KR20120080357A

KR20120080357A - Ceramic substrate for probe card and method for manufacturing the same

Info

Publication number: KR20120080357A
Application number: KR1020110001762A
Authority: KR
Inventors: 고민지
Original assignee: 삼성전기주식회사
Priority date: 2011-01-07
Filing date: 2011-01-07
Publication date: 2012-07-17

Abstract

The present invention relates to a ceramic substrate for a probe card and a method of manufacturing the same. In one embodiment, the ceramic substrate for a probe card is formed of a ceramic sintered body including alumina, and includes a plurality of first vias penetrating through an upper surface and a lower surface. A core substrate on which electrodes are formed; And a glass component formed on at least one of an upper surface and a lower surface of the core substrate, the glass component capable of reacting with the alumina, electrically connected to the first via electrode, and having a diameter smaller than the diameter of the first via electrode. A buffer layer on which two via electrodes are formed; . &Lt; / RTI > The ceramic substrate for a probe card according to the embodiment of the present invention may have excellent mechanical strength and stable thermal expansion characteristics.

Description

Ceramic substrate for probe card and method for manufacturing same {Ceramic substrate for probe card and method for manufacturing the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate for a probe card and a method of manufacturing the same, and more particularly, to a ceramic substrate for a probe card and a method of manufacturing the same having excellent mechanical strength and stable thermal expansion characteristics.

In general, a semiconductor device has a fabrication process of forming contact pads for circuit patterns and inspections on a wafer and an assembly process of assembling wafers having circuit patterns and contact pads into respective semiconductor chips. It is manufactured through.

Between the fabrication process and the assembly process, an inspection process is performed in which an electrical signal is applied to the contact pads formed on the wafer to inspect the electrical properties of the wafer.

The inspection process is a process of inspecting a defect of a wafer to remove a portion of a wafer in which a defect occurs in an assembly process.

In the inspection process, a probe card that performs an interface function between the inspection equipment and the wafer that applies an electrical signal to the wafer is mainly used.

The probe card is formed with a plurality of probes in contact with the contact pads formed on the wafer.

In recent years, as the demand for highly integrated chips increases, circuit patterns formed on the wafer and contact pads connected to the circuit patterns are highly integrated. Corresponding to the highly formed contact pads, the spacing between the probes formed on the probe card is very narrow, and the size of the probe itself is also minutely formed. In addition, probe cards are being manufactured in which the number of channels for applying an electrical signal to the probe is increased according to the high integration of wafer chips.

In addition, since the inspection process of the semiconductor device is performed at a high temperature, the probe card is preferably formed to have a thermal expansion coefficient similar to that of the wafer. This is because a large difference in thermal expansion coefficient between the wafer and the probe card may cause mismatch between the contact pad of the wafer and the probe.

The present invention provides a ceramic substrate for a probe card having excellent mechanical strength and stable thermal expansion characteristics, and a method of manufacturing the same.

One embodiment of the present invention is formed of a ceramic sintered body containing alumina, the core substrate having a plurality of first via electrodes penetrating the upper and lower surfaces; And a glass component formed on at least one of an upper surface and a lower surface of the core substrate, the glass component capable of reacting with the alumina, electrically connected to the first via electrode, and having a diameter smaller than that of the first via electrode. It provides a ceramic substrate for a probe card comprising a; buffer layer on which two via electrodes are formed.

The number of first via electrodes may be 1/2 to 1/5 of the number of second via electrodes.

The diameter of the first via electrode may be formed to be 2 to 3 times larger than the diameter of the second via electrode.

The second via electrode may be electrically connected to the first via electrode by a conductive pattern formed in the buffer layer.

The content of the alumina may be 90 wt% or more of the ceramic sintered body.

The content of the glass component may be 40 to 70wt% of the buffer layer.

A probe may be formed on one surface of the buffer layer to be electrically connected to the second via electrode.

A buildup layer including a conductive pattern electrically connected to the second via electrode may be formed on one surface of the buffer layer.

Another embodiment of the present invention comprises the steps of providing a core substrate formed of a ceramic sintered body comprising alumina, the plurality of first via electrodes penetrating the upper surface and the lower surface; And a second via electrode having a glass component capable of reacting with the alumina on at least one of an upper surface and a lower surface of the core substrate and electrically connected to the first via electrode and having a diameter smaller than that of the first via electrode. Forming the formed buffer layer; provides a method of manufacturing a ceramic substrate for a probe card comprising a.

Forming the buffer layer

Stacking a buffer layer in a green sheet state in which a second via electrode is formed on the core substrate, and baking the buffer layer in the green sheet state.

A conductive pattern may be formed in the buffer layer to electrically connect the second via electrode and the first via electrode.

The number of the second via electrodes may be formed to be 2 to 5 times the number of the first via electrodes.

The diameter of the second via electrode may be formed to be 1/3 to 1/2 of the diameter of the first via electrode.

The content of the alumina may be more than 90w% of the ceramic sintered body.

The content of the glass component may be 40 to 70w% of the buffer layer.

According to this embodiment, mechanical strength can be ensured by the core substrate containing an alumina component. In addition, since the first via electrode formed on the core substrate has a large diameter, positional deviation due to shrinkage may be minimized. In addition, the buffer layer including the glass component is capable of non-shrink firing, it is possible to compensate for the shrinkage deviation of the core substrate.

In addition, a plurality of via electrodes may be formed in the buffer layer to form a circuit pattern required for an inspection process. In this case, the probe can be formed directly and used in the inspection process without forming an additional buildup layer.

In addition, the circuit pattern may be formed by an additional buildup layer. In this case, the circuit pattern required for the inspection process may be completed by a small amount of buildup layers using the first via electrode and the second via electrode already formed.

The buffer layer may include a large amount of glass and may mitigate mismatches caused by differences in thermal expansion coefficients between the core substrate and the wafer during the inspection process.

In addition, according to one embodiment of the present invention, the buffer layer in the green sheet state can be fired together with the fired core substrate. In this case, the already fired core substrate serves to help shrinkage of the buffer layer in the green sheet state, and the glass component included in the buffer layer reacts with alumina of the core substrate to improve adhesion between the core substrate and the buffer layer.

1 is a cross-sectional view schematically showing a ceramic substrate for a probe card according to an embodiment of the present invention.
2A and 2B are cross-sectional views for each process for explaining a method for manufacturing a ceramic substrate for a probe card according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings are the same elements.

1 is a cross-sectional view schematically showing a ceramic substrate for a probe card according to an embodiment of the present invention.

Referring to FIG. 1, a ceramic substrate for a probe card includes a core substrate 110 and buffer layers 120 and 130 formed on upper and lower surfaces of the core substrate. A plurality of first via electrodes 111 are formed on the core substrate 110, and second via electrodes 121 and 131 electrically connected to the first via electrodes 111 on the buffer layers 120 and 130. Is formed.

More specifically, the first buffer layer 120 may be formed on the top surface of the core substrate 110, and the second buffer layer 130 may be formed on the bottom surface of the core substrate 110. The present embodiment has a structure in which a buffer layer is formed on both the upper and lower surfaces of the core substrate, but the present invention is not limited thereto, and the buffer layer may be formed only on at least one of the upper and lower surfaces of the core substrate.

The core substrate 110 may be formed of a ceramic sintered body composed mainly of alumina, and has a high mechanical strength. A small number of first via electrodes 111 may be formed in the core substrate 110 having high mechanical strength.

The buffer layers 120 and 130 may be formed of a ceramic sintered body having a high content of glass, and a larger number of second via electrodes 121 and 131 may be formed than the first via electrode 111. As many via electrodes as necessary for the inspection may be formed in the buffer layer.

Probes (not shown) may be formed on one surface of the buffer layer to be electrically connected to the second via electrodes 121 and 131.

The probe is in direct contact with the contact pad of the wafer, which is the test object, and the signal transmitted from the test equipment is transferred to the probe by the first via electrode and the second via electrode.

In addition, a buildup layer having a conductive pattern connected to the second via electrode may be further formed on one surface of the buffer layer.

The probe card has a problem that the arrangement of the probe is determined according to the circuit pattern of the wafer to be inspected, but there is a problem that a long time is used when the probe card is manufactured at that time according to the circuit pattern of the wafer.

Accordingly, a shared ceramic substrate having a predetermined structure may be prepared, and a buildup layer may be formed on the ceramic substrate to form a probe arrangement structure corresponding to the circuit pattern of the wafer.

The ceramic substrate according to the present embodiment may have a circuit structure that ensures mechanical strength by the core substrate and that the number of via electrodes is expanded by the buffer layer to be used in an actual pattern. In addition, the buffer layer has a feature of having a small coefficient of thermal expansion including a large amount of glass components. As a result, misalignment due to a difference in thermal expansion coefficient between the core substrate and the wafer can be alleviated.

Hereinafter, each component will be described in more detail.

The core substrate 110 may be formed of a ceramic sintered body including alumina. The ceramic sintered body may be formed by sintering a green sheet including alumina powder. A plurality of green sheets may be stacked to form a core substrate 110 having a desired thickness.

The ceramic sintered body is formed of high temperature co-fired ceramics (HTCC), and the content of the alumina in the ceramic sintered body may be 90 to 100 wt% of the ceramic sintered body. The ceramic sintered body may include a small amount of metal oxide together with the alumina, and the content of the metal oxide may be included in 10% or less.

The core substrate 110 may have a plurality of first via electrodes 111 penetrating through an upper surface and a lower surface. The number of the first via electrodes 111 is smaller than the number of the second via electrodes 112 formed in the buffer layer. However, the number of the first via electrodes 111 is not limited thereto, but is 1/2 to 1/5 of the number of the second via electrodes. It can be formed as.

The number of first via electrodes may be formed to have a large diameter instead of being small. The diameter of the first via electrode 111 is not limited thereto, but may be larger than the diameter of the second via electrodes 211 and 131, for example, 2 to 3 times larger than the diameter of the second via electrode. Can be formed twice as large.

The diameter of the first via electrode 111 is not limited thereto, but may be 100 to 300 μm.

If the diameter of the first via electrode 111 is large, a second via electrode electrically connected to the first via electrode may be easily formed, thereby reducing variation due to shrinkage. If the diameter of 111 is too large, the strength of the core substrate may be lowered, and thus may be formed within the above range.

A plurality of second via electrodes 121 and 131 may be formed in the first buffer layer 120 formed on the top surface of the core substrate 110 and the second buffer layer 130 formed on the bottom surface of the core substrate 110, respectively.

The first and second buffer layers 120 and 130 may be formed of low temperature co-fired ceramics (LTCC) including a glass component capable of reacting with alumina, which is a main component of the core substrate 110.

The first and second buffer layers 120 and 130 may be formed by sintering a green sheet including low temperature co-fired ceramic powder, and may form a buffer layer having a desired thickness by stacking a plurality of green sheets.

The glass component may be SiO ₂ , but is not limited thereto. The content of SiO ₂ may be 40 to 70wt% with respect to the buffer layer.

In addition, the buffer layer may include a metal oxide such as B ₂ O ₃ , Al ₂ O ₃ , or Ca, Mg. The content of the B ₂ O ₃ may be 5 to 15wt%, the content of Al ₂ O ₃ may be 20wt% or less. The content of the metal oxides such as Ca and Mg may be 5wt% or less.

The diameter of the second via electrodes 121 and 131 may be smaller than the diameter of the first via electrode, but is not limited thereto, but may be formed to be 1/3 to 1/2 of the diameter of the first via electrode. Can be.

The diameter of the second via electrodes 121 and 131 is not limited thereto, but may be, for example, 50 to 100 μm, and preferably 50 to 70 μm.

The number of the second via electrodes is greater than the number of the first via electrodes, but the number of the second via electrodes is not limited thereto. For example, the number of the second via electrodes may be thousands to tens of thousands.

The second via electrode formed on the buffer layer may be electrically connected to the first via electrode by a conductive pattern formed on the buffer layer.

Referring to FIG. 1, a conductive pattern 122 may be formed in the first buffer layer 120, and the first via electrode 111 and the second via electrode 121 may be electrically connected to each other by an appropriate position structure of the conductive pattern. Can be connected. The conductive pattern may be appropriately formed when laminating the green sheet for buffer layer formation.

As mentioned above, according to this embodiment, mechanical strength can be ensured by the core substrate containing an alumina component. In addition, since the first via electrode formed on the core substrate has a large diameter, positional deviation due to shrinkage may be minimized. In addition, the buffer layer including the glass component is capable of non-shrink firing, it is possible to compensate for the shrinkage deviation of the core substrate.

Hereinafter, the manufacturing method of the ceramic substrate for probe cards which concerns on one Embodiment of this invention is demonstrated.

2A and 2B are cross-sectional views for each process for explaining a method for manufacturing a ceramic substrate for a probe card according to an embodiment of the present invention.

First, as illustrated in FIG. 2A, a core substrate 210 formed of a ceramic sintered body including alumina and having a plurality of first via electrodes 211 penetrating through an upper surface and a lower surface thereof is provided.

More specifically, the green sheet may be formed of a high temperature co-fired ceramic powder containing alumina. Specific components and contents of the green sheet are as described above.

A plurality of green sheets may be stacked to provide a green sheet laminate, and via holes may be formed to penetrate the upper and lower surfaces of the green sheet laminate. Thereafter, the via hole may be filled and fired to prepare a core substrate on which the first via electrode is formed.

The method of forming the via hole is not particularly limited, and may be formed by, for example, laser processing or an etching process. In addition, the method of filling the via hole is not particularly limited, and for example, the method may be performed by filling a conductive paste into the via hole, plating, or the like.

Subsequently, as shown in FIG. 2B, a buffer layer including a glass component capable of reacting with alumina may be formed on at least one of the upper and lower surfaces of the core substrate 210. A plurality of second via electrodes may be formed in the buffer layer, and the second via electrodes may be formed to be electrically connected to the first via electrodes.

2B illustrates a process in which the first buffer layer 220 is stacked on the top surface of the core substrate 210 and the second buffer layer 230 is stacked on the bottom surface of the core substrate 210.

Although not limited thereto, the first buffer layer 220 may be provided by the following process.

First, a green sheet may be formed of a low temperature co-fired ceramic powder containing a glass component, and the green sheet may be laminated to prepare a green sheet laminate. Specific components and contents of the green sheet are as described above.

In the stacking process of the green sheet, a conductive pattern portion may be formed, a via hole connected to the conductive pattern portion may be formed, and the conductive pattern portion and the via hole may be filled.

The first buffer layer in the green sheet state may be stacked on an upper surface of the core substrate. In addition, the second buffer layer in the green sheet state may be stacked on the bottom surface of the core substrate.

Thereafter, the first buffer layer and the second buffer layer in the green sheet state may be fired. The via hole and the conductive pattern portion filled in the firing process may be formed of the second via electrode 221 and the conductive pattern 222, respectively.

The core substrate, which has already been fired in the firing process, serves to help the shrinkage of the buffer layer in the green sheet state. In addition, the glass component included in the buffer layer reacts with the alumina of the core substrate to improve adhesion between the core substrate and the buffer layer.

As described above, the diameter of the second via electrode 221 may be smaller than the diameter of the first via electrode 231. In addition, the number of second via electrodes may be formed to be two to five times the number of first via electrodes.

The core substrate may be shrunk during the firing process so that the diameter of the first via electrode may be increased instead of reducing the number of first via electrodes. The position of the second via electrode formed in the buffer layer may be designed based on the position of the first via electrode of the core substrate after firing.

Although the core substrate may have a positional deviation due to shrinkage, the diameter of the first via electrode may be increased to minimize mismatching between the first via electrode and the second via electrode. In addition, the buffer layer is capable of non-shrink firing to compensate for the shrinkage deviation of the core substrate.

It is intended that the invention not be limited by the foregoing embodiments and the accompanying drawings, but rather by the claims appended hereto. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

110 and 210: core substrate 111 and 211: first via electrode
120, 130, 220, 230: buffer layer 121, 131, 221, 231: second via electrode
122, 222: conductor pattern

Claims

A core substrate formed of a ceramic sintered body including alumina and having a plurality of first via electrodes penetrating the upper and lower surfaces thereof; And
A second material formed on at least one of an upper surface and a lower surface of the core substrate and including a glass component capable of reacting with the alumina, electrically connected to the first via electrode, and having a diameter smaller than a diameter of the first via electrode; A buffer layer on which a via electrode is formed;
Ceramic substrate for a probe card comprising a.

The method of claim 1,
The number of the first via electrodes is 1/2 to 1/5 of the number of the second via electrodes.

The method of claim 1,
And a diameter of the first via electrode is two to three times larger than a diameter of the second via electrode.

The method of claim 1,
And the second via electrode is electrically connected to the first via electrode by a conductive pattern formed in the buffer layer.

The method of claim 1,
The content of the alumina is a ceramic substrate for a probe card that is 90wt% or more of the ceramic sintered body.

The method of claim 1,
The content of the glass component is a ceramic substrate for a probe card is 40 to 70wt% of the buffer layer.

The method of claim 1,
And a probe formed on one surface of the buffer layer to be electrically connected to the second via electrode.

The method of claim 1,
And a build-up layer including a conductive pattern electrically connected to the second via electrode on one surface of the buffer layer.

Providing a core substrate formed of a ceramic sintered body including alumina and having a plurality of first via electrodes penetrating the upper and lower surfaces thereof; And
A second via electrode including a glass component capable of reacting with the alumina on at least one of upper and lower surfaces of the core substrate, electrically connected to the first via electrode, and having a diameter smaller than the diameter of the first via electrode. Forming a formed buffer layer;
Method of manufacturing a ceramic substrate for a probe card comprising a.

10. The method of claim 9,
Forming the buffer layer
Stacking a buffer layer in a green sheet state in which a second via electrode is formed on the core substrate and firing the buffer layer in the green sheet state.

10. The method of claim 9,
And a conductive pattern formed on the buffer layer to electrically connect the second via electrode and the first via electrode.

10. The method of claim 9,
And the number of the second via electrodes is formed to be 2 to 5 times the number of the first via electrodes.

10. The method of claim 9,
And a diameter of the second via electrode is 1/3 to 1/2 of a diameter of the first via electrode.

10. The method of claim 9,
The alumina content is a method of manufacturing a ceramic substrate for a probe card is 90w% or more of the ceramic sintered body.

10. The method of claim 9,
The content of the glass component is a method of manufacturing a ceramic substrate for a probe card is 40 to 70w% of the buffer layer.