JP2023001607A - Wiring board laminate - Google Patents

Abstract

To provide a wiring board laminate capable of conducting a continuity test before mounting a semiconductor chip.SOLUTION: A wiring board laminate includes a support, a first conductive layer provided on the upper surface of the support, and a wiring board provided on the upper surface of the first conductive layer, and has a structure including a wiring arranged on each layer of the wiring board, an electrode connected to the outside by exposing to the outside of the board among wirings, and a wiring net which is a conductor continuum that includes through electrodes for connecting wirings on respective layers. The wiring board laminate is possible to achieve both simple electrical inspection and fine wiring with a high yield.SELECTED DRAWING: Figure 3

Description

The present invention relates to a wiring board laminate having a wiring board on a support.

A semiconductor package is assembled by electrically joining a semiconductor component and a wiring board through solder or the like. In recent years, as semiconductor parts such as HBM (High Band Memory) have become highly functional, semiconductor parts have become expensive. Therefore, it is essential that the wiring board on which the semiconductor components are mounted is of good quality, and an electrical inspection method for the wiring board for ensuring quality is very important.

Conventionally, the following two methods have been adopted as an electrical inspection method for wiring boards, and each method is used according to the situation.

In the first method, as shown in FIG. 1, a pair of electrical inspection probes 201a and 201b to which a certain DC voltage is applied are connected to both ends of a first wiring net 41 formed on a wiring substrate 40, respectively. is brought into contact with the electrical inspection probe 201a and the electrical inspection probe 201b at this time, the ratio of the current and voltage, that is, the electrical resistance value, determines the conduction state of the first wiring net. is.

Note that the above-mentioned wiring net includes through electrodes provided through an insulating layer and electrodes provided as part of the wiring in order to connect wirings belonging to different conductor wiring layers on the wiring board. , refers to a series of structures that are all electrically connected.

In the second method, as shown in FIG. 2, of the pair of electrical inspection probes 201a and 201b to which an alternating voltage is applied, the first electrical inspection probe 201a is attached to the first electrical inspection probe formed on the wiring board 40. The first electrode 41a constituting the wiring net 41 is brought into contact with the other electrical inspection probe 201b, and the external electrode 300 provided outside the wiring board is brought into contact with the first wiring net 41 and the external electrode 300. This is the electrostatic capacitance method for judging the conductive state of the first wiring net 41 from the electrostatic capacitance generated between and. The area of the wiring differs between when there is no wiring problem as shown in Fig. 2(a) and when there is a problem such as a short circuit in the wiring as shown in Fig. 2(b). The measured capacitance value C is different from the measured capacitance value C′. Wiring inspection is performed using this fact.

Since the capacitance method can detect the disconnection of the target wiring and the short-circuit with the wiring adjacent to the wiring at once, it has the advantage of being able to significantly shorten the inspection time compared to the IV method.

In high-end semiconductor packages that use expensive semiconductor parts, the thickness of the redistribution layer (RDL) is thin and difficult to handle. In order to improve it, there is a method of forming a fine wiring portion as an independent wiring portion without connecting it to other wiring portions. On the other hand, when the electrical inspection of a wiring board is performed by the capacitance method, the inspection probe is applied to one side of the wiring board and then to the opposite side, and the quality of the wiring is judged from the capacitance values obtained for each. do. That is, both sides of the wiring board must be exposed, and there is a problem that it is difficult to perform an electrical test on the wiring board formed on the support.

On the other hand, in the fine wiring portion, only one of the electrodes is exposed, and although it is possible to perform an electrical inspection by electrical resistance, the inspection takes a long time because the probe is brought into contact with each terminal, and inspection by the capacitance method is desirable. It is rare. A problem in measuring a wiring board formed on a support by the capacitance method is that sandwiching the support increases the distance between the electrodes of the capacitor, which reduces the capacitance value and makes measurement difficult. Therefore, it is necessary to improve the inter-electrode measurement accuracy.

Next, as a problem with fine wiring boards, in order to prevent the wiring collapse of the fine wiring part, it is necessary to reduce the wiring thickness compared to conventional boards. Therefore, it is difficult to adjust the thickness of the bonding electrode and wiring.

To address the above problem, the prior art discloses a support, a first conductive film provided on the upper surface of the support, an insulating film provided on the first conductive film, and a second conductive film provided on the upper surface of the insulating film. and wherein a second conductive film is used to form a rewiring layer, and the first conductive film, the second conductive film, and the insulating film perform an electrical inspection of the rewiring layer. By providing a laminated sheet that functions as a capacitor for the support, electrical inspection of the rewiring layer formed on the upper surface of the support is possible.

In the prior art, electrical inspection is realized by applying a voltage between the wiring provided in the rewiring layer and the first conductive film and measuring the capacitance. Here, when conducting an electrical inspection, it is necessary to contact two probes to the wiring and measure the capacitance. However, in the structure of the laminated sheet, the first conductive film only exposes the side surface at the end surface of the laminated sheet, and it is difficult to make contact with the probe.

Further, in the example of the formation process of the rewiring layer, the process of forming the wiring pattern on the second conductive film and then removing the portion not covered with the wiring pattern on the second conductive film is illustrated. In this case, the area of the second conductive film is reduced, and the capacitance obtained by the first conductive film, the second conductive film and the insulating film is reduced. In the electrical inspection of wiring, the quality of the wiring is judged by comparing it with the normal state, so it is desirable that the influence of the variation in the obtained capacitance is small. The influence of variation increases and the accuracy of electrical inspection decreases.

WO2020/129299

As described above, in the prior art, it was difficult due to the structure of the substrate to perform the electrical inspection with high precision by the capacitance method in the laminated substrate having fine wiring.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wiring board laminate in which fine wiring is arranged and which can be easily subjected to highly accurate electrical inspection.

A wiring board laminate according to the present invention comprises a support, a first conductive layer provided on the upper surface of the support, and a wiring board provided on the upper surface of the first conductive layer. A conductor continuum is called a wiring net. In this case, the wiring board comprises: a first wiring net having an electrode exposed on at least one surface of the wiring board and electrically connected to the first conductive layer; a second wiring net having an exposed electrode, electrically connected to the first conductive layer, and electrically connected to the first wiring net only through the first conductive layer; An electrode is exposed only on one side, and the wiring net is provided with the first conductive layer, the first and second wiring nets, and a third wiring net electrically insulated by an insulating resin layer. .

A wiring board laminate according to the present invention includes a support, a first conductive layer provided on the upper surface of the support, and a wiring board provided on the upper surface of the first conductive layer. A wiring net is a conductor continuum including wiring arranged on each layer of the wiring, electrodes for connecting to the outside of the wiring exposed to the outside of the substrate, and through electrodes for connecting the wiring of each layer. , the wiring board includes a first wiring net having an electrode exposed on at least one surface of the wiring board and electrically connected to the first conductive layer, and at least one of the wiring board. a second wiring net having an electrode exposed on a surface, electrically connected to the first conductive layer, and electrically connected to the first wiring net only through the first conductive layer; The electrodes are exposed only on one side of the substrate, the first conductive layer and the first and second wiring nets, the third wiring net electrically insulated by an insulating resin layer, and the first wiring net. An insulating layer, and an electrode layer electrically insulated from all of the first, second and second wiring nets and partially exposed to the outside of the wiring board.

According to the present invention, it is possible to realize a wiring board laminated body in which a highly accurate electrical inspection can be performed by a capacitance method before mounting a semiconductor chip and wiring can be easily formed.

1 is a schematic diagram of an electrical inspection method for a wiring board using the IV method; FIG. It is a schematic diagram of an electrical inspection method for a wiring board using a capacitance method. 1A and 1B are schematic diagrams showing an example of a method for inspecting a wiring board laminate and a wiring board according to the first embodiment; FIG. It is a schematic diagram showing a modification of the inspection method of the wiring board according to the first embodiment. FIG. 5 is a schematic diagram showing an example of a wiring board laminate according to a second embodiment; FIG. 10 is a schematic diagram showing a modification of the wiring board inspection method according to the second embodiment;

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same elements or elements having the same functions, and overlapping descriptions are omitted.

(First embodiment)
[Structure of Wiring Board According to First Embodiment]
First, the structure of the wiring board laminate 1 according to the first embodiment will be described. FIG. 3 is a diagram illustrating the wiring board laminate 1 of this embodiment. As shown in FIG. 3 , wiring board laminate 1 includes wiring board 40 , support 104 , and first conductive layer 101 . Note that the wiring board 40 has a first wiring net 41, a second wiring net 42 electrically connected to the first wiring net 41, and electrically connected to the first wiring net and the second wiring net. It has an insulated third wiring net 43 and at least one insulating resin layer 45 .

The insulating resin layer 45 is made of, for example, an insulating resin containing epoxy resin or polyimide resin as a main component. As the insulating resin, for example, a thermosetting insulating resin or a photosensitive insulating resin can be used. The thickness of the insulating resin layer 43 can be, for example, about 3 to 35 μm. The insulating resin layer 45 may contain a filler such as silica (SiO ₂ ). In the insulating resin layer 45, all layers may be composed of build-up layers made of a thermosetting insulating resin or photosensitive insulating resin, or may be composed of a thermosetting insulating resin or a photosensitive insulating resin. Both layers may be formed with build-up layers of insulating resin. As a result of repeated investigations, it was found that the insulating property of the insulator must have a resistance of 10 MΩ or more because measurement errors increase if the insulation is 10 MΩ or less.

The first wiring net 41 and the second wiring net 42, respectively, are formed on the upper layer of the insulating resin layer 45, the wirings 41b, 42b, and the wirings isolated by the insulating resin layer. Penetration electrodes 41c and 42c formed through the insulating resin layer in the thickness direction, and through electrodes 41c and 42c formed further on the insulating resin layer of the outermost layer of the laminated substrate and exposed to the outside for contact with the outside of the laminated substrate. It is configured by connecting electrodes 41a and 42a. Copper, for example, can be used as the material of the wirings 41b and 42b. The thickness of the wirings 41b and 42b can be, for example, approximately 1 to 15 μm.

One ends of the first wiring net 41 and the second wiring net 42 are arranged as the first electrode 41a and the second electrode 42a on the insulating resin layer 45 located at the outermost part of the wiring board 40, exposed to the outside. Therefore, the multilayer wiring board of the present invention can be electrically connected to an electronic component such as a semiconductor chip through this electrode. The first electrode and the second electrode may have a protruding shape, a flat shape, or a recessed shape with respect to the upper surface of the wiring board 40 . Copper, for example, can be used as the material of the electrodes 41a and 42a. For forming the electrodes 41a and 42a, for example, a well-known semi-additive method, subtractive method, or other method may be freely used.

The surfaces of the electrodes 41a and 42a are coated with metals such as Au, Ag, Cu, and Al, alloys thereof, and metal composites such as Cu plated with Au for surface protection and good electrical connection. Alternatively, Sn-, Sn--Pb, Sn--Ag, Sn--Cu, Sn--Ag--Cu, Sn--Bi or Au-based solder may be formed.

The ends of the first wiring net 41 and the second wiring net 42 that are not electrodes are electrically connected to the first conductive layer 101 .

The third wiring net 43 includes a third wiring 43 b formed on the upper layer of the insulating resin layer 45 , a third through electrode 43 c formed in the insulating resin layer 43 , and an outermost portion of the wiring board 40 . It is composed of a third electrode 43a formed further on the insulating resin layer 45. All parts constituting the third wiring net 43 can use the same metal and the same construction method as those of the first and second wiring nets 41 and 42 . The third wiring net 43 is electrically insulated from all of the first conductive layer 101 , the first wiring net 41 and the second wiring net 42 .

Regarding the first wiring net 41 and the second wiring net 42 having the above configuration, the first electrical inspection probe 201a is connected to the first electrode 41a, and the second electrical inspection probe 201b is connected to the second electrode 42a. By contacting them, it is possible to check the presence or absence of disconnection of the wiring through the conductive layer 101 by an electrical resistance test.

Next, as shown in FIG. 4, for the wiring substrate laminate 1 of this structure, a first electrical inspection probe 201a is attached to the first electrode 41a or the second electrode 42a, and a second electrical inspection probe 201a is attached to the first electrode 41a or the second electrode 42a. The probe 201b is brought into contact with the electrode 300 outside the substrate to measure the capacitance C between the first wiring net 41 or the second wiring net 42 and the electrode 300 outside the substrate. The value is compared with a normal value C′ obtained as knowledge in advance to determine whether the wiring is good or bad. In an actual wiring board, the number of wiring nets is larger, but in this method it is possible to collectively inspect all the wiring nets that are electrically connected, and to check which net belongs to which net. Inspection can also be performed by applying a probe to the electrode. Therefore, in a wiring substrate laminate having a large number of wiring nets, the number of inspection points can be suppressed, and the takt time for electrical inspection can be shortened.

A capacitance C is generated between the first wiring net 41, the second wiring net 42, the conductive layer 101, and the external electrode 300 outside the substrate of the wiring substrate laminate 1 having the above configuration. Since the first wiring net 41, the second wiring net 41, and the conductive layer 101 electrically connected to each other and the external electrode 300 outside the substrate are regarded as the electrodes of the capacitor, the capacitance C is the first If a short circuit or disconnection occurs anywhere in the wiring net 41 or the second wiring net 42, the value changes. In the electrical inspection of the electrostatic capacity method, this electrostatic capacity C is compared with the normal C', and the change in the difference is used to determine the quality of the wiring net. For this reason, in a conventional wiring board without the conductive layer 101, for example, the capacitance between the first wiring net 41 and the external electrode 300 outside the substrate is compared with that in a normal state. If disconnection occurs in , the change in capacitance C becomes extremely small, making it difficult to determine whether the wiring net 41 is good or bad. By providing the first conductive layer 101, it is possible to extend the wiring nets 41 and 42 as the electrodes of the capacitor. Therefore, even if disconnection occurs at the end of the wiring net 41, for example, the capacitance C will change significantly compared to normal. It becomes possible to detect disconnection.

For the inspection of the third wiring net 43, as shown in FIG. 4, the first electrical inspection probe 201a is applied to the first electrode 41a or the second electrode 42a, and the second electrical inspection probe is applied to the third electrode 43a. If the probe 201b is brought into contact with the capacitor and the electrode is made up of the first wiring net 41, the second wiring net 42, and the first conductive layer 101, and the electrode is made up of the third wiring net 43, the capacitor is inspected. Often, when disconnection occurs, the electrostatic capacitance C changes, and the disconnection can be detected.

An electrical test is performed on the wiring board laminate 1 of the first embodiment based on a known method. Specifically, as shown in FIG. 4, a first electrical inspection probe 201a is brought into contact with a third electrode 43a, a second electrical inspection probe 201b is brought into contact with an electrode 300 outside the substrate, and a third wiring is formed. An AC voltage is applied to the net 43 and the external electrode 300 outside the substrate, and the capacitance C is measured. The quality of the wiring is determined by comparing the value of the obtained capacitance C with the normal value.

An electrical test is performed on the wiring board laminate 1 of the first embodiment based on the technique of the present invention. Specifically, as shown in FIG. 3, a first electrical inspection probe 201a is brought into contact with the first electrode 41a or the second electrode 42a, and a second electrical inspection probe 201b is brought into contact with the third electrode 43a. Then, an AC voltage is applied to the electrode composed of the first wiring net 41, the second wiring net 42, the first conductive layer 101, and the electrode composed of the third wiring net 43, and the capacitance C is measured. The quality of the wiring is determined by comparing the value of the obtained capacitance C with the normal value.

(Second embodiment)
[Structure of Wiring Board According to Second Embodiment]
Since the electrical inspection by the capacitance method judges the quality by comparison with the normal value, the accuracy of the electrical inspection decreases if the variation of the capacitance C is large. For example, since the third wiring net 43 is composed of fine wiring, the area of the electrode of the capacitor is small, and it is conceivable that the measurement of the capacitance becomes difficult. In addition, depending on the configuration, the distance between the electrodes may increase, making it difficult to measure the capacitance itself. Therefore, in order to improve the inspection accuracy, it is necessary to have a configuration in which a large area can be secured for the fine wiring portion at a short distance.

The structure of the wiring board laminate 1 according to the second embodiment for realizing this will be described. FIG. 5 is a diagram illustrating the wiring board laminate 1 of this embodiment. As shown in FIG. 5 , the wiring board laminate 1 includes a wiring board 40 and a first conductive layer 101 . The wiring board 40 includes a first wiring net 41 and a second wiring net 42 electrically connected by a first conductive layer 101, and a first wiring net 41, a first wiring net 41, and a second wiring net 42 electrically connected to each other. a third wiring net 43 electrically insulated from all of the second wiring nets 42, further electrically insulated from all of the first, second and third wiring nets and the first conductive layer, part of it is the electrode 44a
and an electrode layer 44 exposed to the outside of the substrate.

In FIG. 5, the internal electrode portion 44b of the electrode layer 44 and the electrode 44a of the electrode layer 44 appear to be disconnected, but they are electrically connected in the actual substrate.

In this structure, the third electrode net 43 and the electrode layer 44 face each other with the insulating resin layer 45 interposed therebetween. By reducing the variation rate of the capacitance C, highly accurate electrical inspection can be realized.

Although the method for obtaining a large capacitance C is not limited to this, it is preferable that the distance between the third wiring net 43 and the electrode layer 44 is short. If the single-layered or laminated insulating resin layer 45 separating the two is thicker than 100 μm, the accuracy of the dielectric measurement will be lowered and defects will occur in the inspection. is desirable.

An electrical test is performed on the wiring board laminate 1 of the second embodiment. Specifically, as shown in FIG. 5, a first electrical inspection probe 201a is brought into contact with the third electrode 43a, and a second electrical inspection probe 201a is connected to the electrode 44a continuous from the internal electrode portion 44b and exposed to the outside. By contacting the probe 201b and applying an AC voltage between the third electrode net 43 and the electrode layer 44, the capacitance C is measured. The quality of the wiring is determined by comparing the value of the obtained capacitance C with the normal value.

Regarding the inspection of the third wiring net 43, as shown in FIG. If the probe 201b is brought into contact with the capacitor and the electrode is made up of the first wiring net 41, the second wiring net 42, and the first conductive layer 101, and the electrode is made up of the third wiring net 43, the capacitor is inspected. Often, when disconnection occurs, the electrostatic capacitance C changes, and the disconnection can be detected.

According to the wiring board laminate according to the present invention, it is possible to perform a capacitance electric test of the wiring board having the support with high accuracy.

INDUSTRIAL APPLICABILITY The present invention can be used for wiring substrate laminates used in the manufacture of semiconductor devices.

Reference Signs List 1 Wiring board laminate 40 Wiring board 41 First wiring net 41a First electrode 41b First wiring 41c First electrode Penetration electrode 42 Second wiring net 42a Second electrode 42b Second wiring 42c Second through electrode 43 Third wiring net 43a Third electrode 43b... Third wire 43c... Third through electrode 44... Electrode layer 44a... Electrode layer 44b... Internal electrode part 45 of electrode layer... Insulating resin layer 101 First conductive layer 104 Support 201a First electrical inspection probe 201b Second electrical inspection probe 300 Electrodes outside the substrate

Claims (2)

a support;
a first conductive layer provided on the upper surface of the support;
a wiring board provided on the upper surface of the first conductive layer;
with
A conductor continuum including wiring arranged in each layer of a wiring board, electrodes exposed outside the wiring for connection with the outside, and through electrodes for connecting the wiring of each layer. When calling a wiring net,
The wiring board is
a first wiring net having an electrode exposed on at least one surface of a wiring substrate and electrically connected to the first conductive layer;
A second wiring board having an electrode exposed on at least one surface, electrically connected to the first conductive layer, and electrically connected to the first wiring net only through the first conductive layer. a wiring net of
An electrode is exposed only on one side of a wiring board, and the wiring board includes the first conductive layer, the first and second wiring nets, and a third wiring net electrically insulated by an insulating resin layer. A wiring board laminate characterized by: a support;
a first conductive layer provided on the upper surface of the support;
a wiring board provided on the upper surface of the first conductive layer;
with
A conductor continuum including wiring arranged in each layer of a wiring board, electrodes exposed outside the wiring for connection with the outside, and through electrodes for connecting the wiring of each layer. When calling a wiring net,
The wiring board is
a first wiring net having an electrode exposed on at least one surface of a wiring substrate and electrically connected to the first conductive layer;
A second wiring board having an electrode exposed on at least one surface, electrically connected to the first conductive layer, and electrically connected to the first wiring net only through the first conductive layer. a wiring net of
a third wiring net electrically insulated from the first conductive layer, the first and second wiring nets, and an insulating resin layer, the electrodes being exposed only on one side of the wiring substrate;
an electrode layer electrically insulated from all of the first insulating layer and the first, second, and second wiring nets and partially exposed to the outside of the wiring board;
A wiring board laminate comprising:

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