TWI798069B - probe card - Google Patents

Abstract

A probe card includes a guide plate and a single-layer or multi-layer shielding structure. The guide plate includes an upper surface, a lower surface and at least one guide hole penetrating between the upper surface and the lower surface, and the guide hole has an inner wall surface. At least one layer of the shielding structure is an electromagnetic absorbing material or an electromagnetic reflecting material and is not connected to ground, and each layer of the shielding structure is formed on the inner wall of the guide hole by an atomic layer deposition method or an atomic layer etching method and the thickness is less than 1000 nm.

Description

probe card

The invention relates to a device for testing integrated circuits, in particular to a probe card.

Probe testing is a common way in integrated circuit testing methods, and a probe card is one of the most critical components in a test device used to perform pin testing. However, as the distance between the contact points on the integrated circuit is gradually reduced, the distance between the probes is also reduced. This will cause the signals between the probes to interfere with each other when testing the integrated circuit, thereby affecting the measurement. the result of.

In order to improve the problem of signal interference, existing technologies can be found in Taiwan Invention Patent No. TW I574013 B, Taiwan Invention Patent No. TW I411785 B, US8692570B2, etc. The above-mentioned cases all cover the outer surface of the metal probe with an insulating layer and a shielding layer However, because each probe must be covered with an insulating layer and a shielding layer, it is not only time-consuming and labor-intensive, but also has high production costs. The cost is increased, and the outer surface of each probe is covered with an insulating layer and a shielding layer. In addition to affecting the accuracy of the probe itself, it will also increase the probability of probe damage.

On the other hand, the shielding layer of the existing probe card is made of common metal material, and the shielding layer needs to be further connected to the ground to achieve the shielding effect. However, the grounding will require additional lines and circuits, which also increases the manufacturing and labor costs. overall structural complexity.

Therefore, how to simplify the structure and production process of the probe card while achieving the shielding effect is a problem that those skilled in the art want to solve.

The purpose of the present invention is to solve the problem that in the conventional probe card with shielding function, shielding structures need to be separately deposited on each probe, and additional lines and circuits are required due to grounding, resulting in complicated procedures and high costs. question.

To achieve the above purpose, the present invention provides a probe card, which includes a guide plate and a single-layer or multi-layer shielding structure. The guide plate includes an upper surface, a lower surface and at least one guide hole penetrating between the upper surface and the lower surface, and the guide hole has an inner wall surface. At least one layer of the shielding structure is an electromagnetic absorbing material or an electromagnetic reflecting material and is not connected to ground, and each layer of the shielding structure is formed on the inner wall of the guide hole by an atomic layer deposition method or an atomic layer etching method and the thickness is less than 1000nm.

10: guide plate

11: Upper surface

12: Lower surface

13: Guide hole

131: Inner wall surface

20: shielding structure

21: The first floor

22: shielding layer

23: Second floor

[FIG. 1] is a three-dimensional schematic diagram of a probe card according to an embodiment of the present invention.

[FIG. 2] is a partially enlarged perspective view of a probe card according to an embodiment of the present invention.

[Figure 3] is a schematic cross-sectional view along A-A of [Figure 2].

[Figure 4] is a schematic top view of [Figure 2].

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms "a" and "the" may also include plural forms unless the context dictates otherwise.

Directional terms used herein, such as up, down, left, right, front, back, and their derivatives or synonyms, refer to the orientation of elements in the drawings and do not limit the invention unless the context clearly states otherwise.

Relevant detailed description and technical content of the present invention, now just explain as follows with respect to matching drawing: Referring to "Fig. 1" to "Fig. 4", the present invention discloses a probe card, especially a probe card that has a shielding function but does not need to be grounded, and does not need to form a shielding layer on each probe. The probe card includes A guide plate 10 and at least one shielding structure 20 . The guide plate 10 includes an upper surface 11, a lower surface 12 and at least one guide hole 13, the guide hole 13 runs through the upper surface 11 and the lower surface 12, providing at least one probe (not shown) to pass through , and the guiding hole 13 includes an inner wall surface 131 . Wherein, the guide holes 13 can be arranged on the guide plate 10 according to an array or a pattern according to application requirements. In this embodiment, a cross section of the guide hole 13 is circular. In other embodiments, the cross section of the guide hole 13 can be in other shapes, such as triangle, square, pentagon or other polygons.

In the present invention, the shielding structure 20 can be a single layer or multiple layers, and each layer of the shielding structure 20 is formed by an atomic layer deposition method (Atomic Layer Deposition, ALD) or an atomic layer etching method (Atomic Layer Etching, ALE). On the inner wall surface 131 of the guide hole 13, the thickness of each layer is less than 1000 nm. Through the atomic layer deposition method or the atomic layer etching method, an extremely thin and uniform multilayer film can be produced in the tiny guide hole 13 , and may not be deposited on the probe. At least one layer of the shielding structure 20 is an electromagnetic absorbing material or an electromagnetic reflecting material, in addition to the electromagnetic absorbing material and the electromagnetic reflecting material, in some embodiments, the shielding structure 20 may further include at least one layer of insulating material , formed by depositing a material with better insulation (lower dielectric constant). The shielding structure 20 of the present invention is not connected to the ground. Further, in one embodiment, each layer of the shielding structure 20 is not connected to the ground. On the other hand, the present invention is to directly sink the shielding structure 20 are accumulated in the guide hole 13, so only one-time processing is required, and it is not necessary to coat each probe with a shielding structure.

The electromagnetic absorbing material can be conductive metal or alloy, for example, the electromagnetic absorbing material can be aluminum, tungsten, platinum, titanium, gold, iron or cobalt-nickel alloy; the electromagnetic reflective material can be oxide or nitride, for example For example, the electromagnetic reflective material can be silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), titanium nitride (TiN), tantalum nitride (TaN), cobalt oxide (CoO), nickel oxide ( NiO), iron oxide (Fe ₂ O ₃ ), CoTiO ₂ ; the insulating material may be an oxide, such as aluminum oxide (Al ₂ O ₃ ) or silicon oxide (SiO ₂ ).

In some embodiments, the shielding structure 20 may be or include a multilayer structure of Al ₂ O ₃ /CoO/Al ₂ O ₃ , a multilayer structure of Al ₂ O ₃ /AlN/Al ₂ O ₃ , AlN/Al ₂ O ₃ /Fe ₂ O ₃ /AlN/Al ₂ O ₃ multilayer structure, Si ₃ N ₄ /SiO ₂ multilayer structure or Si ₃ N ₄ /SiO ₂ /AlN/SiO ₂ multilayer structure; and in some implementations In an example, the shielding structure 20 may be multiple stacks _of the aforementioned multilayer structures, such as Al ₂ O ₃ /CoO/Al ₂ O 3 /Al 2 O ₃ /CoO/Al ₂ O ₃ /Al _{2 O 3} /CoO/Al ₂ O ₃ , Si ₃ N ₄ /SiO ₂ /Si ₃ N ₄ /SiO ₂ /Si ₃ N ₄ /SiO ₂ and so on. It can be understood that the aforementioned multilayer structure includes at least one layer of the electromagnetic absorbing material or the electromagnetic reflecting material, and optionally includes at least one layer of the insulating material.

Referring to "Figure 3" and "Figure 4", in this embodiment, the shielding structure 20 is a three-layer structure and is arranged on the inner wall surface 131 of the guide hole 13, the shielding structure 20 includes a first layer 21 1. A shielding layer 22 and a second layer 23. The first layer 21 and the second layer 23 are the insulating materials, which may be different or the same. The shielding layer 22 is the electromagnetic absorbing material and the electromagnetic reflecting material. The first layer 21 is deposited on the inner wall surface 131 , the shielding layer 22 is deposited on the first layer 21 , and the second layer 23 is deposited on the shielding layer 22 . That is to say, the first layer 21 , the shielding layer 22 and the second layer 23 are sequentially stacked from the inner wall surface 131 toward the center of the guiding hole 13 . During operation, The probe is inserted into the second layer 23, and the probe is surrounded by the first layer 21, the shielding layer 22 and the second layer 23, so that the probe is not easily affected by the adjacent probe when transmitting the test signal. The probe is distorted due to interference (coupling), and the integrity of the test signal is better, which can accurately measure the electrical properties of the integrated circuit.

In one embodiment, the diameter of the guide hole 13 is less than 1 mm, the diameter of the probe is less than 50 μm, and the thicknesses of the first layer 21, the shielding layer 22 and the second layer 23 are respectively less than 1000 nm. In one embodiment In some embodiments, the thicknesses are respectively less than 500 nm, and in some embodiments, the thicknesses are respectively between 100 nm and 500 nm. By controlling the diameter of the guide hole 13 and the thickness of the shielding structure 20, the probes can be inserted into the guide hole 13 without touching the second layer 23, avoiding damage to the shielding structure 20 when installing the probes, The accuracy of measurement is affected, and the smaller diameter of the guide hole 13 can make the probes more densely arranged on the guide plate 10 . The shielding structure 20 can internally reflect the electromagnetic wave through the above three-layer structure to reduce the intensity of the electromagnetic wave.

To sum up, with the structure and material selection of the shielding structure 20 of the present invention, the shielding structure 20 may not be connected to ground, such as a ground circuit or a ground potential, which simplifies the overall structure. And using atomic layer deposition (or atomic layer etching) technology, the shielding structure can be deposited in the guide hole of the tiny probe card, and the shielding structure can be deposited on all the guide holes with only one deposition. In the hole, there is no need to deposit a shielding structure for each probe, which not only saves the deposition process, but also reduces the cost of replacing the probes. In addition, the present invention utilizes the setting of the shielding structure to reduce the problem of signal interference when the probe detects the semiconductor element, thereby improving the validity of the detection value and being suitable for semiconductor devices with high-density terminals.

10: guide plate

11: Upper surface

12: Lower surface

13: Guide hole

131: Inner wall surface

20: shielding structure

21: The first floor

22: shielding layer

23: Second floor

Claims (8)

A probe card, comprising: a guide plate, including an upper surface, a lower surface, and at least one guide hole penetrating between the upper surface and the lower surface, the guide hole has an inner wall surface; and a single-layer or multi-layer shielding structure, at least one layer of the shielding structure is an electromagnetic absorbing material or an electromagnetic reflecting material, and the shielding structure is not connected to the ground, each layer of the shielding structure is deposited by an atomic layer deposition method or an atomic layer etching method formed on the inner wall of the guide hole and each having a thickness less than 1000 nm. The probe card according to claim 1, wherein the electromagnetic absorbing material is aluminum, tungsten, platinum, titanium, gold, iron or cobalt-nickel alloy. The probe card as described in claim 1, wherein the electromagnetic reflective material is silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), titanium nitride (TiN), tantalum nitride (TaN), oxide Cobalt (CoO), nickel oxide (NiO), iron oxide (Fe ₂ O ₃ ), or CoTiO ₂ . The probe card according to claim 1, wherein the electromagnetic absorbing material or the electromagnetic reflecting material is not connected to ground. The probe card as claimed in claim 1, wherein the shielding structure further comprises at least one layer of insulating material. A probe card, comprising: a guide plate, including an upper surface, a lower surface, and at least one guide hole penetrating between the upper surface and the lower surface, the guide hole has an inner wall surface; and a multi-layer A shielding structure, the shielding structure includes a first layer deposited on the inner wall surface, a shielding layer deposited on the first layer and a second layer deposited on the shielding layer, the shielding layer is an electromagnetic Absorbing material or an electromagnetically reflective material, the first layer and the second layer are the same or a different insulating Material, each layer of the shielding structure is not connected to the ground, each layer of the shielding structure is formed by an atomic layer deposition method or an atomic layer etching method, and the thickness is less than 1000nm. The probe card according to claim 6, wherein the electromagnetic absorbing material is aluminum, tungsten, platinum, titanium, gold, iron or cobalt-nickel alloy. The probe card as described in claim 6, wherein the electromagnetic reflective material is silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), titanium nitride (TiN), tantalum nitride (TaN), oxide Cobalt (CoO), nickel oxide (NiO), iron oxide (Fe ₂ O ₃ ), or CoTiO ₂ .

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