LGA Mounting Manual - Renesas Electronics
Contents
1. Published by Renesas Electronics Corporation LENESAS SALES OFFICES Renesas Electronics Corporation Refer to http www renesas com for the latest and detailed information Renesas Electronics America Inc 2801 Scott Boulevard Santa Clara CA 95050 2549 U S A Tel 1 408 588 6000 Fax 1 408 588 6130 Renesas Electronics Canada Limited 1101 Nicholson Road Newmarket Ontario L3Y 9C3 Canada Tel 1 905 898 5441 Fax 1 905 898 3220 Renesas Electronics Europe Limited Dukes Meadow Millboard Road Bourne End Buckinghamshire SL8 5FH U K Tel 44 1628 585 100 Fax 44 1628 585 900 Renesas Electronics Europe GmbH Arcadiastrasse 10 40472 Dusseldorf Germany Tel 49 211 6503 0 Fax 49 211 6503 1327 Renesas Electronics China Co Ltd Room 1709 Quantum Plaza No 27 ZhiChunLu Haidian District Beijing 100191 P R China Tel 86 10 8235 1155 Fax 86 10 8235 7679 Renesas Electronics Shanghai Co Ltd Unit 301 Tower A Central Towers 555 Langao Road Putuo District Shanghai P R China 200333 Tel 86 21 2226 0888 Fax 86 21 2226 0999 Renesas Electronics Hong Kong Limited Unit 1601 1613 16 F Tower 2 Grand Century Place 193 Prince Edward Road West Mongkok Kowloon Hong Kong Tel 852 2265 6688 Fax 852 2886 9022 9044 Renesas Electronics Taiwan Co Ltd 13F No 363 Fu Shing North Road Taipei 10543 Taiwan Tel 886 2 8175 9600 Fax 886 2 8175 9670 Renesas Electronics Singapore Pte Ltd2. e gt e a o LI gt LI e gt LI o xi Figure 3 3 Image Recognition Result for LGA with Reinforcement Land Recognition Function 3 3 2 Placement Nozzle Although LGA package devices have a resin molding structure we still recommend using a suction collet that has a built in spring to reduce the impact load applied to devices during mounting Placement nozzle lt Spring to reduce mechanical shock during placement LGA suction ee ee Mounting board Solder paste Figure 3 4 Placement Nozzle Example The optimal placement condition must be determined following issues into consideration the push in amount which can cause solder paste squashing positional displacement and the placement positional tolerance determined according to the LGA package self alignment and other issues R50ZZ0006EJ0100 Rev 1 00 lt 2 AS Page 8 of 15 Mar 19 2014 KENES LGA Mounting Manual 3 The Mounting Process 3 3 3 Placement Positional Error Tolerances This section presents an example of results of self alignment evaluation for 0 5 mm pitch LGA packages We set the solder printing positional error and LGA placement positional error as reverse direction respectively evaluate and examine the tolerance Mounting Conditions 1 Solder paste M705 235C 32 11 Sn 3Ag 0 5Cu 2 Stencil 0 30 mm x 0 10 mm 3 Reflow condition 150 C to 180 C main heating at 250 C air reflow Solder p
3. 0 35 mm 0 25 mm 0 30 mm O Pass 0 Open Drop rod ao we a Mounting oe gt d board mD wes ot Be eb 4 Baie y um QO PJ od de Tadd aed me 4 Fp DE da e epi 4 sa EP 0 25 mm x 0 10 mmt menage Fixed span LO ry se yo Eo Impact bending test method Ea mt E ar E xib uio g ch D JEITA ED 4702B TCI ay ee Oe Go ete Apply impact z o o x E o e o Board deformation ppm 0 005 0 010 Time s Board strain waveform example 0 35 mm x 0 10 mmt Note 1 Reinforcement land solder mask 0 9 mm square x 0 10 mm thickness Figure 5 1 Impact Bending Test Inspection Result and Test Method R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 14 of 15 Mar 19 2014 LGA Mounting Manual 5 Reliability Evaluation Data 5 2 Temperature Cycle Test Results This section presents an example of temperature cycle test results for LGA package types mounted with a lead free solder paste SAC305 Sn 3Ag 0 5Cu Although single sided mounting provided superior results fully adequate temperature cycle characteristics were achieved even by double sided mounting that assumes the use of high density mounting equipment Table 5 2 Temperature Cycle Test Results Comparison Sample 1 Sample 2 Sample 3 lands We o T o Y OO CO IET EEE R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 15 of 15 Mar 19 2014 LGA Mounting Manual Publication Date Rev 1 00 Mar 19 2014
4. OC ya Y Solder printing N of RRA O V EN R away e oa ORO Z O e e O 2 02 O Oo o C a e D O V After reflow weds Figure 4 3 X Ray Inspection Examples For the 0 65 mm pitch LGA package neither opens nor shorts were found with metal mask apertures of 40 30 to 00 45 mm For the 0 5 mm pitch LGA package neither opens nor shorts were found with metal mask apertures of 00 25 to 0 35 mm R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 13 of 15 Mar 19 2014 LGA Mounting Manual 5 Reliability Evaluation Data 5 Reliability Evaluation Data 5 1 Impact Resistance This section presents the evaluation results of impact resistance for LGA which is mounted on the board The evaluation is impact bending test which is stipulated in JEITA ED 4702B and high speed deformation is applied to the board This result showed that even LGA packages without reinforcement lands are resistant to ordinary impacts 1500 ue This result also showed that LGA packages with reinforcement lands have relatively better resistance to impacts and that the use of LGA packages with reinforcement lands is preferable for equipment that requires increased impact resistance Table 5 1 Impact Bending Test Results Solder paste M705 235C 32 11 Sn 3Ag 0 5Cu Reflow conditions Preheating at 150 C to 180 C for 90 seconds main heating at 250 C Solder Mask Mounting Board Deformation Lands Present 0 25 mm 60 30 mm
5. activated fluxes and RA activated fluxes The table below lists the features of these three types Table 3 2 Flux Types and Their Characteristics Flux Type Characteristic R type ROL type Non activated fluxes Noncorrosive Non activated Rosin Rosin Low activity levels RMA type ROM type Mildly activated fluxes Noncorrosive These fluxes have better Rosin Mildly Activated Rosin Moderate activity levels solderability than the R type fluxes RA type ROH type Highly activated fluxes These fluxes have better solderability Rosin Activated Rosin High activity levels than the R and RMA type fluxes They are however strongly corrosive R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 5 of 15 Mar 19 2014 LGA Mounting Manual 3 The Mounting Process 3 Characteristics Required in the Solder Paste Printing e Solder powder size A particle size of less than 1 4 to 1 5 the thickness of the stencil is most commonly selected to assure the release characteristics in solder printing e Viscosity is too high the release characteristics of the solder can be degraded and result in thin pringing If the viscosity is too low print blotting and or print droop may occur For printing applications a viscosity of around 200 to 300 Paes 25 C is commonly used Before and After Reflow e Before reflow Solder paste should have minimal aged deterioration during manufacturing and good printability Solder paste should have minimal
6. 00 Page 4 of 15 Mar 19 2014 RENES LGA Mounting Manual 3 The Mounting Process 3 2 Solder Paste Printing 3 2 1 Solder Paste The main components of solder paste are solder powder and flux 1 Solder Powder e Solder powder contains a range of solder powder size as shown below and this range affects the printability of the solder paste e The land pitch as listed in the table below should be taken into consideration when selecting the solder powder Note that solder paste with a fine particle size has issues such as the easier formation of capillary balls and degraded wettability This means that thorough evaluation is required during materials selection Source Senju Metal Industry Co Ltd Solder powder Type 2 Type size range 0 075mm to 0 045mm 0 04 O 0 025mm to E ami tao ro IN Ki o KE Eo es Sn 3Ag 0 5Cu Solder powder Figure 3 1 Electron Microscope Images of Solder Powder in Solder Paste Table 3 1 Land Pitch and Ranges of Solder Powder Sizes in Solder Paste Land Pitch mm C a a 1 1 1 j ar 1 os oes oso oso a Oo o Oo nul Y 4 5 1 O l 4 1 a MEC ME 1 S i e 2 Flux Solder Powder Size Range e There are three main types of flux rosin based fluxes synthetic resin fluxes and water soluble fluxes e There are three types of rosin based fluxes according to their activation level R rosin fluxes RMA mildly
7. 3 The Mounting Process Recommended design values of stencil 00 25 mm to 60 35 mm Thickness 0 10 mm 0 65 mm pitch LGA within 0 12 mm Sample solder material M705 235C 32 11 or equivalent M705 solder composition Sn 3Ag 0 5Cu Precision placement positional tolerance e Placement system with recognition system Placement positional tolerances based on recognition of all lands or outline recognition 0 5 mm pitch LGA within 0 10 mm 0 65 mm pitch LGA within 0 12 mm Conditions 0 5 mm pitch placement loading up to 180 g Placement speed 39 5 mm second to 275 mm second Placement push in depth 0 to 0 5 mm 0 65 mm pitch placement loading 60 g to 250 g Placement KE 760 Juki Corporation or equivalent The same as for earlier BGA products Placement speed 39 5 mm second to 395 mm second Placement push in depth 0 to 2 0 mm The reflow thermal conditions specified in the e Reflow equipment delivery specifications document must be followed Reflow soldering conditions Air reflow or nitrogen reflow equipment the same equipment as used for earlier BGA products Notes LGA package products can be mounted with the same conditions as BGA package and they can also be mounted at the same time when QFP SOP and similar package products are mounted 1 Manufactured by Senju Metal Industry Co Ltd The LGA mounting process is described in detail in the following pages R50ZZ0006EJ0100 Rev 1
8. aged deterioration after printing it should have a long viscosity retention time and should not cause shape collapse to occur The flux and the solder powder must not separate e After reflow Solder paste should have good solderability and capillary balls must not be formed Note that no solder powder oxidation occurs and select a solder powder with a narrow particle size distribution Also select a flux whose solvents have a low boiling point and select a solder with a high molecular weight rosin and relatively low volume of flux itself Flux residues must not affect end product reliability Note The user should select the solder paste according to the application R50ZZ0006EJ0100 Rev 1 00 lt 2 AS Page 6 of 15 Mar 19 2014 KENES LGA Mounting Manual 3 The Mounting Process 3 2 2 Stencil Examples The table below lists stencil design examples for various land sizes The aperture dimensions and The thickness must be selected by taking post reflow soldering open connections and solder bridges into account Table 3 3 Stencil Design Examples Unit mm LGA land size 0 30 0 35 Mounting pad design 0 30 0 35 Stencil Aperture diameter 0 25 0 30 0 35 3 2 3 Inspection Following Solder Printing The amount of solder paste has a large effect on the connection quality In some cases only using a 2D inspection for the paste volume inspection will be inadequate for evaluating the post printing print quality We th
9. of physical injury and injury or damage caused by fire in the event of the failure of a Renesas Electronics product such as safety design for hardware and software including but not limited to redundancy fire control and malfunction prevention appropriate treatment for aging degradation or any other appropriate measures Because the evaluation of microcomputer software alone is very difficult please evaluate the safety of the final products or systems manufactured by you Please contact a Renesas Electronics sales office for details as to environmental matters such as the environmental compatibility of each Renesas Electronics product Please use Renesas Electronics products in compliance with all applicable laws and regulations that regulate the inclusion or use of controlled substances including without limitation the EU RoHS Directive Renesas Electronics assumes no liability for damages or losses occurring as a result of your noncompliance with applicable laws and regulations Renesas Electronics products and technology may not be used for or incorporated into any products or systems whose manufacture use or sale is prohibited under any applicable domestic or foreign laws or regulations You should not use Renesas Electronics products or technology described in this document for any purpose relating to military applications or use by the military including but not limited to the development of weapons of mass destruction When exporting the Renes
10. 80 Bendemeer Road Unit 06 02 Hyflux Innovation Centre Singapore 339949 Tel 65 6213 0200 Fax 65 6213 0300 Renesas Electronics Malaysia Sdn Bhd Unit 906 Block B Menara Amcorp Amcorp Trade Centre No 18 Jin Persiaran Barat 46050 Petaling Jaya Selangor Darul Ehsan Malaysia Tel 60 3 7955 9390 Fax 60 3 7955 9510 Renesas Electronics Korea Co Ltd 12F 234 Teheran ro Gangnam Ku Seoul 135 920 Korea Tel 82 2 558 3737 Fax 82 2 558 5141 http www renesas com O 2014 Renesas Electronics Corporation All rights reserved Colophon 3 0 LGA Mounting Manual LENESAS Renesas Electronics Corporation R50ZZ0006EJ0100
11. C T D a V lt Q 5 C Q LGA Mounting Manual All information contained in these materials including products and product specifications represents information on the product at the time of publication and is subject to change by Renesas Electronics Corp without notice Please review the latest information published by Renesas Electronics Corp through various means including the Renesas Electronics Corp website http www renesas com Renesas Electronics www renesas com Rev 1 00 Mar 2014 10 L E I2 Notice Descriptions of circuits software and other related information in this document are provided only to illustrate the operation of semiconductor products and application examples You are fully responsible for the incorporation of these circuits software and information in the design of your equipment Renesas Electronics assumes no responsibility for any losses incurred by you or third parties arising from the use of these circuits software or information Renesas Electronics has used reasonable care in preparing the information included in this document but Renesas Electronics does not warrant that such information is error free Renesas Electronics assumes no liability whatsoever for any damages incurred by you resulting from errors in or omissions from the information included herein Renesas Electronics does not assume any liability for infringement of patents copyrights or other intellectual
12. Dord A nd E A II E T E 2 2 1 IVA UENO AE SOUCHE ontario OE EEEE E E EEGA 2 22 Mounting Pad Design Example cccccccceccccceceecceeeeeaaeeseeeeeeeeeeeeeeeeeeeeeaeaaaeeeessseeeeeeeeeeeeeeeeeeeeeeeaaasaaaaenseeeeeeeeess 2 9a eoan O AAA E E E E IA 4 3 1 Perik orhe LGA Momint Proces S ps 4 3 2 Sala ia oa e e EE e a TTT TTT TTE 5 Ial vie sid E o E E O o E ee eT re 5 322 ci A e O Oo II E EAEE E 7 322 Inspection Following Solder Printing cc cccssssssssssseseeeeeceeeeeeeeeeeaaesseessseeeeeceeeeeeeeeeeaaaasassasseeeeeeeeeeeeeeaaaas 7 3 3 Moun ne placement AAPP 8 3 3 1 Mage RECON ai 8 2 direis MAA TTRTTTTTTETTTTTTRTTTrFTTT TE 8 3 Placement Positional Error Tolerances cs css scossssesssesncnacesadedacomanebastiassbacobascnaccbatedacomaceaaccbeneaaennuwecbsoeebebacomatens 9 de WW NCO A E o En E PTT TTTTR 10 4 1 Package Heat Resistance EENE 10 4 1 1 Storage Conditions After Opening Moisture Proof PackIN8 oooonnnnnnccnnnoncncccnnnnnnnononnnnnnnnnnnnnnnnnnnnnnnonnnnnnnnos 11 4 1 2 Darme C ONUNIONS sus sana ek oa KES E eT ert ae ka 11 4 2 BOGS T odio AA o o PS ES GEO CO E Ea EEE ERE 12 4 3 Post Reflow soldered Area Inspection srta AKKO kas va Ska dna e kova aa 13 Sy REUN Te PIA OY Osman sm nn a o e kn a a enn ro nk vabo 14 5 1 IT AC dl 51S CE enoe E E T E E E EE E E E E EE E E 14 5 2 Temperature Cycle Test Results ss sssssssssssss esesesssssnsssssssssssssseteeeeenennnesssssssssssssereeeeenn
13. Mar 19 2014 LGA Mounting Manual 4 The Reflow Process 4 3 Post Reflow Soldered Area Inspection Since the soldered section of the LGA package is the bottom surface of the package the soldering cannot be inspected by ordinary visual inspection X ray based inspection methods can therefore be effective This section presents examples of X ray inspection of soldered sections Open circuits and solder shorts that could not be seen with visual inspection can be verified with X ray inspection We recommend that the inspection results for each quality item be provided as feedback for the process management conditions such as the printing mask design printing positional error allowable range and mounting position allowable range Table 4 3 Mounting Conditions Package Type Placement Force Placement Push In Reflow Temperature LFLGA336 14x14 0 65 nej 250 C IC mm LFLGA304 13x13 0 5 9 Air Reflow Note 1 The placement force indicates the placement nozzle spring force Table 44 M ting Result able ounting Kesults Metal mask thickness 100 um Metal mask aperture 0 20 mm 0 Zon mm 0 30 mm 0 35 mm 0 40 mm 0 45 mm LFLGA336 14x14 0 65 PF A y 0 10 0 10 0 10 0 10 Notes 1 Solder open 2 Solder short LFLGA336 14x14 0 65 0 65 mm pitch LFLGA304 13x13 0 5 0 5 mm pitch Lo 0 25 mm 0 45 mm 0 20 mm 0 40 mm e D U 2 U T BG H E es 0 G ou oo ou D 0 9 0 kau SA s oo oc Aa AL OUJ EAS e en g 4 Ot
14. as Electronics products or technology described in this document you should comply with the applicable export control laws and regulations and follow the procedures required by such laws and regulations It is the responsibility of the buyer or distributor of Renesas Electronics products who distributes disposes of or otherwise places the product with a third party to notify such third party in advance of the contents and conditions set forth in this document Renesas Electronics assumes no responsibility for any losses incurred by you or third parties as a result of unauthorized use of Renesas Electronics products This document may not be reproduced or duplicated in any form in whole or in part without prior written consent of Renesas Electronics Please contact a Renesas Electronics sales office if you have any questions regarding the information contained in this document or Renesas Electronics products or if you have any other inquiries Note 1 Renesas Electronics as used in this document means Renesas Electronics Corporation and also includes its majority owned subsidiaries Note 2 Renesas Electronics product s means any product developed or manufactured by or for Renesas Electronics 2012 4 LGA Mounting Manual Table of Contents ME 6 PAC US E E l 1 1 Overview orf tbe LOA Pac SUS TTTTTTTTTTTE kh o m F l ka LOGA Package A l 1 3 PSA ea O E E E ET EA E E E E l Zo MOMEN
15. e support devices or systems surgical implantations etc or may cause serious property damages nuclear reactor control systems military equipment etc You must check the quality grade of each Renesas Electronics product before using it in a particular application You may not use any Renesas Electronics product for any application for which it is not intended Renesas Electronics shall not be in any way liable for any damages or losses incurred by you or third parties arising from the use of any Renesas Electronics product for which the product is not intended by Renesas Electronics You should use the Renesas Electronics products described in this document within the range specified by Renesas Electronics especially with respect to the maximum rating operating supply voltage range movement power voltage range heat radiation characteristics installation and other product characteristics Renesas Electronics shall have no liability for malfunctions or damages arising out of the use of Renesas Electronics products beyond such specified ranges Although Renesas Electronics endeavors to improve the quality and reliability of its products semiconductor products have specific characteristics such as the occurrence of failure at a certain rate and malfunctions under certain use conditions Further Renesas Electronics products are not subject to radiation resistance design Please be sure to implement safety measures to guard them against the possibility
16. erefore recommend the adoption of 3D inspection especially when manufacturing high reliability equipment We recommend that you consider the examples of 3D inspection equipment introduced below and examine the inspection Inspection photograph taken from oblique side equipment Inspection photograph taken from directly above Source Electronics Mounting Technology Author Takuo Kajima Anritsu Soldering evaluation Design value 2D tester OK Xx the design value the volume is amen aes below the Although the area is close to Figure 3 2 3D Inspection Unit Example R50ZZ0006EJ0100 Rev 1 00 lt 2 AS Page 7 of 15 Mar 19 2014 KENES LGA Mounting Manual 3 The Mounting Process 3 3 Mounting placement 3 3 1 Image Recognition When mounting devices using image recognition of lands mounting equipment that includes land recognition software is required The adequate recognition ability to differentiate between signal lands pins and reinforcement lands which have a different shape and size is necessary when performing land recognition of LGA packages that have reinforcement lands All holes recognition method All land recognition method Heer eS PTTTTT TTT TT TT 2 ee SSSseeseeseeeeeeeaeese oF S42646444CE POSSESSES ve ee oo Li gt LI 4 LJ a 40D III NM a a A LAK KD DD DL DAA LLA Seeee ere PCeeseseseseves PMeeeteptetrettoto LI e gt o a LI kud
17. nitial guideline The total baking time must not exceed 96 hours if devices are baked repeatedly Furthermore if the 30 RH spot on the indicator card is pink when the moisture proof packing is opened the products should be baked before mounting Note The bake time is stipulated individually for each products See the delivery specifications document for details R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 11 of 15 Mar 19 2014 LGA Mounting Manual 4 The Reflow Process 4 2 Solderability e Reflow temperature It is important to set the temperature profile which is lower than the guaranteed heat tolerance temperature for the mounted components It is also important to set the temperature at the solder joint so as to exceed the lower limit temperature which solder paste maker recommends If this temperature range is exceeded solder shorting or device reliability degradation may occur and if this temperature range is not reached end product quality may be reduced by failure to melt the solder or insufficient solder joint strength e Atmosphere We recommend solder mounting in a nitrogen N2 atmosphere which provides improved solder wettability Package heat tolerance temperature upper limit package surface O D Q 0 Lower limit of recommended temperature for the solder paste for the solder joint Time S Figure 4 22 Soldering Profile R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 12 of 15
18. nnnnniss 15 R50ZZ0006EJ0100 Rev 1 00 LENES AS Contents 1 Jan 22 2014 LGA Mounting Manual 1 The LGA Package 1 The LGA Package 1 1 Overview of the LGA Package The land grid array LGA package is a resin molding package in which the external pins have a land structure and are arranged in a matrix on the bottom surface of the package The LGA package is mounted by reflow The LGA package is widely used for microcontrollers and other semiconductor devices in consumer equipment 1 2 LGA Package Structure The figures below show the external appearance and structure of a Renesas LGA package o o o_O OO E a a o AA o ae EET RN Die attach LGA pin Figure 111 LGA Package Figure 1 2 LGA Package Cross Section 1 3 LGA Lineup The table below lists Renesas lineup of miniature thin form LGA packages Table 1 1 LGA Lineup Pin counts for different package dimensions Terminal Body Size mm di AA o o a Note Cells marked with a delta A indicate which are under planning R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 1 of 15 Mar 19 2014 LGA Mounting Manual 2 Mounting Board Design 2 Mounting Board Design 2 1 Mounting Pad Structure There are two types of mounting pad solder mask defined SMD in which the solder resist overlays the mounting pads nd non solder mask defined NSMD in which the solder resist does not overlay the pads While the NSMD structure is the most common mounting pad structure users sho
19. property rights of third parties by or arising from the use of Renesas Electronics products or technical information described in this document No license express implied or otherwise is granted hereby under any patents copyrights or other intellectual property rights of Renesas Electronics or others You should not alter modify copy or otherwise misappropriate any Renesas Electronics product whether in whole or in part Renesas Electronics assumes no responsibility for any losses incurred by you or third parties arising from such alteration modification copy or otherwise misappropriation of Renesas Electronics product Renesas Electronics products are classified according to the following two quality grades Standard and High Quality The recommended applications for each Renesas Electronics product depends on the product s quality grade as indicated below Standard Computers office equipment communications equipment test and measurement equipment audio and visual equipment home electronic appliances machine tools personal electronic equipment and industrial robots etc High Quality Transportation equipment automobiles trains ships etc traffic control systems anti disaster systems anti crime systems and safety equipment etc Renesas Electronics products are neither intended nor authorized for use in products or systems that may pose a direct threat to human life or bodily injury artificial lif
20. rinting positional error vs placement positional error tolerances LGA placement reinforcement lands none positional error 0 00 005 010 015 020 0 25 0 30 AH p a 0 00 Z 7 Self alignment region i Y 0 05 o O o ee O A e 0 10 LY Pn Top view PAD Solder paste schematic L Solder printing l positional error g u 0 15 EGI o ed e Side view Solder paste schematic Mounti g board Placement center 0 20 7 o NG CMOK 0 25 E O uu 0 o G O E V O OL 0 D O U O lt O Placement positional error tolerance 0 11 mm 0 30 Solder printing positional error mm Figure 3 5 Placement Positional Error Evaluation Figure 3 6 Placement Positional Error Evaluation Results As a result of this evaluation the 0 5 mm pitch LGA package placement positional error tolerances were found to be as follows e Solder paste printing positional error 0 10 mm e LGA package placement positional error 0 10 mm R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 9 of 15 Mar 19 2014 LGA Mounting Manual 4 The Reflow Process 4 The Reflow Process The reflow temperature profile must be determined based on the ability of the mounted devices to withstand heat and their solderability 4 1 Package Heat Resistance To prevent adsorption of moisture after the moisture proof packing has been opened within the limits of the s
21. structure is used for the reinforcement pads and an NSMD structure is used for all other pads While the reinforcement lands on the package have a complex shape the form of the reinforcement pads on the mounting board is simplified Also the aperture size of the metal mask used for solder printing for the reinforcement pads is set to be roughly 80 of the SR aperture area If an excessive amount of solder is applied to the reinforcement pad areas a phenomenon in which the package floats up can occur during reflow soldering due to the influence of the melted solder This can result in insufficient solder connections to the signal pins Unit mm SR aperture Pad Printing mask size 0 28 to 60 3 gt Line 1 C section Pad diameter 0 05 to 0 1 _ Mounting pad for the C section D section E section Line 2 Line 3 0 745 Package TopView Line 2 Pad Line 1 ia Line 1 SR aperture SR aperture Se Pad for the E section Printing mask size Line 3 About 80 of the SR f aperture area Printing Mounting pad for the D section mask thickness 100 um Figure 2 2 Design Example for 0 5 mm pitch 5x5 64 Pin FLGA R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 3 of 15 Mar 19 2014 LGA Mounting Manual 3 The Mounting Process 3 1 Details of the LGA Mounting Process Solder paste solder cream Lead free solder Printing positional tolerances 0 5 mm pitch LGA within 0 10 mm
22. torage condition after the opening moisture proof packing perform the reflow soldering operation under the following conditions If time longer than the limits has elapsed the semiconductor devices must be baked under the baking conditions shown Table 4 1 Component Heat Tolerance Heat tolerance temperature for 260 C Maximum reflow temperature package surface temperature Under 260 C Time at temperatures over 255 C Under 30 seconds Time at temperatures over 217 C 60 to 150 seconds Time at the preheat temperature of 150 C to 200 C 60 to 120 seconds 260 Cmax Max 30s max 60 to 120s 60 to 150s Maximum reflow temperature package surface temperature C Time S Figure 4 1 Reflow Heat Resistance Temperature Profile e Investigate means to assure that the heating slope is 1 to 3 C second e Set the cooling slope based on issues such as circuit board warping R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 10 of 15 Mar 19 2014 LGA Mounting Manual 4 The Reflow Process 4 1 1 Storage Conditions After Opening Moisture Proof Packing Table 4 2 Storage Conditions C iem f coos fme OO O Time 168 hours Note The time from opening the moisture proof packing until the last reflow soldering has been completed 4 1 2 Baking Conditions If the stipulated time after opening the moisture proof packing has elapsed the corresponding semiconductor products should be baked Use 10 hours at 125 C as an i
23. uld determine the mounting pad structure based on consideration of the board wiring design The LGA land type is the NSMD type in which the solder resist does not cover any of the land area The mounting pad form on the mounting board is made to be the same as that of the LGA itself and soldering connection geometry with a good vertical balance after reflow soldering can be achieved by designing with an NSMD structure in which the solder resist does not cover any of the pad area Solder resist Mounting pad Mounting board Figure 2 1 Pad Structure NSMD structure 2 2 Mounting Pad Design Example This section presents a mounting pad design example for the mounting board that is matched to the LGA package land SIZe Table 2 1 Mounting Pad Design Example Unit mm LGA land size 0 25 0 30 0 35 Mounting pad design 0 25 0 30 0 35 R50ZZ0006EJ0100 Rev 1 00 LEN ESAS Page 2 of 15 Mar 19 2014 LGA Mounting Manual 2 Mounting Board Design Mounting Pad Design Example for LGA Packages with Reinforcement Lands Some LGA packages have the reinforcement lands which are located in the four corners Since these reinforcement lands increase the resistance to stress of the solder joint we recommend designing a mounting pad that matches the reinforcement land specifications if an LGA product that has reinforcement lands at the four corners is used Figure 2 2 shows a mounting pad design for a 5x5 64 pin FLGA package An SMD
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