JP2001174507A - Anisotropic conductive sheet for package evaluation and method of package evaluation using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive sheet for package evaluation capable of preventing a defective contact in an electrical connection between a package and a substrate for evaluation, and a method of package evaluation using the conductive sheet. SOLUTION: This anisotropic conductive sheet for package evaluation is provided between a package and a substrate for evaluation and allows the electrodes provided on the surfaces of the package and substrate opposed to each other to be connected electrically to each other when the characteristics of the package having a plurality of electrodes disposed on one surface of a main body as external terminals are evaluated. A bump having a conductivity and an elasticity is formed of at least any one of the surfaces opposed to the package of the anisotropic conductive sheet and substrate for evaluation at a portion corresponding to the electrode position on the package and substrate side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anisotropic conductive sheet for evaluating a package and a method for evaluating a package using the anisotropic conductive sheet.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller, faster, and more sophisticated, technological developments in packaging technology have also been developed to reduce the size, thickness, increase the number of pins, and increase the number of dimensions. In recent years, in particular, a package (for example, a chip size package (CSP)) having a body size equal to or slightly larger than a semiconductor chip and having a structure in which external terminals do not protrude from the body has been widely used. Was.

FIG. 8 schematically shows a state in which the electrical characteristics (RF or DC characteristics) of a package in which external terminals are arranged on the lower surface side of a main body are to be evaluated using a conventional process. This package 50 has a plurality of electrode pads 51 arranged substantially flush on the lower surface side of the main body. In the figure, a state after a predetermined circuit board is die-bonded in the main body using solder or resin. Is shown. In the process of evaluating the package 50, the package body is disposed on the evaluation substrate 53 via the anisotropic conductive sheet 55 and is urged against the evaluation substrate 53. The evaluation substrate 53 has a plurality of electrodes 54 on the upper surface side corresponding to the electrode pads 51 on the package 50 side.

The anisotropic conductive sheet 55 used here
Has a structure (not shown) in which a plurality of conductive fibers are arranged in the thickness direction of the sheet in the insulator and also provided with a conductive filler,
It has the property of activating conductivity only in the part pressed in the vertical direction. Due to such properties, when the package 50 is urged against the evaluation substrate 53, the anisotropic conductive property is obtained. The corresponding electrode pads 51 on the package 50 and the electrodes 54 on the evaluation substrate 53 are electrically connected to each other via the sheet 55.

[0005]

However, in such a conventional evaluation process, when the flatness is not good on the lower surface side of the package 50, that is, on the side where the electrode pads 51 are provided, as shown in FIG. Even if the package 50 is urged against the evaluation substrate 53, the electrode pads 51 or the electrodes 54 cannot secure a sufficient contact state with the anisotropic conductive sheet 55, and particularly, a large number of ports. However, there is a problem that a contact failure is likely to occur when evaluating a package having the above. This problem is caused by the problem of the electrode 54 of the evaluation substrate 53.
In the case where flatness is not good (not shown) on the side where is provided, the same occurs as in the above case. In recent years, socket type jigs are often applied to packages incorporating a high frequency band MMIC (monolithic microwave integrated circuit). This may cause problems such as poor reproducibility of measured values and deterioration of isolation between adjacent electrodes.

[0006] For example, in Japanese Patent Application Laid-Open No. Hei 5-47428, a method for satisfactorily connecting electrodes between electronic components is as follows.
A connection method of an electronic component using an anisotropic conductive film in which a conductive portion having a protruding electrode structure is formed in a through-hole portion of a porous insulating film is disclosed. According to this method, a natural oxide film on the surface of the conductive portion is destroyed by applying an ultrasonic wave after energizing the two electronic components with an anisotropic conductive film interposed between the electronic components. It is configured so that alloy joining is caused on the new surfaces of both electrode metals to ensure connection. However, in this case, it is necessary to apply an ultrasonic wave every time the electronic component is connected, so that the operation is troublesome.

Accordingly, the present invention has been made in view of the above technical problems, and a conductive sheet for evaluating a package and a package using the same, which can prevent contact failure in electrical connection between the package and an evaluation board. The purpose is to provide an evaluation method.

[0008]

According to a first aspect of the present invention, there is provided a method for evaluating characteristics of a package having a plurality of electrodes arranged on at least one surface of a main body as external terminals.
The anisotropic conductive sheet for package evaluation, which is interposed between the package and the evaluation substrate and electrically connects corresponding ones of the electrodes provided on the surfaces facing each other, the anisotropic conductive sheet for package evaluation, At least one of the surface of the conductive sheet facing the package and the evaluation substrate has a conductive and elastic bump formed at a position corresponding to the electrode position on the package or the evaluation substrate side. It was done.

According to a second aspect of the present invention, a bump group formed by assembling bumps having an area smaller than the area of the package and the electrode on the evaluation substrate side is formed at least at a portion corresponding to the electrode position. It is characterized by having.

Further, the third invention of the present application is characterized in that the bump group is formed in substantially the entire area of the surface facing the package and the evaluation substrate.

Still further, a fourth invention of the present application is directed to a method for manufacturing a semiconductor device, comprising: the package and the evaluation substrate interposed between at least one of the surfaces facing the evaluation substrate and the package. An outer wall portion for guiding the outer peripheral portion is provided.

Further, the fifth invention of the present application is directed to evaluating the characteristics of a package having a plurality of electrodes arranged on one surface side of a main body as external terminals, when evaluating the characteristics of a package and an evaluation substrate on opposing surfaces. In a package evaluation method of electrically connecting corresponding ones of the provided electrodes, between the package and the evaluation substrate,
The bump formed on the anisotropic conductive sheet is brought into contact with the package and the electrode on the evaluation substrate side with the anisotropic conductive sheet according to any one of claims 1 to 4 interposed therebetween. In addition, the package is urged against the evaluation substrate.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Embodiment 1 FIG. FIG. 1 shows an electrical characteristic (for example, RF or D) of a package in which external terminals are arranged on the lower surface side of a main body using the anisotropic conductive sheet according to Embodiment 1 of the present invention.
FIG. 4 is an explanatory cross-sectional view schematically showing a state in which C characteristic is to be evaluated. The package 1 used here is conventionally
Known as a surface mount type multiport leadless package, a plurality of electrode pads 3 are two-dimensionally arranged on the lower surface side of the package body as external terminals connected to electrodes on a substrate. These electrode pads 3
Are exposed substantially flush with the lower surface of the package body. The figure shows a package in a state after a high frequency band MMIC substrate (monolithic microwave integrated circuit substrate) is die-bonded using solder or resin in the main body.

On the other hand, a substrate 7 (hereinafter referred to as an evaluation substrate) for evaluating electrical characteristics such as input / output current, input / output voltage, and power supply of the package 1 has a plurality of substrates on its upper surface. An electrode 8 is provided. Each of these electrodes 8 corresponds to one of the electrode pads 3 exposed on the lower surface side of the package 1.

In the process of evaluating the electrical characteristics of the package 1, the package body is placed on the evaluation substrate 7 via the anisotropic conductive sheet 5 and pressed against the anisotropic conductive sheet 5. Then, it is urged against the evaluation substrate 7. The anisotropic conductive sheet 5 interposed between the package 1 and the evaluation substrate 7 is a so-called fiber-embedded type, in which conductive fibers such as metal fibers and carbon fibers are embedded in a rubber insulator. And has a structure (not shown) provided with a conductive filler, and has a property of effecting conductivity only in a vertically pressed portion.

In this embodiment, a plurality of bumps 5a having a predetermined height are formed integrally with the sheet body on the upper surface of the anisotropic conductive sheet 5, ie, the surface facing the package 1, and Are arranged so as to correspond to the positions of the respective electrode pads 3. The bumps 5a formed integrally with the sheet body have conductivity and elasticity due to the structure of the anisotropic conductive sheet 5 described above.

FIG. 2 is an explanatory sectional view showing a state in which the package 1 is urged against the evaluation substrate 7 via the anisotropic conductive sheet 5 on which the bumps 5a are formed. In this evaluation process, the pressing member 11 made of an insulating material such as silicon rubber is vertically lowered on the upper surface side of the package 1 to apply an urging force to the package 1. In this case, the package 1 is attached to the evaluation substrate 7 so that each bump 5a on the anisotropic conductive sheet 5 comes into contact with the corresponding electrode pad 3 on the package 1 side and is elastically deformed. Inspire. Thereby, a sufficient contact state is ensured between the electrode pad 3 on the package 1 side and the bump 5a on the anisotropic conductive sheet 5 side. Accordingly, on the lower surface side of the anisotropic conductive sheet 5, a contact state between the electrode 8 on the evaluation substrate 7 side and the anisotropic conductive sheet 1 is ensured.

In this embodiment, since each of the bumps 5a protrudes from the plane of the sheet 5, it is easy to come into contact with the electrode pads 3 on the package 1 side. For this reason, as shown in FIG. 2, even when the flatness is not good on the lower surface side of the package 1, sufficient contact between the electrode pads 3 on the package 1 side and the bumps 5a on the anisotropic conductive sheet 5 side is sufficient. As a result, an electrical connection can be realized between the electrode pad 3 on the package 1 and the electrode 8 on the evaluation substrate 7 based on the characteristics of the anisotropic conductive sheet 5. can do. In this way, by ensuring the electrical connection between the package 1 in which the high-frequency band MMIC (monolithic microwave integrated circuit) is incorporated and the evaluation board 7, the reproducibility of the measured values in the high-frequency band is ensured. It is possible to eliminate the possibility that a defect or deterioration of isolation between adjacent electrodes occurs. Further, in the anisotropic conductive sheet 5, the bumps 5a have elasticity, and the pressing members 11
Is returned to its original shape when it is removed, so that it can be used repeatedly.

In the first embodiment, the case where the bumps 5a are formed on the surface facing the package 1 in the anisotropic conductive sheet 5 has been described. However, the present invention is not limited to this. Such a bump 5a may be formed on the surface facing the evaluation substrate 7. In this case, as in the case described above, it is possible to secure a contact state between the electrode 8 on the evaluation substrate 7 side having poor flatness and the bump 5 a formed on the anisotropic conductive sheet 5. it can.

Hereinafter, another embodiment of the present invention will be described. In the following description, the first embodiment described above is used.
The same reference numerals are given to the same components as in the above, and further description is omitted. Embodiment 2 FIG. FIG. 3 is a cross-sectional explanatory view schematically showing a state in which electrical characteristics of a package are to be evaluated using the anisotropic conductive sheet according to Embodiment 2 of the present invention. In this case, anisotropic conductive sheet 15 is interposed between package 1 and evaluation substrate 7 during the process of evaluating the electrical characteristics of package 1 as in the first embodiment. In the second embodiment,
On both surfaces of the anisotropic conductive sheet 15, that is, on the surface facing the package 1 and the evaluation substrate 7, bumps 15a and 15b having a predetermined height are formed integrally with the sheet body. These bumps 15a and 15b are arranged so as to correspond to the positions of the respective electrode pads 3 on the package 1 side and the electrodes 8 on the evaluation substrate 7 side.

In the process of evaluating the electrical characteristics of the package 1, when the package 1 is urged against the evaluation substrate 7, the upper surface of the anisotropic conductive sheet 15
Each bump 15a abuts on the electrode pad 3 on the package 1 and is elastically deformed to ensure a sufficient contact state between the electrode pad 3 on the package 1 and the bump 15a on the anisotropic conductive sheet 15 side. . On the other hand, on the lower surface side of the anisotropic conductive sheet 15, each bump 15b abuts on the electrode 8 on the evaluation substrate 7 side and is elastically deformed, so that the electrode 8 on the evaluation substrate 7 side and the electrode 8 on the anisotropic conductive sheet 15 side And a sufficient contact state with the bump 15b.

Accordingly, even when the flatness on the lower surface side of the package 1 and the upper surface side of the evaluation substrate 7 is not good, the gap between the electrode pads 3 on the package 1 and the bumps 15a on the anisotropic conductive sheet 5 can be improved. And the electrode 8 on the evaluation substrate 7 side.
And the bumps 15b on the side of the anisotropic conductive sheet 15 can secure a sufficient contact state, and the electrode pads 3 on the package 1 side and the electrodes 8 on the evaluation board 7 side can be more reliably maintained. Electrical connection can be realized.

Embodiment 3 FIG. FIG. 4 is an explanatory cross-sectional view schematically showing a state in which electrical characteristics of a package are to be evaluated using the anisotropic conductive sheet according to Embodiment 3 of the present invention. In the third embodiment, on the upper surface of the anisotropic conductive sheet 25, a bump group 27 formed by collecting bumps 27a having an area smaller than the area of the electrode pads 3 on the package 1 side is formed. These bump groups 27
Are arranged at positions corresponding to the electrode pads 3 and the vicinity thereof. Further, the anisotropic conductive sheet 25 has the same characteristics as those in the first embodiment, and the bumps 27 a forming the bump group 27 have conductivity and elasticity, respectively. I have.

FIG. 5 is an explanatory sectional view showing a state in which the package 1 is urged against the evaluation substrate 7 via the anisotropic conductive sheet 25 on which the bump group 27 is formed. When the package 1 is urged against the evaluation substrate 7, the bumps at the portions of the bump groups 27 formed on the anisotropic conductive sheet 25 that face the electrode pads 3 on the package 1 side 27a comes into contact with the electrode pad 3 and is elastically deformed. This ensures a sufficient contact state between the electrode pads 3 on the package 1 side and the bumps 27a on the anisotropic conductive sheet 25 side. Also,
Accordingly, on the lower surface side of the anisotropic conductive sheet 25, a contact state between the electrode 8 on the evaluation substrate 7 side and the anisotropic conductive sheet 1 is ensured.

In the third embodiment, since the area of the bump 27a is smaller than that of the electrode pad 3, if at least the bump 27a facing the electrode pad 3 exists in each bump group 27, the bump 27a Can contact the electrode pads 3, and a contact state is secured between the electrode pads 3 on the package 1 side and the bumps 27 a on the anisotropic conductive sheet 25 side. That is, in this case, the positioning of the anisotropic conductive sheet 25 with respect to the package 1 during the process of evaluating the package 1 is relatively easy, and the electrode pads 3 on the package 1 and the electrodes 8 on the evaluation substrate 7 are relatively easily positioned. Electrical connection can be more reliably realized between them. The anisotropic conductive sheet 25 can be used repeatedly because the bumps 27a in the bump group 27 have elasticity.

Embodiment 4 FIG. 6 is a cross-sectional explanatory view schematically showing a state in which electrical characteristics of a package are to be evaluated using the anisotropic conductive sheet according to Embodiment 4 of the present invention. This anisotropic conductive sheet 35 has an upper surface and a lower surface, as in the third embodiment,
Bump group 3 in which bumps 37a and 38a having an area smaller than the area of electrode pad 3 on package 1 are collected.
In the fourth embodiment, the bump groups 37 and 38 are formed in substantially the entire upper surface and lower surface of the anisotropic conductive sheet 35.

As described above, by providing the bump groups 37 and 38 over substantially the entire upper and lower surfaces of the anisotropic conductive sheet 35, the electrode pads 3 on the package 1 side and the evaluation substrate 7 are provided.
Bumps 3 of anisotropic conductive sheet 35 with respect to side electrode 8
The alignment of 7, 38 is almost unnecessary. Further, in this case, the anisotropic conductive sheet 35 is provided with various packages 1 or evaluation substrates 7 having different positions of the electrode pads 3 or the electrodes 7.
It is possible to correspond to.

Embodiment 5 FIG. 7 is a cross-sectional explanatory view schematically showing a state in which electrical characteristics of a package are to be evaluated using the anisotropic conductive sheet according to Embodiment 5 of the present invention. This anisotropic conductive sheet 45 has a package 1 on its upper surface as in the case of the first embodiment.
In the fifth embodiment, an outer wall portion 45d having a predetermined height is further provided on the peripheral portion of the upper surface in the bump 45a arranged corresponding to the position of each electrode pad 3 on the side. I have.

The outer wall portion 45d guides the outer peripheral portion of the package 1 when it is interposed between the package 1 and the evaluation board 7 during the evaluation process of the package 1, and serves as an electrode pad on the package 1 side. 3 and the corresponding bump 45a on the anisotropic conductive sheet 45 side can be accurately positioned. By providing such an outer wall portion 45d, the alignment of the anisotropic conductive sheet 45 with respect to the package 1 is facilitated, and the electrical connection between the electrode pads 3 on the package 1 side and the electrodes 8 on the evaluation substrate 7 side is more reliably achieved. Connection can be realized. In the fifth embodiment, the outer wall portion 45 d
Is described, but the present invention is not limited to this. The outer wall 45d is formed on the upper surface of the anisotropic conductive sheet 45, and the evaluation substrate 7 of the anisotropic conductive sheet 45 is formed. An outer wall portion for guiding the outer peripheral portion of the evaluation substrate 7 may be formed on the surface opposed to.

The present invention is not limited to the illustrated embodiment, and it goes without saying that various improvements and design changes can be made without departing from the spirit of the present invention.

[0031]

According to the first aspect of the present invention, when evaluating the characteristics of a package having a plurality of electrodes arranged on at least one surface side of the main body as external terminals, the characteristic between the package and the evaluation board is evaluated. In the anisotropic conductive sheet for package evaluation that is interposed between and electrically connects corresponding ones of the electrodes provided on the surfaces facing each other, the package of the anisotropic conductive sheet and the evaluation substrate At least one of the opposing surfaces has a portion corresponding to an electrode position on the package or evaluation substrate side,
Since bumps having conductivity and elasticity are formed, the bumps on the anisotropic conductive sheet side can be used as the electrodes on the package side and the electrodes on the evaluation substrate side even when the flatness of the package and the evaluation substrate is not good. , And electrical connection can be reliably realized between the electrode on the package side and the electrode on the evaluation substrate side. As a result, it is possible to prevent poor reproducibility of measured values of the high-frequency characteristics due to poor contact. Further, the anisotropic conductive sheet has elasticity in the bumps, and thus can be used repeatedly.

Further, according to the invention of claim 2 of the present application, a bump group in which bumps having an area smaller than the area of the package and the electrode on the evaluation substrate side are gathered at least at a portion corresponding to the electrode position. Since each bump group has at least a bump facing the package-side electrode, the bump can contact the package-side electrode, and the package-side electrode and the anisotropic conductive material are formed. A contact state with the bump on the sheet side can be ensured. That is, according to the present invention, during the package evaluation process, the positioning of the anisotropic conductive sheet with respect to the package is relatively easy, and the electrical connection between the package side electrode and the evaluation board side electrode is made more reliable. Connection can be realized. The anisotropic conductive sheet can be used repeatedly because the bumps in the bump group have elasticity.

Further, according to the invention of claim 3 of the present application, the bump group is formed in substantially the entire area of the surface facing the package and the evaluation substrate, and the electrodes on the package side and the electrodes on the evaluation substrate side are formed. It is almost unnecessary to align the bumps of the anisotropic conductive sheet with respect to the above, and it is possible to more reliably realize the electrical connection between the electrode on the package side and the electrode on the evaluation substrate side. Further, the anisotropic conductive sheet can be used for various packages or evaluation substrates in which the positions of the electrodes are different.

Further, according to the invention of claim 4 of the present application, at least one of the surfaces facing the package and the evaluation substrate is interposed between the package and the evaluation substrate. Since the outer wall portion for guiding the outer peripheral portion of the package is provided, the anisotropic conductive sheet with respect to the package is positioned so that the electrodes on the package side and the bumps on the anisotropic conductive sheet side corresponding thereto are accurately positioned. Positioning can be easily performed. As a result,
Electrical connection can be more reliably realized between the electrode on the package side and the electrode on the evaluation substrate side.

Further, according to the fifth aspect of the present invention, the first aspect of the present invention is provided between the package and the evaluation board.
The anisotropic conductive sheet according to any one of claims 1 to 4 is interposed, and the bumps formed on the anisotropic conductive sheet are in contact with the package and the electrode on the evaluation substrate side.
Since the above package is urged against the evaluation board,
A sufficient contact state can be secured between the bumps on the anisotropic conductive sheet side and the electrodes on the package and the substrate for evaluation. Thereby, electrical connection can be reliably realized between the electrode on the package side and the electrode on the evaluation substrate side.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view schematically showing a state in which a package is to be evaluated using an anisotropic conductive sheet according to Embodiment 1 of the present invention.

FIG. 2 is an explanatory cross-sectional view showing an enlarged state of contact between the anisotropic conductive sheet and a package.

FIG. 3 is a cross-sectional explanatory view schematically showing a state where a package is to be evaluated using an anisotropic conductive sheet according to a second embodiment of the present invention.

FIG. 4 is an explanatory sectional view schematically showing a state in which a package is to be evaluated using an anisotropic conductive sheet according to a third embodiment of the present invention.

FIG. 5 is an enlarged sectional explanatory view showing a contact state between an anisotropic conductive sheet and a package according to the third embodiment.

FIG. 6 is an explanatory cross-sectional view schematically showing a state in which a package is to be evaluated using the anisotropic conductive sheet according to Embodiment 4 of the present invention.

FIG. 7 is an explanatory sectional view schematically showing a state in which a package is to be evaluated using an anisotropic conductive sheet according to a fifth embodiment of the present invention.

FIG. 8 is an explanatory cross-sectional view schematically showing a state where a package is to be evaluated using a conventional anisotropic conductive sheet.

FIG. 9 is an enlarged cross-sectional explanatory view showing a contact state between a conventional anisotropic conductive sheet and a package.

[Explanation of symbols]

1 package, 3 electrode pads, 5 anisotropic conductive sheet, 5a bump, 7 evaluation board, 8 electrodes, 27 bump group, 45d outer wall

Claims (5)

[Claims] When evaluating the characteristics of a package having a plurality of electrodes arranged on at least one side of a main body as external terminals, the package is interposed between the package and an evaluation board, and is provided on a surface opposed to the two. In the package evaluation anisotropic conductive sheet for electrically connecting corresponding ones of the provided electrodes, at least one of the surface of the anisotropic conductive sheet facing the package and the evaluation substrate includes the package. Alternatively, an anisotropic conductive sheet for package evaluation, wherein bumps having conductivity and elasticity are formed in portions corresponding to electrode positions on the evaluation substrate side. 2. A bump group formed by assembling bumps having an area smaller than the area of the package and the electrode on the evaluation substrate side is formed at least at a portion corresponding to the electrode position. Item 2. An anisotropic conductive sheet for package evaluation according to item 1. 3. The anisotropic conductive sheet for package evaluation according to claim 2, wherein the bump group is formed in substantially the entire area of the surface facing the package and the substrate for evaluation. 4. An outer wall portion which guides an outer peripheral portion of the package in a state interposed between the package and the evaluation substrate on at least one of the surface facing the package and the evaluation substrate. The anisotropic conductive sheet for package evaluation according to any one of claims 1 to 3, wherein: 5. When evaluating characteristics of a package having a plurality of electrodes arranged on one surface side of a main body as external terminals, corresponding ones of the electrodes provided on the opposing surfaces of the package and the evaluation substrate, respectively. A package evaluation method for electrically connecting the package and the evaluation board, between the package and the evaluation board.
The package, wherein the anisotropic conductive sheet according to any one of claims 4 is interposed, so that the bump formed on the anisotropic conductive sheet contacts the package and the electrode on the evaluation substrate side. A package evaluation method, wherein a package is urged against an evaluation substrate.