Sockets - Altera Corporation

Altera Corporation 1

Selecting Sockets

for Altera Devices

January 1999, ver. 3 Application Note 80

A-AN-080-03

Introduction

Surface-mount assembly places unique demands on the development and

manufacturing process by requiring different CAD symbols for printed

circuit board (PCB) layout, different soldering processes for production

(reflow vs. wave solder), and different test and reliability issues.

Socketing surface-mount devices allows you to ease some of the demands

of surface-mount assembly. Conventional mounting techniques can be

used on socketed devices, either by through-hole soldering them to a PCB

or by mounting them onto a socketed carrier board for wire-wrap

applications.

This application note discusses the following topics:

■

Mechanical considerations for J-lead sockets

■

Socket evaluation for J-lead packages

■

Socket evaluation for quad flat pack (QFP) packages

■

Socket evaluation for ball-grid array (BGA) packages (including

FineLine BGA

™

packages)

■

Socket evaluation for pin-grid array (PGA) packages

■

Packaging operations for wire-wrap applications

■

Socket and insertion/extraction tool manufacturers

Mechanical

Considerations

for J-Lead

Sockets

J-lead devices make contact with electrical sockets from either the bottom

or the side of the leads. Depending on how the devices are held in place,

the sockets can bend the leads and make the electrical contact unreliable.

Accordingly, you must consider the type of package, the number of

device insertions and removals, and the amount of lead deformation

before choosing a socket.

Once a design enters the production phase, cost becomes a major concern.

As a result, low-cost production sockets, designed to hold a device

permanently and securely, are available. However, these sockets must

exert a reasonable force on the device leads to prevent the device from

popping out of the socket. After several insertions, this force can deform

the leads, causing them to short out or fail to make contact and rendering

the device unusable. Therefore, Altera strongly recommends using a

burn-in socket during the design and development phases of a project,

and a low-cost production socket during the production phase.

Burn-in sockets are zero-insertion-force (ZIF) sockets that do not

deform a device’s leads.

2 Altera Corporation

AN 80: Selecting Sockets for Altera Devices

Production sockets must be chosen carefully. If a device must be removed

more than 10 times, Altera recommends using non-deforming, low-

insertion-force (burn-in) sockets. In high-stress environments (e.g., strong

G-forces, thermal shock, and high humidity), sockets with high-insertion

forces and optional retention clips are needed. To reduce the possibility of

damaging device pins, most high-quality sockets include a standoff

mechanism that prevents a device from being forced too far into a socket.

Socket

Evaluation for

J-Lead

Packages

Altera tested available production sockets for use with 44-, 68-, and 84-pin

windowed ceramic J-lead chip carrier (JLCC) packages. Although tests

were performed using JLCC packages, the following information also

applies to plastic J-lead chip carrier (PLCC) packages. Each socket was

subjected to three tests:

■

The change in the gap between the corner pins of each device was

measured before and after each of 10 insertions.

■

Each pin of the socket was wired in series and tested for open circuits

lasting longer than 10 µs. This open circuit test was performed while

the socket was attached to a vibration block. The amplitude of

vibration was 3.0 mm peak-to-peak at a frequency that oscillated

between 10 Hz and 55 Hz in 1-minute cycles for 2 hours. The

vibration test was performed on all three axes at a temperature of

70° C.

■

The actual point of contact between the socket pin and the device lead

was photographed to determine the direction of the forces and the

amount of surface contact between them.

Altera Corporation 3

AN 80: Selecting Sockets for Altera Devices

Altera tested sockets from eight manufacturers. Tables 1 through 3 show

the results of the 44-, 68-, and 84-pin production sockets that passed the

open-and-short circuit test. Sockets are ranked by their ability to maintain

the device’s pin integrity after multiple device insertions.

Table 1. Summary of 44-Pin Production Socket Analysis

Vendor & Part Number Comments

Thomas & Betts Corporation

PCS-044A-1 Least pin deformation. Contact force has a downward component. No retainer

clip option.

AMP, Inc.

821575-1 Moderate pin deformation. Contact force has a downward component. No

retainer clip option.

Table 2. Summary of 68-Pin Production Socket Analysis

Vendor & Part Number Comments

Thomas & Betts Corporation

PCS-068A-1 Least pin deformation. Contact force has a downward component. No retainer

clip option.

ITT/Cannon Corporation

LCS-68-12 Low pin deformation. Contact force has a downward component. Has a retainer

clip option.

AMP, Inc.

821574-1 Moderate pin deformation. Contact force has a downward component. No

retainer clip option.

Table 3. Summary of 84-Pin Production Socket Analysis

Vendor & Part Number Comments

Thomas & Betts Corporation

PCS-084A-1 Least pin deformation. Contact force has a downward component. No retainer

clip option.

ITT/Cannon Corporation

LCS-84-12 Moderate pin deformation. Contact force has a downward component. Has a

retainer clip option.

AMP, Inc.

822281-1

(for surface mount)

Moderate pin deformation. Contact force has a downward component. No

retainer clip option. Designed for plastic packages.

AMP, Inc.

821573-1 Large pin deformation. Very tight fit. No retainer clip option. Due to pin

deformation, Altera recommends a maximum of three insertions. Designed for

ceramic packages.

FCI

QILE-84P-410T Large pin deformation. Very tight fit. No retainer clip option. Due to pin

deformation, Altera recommends a maximum of three insertions.

4 Altera Corporation

AN 80: Selecting Sockets for Altera Devices

Vendors may provide additional information about their products, such

as material selection, prevention of solder ingress during wave soldering,

or lead shape. Altera recommends qualifying sockets before committing

to a particular vendor.

Table 4 shows the contact distances for Altera

packages. These

measurements should be used to select a socket, preferably with internal

stand-offs, for use with Altera devices.

Socket

Evaluation for

QFP Packages

Because QFP packages are more susceptible to lead deformation,

production sockets must be rigorously qualified. Altera recommends

using a burn-in socket for QFP packages because of the socket’s reliability.

While sockets should always be qualified, Table 5 suggests sockets based

on the number of pins and type of QFP package.

Table 4. Device Contact Distances

Package Pins Contact Distance (Minimum mils) Contact Distance (Maximum mils)

PLCC 20 385 395

PLCC, JLCC 28 485 495

PLCC, JLCC 44 685 695

PLCC, JLCC 68 985 995

PLCC, JLCC 84 1,185 1,195

Table 5. Socket Vendor Information for QFP Packages

Package Type Number of Pins Socket Vendor Part Number

Thin quad flat pack (TQFP) 32 Yamaichi IC51-0324-1498

Plastic quad flat pack (PQFP) 44 Yamaichi IC51-467-KS11258

TQFP 44 Yamaichi IC51-0444-1568

PQFP 100 Yamaichi IC51-1004-814-2

Ceramic quad flat pack (CQFP) 100 Yamaichi IC51-1004-814-2

TQFP 100 Yamaichi IC51-1004-809

PQFP 132 Yamaichi IC51-1324-828

TQFP 144 Yamaichi IC51-1444-1354-7

PQFP 160 Yamaichi IC51-1604-845-4

PQFP 208 Yamaichi IC51-2084-1052-11

Power quad flat pack (RQFP) (square heat sink) 208 Yamaichi IC51-2084-1052-11

RQFP (round heat sink) 208 Yamaichi IC51-1052KS-13087

CQFP 208 Yamaichi IC51-1509-KS14057

RQFP (square heat sink) 240 Yamaichi IC51-1655KS-13666

RQFP (round heat sink) 240 Yamaichi IC51-2404-1655-2

RQFP 304 Yamaichi IC51-3044-1471-2

Contact Distance

 
Altera Corporation  5
AN 80: Selecting Sockets for Altera Devices
 
Socket 
Evaluation for 
BGA Packages
 
Table 6 lists socket vendor information for Altera BGA and 
FineLine BGA packages.
 
Note:
 
(1) These socket recommendations may change due to package enhancements. Please contact Altera Applications for 
more information.
 
Socket 
Evaluation for 
PGA Packages
 
Table 7 lists socket vendor information for PGA packages.
 
Table 6. Socket Vendor Information for BGA Packages
 
Package Type Ball Pitch (mm) Number of Pins Socket Vendor Part Number
 
BGA 1.50 225 Enplas BGA-225-1.5-01A
1.27 256 Yamaichi NP276-37206-AC03327
CTi 8227-256-1-00
356 CTi 8235-356-1-00
CTi 8235-356-0-00
600 Yamaichi NP276-100522-AC09796
FineLine BGA 1.00 100 Loranger 110SQ-100B6617 
 
(1)
 
256 Loranger 170SQ-256B6618C 
 
(1)
 
484 Loranger 230SQ-484B6617 
 
(1)
 
672 Loranger 270SQ-672B6617 
 
(1)
 
Table 7. Socket Vendor Information for PGA Packages
 
Number of 
Pins
Socket Vendor Part Number
 
403 Yamaichi 
 
(1)
 
NP178-64401-KS14828
AMP 
 
(1)
 
1-382320-7
Berg Electronics
 
(2)
 
Mill-Max
 
(2)
 
503 AMP 
 
(1)
 
, 
 
(3)
 
382876-6
Yamaichi 
 
(1)
 
NP236-102002-AC01601
3M/Textool 
 
(1)
 
2-0503-01357-050-019-002
Berg Electronics
 
(2)
 
Mill-Max
 
(2)
 
599 Yamaichi NP236-102002-AC05625
Berg Electronics
 
(2)
 
Mill-Max
 
(2)
 

6 Altera Corporation

AN 80: Selecting Sockets for Altera Devices

Notes:

(1) ZIF sockets are available for 403- and 503-pin PGA packages.

(2) This low-profile PCB socket has no standard part number. Contact the vendor for

more information.

(3) Although the socket was created for 560-pin PGA packages, it is compatible with

503-pin packages.

Table 8 lists socket tools for inserting and extracting PGA packages in

non-ZIF sockets.

Packaging

Operations for

Wire-Wrap

Applications

Wire-wrap applications require a through-hole mount that is compatible

with the J-lead package. The sockets specified do not typically conform

mechanically to most wire-wrap panels. Wire-wrap cards have machined

receptacles in rows with 100-mil spacing between receptacles and 300-mil

spacing between rows. Carrier boards provide an effective way to bridge

the gap. Mounting a socket to a carrier board provides the convenience of

wire wrap, while occupying a relatively small area on a device. Some

carrier boards have signal routing with shorter paths or 45° bends to

minimize signal reflection.

Socket &

Insertion/

Extraction Tool

Manufacturers

Table 9 shows telephone numbers for various socket manufacturers.

Contact the appropriate manufacturer for additional information.

Table 8. Socket Tools for PGA Package Insertion & Extraction in Non-ZIF

Sockets

Action Tool Vendor Part Number

Insertion Com-Kyl 181-MIC

Extraction Com-Kyl 281-MIC

Table 9. Socket & Insertion/Extraction Tool Manufacturers (Part 1 of 2)

Product Company Telephone

Number

Production

sockets 3M/Textool Corporation

AMP, Inc.

Thomas & Betts Corporation

Framatome Connectors International (FCI)

ITT/Cannon Corporation

Berg Electronics

Mill-Max

IronWood Electronics

(800) 328-0411

(800) 522-6752

(508) 699-9800

(408) 946-9666

(714) 557-4700

(510) 651-2700

(516) 922-6000

(612) 452-8100

Altera Corporation 7

AN 80: Selecting Sockets for Altera Devices

Conclusion

Information in this application note is based on tests performed by Altera

and on information provided to Altera by various vendors. Altera

assumes no liability for the use of third-party products mentioned in this

document.

Test and

burn-in

sockets

3M/Textool Corporation

AMP, Inc.

Advanced Interconnections Corporation

Dai-Ichi Seiko Company, Ltd. (Japan)

Emulation Technology, Inc.

Yamaichi

Enplas

IronWood Electronics

(800) 328-0411

(800) 522-6752

(401) 823-5200

(81) 0482-53-3131

(408) 982-0660

(408) 456-0797

(408) 749-8124

(612) 452-8100

Carrier

boards and

wire-wrap

adapters

Advanced Interconnections Corporation

Emulation Technology, Inc. (401) 823-5200

(408) 982-0660

PGA socket

insertion/

extraction

tools

Com-Kyl (408) 734-9660

Table 9. Socket & Insertion/Extraction Tool Manufacturers (Part 2 of 2)

Product Company Telephone

Number

Altera and FineLine BGA are trademarks and/or service marks of Altera Corporation in the United States and

other countries. Altera acknowledges the trademarks of other organizations for their respective products or

services mentioned in this document. Altera products are protected under numerous U.S. and foreign patents

and pending applications, maskwork rights, and copyrights. Altera warrants performance of its

semiconductor products to current specifications in accordance with Altera’s standard warranty, but reserves

the right to make changes to any products and services at any time without notice. Altera assumes no

responsibility or liability arising out of the application or use of any information, product, or

service described herein except as expressly agreed to in writing by Altera Corporation.

Altera customers are advised to obtain the latest version of device specifications before

relying on any published information and before placing orders for products or services.

101 Innovation Drive

San Jose, CA 95134

(408) 544-7000

http://www.altera.com

Applications Hotline:

(800) 800-EPLD

Customer Marketing:

(408) 544-7104

Literature Services:

(888) 3-ALTERA

lit_req@altera.com

AN 80: Selecting Sockets for Altera Devices

8 Altera Corporation

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