- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385634 > MR2504 (ON SEMICONDUCTOR) Medium-Current Silicon Rectifiers(中等電流整流器) PDF資料下載
參數(shù)資料
| 型號： | MR2504 |
| 廠商： | ON SEMICONDUCTOR |
| 元件分類： | 參考電壓二極管 |
| 英文描述： | Medium-Current Silicon Rectifiers(中等電流整流器) |
| 中文描述： | 25 A, 400 V, SILICON, RECTIFIER DIODE |
| 封裝： | PLASTIC, 2 PIN |
| 文件頁數(shù)： | 7/8頁 |
| 文件大?。?/td> | 91K |
| 代理商： | MR2504 |
MR2502, MR2504, MR2510
http://onsemi.com
7
ASSEMBLY AND SOLDERING INFORMATION (continued)
3.
Ovens
are good for batch soldering and are production
limited. There are handling problems because of slow
cooling. Response time is load dependent, being a
function of the watt rating of the oven and the mass of
parts. Large ovens may not give an acceptable
temperature gradient. Capital cost is low compared to
belt furnaces and flame soldering.
4.
Hot Plates
are good for soldering small quantities of
prototype devices. Temperature control is fair with
overshoot common because of the exposed heating
surface. Solder flow and positioning can be corrected
during soldering since the assembly is exposed.
Investment cost is very low.
Regardless of the heating method used, a soldering profile
giving the time–temperature relationship of the particular
method must be determined to assure proper soldering.
Profiling must be performed on a scheduled basis to
minimize
poor
soldering.
relationship will change depending on the heating method
used.
The
time–temperature
SOLDER PROCESS EVALUATION
Characteristics to look for when setting up the soldering
process:
I Overtemperature
is indicated by any one or all three of
the following observations.
1. Remelting of the solder inside the button rectifier
shows the temperature has exceeded 285
°
C and is
noted by “islands’’ of shiny solder and solder
dewetting when a unit is broken apart.
2. Cracked die inside the button may be observed by a
moving reverse oscilloscope trace when pressure is
applied to the unit.
3. Cracked plastic may be caused by thermal shock as
well as overtemperature so cooling rate should also be
checked.
II Cold soldering
gives a grainy appearance and solder
build–up without a smooth continuous solder fillet. The
temperature must be adjusted until the proper solder
fillet is obtained within the maximum temperature
limits.
III Incomplete solder fillets
result from insufficient solder
or parts not making proper contact.
IVTilted buttons
can cause a void in the solder between
the heatsink and button rectifier which will result in
poor heat transfer during operation. An eight degree tilt
is a suggested maximum value.
V Plating problems
require a knowledge of plating
operations for complete understanding of observed
deficiencies.
1. Peeling or plating separation is generally seen when a
button is broken away for solder inspection. If heatsink
or terminal base metal is present the plating is poor and
must be corrected.
2. Thin plating allows the solder to penetrate through to
the base metal and can give a poor connection. A
suggested minimum plating thickness is 300
microinches.
3. Contaminated soldering surfaces may out–gas and
cause non–wetting resulting in voids in the solder
connection. The exact cause is not always readily
apparent and can be because of:
(a) improper plating
(b) mishandling of parts
(c) improper and/or excessive storage time
SOLDER PROCESS MONITORING
Continuous monitoring of the soldering process must be
established to minimize potential problems. All parts used
in the soldering operation should be sampled on a lot by lot
basis by assembly of a controlled sample. Evaluate the
control sample by break–apart tests to view the solder
connections, by physical strength tests and by dimensional
characteristics for part mating.
A shear test is a suggested way of testing the solder bond
strength.
POST SOLDERING OPERATION CONSIDERATIONS
After soldering, the completed assembly must be
unloaded, washed and inspected.
Unloading
must be done carefully to avoid unnecessary
stress. Assembly fixtures should be cooled to room
temperature so solder profiles are not affected.
Washing
is mandatory if an acid flux is used because of
its ionic and corrosive nature. Wash the assemblies in
agitated hot water and detergent for three to five minutes.
After washing; rinse, blow off excessive water and bake
30 minutes at 150
°
C to remove trapped moisture.
Inspection
should be both electrical and physical. Any
rejects can be reworked as required.
SUMMARY
The Button Rectifier is an excellent building block for
specialized applications. The prime example of its use is the
output bridge of the automative alternator where millions
are used each year. Although the material presented here is
not all inclusive, primary considerations for use are
presented. For further information, contact the nearest
ON Semiconductor Sales Office or franchised distributor.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MR2508L | AUTOMOTIVE RECTIFIER DIODES |
| MR2510L | AUTOMOTIVE RECTIFIER DIODES |
| MR2512L | AUTOMOTIVE RECTIFIER DIODES |
| MR2500L | AUTOMOTIVE RECTIFIER DIODES |
| MR2501L | AUTOMOTIVE RECTIFIER DIODES |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MR2504L | 制造商:EIC 制造商全稱:EIC discrete Semiconductors 功能描述:AUTOMOTIVE RECTIFIER DIODES |
| MR2506 | 制造商:EIC 制造商全稱:EIC discrete Semiconductors 功能描述:AUTOMOTIVE RECTIFIER DIODES |
| MR2506L | 制造商:EIC 制造商全稱:EIC discrete Semiconductors 功能描述:AUTOMOTIVE RECTIFIER DIODES |
| MR2508 | 制造商:EIC 制造商全稱:EIC discrete Semiconductors 功能描述:AUTOMOTIVE RECTIFIER DIODES |
| MR2508L | 制造商:EIC 制造商全稱:EIC discrete Semiconductors 功能描述:AUTOMOTIVE RECTIFIER DIODES |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。