JP2002016208A - Integrated circuit device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated circuit device, which is adjacent to and between leads of a semiconductor element mounted on a circuit board, and can easily detect foreign matters which cause defects in condition due to a short circuit, and to provide its manufacturing method. SOLUTION: In a region E including an intermediate layer 3aM or reverse surface 3a2 of a wiring board 3 present across between the leads 2a of the semiconductor element 2 electrically connected to a circuit electrode 31 of the wiring board 3, the element 4 and circuit electrode 31 which are mounted are not present, so that the foreign matter γ can easily be detected, which is located adjacent between the leads 2a and fixed to or stuck on the circuit board 3. Furthermore, the element 4 and circuit electrode 31 are arranged on the intermediate layer 3aM or on reverse surface 3a2 in a region F of the wiring board 3 directly below the leads 2a to integrate the integrated circuit device to high density and also easily detected the foreign matters, etc., which can possibly short-circuits by optically seeing through between the leads 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated circuit device and a method of manufacturing the same.
The present invention relates to an integrated circuit device configured by electrically connecting a semiconductor element such as an IC chip to a back surface and a method of manufacturing the same.

[0002]

2. Description of the Related Art For example, there is an integrated circuit device in which a semiconductor element such as an IC chip and an element such as a resistance chip are mounted on the front and back surfaces of a wiring board by soldering or the like.

In recent years, semiconductor chips have been reduced in size due to high density and high integration, and terminals, for example, QFP type ICs
As the number of leads of a chip has increased, the lead pitch has been narrowed. As a result, in this type of integrated circuit device, a conduction failure may occur due to a short circuit due to a foreign material of a conductive material bridging between the narrowed leads.

For this reason, after soldering in the manufacturing process, in order to prevent a wiring defect, particularly a conduction failure caused by a short circuit between the leads of the semiconductor element, the presence or absence of foreign matter adjacent between the leads is detected by visual observation or image processing. Foreign matter contamination inspection. To detect a foreign object by this image processing or the like, the object is irradiated with illumination light to determine the state of the reflected light from the object.

[0005]

In the conventional integrated circuit device and the method of manufacturing the same, the reflected light of the foreign matter and the reflected light of the surrounding object have a similar color in the light source color system due to the effect of the illumination light, and the foreign matter is recognized. An erroneous determination may occur.

[0006] In addition, it is required that this type of integrated circuit device not only has a high density and a high density but also has a small size, but also has a minimum cost and a low cost. Therefore, there is a demand for an integrated circuit device and a manufacturing method thereof capable of minimizing defects in the latter half of a value-added manufacturing process and preventing defects from occurring downstream of the manufacturing process.

The present invention has been made in view of such circumstances, and has as its object to detect a foreign substance which is adjacent between leads of a semiconductor element mounted on a wiring board and which causes conduction failure due to a short circuit. An object of the present invention is to provide an integrated circuit device having a configuration that is easy to perform and a method of manufacturing the same.

[0008]

According to the first and second aspects of the present invention, a semiconductor device having a plurality of leads and a circuit electrode electrically connected to the plurality of leads is provided. An integrated circuit device comprising: a wiring substrate mounted on a surface of a substrate, wherein a mounted component and a conductor member are arranged in a region including an intermediate layer of the wiring substrate and a back surface of the substrate, excluding a region crossing between leads extending from the semiconductor element. Therefore, it is possible to easily detect a foreign substance that is adjacent to between the leads and that is fixed or adhered to the wiring board.

[0009] If the mounted components or the conductor members are arranged in the region including the intermediate layer of the wiring substrate and the back surface of the wiring substrate immediately below the plurality of leads, the integrated circuit device can be integrated with high density and high integration. It is desirable to provide a structure that makes it easy to optically see through the leads, for example, because it is possible to easily detect foreign substances or the like that can short-circuit by bridging the leads.

According to the third and fourth aspects of the present invention, there is provided a method of manufacturing an integrated circuit device according to the first aspect, wherein the manufacturing method includes a step of applying a solder paste to circuit electrodes of a wiring board in advance. A step of electrically connecting a plurality of leads of the semiconductor element to the circuit electrodes by soldering; a step of applying a moisture-proof material to the wiring board on which the semiconductor element is mounted; and a circuit of the wiring board on which the semiconductor element is mounted. A step of inspecting a wiring state and a circuit function of the electrode; and a step of discriminating a foreign substance capable of bridging between leads extending from the semiconductor element by a color difference from a surrounding object. The initial stage of the process of inspecting the appearance and function of an electronic circuit formed by electrically connecting a semiconductor element and a standard element which is a mounted component to a circuit electrode by soldering Easily detectable, it is also possible to foreign object detection to determine visually the color difference.

The color difference between the foreign object and the surrounding object is determined by determining the density of the image of the object to be detected by applying the transmitted illumination light from the back side of the wiring board on which the semiconductor element is fixed. If the discrimination is made based on the light amount difference or the lightness or darkness between the image of the substrate between the leads and the image of the foreign matter that can bridge between the leads, the conductive foreign matter can be seen between the leads by visual inspection. This is preferable because it is possible to prevent a conduction failure due to a short circuit due to crosslinking or the like.

According to the fifth and sixth aspects of the present invention, the foreign objects that can be cross-linked between the leads of the semiconductor element, which are determined based on the color difference, are not limited to those that are fixed to the wiring board. At the time of the inspection process in which the metallic foreign matter is adhered and the foreign matter is distinguished from the surrounding matter based on the color difference, not only the bridge between the leads but also the semiconductor element is applied in the process of applying a moisture-proof material. In the process of curing the moisture-proof material applied to the electrically connected wiring board, a substance having a size of a foreign substance that can bridge between leads due to, for example, a change of the foreign substance is determined as abnormal, so that the appearance and the function test are performed. This can be detected at an early stage of the process, and waste of performing detailed appearance inspection and function inspection in the subsequent process can be eliminated.

If the time at which the moisture-proof material is securely cured at the time of shipment from the factory, for example, the time for performing the foreign matter determination based on the color difference before the final inspection process is set, the foreign matter adhering to the wiring board is cured. Since the integrated circuit device is packaged with the moisture-proof material, conduction failure such as a short circuit due to foreign matter can be prevented, which is desirable.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an integrated circuit device and a method of manufacturing the same according to the present invention will be described by using a QFP (Quad Flat Pad).
An embodiment embodied in an integrated circuit device to be mounted on a multilayer wiring board having semiconductor elements having leads in four directions of a package type will be described with reference to the drawings. The semiconductor element mounted on the wiring board of the integrated circuit device is not limited to the QFP type, and may be a PGA type or the like as long as the lead extends from the semiconductor element. FIG. 1 is a schematic exploded perspective view of an integrated circuit device according to an embodiment of the present invention. FIG. 2 is a schematic sectional view taken along line II-II in FIG. Also,
FIG. 3 is a schematic block diagram of a manufacturing method according to the embodiment of the present invention. FIG. 4 shows a step of detecting foreign matter adjacent between leads of a semiconductor element in the appearance inspection in the inspection step in FIG. It is a block diagram.

As shown in FIG. 1, an integrated circuit device 1 includes a semiconductor element 2, a wiring board 3, and components to be mounted (hereinafter, referred to as a component).
4).

As shown in FIG. 1, the semiconductor element 1 is provided with leads in four directions, and the ends 2a of the leads are electrically connected to circuit electrodes 31 of the wiring board 3, which will be described later. A solderable surface is formed. Although the leads 2a are schematically described with 16 pins in FIG. 1, they may have any of 44, 100, or 300 pins.

The wiring substrate 3 is a substrate on which multilayer wiring is performed. The circuit electrodes 31 as wiring layers are formed on the front surface, the back surface, and the intermediate layer of the substrate 3. This circuit electrode 31
Is formed of a conductor member such as copper foil, a copper alloy, and aluminum. As shown in FIG. 2, a substrate surface (hereinafter, referred to as a front surface) 3a1 on a side to which the semiconductor element 2 is fixed, and a surface (hereinafter, referred to as a rear surface) 3 opposite to the side to which the semiconductor element is fixed.
a2, the inside of the substrate 3 (hereinafter referred to as an intermediate layer) 3aM includes:
Circuit electrodes 31a, 31b, 31c are arranged respectively. As shown in FIG. 2, an end portion (hereinafter, referred to as a land) 31r of a circuit electrode 31 electrically connected to the semiconductor element 2 and the standard element 4 has a solder paste (not shown) to be described later in a manufacturing method. Is applied or printed.

Although the circuit electrode 31c disposed on the intermediate layer 3aM is described as a single layer in the present embodiment, it may be formed as a multilayer or a laminate of two or more layers. This wiring board 3
Are formed by a manufacturing method such as thick film printing, green sheet lamination, or green sheet printing.

The standard element 4 is a component mounted on the wiring board 3 such as a resistor, a capacitor, or a quartz oscillator, a relay, a sensor, etc., and a square flat plate as shown in FIG. And is electrically connected to and fixed to the circuit board 31.

Here, if the semiconductor element 2 and the standard element 4 are surface-mounted on the wiring board 3 with the solder paste printed on the circuit electrodes 3a of the wiring board 3, electrical connection is easy.

The arrangement for mounting the semiconductor element 2, the circuit electrode 31 of the wiring board 3, and the standard element 4 will be described later in detail.

In the method of manufacturing the integrated circuit device 1 having the above-described structure, as shown in FIG.
Step P1, a second step P2 of applying or printing a solder paste to the circuit electrodes 31, a third step P3 of mounting a standard element 4 such as a resistor on the wiring board 3, and mounting the semiconductor element 2 on the wiring board 3. A fourth step P4 for performing soldering, a fifth step P5 for performing soldering, a sixth step P6 for applying a moisture-proof material to the wiring board 3 on which the semiconductor element 2 and the standard element 4 are mounted, and applying electric power to the circuit electrodes 31 by soldering. A seventh step P7 for inspecting the appearance and the function of the standard element 4 and the semiconductor element 2 fixedly connected and fixed, and an eighth step P8 for accommodating the wiring board 3 forming the integrated circuit device. ing.

The first step P1 is a step of supplying the stacked wiring boards 3 to the next step. When the wiring board 3 is a thin-film board, the wiring board 3 is held in a magazine or the like before the wiring board 3 is held. Sent out sequentially. When the spacing between the leads 2a extending from the semiconductor element 2 mounted on the wiring substrate 3 is a fine pitch, the front surface 3a1 and the rear surface 3a2 of the wiring substrate 3
It is desirable that the dust adhering to the surface be washed and then sent to the next step.

In the second step P2, the semiconductor element 2 and the standard element 4 are electrically connected to and fixed to the lands 31r of the circuit electrodes 31 arranged on the wiring board 3.
A step of applying or printing a solder paste on the
For example, the solder paste is printed using a screen mask that matches the land 31r.

The third step P3 includes a resistor having a large number of parts,
The standard element 4 such as a capacitor is connected to the land 31 of the circuit electrode 31.
In this step, it is desirable that the positions of the wiring board 3 and the standard element 4 are automatically corrected by, for example, image recognition, and then automatically mounted.

In the fourth step P4, the semiconductor element 2 is mounted on the land 31r of the circuit electrode 31, and the leads 2a extending from the semiconductor element 2 are mounted in the specified land 31r of the circuit electrode 31. Therefore, it is desirable to automatically mount the semiconductor element 2 and the lead 2a and the land 31r while correcting the position by image recognition.

In the fifth step P5, according to the type of the wiring board 3 to be mounted, a predetermined temperature characteristic (for example, a relation between temperature and time) is controlled by hot air or infrared rays, thereby melting the solder paste and automatically soldering. Attach.

The sixth step P6 is a packaging step of applying a moisture proof material (not shown) to the semiconductor element 2 and the standard element 4 which are electrically connected and fixed to the wiring board 3 by soldering. In order to prevent the malfunction of the integrated circuit device caused by the migration phenomenon caused by the operation in the humid air, the moisture proof material is at least a lead 2a which is a conductor portion having a surface enabling soldering. , Land 31r and the like.

The seventh step P7 is a step of inspecting the appearance and function of the semiconductor element 2 and the standard element 4 mounted on the wiring board 3 by soldering. In the functional inspection of the structural inspection items such as the wiring state, a failure is detected in an electrical inspection item related to a circuit function such as a timing error and a malfunction due to interference between signals.

The details of the appearance inspection, particularly the inspection relating to the periphery of the lead 2a of the semiconductor element 2, will be described later.

The eighth step P8 is a step in which all mounting, packaging and inspection are completed and the wiring board 3 constituting the integrated circuit device is housed. For example, when the wiring board 3 is a thin-film board, , Is housed after being removed from the magazine.

The multilayer wiring board 3 according to the present embodiment is
In the integrated circuit device in which the semiconductor element 3 and the standard element 4 are electrically connected to the front and rear surfaces of the wiring board 3, first, the mounting on one side of the wiring board 3 is performed from the second step P2 to the seventh step P7. Further, the wiring board 3 is turned over, and the mounting on the opposite surface is similarly performed from the second step P2 to the seventh step P7. Of the inspection in the seventh step P7, the function inspection may be performed when both surfaces are mounted.

Here, an arrangement for mounting the semiconductor element 2, the circuit electrode 31, and the standard element 4, which is a feature of the embodiment of the present invention, will be described with reference to FIGS.

Between the leads 2a of the mounted semiconductor element 2, an element mounted on an intermediate layer or a back surface with respect to the substrate surface 3a1 on the circuit electrode side 31a for fixing the semiconductor element 2, that is, a so-called semiconductor Components such as element 2 and standard element 4,
Alternatively, an arrangement having no circuit electrode 31 is a feature of the present embodiment.

A specific example will be described below with reference to FIGS. 1 and 2. First, as shown in FIG. 1, a standard element 4 (1) is
On a1, they are spaced apart from each other. For this reason, since the standard element 4 does not overlap with the lead 2a, the standard element 4 does not hinder the detection of foreign matter adjacent between the leads and can be easily detected. It is possible.

Next, the surface 3a on which the semiconductor element 2 is mounted
1 with respect to the circuit electrode 31b provided on the back surface 3a2.
And a standard element 4 (2) fixed to the circuit electrode 31b
2 means at least a region E between the leads 2a extending from the semiconductor element 2, that is, a region E sandwiched between adjacent leads 2a (enclosed by a two-dot chain line in FIG. 2), like the standard element 4 (2) in FIG. For example, in a region E including the intermediate layer 3aM of the wiring board 3 and the back surface 3a2 of the wiring board 3 traversing between the leads 2a,
They are arranged so as not to have them (hereinafter, referred to as the arrangement of Case I). Alternatively, the circuit electrodes 31b (3), 31 of FIG.
As shown in b (4), it is arranged so as to fit in a region F immediately below the surface of the lead 31 (surrounded by a two-dot chain line in FIG. 2) (hereinafter, referred to as case II arrangement). This allows
By arranging the case I or the case II, the circuit electrodes 31b and 31c different from the circuit electrode 31a to which the standard element 4 and the lead 2a are fixed do not interfere.
Detection can be easily performed, and the semiconductor element 2 and the standard element 4 can be densely stacked on the circuit electrodes 31 of the wiring board 3. Therefore, the leads 2a can be bridged and short-circuited by making the leads 2a optically transparent in the inspection step P7 described in the later-described manufacturing method by making the integrated circuit device 1 highly dense and highly integrated. It is possible to easily detect foreign matter γ (see FIG. 5) and the like.

In the method of manufacturing the integrated circuit device 1 having the above-described configuration, the seventh step P7, which is a feature of the embodiment of the present invention, particularly the step of performing an appearance inspection will be described below with reference to FIGS. explain. FIG. 4 is a block diagram showing a step of detecting a foreign substance adjacent between the leads 2a of the semiconductor element 2 in the appearance inspection, and FIG. 5 shows a relationship between the lead 2a and the adjacent foreign substance in FIG. It is a schematic diagram. FIG.
FIG. 4 is a block diagram showing an inspection order in a seventh step P7 in FIG.

In a device 100 for detecting foreign matter γ adjacent between leads 2a of semiconductor device 2 (hereinafter referred to as a foreign matter detecting device between leads) 100 shown in FIG. 4, semiconductor device 2 of integrated circuit device 1 is fixed. A light source L for applying transmitted illumination light from a surface opposite to the front surface 3a1, that is, a back surface 3a2, and a magnifying mirror R for enlarging around a lead 2a extending from the semiconductor element 2.
And a foreign matter discriminating device S for discriminating, through a magnifying glass R, a color difference generated by the transmitted illumination.
In the inter-lead foreign matter detection device 100, the foreign matter determination device S may be a device that performs a visual determination with human eyes, or may be an image processing determination device AS that is integrated with the magnifying glass R. Note that the integrated circuit device 1 in FIG. 4 is the same schematic cross-sectional view as FIG. 2, and the reference numerals in the drawing are the same.

The light source L may be any light source that emits visible light or polarized light similar to sunlight. In the case of the same light amount, a spot light illuminating around the lead 2a is preferably smaller in power consumption than a whole irradiation light irradiating the entire integrated circuit device 1.

The magnifying glass R only needs to be able to enlarge an object to be detected, such as a foreign substance, adjacent to the lead 2a and the lead 2a to such an extent that the lead 2a can be distinguished by the color difference generated by the above-mentioned transmitted illumination.

The foreign matter discriminating device S is a color difference discriminating device for illuminating the object to be detected with transmitted illumination to determine the density of the image of the object to be detected. The determination is made based on the difference in the amount of transmitted light from the shadow image or the brightness.

A method of manufacturing the integrated circuit device 1 using the inter-lead foreign matter detecting device 100 having the above-described configuration, and in particular, features of a process of performing an appearance inspection will be described below. Appearance inspection using foreign matter detection device 100 between leads (hereinafter referred to as foreign matter detection)
The process P7a includes a process S1 of illuminating between the leads 2a of the integrated circuit device 1, a process S2 of determining a color difference of a shadow image generated by illuminating the object with the transmitted illumination, and a process of bridging or bridging the lead 2a. And a step S1 of determining that the foreign matter is abnormal.

The foreign substance detection step P7a is performed in the initial stage of the appearance and function inspection step P7 after the packaging step P6 of applying a moisture-proof material to the integrated circuit device 1, and the foreign substance γ bridging the lead 2a. In addition, after the foreign substance detection step P7a is completed, a substance having a size that can be crosslinked due to the displacement of the foreign substance γ or the like is determined to be abnormal. Thereby, it is possible to eliminate wastefulness of performing a detailed appearance inspection and a function inspection performed in a later process.

FIG. 5 shows a method of determining an abnormality.
Will be described below. Semiconductor element 2 shown in FIG.
In FIG. 5B, the lead 2a and the foreign matter .gamma.
When the foreign matter γ is bridged between the leads 2a, that is, when the foreign matter γ is arranged close to each other without contact, the length W of the foreign matter γ in the longest direction is
Is equal to the length t sandwiched between the leads 2a.
If it is larger than the inscribed circle φ that is in contact with a, it is determined that the length is such that it can be crosslinked, and it is determined that there is abnormality. In addition, the foreign matter detection process P7a
In the above, at least a foreign matter γ having a length W bridged between the leads 2a is determined to be an abnormal foreign matter.

Here, the foreign matter detection step P7a is performed before the moisture-proof material applied in the sixth step P6 is cured and before the final inspection in the eighth step of performing a function test or before shipment from the factory. In addition, it is desirable to carry out at the initial stage of the eighth step before curing (see FIG. 6). Thereby, it is possible to eliminate the foreign matter which can be cross-linked and short-circuited in the foreign matter detection step 7a. Further, after the moisture-proof material is cured, the foreign matter γ is fixed to the integrated circuit device 1 by the moisture-proof material. It is possible to prevent conduction failure such as short circuit due to foreign matter. Therefore, although there is a possibility that the foreign matter γ may be fixedly attached to the integrated circuit device 1 due to packaging, the presence of foreign matter that does not cause a conduction failure is acceptable. It can be manufactured inexpensively without extremely increasing the cleanliness of the space.

[Brief description of the drawings]

FIG. 1 is a schematic exploded perspective view of an integrated circuit device according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view taken along line II-II in FIG.

FIG. 3 is a block diagram illustrating an outline of a method of manufacturing an integrated circuit device according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a step of detecting foreign matter adjacent between leads of a semiconductor element in the appearance inspection in the inspection step in FIG. 3;

5 is a schematic diagram illustrating a relationship between a lead of the integrated circuit device mounted on the wiring board in FIG. 4 and electrically connected to a circuit electrode and an adjacent foreign substance.

FIG. 6 is a block diagram showing an inspection order in a seventh step in FIG.

[Explanation of symbols]

Reference Signs List 1 integrated circuit device 2 semiconductor element 2a lead 3 wiring board 3a1, 3a2, 3aM front surface, back surface, inside (intermediate layer) to which semiconductor device 2 is fixed 4 standard device 31 circuit electrode 31a, 31b, 31c front surface, back surface, inside Corresponding circuit electrode 31r Land (end electrically connected to and fixed to semiconductor element 2 or element 4) 100 Foreign matter detecting device between leads L light source R Magnifying glass S Foreign matter discriminating device P1 to P8 Method of manufacturing integrated circuit device Step P7a Step of detecting foreign matter S1 Step of transmitting and illuminating between the leads of the integrated circuit device S2 Step of determining the color difference of the object to be detected S3 Step of determining that a crosslinked or crosslinkable foreign substance is abnormal γ Foreign matter

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroyuki Shirakawa 3 Iyama, Shinomecho, Anjo-shi, Aichi Anden F-term (reference) 5E336 AA04 BB03 BC34 CC01

Claims (6)

[Claims] 1. An integrated circuit device comprising: a semiconductor element having a plurality of leads; and a wiring board having a circuit electrode electrically connected to the plurality of leads and mounting the semiconductor element on a substrate surface. Wherein the mounted component and the conductive member are arranged in a region including an intermediate layer of the wiring substrate and a back surface of the substrate except for a region crossing between the leads extending from the semiconductor element. . 2. The mounting component or the conductor member is arranged in a region including the intermediate layer and the back surface of the wiring board immediately below the plurality of leads. 3. The integrated circuit device according to claim 1. 3. The method of manufacturing an integrated circuit device according to claim 1, further comprising: applying a solder paste to the circuit electrodes of the wiring substrate in advance; and the plurality of leads of the semiconductor element and the circuit electrodes. Electrically connecting by soldering, applying a moisture-proof material to the wiring board on which the semiconductor element is mounted, wiring state and circuit of the circuit electrode of the wiring board on which the semiconductor element is mounted Manufacturing the integrated circuit device, including a step of inspecting a function, wherein the inspecting step includes a step of determining a foreign substance capable of bridging between the leads extending from the semiconductor element by a color difference from a surrounding object. Method. 4. The method according to claim 1, wherein the color difference is determined with respect to the substrate surface on the circuit electrode side to which the semiconductor element is fixed.
It is an appearance inspection for determining the density of an image of an object to be detected by applying transmitted illumination light from the back surface of the substrate, and a light amount difference of transmitted light between the image of the substrate and the image of the foreign material between the leads. 4. The method for manufacturing an integrated circuit device according to claim 3, wherein the determination is made based on brightness. 5. The foreign matter that can be cross-linked is a metallic foreign matter that adheres or adheres to the substrate, and in the inspection step, a foreign substance that bridges between the leads or a curing process of the moisture-proof material. 5. The method for manufacturing an integrated circuit device according to claim 3, wherein a foreign substance having a size capable of bridging between the leads is determined. 6. The step of discriminating a foreign substance capable of bridging between leads of the semiconductor element by a color difference from a surrounding object, after the step of applying the moisture-proof material is completed, the moisture-proof material is in the wiring state and The integrated circuit according to any one of claims 3 to 5, wherein the process is performed before the curing time so that the circuit function is cured before the final inspection of the process or the factory shipment. Device manufacturing method.