MFC-8220
SERVICE MANUAL
4-67
5. GUIDELINES FOR LEAD FREE SOLDER
Information on Manually Repairing PCB Soldered with Lead-Free Solder
This document provides information on how to correctly make manual repairs to a printed circuit
board (PCB) soldered with lead-free solder.
1. Characteristics of lead-free solder
Melting point higher than that of conventional tin-lead solder
(Lead-free solder: approx. 220'C, Conventional tin-lead solder: approx. 180'C)
Relatively poor solder wettability and spread (difficult to wet and spread), and hard
Appearance (dull and grainy surface) different from that of conventional solder
Relatively poor wettability, rough surface (bumps are likely to be formed), and solder
dragging
Poor solder elevation
Poor thermal conductivity and heat resistant (difficult to melt)
2. Metal composition & wire solder
The metal composition of lead-free solder allowed for use on PCBs for Brother's products is
following.
LF
Indication
Compositon
Manufacture
r
Origin Name
1
Sn/Ag/Cu
Nihon
Genma
Japan DHB-RMA3
NP303
H
only
Component-
side
Sn/Ag/Cu Nihon
Genma
Japan DHB-RMA3
NP303
We use wire solder which is indicated by digit after LF indication on PCB.
Wire solder made in the contries except Japan are under investigation,and will be evaluated.
3. Appearance quality criteria
The appearance of the surface of portions soldered with lead-free solder is basically the
same as that for those soldered with conventional lead-tin solder, except for the following
points.
1) The surface of a portion soldered with lead-free solder is dull and not smooth.
2) Shrinkage cracks can be observed on the surface of a portion soldered with lead-free
solder. (They can be observed using a magnifying glass with approx. 10x
magnification.)
Shrinkage
cracks
Figure 1 Shrinkage Cracks
4. Identification of lead-free solder on PCBs
For PCBs that use lead-free solder, "LF" is indicated by silk-screen printing or attaching a
label. "LF" stands for lead free and indicates that the PCBs bearing such an indication have
been soldered with lead-free solder. A digit is given in a box following "LF" if produced by
silk-screen printing or follows "LF" without a box on an attached label, the digit indicating the
metal composition and wire solder.
Содержание MFC-8220
Страница 60: ...MFC 8220 SERVICE MANUAL 3 5 1 3 4 ROM Fig 3 6 ...
Страница 150: ...CHAPTER 4 DISASSEMBLY AND RE ASSEMBLY 4 72 EM4 EM4 EM4 Molykote EM D110 4 mm dia ball Eject roller ASSY ...
Страница 170: ...MFC 8220 SERVICE MANUAL 5 17 9 Insert the power cord to the machine Fig 5 26 Power cord Machine ...
Страница 244: ...CHAPTER 7 MAINTENANCE MODE 7 6 Fig 7 2 a b c d e f g h i j ...
Страница 312: ...APPENDIX 4 CIRCUIT DIAGRAM A 48 Appendix 4 1 Main PCB Circuit Diagram 1 6 ...
Страница 313: ...MFC 8220 SERVICE MANUAL A 49 Appendix 4 2 Main PCB Circuit Diagram 2 6 ...
Страница 314: ...APPENDIX 4 CIRCUIT DIAGRAM A 50 Appendix 4 3 Main PCB Circuit Diagram 3 6 ...
Страница 315: ...MFC 8220 SERVICE MANUAL A 51 Appendix 4 4 Main PCB Circuit Diagram 4 6 ...
Страница 316: ...APPENDIX 4 CIRCUIT DIAGRAM A 52 Appendix 4 5 Main PCB Circuit Diagram 5 6 ...
Страница 317: ...MFC 8220 SERVICE MANUAL A 53 Appendix 4 6 Main PCB Circuit Diagram 6 6 ...
Страница 318: ...APPENDIX 4 CIRCUIT DIAGRAM A 54 Appendix 4 7 Engine PCB Circuit Diagram 1 2 ...
Страница 319: ...MFC 8220 SERVICE MANUAL A 55 Appendix 4 8 Engine PCB Circuit Diagram 2 2 ...
Страница 320: ...APPENDIX 4 CIRCUIT DIAGRAM A 56 Appendix 4 9 NCU PCB Circuit Diagram Europe ...
Страница 321: ...MFC 8220 SERVICE MANUAL A 57 Appendix 4 10 NCU PCB Circuit Diagram U S A ...
Страница 322: ...APPENDIX 4 CIRCUIT DIAGRAM A 58 Appendix 4 11 Control Panel PCB Circuit Diagram ...
Страница 323: ...MFC 8220 SERVICE MANUAL A 59 Appendix 4 12 Low voltage Power Supply PCB Circuit Diagram ...
Страница 324: ...APPENDIX 4 CIRCUIT DIAGRAM A 60 Appendix 4 13 High voltage Power Supply PCB Circuit Diagram 100V ...
Страница 325: ...MFC 8220 SERVICE MANUAL A 61 Appendix 4 14 High voltage Power Supply PCB Circuit Diagram 200V ...
Страница 326: ...APPENDIX 4 CIRCUIT DIAGRAM A 62 Appendix 4 15 Back Light PCB Circuit Diagram ...
Страница 328: ...February 04 SM FAX026 6 8X5913 Printed in Japan ...