Spring contacts hold up during shock and vibration

彈針在沖擊與振動期間保持良好接觸

 

Test results show these versatile components are durable and stable for such harsh environments as medical and military technology.

測試結果表明這些多用途的組件在醫療和軍事技術中如此苛刻的環境中，都經久耐用，穩定可靠。 

 

When selecting a connector for a given application, design engineers are faced with the challenge of balancing many needs, both technically and commercially. While many connector systems can be purchased off-the-shelf or through traditional sales channels, many standard products trade performance for wider market acceptance. 

為指定應用選擇連接器時，設計工程師面臨平衡很多需要的挑戰，這些需要既有技術性的，也有商業性的。很多連接器系統可從貨架購買，也可以通過傳統的銷售渠道購買，而很多標準產品貿易具有更為廣泛的市場接受度。

 

Spring contact technology delivers a diverse range of building blocks, including:

彈針技術提供各種各樣的構建特點，包括：

 

Simplifying product design through elimination of mating counterparts;

消除了配接配對體，從而簡化了產品設計；

Enabling higher-density connections where needed (0.4-mm between centers is       possible from stocked components); 

能夠在需要地方進行更高密度的連接 (現有組件的中心距可以為 0.4 mm)；

Shortening board-to-board heights to less than 3 mm;

將板到板高度縮短到小于 3 mm；

Extending product lifetime with greater than 50,000 reliable mating cycles; 

將產品壽命延長到 50,000 次可靠配接以上；

Exceptional blind mating characteristics, allowing for simple product assembly or relaxation of critical dimensions.

優異的盲配連接特性，使產品組裝非常簡便，關鍵尺寸也很寬松。

 

In addition, correctly specified spring contacts also offer a stable, highly consistent interface, even under the harshest conditions. These characteristics are why many top defense and medical technology companies choose spring contacts and connectors for interconnections. 

此外，正確指定的彈針即使在最苛刻的條件下也能提供穩定、高度一致的接口。這些特性是很多一流國防和醫療技術公司為其連接選擇彈針和連接器的原因所在。

 

 

How the signal ‘sees’

信號如何“看到” 

 

Differentiating what appears to be a simple electromechanical component is critical in understanding how to select the correct contact for a given application. It is useful to understand how the internal design of these contacts aids their overall performance and durability. 

辨別什么是一個簡單的機電組件對了解如何為指定應用選擇正確彈針至關重要。了解這些彈針的內部設計如何幫助它們的整體性能和耐用性是很有用的。 

 

When defining “stable” and “consistent” in relation to a spring contact, it’s important to consider how the signal “sees” the connection medium and how this varies between mating cycles or during changes in the external environment, such as temperature or shock. This “path of least resistance” is useful in understanding how the signal will behave. The signal will transfer along the contact at different but distinct points, which for a single-sided contact can be classified and defined as R1, R2, and R3. Total resistance can be defined as R1+R2+R3, and so forth. 

定義彈針的“穩定性”和“一致性”時，切記要考慮信號是如何“看到”連接介質的，以及在配接與配接之間或溫度或沖擊等外部環境變化期間信號“看到”連接介質的結果的差異?！白钚‰娮杪窂健庇兄诹私庑盘柕男袨椤Ｐ盘枌⒀亟厝徊煌挠|點傳輸，對于單端觸點，可分類并定義為 R1、R2 和 R3。總電阻可定義為 R1+R2+R3，依此類推。 

 

?R1 is influenced by several factors, including the material and condition of the target and plunger, the surface area and shape of the plunger tip, and the amount of force applied. In general, the highest bearable force should be selected to minimize contact resistance; however, spring contact force can be modified easily by changing the internal spring design and/or material, or simply changing the compressed mechanical height at which the contact finishes. This lets you balance the total force of interconnect against board thickness or reinforcement to minimize flexing. For arrays of connectors, this can be a critical factor, as in eliminating additional weight for airborne or portable applications, which is normally required with incumbent connector technology.

?R1 受幾個因素的影響，包括目標和頂桿的材料和狀況、頂尖的表面積和形狀以及所施加的力的大小。一般而言，最大可承受力的選擇應最大程度地減少接觸電阻；但是，彈簧接觸力可輕易地通過更改內部彈簧設計和/或材料，或者簡單地更改壓縮機構接觸高度來更改。這使你可以在連接的總作用力和板厚度或牢固度之間找到平衡，最大程度地減小撓曲。對于連接器陣列，這是一個關鍵因素，如為空中應用或便攜應用（通常需要責任重大的連接器技術）消除額外的重量。

 

 

 

FIGURE 1. Spring contacts, shown here as stand-alones and as part of connector systems, stood up to rugged vibration testing conducted by the employer of this article’s author.

圖 1.彈針，此處顯示的是單獨使用的或作為連接器系統的一部分，經過本文作者所在公司進行的嚴格振動測試。

 

One important benefit of spring contacts is that force is generated linearly and requires significantly less printed circuit board (PCB) real estate than conventional bent-metal or plug-and-socket systems, providing more room for functional components in the finished article. 

彈針的一個重要優點是作用力是線性產生的，與傳統彎曲金屬或插接系統相比，只需要極少的印刷電路板 (PCB) 空間，為成品中的功能組件提供更多的空間。 

 

Customized tips can also be accommodated to pierce or wipe away contaminants or surface oxides, although for the majority of applications, a spherical tip provides significant surface area to satisfy the most demanding of requirement. 

定制的尖部也容易刺破或擦去污染物或表面氧化物，盡管對于大多數應用而言，球形頂部提供更多的表面積來滿足最苛刻的要求。 

 

?R2 is the point of signal transfer between plunger and barrel. To ensure the signal avoids the long, thin, variable path that is the spring, mechanical systems referred to as bias are used. These systems reliably hold the plunger in contact against the internal barrel wall, providing a constant, sliding, low-resistance connection. The bias system ensures the resistance remains stable and consistent, irrespective of height, shock, or vibration. Several systems of bias exist. 

?R2 是頂針與套殼體之間的信號傳輸點。為了確保信號避免長而薄的可變路徑（彈簧、機械系統），使用了偏置。這些系統可靠地將觸彈針內的頂針固定到殼體內壁，提供恒定、滑動、低電阻的連接。偏置系統確保電阻保持穩定一致，不受高度、沖擊或振動的影響。有幾種偏置系統。 

 

In addition to bias, the manufacturing technique and plating of the barrel itself influences R2 over the lifetime of the contact. Deep drawn parts offer the ability to pre-plate the internal working faces with gold, while also work-polishing and hardening the wall to optimize product lifetime. Conversely, machined parts allow for flange-like mounting features, but are more challenging to internally plate. 

除了偏置以外，殼體本身的制造技術和鍍層也會在彈針的整個使用壽命期限內影響 R2。深沖部件提供了對內部工作面鍍金的能力，還可以在工作時拋光和硬化殼壁以延長產品壽命。相反地，機制部件允許法蘭安裝功能，但是內部鍍層更有挑戰性。

 

FIGURE 2. These reliable connector systems all use spring contacts.

圖 2. 這些可靠的連接器系統全部使用彈針。

 

 

The bias-ball system is the most aggressive, providing a highly consistent connection between the plunger and barrel by compressing a ball against an angled plunger. With this system, contact lifetime is approximately 50,000 cycles, after which internal wear creates a less-stable connection. 

偏置球系統最有積極性，通過將球壓到一個傾斜的頂桿，在頂針和客體之間提供極其一致的連接。通過這個系統，彈針的使用壽命約為 50,000 次，之后內部磨損將降低連接的穩定性。 

 

Bias-plunger and bias-spring systems are less aggressive, and subsequently deliver a less consistent, yet still acceptable, connection between plunger and barrel. Both systems use the spring or plunger instability against its counterpart to create the bias effect. The lifetime of such a system typically is 100,000 cycles maximum. 

偏置頂針和偏置彈簧系統的積極性較低，因而在頂桿和套筒之間提供一致性較低但仍可接受的連接。兩種系統都使用彈簧或頂針相對于其配對體的不穩定性來形成偏置效果。此類系統的使用壽命通常最大為 100,000 次。

 

FIGURE 3. The eccentric bias system, which uses a contact with a backdrilled plunger, exhibits this typical resistance stability over multiple mating cycles.

圖 3. 偏心系統，使用后鉆孔頂針，顯示多次配接時的典型電阻穩定性。

 

Patented technology called eccentric or E-bias uses a contact with a backdrilled plunger, maximizing possible stroke length and increasing the contact area between barrel and plunger to minimize signal loss. The backdrilled hole can be offset or angular to the spring’s natural center line and exploits the spring’s natural tendency to straighten, generating a sound side loading between plunger and barrel at all times. The benefit of such a system is stable low loss, coupled with a minimum 100,000-cycle lifetime. 

專利技術“偏心”或 E-bias 使用一個具有后鉆孔頂針的觸點，最大程度地增加沖擊長度，增大套客體和頂針之間的面積，從而最大程度地減少信號損失。后鉆孔可以偏離彈簧自然中心線，或與中心線呈一個角度，利用彈簧的自然趨勢伸直，在頂針和客體之間始終形成一個可觀的側作用力。此類系統的優點是穩定的低損失，使用壽命至少可達 100,000 次。 

 

?R3 resistance is the point of transfer between the barrel and PCB. This figure is often negligible for many designs, but is influenced by board-termination technique. Standard surface-mount technology or through-hole techniques provide adequate performance. 

?R3 電阻是套客體與 PCB 之間的傳輸點。對于很多設計，這個數字通?？梢院雎圆挥?，但它受電路板終端技術的影響。標準表面貼裝技術或通孔技術提供足夠的性能。

 

 

Shock treatment

沖擊處理 

Performance under shock and vibration is often critical in performance applications. To better understand how spring contacts operate during such conditions, we have carried out extensive product testing on key bias types. The objective of the test process was to examine how the signal-path loss varied after exposure to different levels of vibration, and if discontinuities could be forced through long-term fretting wear or by unbiasing the spring contact with excessive shock. 

沖擊和振動下的性能通常在高性能應用中都很關鍵。為了更好的理解在此類情形下彈針是如何工作的，我們對主要的偏置類型進行了大量的產品測試。測試的目標是檢驗在施加不同程度的振動之后，信號路徑損失是如何變化的，以及是否會通過長期接觸磨損或通過用過度沖擊使彈簧不偏置而形成不連續性。

 

FIGURE 4. This cross-section of a typical spring contact shows its basic elements, all of which have an effect on the contact’s performance.

圖 4. 典型彈針的剖面圖顯示了其基本元件，所有元件都會影響觸點的性能。

 

Testing was conducted in accordance with EIA 364, with the product resistance measured initially and at each subsequent change in vibration, as follows: 

測試根據 EIA 364 進行，最初量得的產品電阻和以后振動中每次改變時量得的電阻如下：

 

Mechanical shock: 58 Gs, 11 milliseconds, 1?2 sine wave, 3 blows/direction/axis, 3 axis; 

機械沖擊：58 Gs，11 毫秒，1?2 正弦波，3 擊/方向/軸，3 軸；

Initial vibration: 3.1 Gs RMS to EIA 364 Procedure 28

初階振動：3.1 Gs RMS，符合 EIA 364 程序 28

Power spectral density 0.02; 

功率譜密度 0.02；

50 to 500 Hz; 

50 至 500 Hz；

1 hour/axis, 3 axis;

1 小時/軸，3 軸；

Secondary vibration: 5.35 Gs RMS to EIA 364 Procedure 28

二階振動：5.35 Gs RMS，符合 EIA 364 程序 28

Power spectral density 0.02;

功率譜密度 0.02；

50 to 2000 Hz; 

50 至 2000 Hz；

1 hour/axis, 3 axis;

1 小時/軸，3 軸；

Tertiary vibration stage: 7.56 Gs RMS to EIA 364 Procedure 28

三階振動：7.56 Gs RMS，符合 EIA 364 程序 28

Power spectral density 0.04; 

功率譜密度 0.04；

50 to 2000 Hz; 

50 至 2000 Hz；

1 hour/axis, 3 axis;

1 小時/軸，3 軸；

Final vibration stage: 9.26 Gs RMS to EIA 364 Procedure 28

最后一階振動：9.26 Gs RMS，符合 EIA 364 程序 28

Power spectral density 0.06; 

功率譜密度 0.06；

50 to 2000 Hz; 

50 至 2000 Hz；

1 hour/axis, 3 axis.

1 小時/軸，3 軸。

 

The results of this testing process demonstrate how any bias system improves contact performance, but an eccentric bias enables a reduction in piece-part count while retaining stability. 

測試結果說明任一偏置系統是如何改善彈針性能的，但是偏心能夠在保持穩定性的同時減少拼接件的數量。

 

FIGURE 5. This sample random vibration profile at 9.26G root mean square (RMS) on the Y axis shows stable performance.

圖 5. 本示例在 Y 軸上隨機進行振動，在 9.26G 均方根 (RMS) 處顯示穩定性能。

 

Biased battery contacts offer exceptional stability during the most severe of shock conditions. 

偏置電池彈針在最惡劣的的沖擊條件下也能提供異常優秀的穩定性。 

 

The force needed to create a disconnect can be calculated using the following formula: 

可使用以下公式計算形成連接中斷所需的作用力： 

 

Force = mass χ acceleration.

作用力 = 質量 χ 加速度。 

 

Therefore: 

因此： Acceleration = force ÷ mass

　　　加速度 = 作用力 ÷ 質量 

where force is the spring force at rated stroke, and mass is the mass of the plunger. 

其中，作用力是額定沖擊下的彈簧作用力，質量是頂桿的質量。

 

FIGURE 6. Within a spring contact system, the points of transfer are where the tip meets the target, where the barrel and plunger meet, and where the barrel meets the printed circuit board.

圖 6. 在一個彈簧觸彈針系統中，傳輸點是頂針與目標相接觸的地方、客體與頂針相接觸的地方以及套客體與印刷電路板相接觸的地方。

 

For a typical bias ball spring contact: 

對于典型偏置球彈針： 

Force = 65.2g, mass = 0.01587g, and acceleration = 65.2 ÷ 0.01587, or 4108. 

作用力 = 65.2g，質量 = 0.01587g，加速度 = 65.2 ÷ 0.01587（即 4108）。

 

FIGURE 7. The eccentric bias system, a patented system shown on the far left, is fundamentally different from other bias systems, including ball, plunger, and spring.

圖 7. 最左側的偏心系統是一種專利系統，與其他偏置系統有根本性的不同，包括球、頂桿和彈簧。

 

To achieve disconnection, the contact must be exposed to well in excess of 4000 G shock. 

要實現連接中斷，觸點必須受到 4000 G 以上的沖擊．

 

 

Spring into action 

彈簧作用 

Spring contacts in all form factors can be quickly engineered into highly reliable connector systems, including cabled, coaxial, surface-mount, and double-sided varieties. 

各種外形的彈簧觸彈針都能夠快速結合到極其可靠的連接器系統中，包括接線式、同軸、表面安裝和雙面種類。

 

FIGURE 8. This is the classical shock profile derived from the EIA 364 Procedure 28, which is a vibration test.

圖 8. 這是一個來自 EIA 364 程序 28 (振動測試) 的經典沖擊曲線。

 

Spring contacts can be a useful tool in your design toolbox, exhibiting durability, stability, and the adaptability to meet many interconnect challenges. 

彈簧觸彈針是你的設計工具箱中的一個有用工具，它具有滿足很多連接挑戰的耐用性、可靠性和適應性．