MIL-STD-202H.pdf - 第167页

MI L - S TD - 202 - 210 4.3. 4 Tes t conditions. U nl e s s ot her w i s e s pe c i f i ed i n t he i ndi v i dual s pe c i f i c a t i on , t he t e s t s h all be perform ed on all solder ter minations atta c he d t o …

100%1 / 305
MIL-STD-202-210
4.1.4 Mounting board. A mounting board, in accordance with NEMA grade FR-4 of IPC 4101
, 9 square inches
(i.e., 3 x 3, 1 x 9, etc.), minimum area, .062 inch ±.0075 inch (1.57 mm ±.191 mm) thick, shall be used, unless
otherwise specified. Component lead holes shall be drilled such that the diametrical clearance between the hole and
component terminals shall not exceed .015 inch (0.38 mm). Metal eyelets or feed-throughs shall not be used.
Surface mount boards, when specified in the individual specification, shall have pads of sufficient size and number to
accommodate the component being tested.
4.1.5 Solder iron. A solder iron, capable of maintaining a temperature of 350°C ±10°C, shall be used.
4.1.6 Reflow chambers. The reflow chambers or equivalent (Vapor Phase Reflow (VPR) chamber, Infrared Reflow
(IRR) oven, air circulating oven, etc.) shall be of sufficient size to accommodate the mounting board and components
to be tested. The chamber shall be capable of generating the specified heating rate, temperatures, and
environments.
4.1.7 Temperature measurement. Low mass thermocouples that do not affect the heating rate of the sample shall
be used. A temperature recording device is recommended. The equipment shall be capable of maintaining an
accuracy of ±1°C at the temperature range of interest.
4.2. Materials.
4.2.1 Solder. The solder or solder paste shall be tin-lead alloy with a nominal tin content of 50 percent to 70
percent in accordance with J-STD-006, “Requirements for Electronic Grade Solder Alloys and Fluxed and Non-
Fluxed Solid Solders for Electronic Soldering Applications” or J-STD-005, “Requirements for Soldering Pastes”.
When specified in the individual specification, other solders can be used provided they are molten at the specified
temperature.
4.2.2 Flux. When flux is used, it shall conform to type A of J-STD-004
, “Requirements for Soldering Fluxes”, or as
specified in the individual specification.
4.2.3 VPR fluid. A perfluorocarbon fluid that has a boiling point of 215°C shall be used.
4.3 Procedure.
4.3.1 Special preparation of specimens. Any special preparation of specimens prior to testing shall be as specified
in the individual specification. This could include specific instructions such as bending or any other relocation of
terminations, cleaning, application of flux, pretinning, or attachment of heat sinks or protective shielding (see 4.1.2),
prior to the solder immersion.
4.3.2 Preparation of solder bath. The molten solder shall be agitated to assure that the temperature is uniform.
The surface of the solder shall be kept clean and bright.
4.3.3 Application of flux. When flux is used, the terminations to be tested shall be immersed in the flux (see 4.2.2),
which is at room ambient temperature, to the depth specified for the solder dip. The duration of the immersion shall
be from 5 seconds to 10 seconds.
2
北测（上海）电子科技有限公司
联系方式：xuyj@beice-sh.com 13917165676
MIL-STD-202-210
4.3.4 Test conditions. Unless otherwise specified in the individual specification, the test shall be performed on all
solder terminations attached to the component part. There are six types of soldering techniques covered by these
test conditions. The test conditions are outlined below and in table I.
Test condition A: Solder iron - Hand soldering of solder cups, through hole components, tab and post
terminations, solder eyelet terminations.
Test condition B: Solder dip - Simulates hot solder dipping (tinning) of leaded components.
Test condition C: Wave solder - Simulates wave solder of topside board mount product.
Test condition D: Wave solder - Simulates wave solder of bottomside board mount product.
Test condition H: VPR - VPR environment without preheat.
Test conditions I, J, K: Infrared/Convection reflow - Simulates IRR, natural convection, and
forced air convection reflow environments.
4.3.4.1 Test condition A: Solder iron.
a. When testing a solder cup, tab and post termination, or solder eyelet termination, the applicable wire size,
properly prepared for the solder termination, shall be attached in the appropriate manner.
When testing a board mount component, the component shall be placed on a mounting board (see 4.1.4).
b. When specified, the components shall be fluxed (see 4.3.3).
c. Unless otherwise specified, a solder iron in accordance with 4.1.5 shall be used.
d. The solder iron shall be heated to 350°C ±10°C and applied to the termination for a duration of 4 seconds to 5
seconds as specified in table I. The solder and iron shall be applied to the area of the assembly closest to
the component body that the product is likely to experience. For surface mount components, the iron shall be
placed on the pad only.
e. Remove the iron and allow the component to cool and stabilize at room ambient conditions. If flux was used,
the component shall be cleaned using an appropriate cleaning solution.
f. The component shall be visually examined under 10X magnification.
4.3.4.2 Test condition B: Solder dip.
a. Place the component in an appropriate fixture (see 4.1.3).
b. When specified, the leads shall be fluxed (see 4.3.3).
c. The specific combination of temperature, immersion and emersion rate, immersion duration, and number of
heats shall be as specified in table I. Unless otherwise specified, terminations shall be immersed to within
.050 inch (1.27 mm) of the component body. Terminations shall be immersed simultaneously, if the geometry
of the component permits.
d. After the solder dip, the component shall be allowed to cool and stabilize at room ambient conditions. If flux
was used, the component shall be cleaned using an appropriate cleaning solution.
e. The component shall be visually examined under 10X magnification.
3
北测（上海）电子科技有限公司
联系方式：xuyj@beice-sh.com 13917165676
MIL-STD-202-210
4.3.4.3 Test condition C: Wave solder - topside board mount component.
a. The component under test shall be mounted on a mounting board (see 4.1.4).
Wire leads: Wire leads shall be brought through the board holes and bent at least 30 degrees from a line
perpendicular to the board. Leads shall extend from .050 inch to .100 inch (1.27 mm to 2.54 mm) from the
bottom of the board. Axial leads shall be bent at a 90° angle at a point between .06 inch and .08 inch (1.5
mm and 2.1 mm) from the body, eyelet fillet or weld unless otherwise specified (see figure 1).
Pin leads: Where the component is designed with rigid pin leads, the full length of the termination shall be
retained. Pin leads shall not be cut or bent (see figure 1).
b. When specified, the leads shall be fluxed (see 4.3.3).
c. The specific combination of temperature, duration, and number of heats shall be as specified in table I.
d. The components, mounted on the board, shall be immersed in the solder pot so that the bottom of the board
floats on the molten solder.
e. After the float, the components shall be allowed to cool and stabilize at room ambient conditions. If flux was
used, the components shall be cleaned using an appropriate cleaning solution.
f. The components shall be visually examined under 10X magnification.
4.3.4.4 Test condition D: Wave solder - bottomside board mount product.
a. Place the component in an appropriate fixture (see 4.1.3).
b. When specified, the terminations shall be fluxed (see 4.3.3).
c. The specific combination of temperature, preheat conditions, immersion and emersion rates, immersion
duration, and number of heats shall be as specified in table I.
d. The component shall be preheated and fully immersed in the solder bath in accordance with 4.3.4.4c.
e. After the immersion, the component shall be allowed to cool and stabilize at room ambient conditions. If flux
was used, the component shall be cleaned using an appropriate cleaning solution.
f. The component shall be visually examined under 10X magnification.
4
北测（上海）电子科技有限公司
联系方式：xuyj@beice-sh.com 13917165676