machine
placement.
When corresponding with TE personnel, use the terminology provided in this specification to
facilitate your inquiries for information. Basic terms and features of these connectors are provided in
Figure 1.
Figure 1
©2008 Tyco Electronics Corporation,
Singapore
All International Rights Reserved
* Trademark
| Indicates change
1 of 9
AMP-QA-182 REV. C
LOC DY
114-1114
2.
2.1.
REFERENCE MATERIAL
Customer Assistance
Product Part Number 390112 and Product Code 4320 are representative of AMP SO DIMM 144-
position sockets. Use of these numbers will identify the product line and expedite your inquiries
through a TE service network established to help you obtain product and tooling information.
2.2.
Drawings
TE Customer Drawings for product part numbers are available from the service network. The
information contained in Customer Drawings and this specification takes priority over any other
document available through TE.
2.3.
Instructional Material
TE instruction sheets (408-series) contain detailed assembly instructions for tooling. Documents
available which pertain to this product are:
408-6927 Design Recommendations for PC Board Support Fixture
2.4.
Specifications
TE Product Specification 108-1739 provides product performance and test information.
2.5.
Bulletins
TE Corporate Bulletin 402-40 is available upon request and can be used as a guide to soldering.
This bulletin provides information on various flux types and characteristics with the commercial
designation and flux removal procedures. A checklist is attached to the bulletin as a guide for
information on soldering problems.
3.
3.1.
REQUIREMENTS
Material
The socket housing is made of high temperature plastic. The contact is made of phosphor bronze
plated with gold over nickel, and the solder tine is plated with gold over nickel.
3.2.
Storage
The sockets should remain in the shipping containers until ready for use to prevent deformation to
the contact solder tines or damage to the housings. The sockets should be used on a first in, first
out basis to avoid storage contamination that could adversely affect signal transmissions.
3.3.
Chemical Exposure
Do not store sockets near any chemical listed below as they may cause stress corrosion cracking in
the contact solder tines.
Alkalies
Amines
Ammonia
Carbonates
Citrates
Nitrites
Phosphates Citrates
Sulphur Nitrites
Sulphur Compounds
Tartrates
3.4.
PC Board
A.
Material and Thickness
Board material typically is glass epoxy (FR-4, G-10, or equivalent). Board thickness is
recommended to be a minimum of 1.57.
Rev C
2 of 9
114-1114
B.
Recommended Layout
Recommended solder circuit pad pattern and pad dimensions, as well as tolerances, are
shown in Figure 2.
The alignment post holes on the pc board require precise drilling dimensions and the location
of the circuit pads to these holes is critical. In addition to the circuit pads required for each
contact solder tine
(144
places), there must be a circuit pad for each latch solder foot. See
Figure
2.
Rev C
3 of 9
114-1114
3.5.
Solder Paste Characteristics
A1. SnPb alloy composition type shall be 63 Sn/37 Pb, 60 Sn/40 Pb, or 62 Sn/36 Pb/2 Ag.
A2. Pb-free solder alloy composition type shall be Sn95.5Ag3.9Cu0.6, allowing variation of the Ag
content between 3.0-4.0 wt% and Cu content between 0.5-1.0 wt% with the balance being Sn.
B.
C.
Flux incorporated in the paste shall be rosin, mildly active (RMA) type.
Paste will be at least 80% solids by volume.
3.6.
Solder Volume
Minimum solder volume (V) before curing for each circuit pad is calculated by multiplying the pad
length (a) by the pad width (b) by the stencil thickness (Tp):
V= 0.15 mm
3
a = aperture dimension corresponding to pad width
b = aperture dimension corresponding to pad length
Tp = stencil thickness
The stencil aperture is determined by the circuit pad size and stencil thickness. It may be any shape
as long as it prevents solder bridging from one pad to another. Generally, the thinner stencil will
need a larger aperture to maintain the given volume of solder paste.
All traces must be covered by solder mask in the solder deposit area. Exposed traces could
cause bridging and create a short, or wick solder away from the solder tines, producing a weak
solder joint.
3.7.
Solder Mask
Solder mask is recommended between all pads. If a trace is run between adjacent pads on the
solder side of the pc board, a solder mask MUST be applied over the trace to prevent bridging and
wicking of solder away from the contact solder tines. Additionally, there should be solder mask
covering any traces in the area of the latch solder foot deposit. Liquid photo image-able or dry film
solder masks are recommended.
3.8.
Polarization
The sockets are polarized to the pc board by alignment post diameter differences. The post
diameter of the SDRAM and SGRAM sockets are opposite one another, preventing the placement
of the wrong socket onto the pc board.
The module is polarized to the socket by a keying feature (notch) and the corresponding voltage
key in the socket. This prevents the module from being oriented incorrectly in the socket.
Rev C
4 of 9
114-1114
3.9.
Socket Placement
A.
Registration
The socket alignment posts must be placed over their intended pc board holes, and placed so
that the socket is parallel with the pc board, then gently pressed downward on the socket
housing and over each latch solder foot simultaneously.
When handling the sockets, pick them up by the housing only.
B.
Seating Forces
Because the socket alignment posts are for polarization only (clearance and fit), the force
required to seat the socket is minimal. Apply only that force necessary to seat the contact
solder tines and each latch solder foot into the top surface of the solder paste.
C.
Coplanarity
Optimally, the socket contact solder tines should be centered on the pc board circuit pads, as
well as each solder latch foot should be centered on its solder pad. However, slight
misalignment is permissible as shown in Figure 3.
Figure 3
3.10.
Soldering
A.
Process
The socket is compatible with both infrared reflow and forced convection soldering processes.
Information on soldering and soldering variables can be found in Corporate Bulletin 402-40.
Due to the many variables involved with reflow processes (component density, location,
orientation, etc.), it is recommended that the user conduct trial runs under actual
manufacturing conditions to ensure product/process compatibility.
B.
Temperature and Time
The reflow temperature to which the socket housing is subjected shall not exceed 260°C for 40
seconds.
As reflow time increases, the housing may become yellow, but the quality of the product will
not be affected. Excessive temperatures may cause housing degradation.
Rev C
5 of 9
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
