How board-to-board connector Achieve
Robustness
White Paper: How board-to-board connector Achieve Robustness and What Factors Affect the Connector
Whether in the aaerospace sector, industrial automation, transportation, or healthcare: board-to-board connector must always ensure reliable signal transmission and must not fail under any circumstances. At the same time, they are exposed to a range of environmental stresses: Mechanical stresses such as shock, vibration, and oscillations jeopardize the stability of data transmission, as do thermal and chemical environmental influences caused by extreme temperatures, severe temperature fluctuations, harmful gases, moisture, and dirt. Manufacturers of high-quality printed circuit board connector therefore employ a wide range of measures to fortify their board-to-board connectors against these stresses.
Ruggedness of board-to-board connectors despite miniaturization
Modern electrical engineering is subject to one trend more than ever: miniaturization. Assemblies and their components must not only become increasingly powerful but also increasingly smaller. Nevertheless, they are often used under harsh real-world conditions. Components, as well as connector, are therefore becoming increasingly delicate while withstanding the same level of stress. However, a high-quality connector not only withstands this stress just as well as its older, larger counterpart—it actually performs even better. This is due to advancements in material composition and product design, such as improvements in the geometry of the insulating body.
A wide variety of factors influence the robustness of a board-to-board connector:
A wide variety of factors influence the robustness of a board-to-board connector:
- Surface
- , contact design
- , contact system
- , termination technology,
- insulator
- design, tolerance range
Surface as an influencing factor
One influencing factor is the contact surface (contact surface). This significantly determines the service life of the connector, which is typically measured in mating cycles (mating cycles). During field use, the connector (connector) is subjected to certain micro-movements. These lead to surface abrasion and, consequently, to oxidation. The result is increased contact resistance (contact resistance) and, therefore, poorer signal transmission quality.
A high-quality and durable contact plating is therefore crucial for minimizing surface abrasion.
Read our free white paper to learn what to consider when selecting a contact surface.
A high-quality and durable contact plating is therefore crucial for minimizing surface abrasion.
Read our free white paper to learn what to consider when selecting a contact surface.
Contact design as an influencing factor
The contacts of a printed circuit board connector are stamped or turned. However, during the stamping process, an inhomogeneous, sharp-edged surface forms on the underside of the stamped strip that is visible under a microscope. Conventional systems make contact along this sheared edge, which results in increased surface abrasion and, consequently, higher contact resistance.
Free white paper on connector robustness
In the free white paper, you’ll learn, for example, how to minimize contact resistance by choosing the right contact design. We’ll also explain, based on various influencing factors, how wire-to-board connector achieve robustness and what exactly needs to be considered.
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Contact system as an influencing factor
Klassische zweiteilige Steckverbinder verfügen über einen Messer- und einen Federkontakt. Im Falle starker Schockeinwirkung kann die Messerleiste jedoch von der Federleiste abheben. Damit es nicht zu einer solchen Kontaktunterbrechung kommt, kann mithilfe einer doppelseitigen Federleiste für Redundanz und somit für Kontaktsicherheit gesorgt werden, denn durch die zweite Feder ist die Signalübertragung zu jeder Zeit mindestens über einen Kontaktpunkt sichergestellt.
Noch robuster sind dagegen Steckverbinder mit sogenanntem „genderneutralem“ Kontaktsystem. Die Besonderheit besteht dabei in den identischen Kontaktgeometrien der Steckerhälften.
Noch robuster sind dagegen Steckverbinder mit sogenanntem „genderneutralem“ Kontaktsystem. Die Besonderheit besteht dabei in den identischen Kontaktgeometrien der Steckerhälften.
Influencing Factor: termination technology
There are various ways to mount connector on printed circuit boards.
One of these is the aforementioned press-fit technology. Its goal is to achieve the highest possible retention forces between the “ connector ” and the PCB while minimizing the “ press-in force ” as much as possible. These retention forces determine the mechanical connection, which in turn must withstand shock and vibration.
However, press-fit technology is not always suitable—for example, when printed circuit boards are to be populated on both sides or when the minimum distance to components in the direction of the force cannot be maintained. Another option for establishing a reliable and durable connection between connector and the printed circuit board is surface-mount technology (SMT). Using solder paste, the connector are soldered to defined lands on the printed circuit board, known as solder pads.
One of these is the aforementioned press-fit technology. Its goal is to achieve the highest possible retention forces between the “ connector ” and the PCB while minimizing the “ press-in force ” as much as possible. These retention forces determine the mechanical connection, which in turn must withstand shock and vibration.
However, press-fit technology is not always suitable—for example, when printed circuit boards are to be populated on both sides or when the minimum distance to components in the direction of the force cannot be maintained. Another option for establishing a reliable and durable connection between connector and the printed circuit board is surface-mount technology (SMT). Using solder paste, the connector are soldered to defined lands on the printed circuit board, known as solder pads.
Design of the insulating body as an influencing factor
The insulation body geometry of a board-to-board connector also helps protect the contacts from damage during operation or installation. It should be designed so that the vulnerable contacts are shielded inside the connector.
Insertion chamfers further prevent damage during assembly by compensating for any misalignment of the circuit boards in any direction when mating. An additional catch area enables the two connector halves to be mated without damage even in the event of center or angular misalignment.
Insertion chamfers further prevent damage during assembly by compensating for any misalignment of the circuit boards in any direction when mating. An additional catch area enables the two connector halves to be mated without damage even in the event of center or angular misalignment.
Influencing factor Tolerance range
The tolerance range of a connector plays a decisive role in assessing its robustness. If the connector cannot compensate for given tolerances, mechanical movements lead to wear or even damage to the connection.
In the field, for example, stresses arise not only in the x and y directions but also in the z direction. This raises the question of a connector’s “effective mating length” (overlap security). This term describes the overlap area between the blade and spring contactsFemale, thereby accommodating not only different board-to-board distances but also—depending on the size of this area—varying tolerance ranges.
Read the free white paper to learn what other factors influence the tolerance range and how to compensate for them.
Request the white paper »
In the field, for example, stresses arise not only in the x and y directions but also in the z direction. This raises the question of a connector’s “effective mating length” (overlap security). This term describes the overlap area between the blade and spring contactsFemale, thereby accommodating not only different board-to-board distances but also—depending on the size of this area—varying tolerance ranges.
Read the free white paper to learn what other factors influence the tolerance range and how to compensate for them.
Request the white paper »
Testing procedure
There are various testing methods to thoroughly evaluate board-to-board connectors in terms of their robustness. These methods examine variables such as dielectric withstanding voltage and contact resistance both before and after a stress test, and the condition of the contacts is visually inspected. For example, the effects of 500 mating cycles on the dielectric withstanding voltage can be assessed, or a climatic test can determine whether several hours at -55°C followed by 125°C have a negative impact on the contact resistance of the connector. In the temperature shock test, the connector must withstand 100 rapid cycles between these extreme temperatures, each lasting 30 minutes. Furthermore, the axial and angular angular misalignment during mating, as well as the tolerance range when mated, should not only be verified theoretically using a CAD model but also extensively tested in practice, with their load-bearing capacity empirically confirmed. It is equally important that various tests critical to the contact surface (contact surface) be conducted in combination to simulate real-world conditions. For example, mating cycles and mixed flowing gas tests could be performed in combination to ensure that the connector’s performance in terms of contact resistance (contact resistance) and dielectric strength (dielectric withstanding voltage) has not deteriorated and that the contacts have not been damaged.
Free webinar on the reliability of board-to-board connectors
Do you need detailed knowledge to select the right connection technology based on your requirements?
Then schedule a free webinar with us.
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Then schedule a free webinar with us.
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Your design – your choice
Depending on the application’s requirements, a board-to-board connector must meet various robustness criteria. For example, does it need to compensate for high tolerances? Is it exposed to high shock loads or vibrations? Is it used in environments subject to extreme heat or cold? Or does the connection solution need to be protected against moisture, corrosive gases, or dirt? If a user bases their choice of connection solution on these questions, they can be confident that their connector is optimally equipped for field use.
Any questions?
Then please contact us!
Submit an inquiry via the form
+1 (806) 304-0402
sales@eptusa.com
Then please contact us!
Submit an inquiry via the form
+1 (806) 304-0402
sales@eptusa.com