JP2003017864A - Multilayer board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a junction section, between the electrode of components and the land of a multiplayer board, from being recognized as being abnormal by mistake and to accurately judge the junction section of electronic components being incorporated between inner layers. SOLUTION: A land 2b and an inner via hole 2c are arranged at a position, where the X-ray transmission image of the junction section of components and the land 2b on the surface overlaps with that of the inner via hole 2c. Additionally, the arrangement is such that the X-ray transmission image of the junction section of inner-layer components 11 and a land 23 and that of the via hole 2c do not overlap that of the junction section of an electrode 1a and the land 2b.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a CSP (chip
The present invention relates to a multilayer substrate for mounting components such as size / package components, and more particularly to a multilayer substrate in which three or more layers are electrically connected in the thickness direction through inner via holes.
The present invention also relates to a multilayer substrate having electronic components built in between inner layers.

[0002]

2. Description of the Related Art FIGS. 9 and 10 are a plan view and a side sectional view, respectively, of a conventional multilayer substrate, in which an electrode 1a is formed on the lower surface of a chip carrier 1 of a CSP component. A conductive pattern 2a is formed on the upper surface of the multilayer substrate 2 so as to substantially face the electrode 1a of the chip carrier 1.
A land 2b is formed on a so as to face the electrode 1a of the chip carrier 1.

Further, as clearly shown in FIG. 9, an inner via hole (hereinafter simply referred to as a via hole) is formed at an arbitrary position inside the multilayer substrate 2 for electrically connecting the inner layers in the thickness direction. 2c is formed. And
When the CSP component is mounted on the multilayer substrate 2 in the LGA (land grid array) type, cream solder is arranged on the land 2b side of the multilayer substrate 2 for reflow soldering. The solder 3 shown in FIG. 10 shows a state in which cream solder is reflow-soldered.

[0004]

By the way, FIG. 9 and FIG.
When CSP components are mounted on the multilayer substrate 2 as shown in 0, it is tested whether there is too much solder 3 at the joint between the electrode 1a side of the chip carrier 1 and the land 2b side of the multilayer substrate 2 to cause a short circuit. Therefore, from the upper side of the multilayer substrate 2, X
X-ray transmission image is transmitted through the X-ray on the lower side of the multilayer substrate 2.
An image is taken with a line CCD camera or the like.

However, in the above-mentioned conventional multilayer substrate 2, the via hole 2c is located at an arbitrary position, that is, the land 2b.
In the X-ray transmission image, the transmission image of the via hole 2c is adjacent to the transmission image of the junction between the electrode 1a of the chip carrier 1 and the land 2b of the multilayer substrate 2 as shown in FIG. There is a problem in that they appear to be separated or separated, and therefore, even if the joint is normal, it is erroneously recognized as abnormal. Here, the diameter of the via hole 2c is 0.1 to
The land 2b has a diameter of about 0.15 mm and a diameter of about 0.3 to 0.5 mm. When a via hole image smaller than the land image is seen near the land image as shown in FIG. Become.

Electronic parts may be mounted not only on the surface of the multilayer board but also on the inner layers. In this case, when the junction of the electrode of the electronic component and the land in the inner layer is confirmed by the X-ray transmission image, this junction overlaps with the transmission image of the via hole 2c and the junction of the electrode 1a and the land 2b on the surface. If it is arranged like this, it becomes difficult to make an accurate determination.

In view of the above-mentioned problems of the conventional example, the present invention provides a multi-layered substrate capable of preventing erroneous recognition as abnormal even if the joint between the electrode of the component and the land of the multi-layered substrate is normal. The purpose is to Another object of the present invention is to provide a multi-layer substrate capable of accurately judging the quality of the joint portion of the electronic component embedded between the inner layers.

[0008]

In order to achieve the above-mentioned object, the present invention has a first land for connecting electrodes of a first component formed on the surface thereof, and electrically connecting the inner layers in the thickness direction. In the multilayer substrate in which the inner via hole for electrically connecting is formed, the X-ray transmission image of the joint between the electrode of the first component and the first land overlaps with the X-ray transmission image of the inner via hole. The first land and the inner via hole are arranged at the positions. With the above configuration, the transmission image of the via hole is not seen as being adjacent to or separated from the transmission image of the junction between the electrode of the chip carrier and the land of the multilayer substrate.
Even if the joint between the electrode of the component and the land of the multilayer substrate is normal, it can be prevented from being erroneously recognized as abnormal.

In order to achieve the above object, the present invention also forms an inner via hole for electrically connecting the inner layers in the thickness direction, and connects a second component on the land between the inner layers. In the multilayer substrate, the X-ray transmission image of the junction of the electrode of the second component and the second land does not overlap with the X-ray transmission image of the inner via hole, and the second land and the inner The via hole and the via hole are arranged. With the above configuration, it is possible to accurately determine the joint portion of the electronic component embedded between the inner layers.

In order to achieve the above object, the present invention also has a first land for connecting the electrodes of the first component formed on the surface, and a second land on the second land between the inner layers. X-ray transmission image of the joint of the electrode of the first component and the first land, and X-ray of the joint of the second component and the second land in the multilayer substrate to which the component of FIG.
The first and second lands are arranged at positions where the line transmission images do not overlap. With the above configuration, it is possible to accurately determine the joint portion of the electronic component embedded between the inner layers.

According to the present invention, the third component is connected to the third land between the inner layers, and the X-ray transmission of the joint between the electrode of the second component and the second land is performed. The second land or the third land and the inner land at a position where the image, the X-ray transmission image of the junction of the electrode of the third component and the third land, and the X-ray transmission image of the inner via hole do not overlap. The via hole and the via hole are arranged. With the above configuration, it is possible to accurately determine the joint portion between the electronic component mounted on the surface and the electronic component embedded between the inner layers.

The present invention also provides the first aspect of claim 1.
The X-ray transmission image of the electrode of the component and the joint of the first land and the joint of the second component and the second land of claim 4 are arranged at positions not overlapping. . With the above configuration, it is possible to accurately determine the joint portion between the electronic component mounted on the surface and the electronic component embedded between the inner layers.

The present invention is also characterized in that the X-ray transmission image is an image when X-rays are transmitted in the thickness direction of the multilayer substrate. The present invention is also characterized in that the X-ray transmission image is an image when X-rays are transmitted obliquely with respect to the thickness direction of the multilayer substrate. The present invention is also characterized in that the X-ray transmission image is an image when X-rays of a substantially point light source are transmitted in the thickness direction of the multilayer substrate or obliquely with respect to the thickness direction. With the above configuration, it is possible to increase the degree of freedom in the arrangement position of the land.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 is a plan view showing a first embodiment of a multilayer substrate according to the present invention, FIG. 2 is a side sectional view showing the multilayer substrate of FIG. 1, and FIG. 3 is an X-ray transmission image of the multilayer substrate of FIG. FIGS. 4A and 4B are explanatory views showing a comparison between a conventional example and an actual X-ray transmission image of the present invention.

In the multilayer substrate 2 of the present invention, as shown in FIGS. 1 and 2, all the via holes 2c are formed so as to overlap the lands 2b in the thickness direction of the multilayer substrate 2. Therefore, in the X-ray transmission image, as shown in FIG.
Is superimposed on the transmission image of the junction between the electrode 1a of the chip carrier 1 and the land 2b of the multilayer substrate 2. Note that the other configurations are the same as those of the conventional example, and thus description thereof will be omitted.

FIGS. 4 (a) and 4 (b) show an actual X-ray transmission image of the conventional example and the present invention, respectively. In the conventional example shown in FIG. 4 (a), the transmission image of the via hole 2c is a junction portion. They appear to be adjacent to or separated from the transmission image, and are erroneously recognized as abnormal even if the joint is normal. On the other hand, in the present invention shown in FIG. 4B, the transmission image of the via hole 2c overlaps with the transmission image of the joint portion, so that the transmission image of the via hole 2c may be adjacent to or separated from the transmission image of the joint portion. Therefore, it can be prevented from being erroneously recognized as abnormal even if the joint is normal.

By the way, when the X-ray transmission images of the via hole 2c and the junction of the electrode 1a and the land 2b are arranged to overlap with each other, it is not limited to the case of irradiating substantially parallel X-rays from directly above the multilayer substrate 2. Alternatively, as shown in FIG. 5, the X-rays may be arranged so as to overlap each other when they are obliquely irradiated (for example, −30 ° to 30 °). Also, X to irradiate
It is not limited to the case where X-ray transmission images of equal magnification are obtained by making the lines substantially parallel to each other, and also when the enlarged image is obtained by using X-rays as a point light source as shown in FIG. 6, the joint portion of the electrode 1a and the land 2b And the X-ray transmission images of the via hole 2c may be arranged to overlap each other.

Next, a second embodiment will be described with reference to FIG. The second embodiment further deals with the structure in which the component 11 is mounted on the land 12 between the inner layers of the multilayer substrate 2. In such a structure, the transmission image of the junction between the electrode of the component 11 and the land 12 is arranged so that the transmission image of the via hole 2c or the electrode 1a on the surface and the transmission image of the junction of the land 2b on the surface overlap. If so, accurate determination becomes difficult. Therefore, in the structure in which the component 11 is mounted between the inner layers, the transmission image of the joint between the electrode of the component 11 and the land 12 is the transmission image of the via hole 2c and the transmission image of the joint between the electrode 1a and the land 2b on the surface. By arranging so that they do not overlap, accurate determination is possible.

Also in the second embodiment,
In addition to the case of irradiating the X-ray from directly above the multilayer substrate 2 as shown in FIG. 7, the case of obliquely irradiating or obtaining a magnified image by using the X-ray as a point light source as shown in FIG. Accurate determination is possible by arranging the transmission image of the junction between the electrode 11 and the land 12 so that the transmission image of the via hole 2c does not overlap with the transmission image of the junction between the electrode 1a and the land 2b on the surface. Becomes

[0020]

As described above, according to the first aspect of the present invention, the X-ray transmission image of the contact portion of the electrode and the land of the component on the surface and the X-ray transmission image of the inner via hole overlap each other. Since the land and the inner via hole are arranged, the transmission image of the via hole is not seen adjacent to or away from the transmission image of the junction of the electrode of the chip carrier and the land of the multilayer substrate, and therefore Even if the joint between the electrode and the land of the multilayer substrate is normal, it can be prevented from being erroneously recognized as abnormal. According to the invention described in claim 2, since the X-ray transmission image of the joint portion of the component and the land arranged between the inner layers and the X-ray transmission image of the inner via hole do not overlap each other, it is built in between the inner layers. The joint portion of the electronic component can be accurately determined. According to the invention described in claim 3, the X-ray transmission image of the joint portion of the electrode and the land of the component arranged on the surface and the X-ray transmission image of the joint portion of the component and the land arranged between the inner layers are overlapped. Since the position is set so as not to become, it is possible to accurately determine the joint portion of the electronic component embedded between the inner layers. According to the invention described in claims 4 and 5, it is possible to accurately determine the joint portion between the electronic component mounted on the surface and the electronic component embedded between the inner layers. According to the invention described in claims 6, 7 and 8, the degree of freedom in the arrangement position of the land can be increased.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of a multilayer substrate according to the present invention.

FIG. 2 is a side sectional view showing the multilayer substrate of FIG.

FIG. 3 is an explanatory diagram showing an X-ray transmission image of the multilayer substrate of FIG.

FIG. 4 is an explanatory diagram showing an actual X-ray transmission image of a conventional example in comparison with an actual X-ray transmission image of the present invention.

5 is a diagram showing a modification of the multilayer substrate of FIG. (A) Side sectional view (B) Explanatory drawing showing an X-ray transmission image

6 is a side sectional view showing another modified example of the multilayer substrate of FIG.

FIG. 7 is a diagram showing a multilayer substrate according to a second embodiment of the present invention. (A) Side sectional view (B) Explanatory drawing showing an X-ray transmission image

8 is a side sectional view showing a modified example of the multilayer substrate of FIG.

FIG. 9 is a plan view showing a conventional multilayer substrate.

FIG. 10 is a side sectional view showing the multilayer substrate of FIG.

11 is an explanatory diagram showing an X-ray transmission image of the multilayer substrate of FIG.

[Explanation of symbols]

1 chip carrier 1a electrode 2 Multi-layer board 2b, 12 lands 2c Inna beer hall 11 parts

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2G001 AA01 BA11 CA01 DA09 GA01                       GA06 HA09 HA13 KA03 KA05                       LA11 MA05                 5E346 AA43 BB16 FF45 GG32 GG33                       HH33

Claims (8)

[Claims] 1. A first for connecting electrodes of a first part
Of the land of the first component is formed on the surface and an inner via hole for electrically connecting the inner layers in the thickness direction is formed. A multilayer substrate, wherein the first land and the inner via hole are arranged at a position where the X-ray transmission image and the X-ray transmission image of the inner via hole overlap each other. 2. A multilayer board in which an inner via hole is formed for electrically connecting the inner layers in the thickness direction, and a second component is connected to a land between the inner layers, wherein: A multilayer structure in which the second land and the inner via hole are arranged at a position where the X-ray transmission image of the junction between the electrode and the second land does not overlap with the X-ray transmission image of the inner via hole. substrate. 3. A first for connecting electrodes of a first part
Of the above-mentioned land are formed on the surface, and the second component is connected to the second land between the inner layers, the X-ray of the junction of the electrode of the first component and the first land The first image is placed at a position where the transmission image and the X-ray transmission image of the joint between the electrode of the second component and the second land do not overlap.
And a second land is arranged. 4. A third part is connected on a third land between inner layers, and an X-ray transmission image of an electrode of the second part and a joint portion of the second land and a third part of the third part are connected. The second or third land and the inner via hole are arranged at positions where the X-ray transmission image of the junction between the electrode and the third land does not overlap with the X-ray transmission image of the inner via hole. The multilayer substrate according to claim 1. 5. The X of the joint between the electrode and the first land of the first component according to claim 1 and the joint of the second component and the second land according to claim 4. A multi-layer substrate, which is arranged at a position where line-transmission images do not overlap. 6. The multilayer substrate according to claim 1, wherein the X-ray transmission image is an image when X-rays are transmitted in the thickness direction of the multilayer substrate. 7. The X-ray transmission image is an image when X-rays are transmitted obliquely with respect to the thickness direction of the multilayer substrate, according to any one of claims 1 to 5. Multilayer board. 8. The X-ray transmission image is an image when X-rays of a substantially point light source are transmitted in the thickness direction of the multilayer substrate or obliquely with respect to the thickness direction. The multilayer substrate according to any one of 1.