JP5043962B2 - Electronic substrate inspection apparatus and electronic substrate inspection method - Google Patents

Description

  The present invention relates to an electronic substrate inspection apparatus and inspection method for inspecting a conduction state between a plurality of via holes provided on an electronic substrate using a stylus probe.

In order to check the conduction state between a large number of copper foil pads provided on the electronic board, a stylus probe (hereinafter abbreviated as a probe) is brought into contact between the copper foil pads on the electronic board to determine the conduction state or circuit resistance. A stylus inspection apparatus and method for measuring normality and abnormality of an electronic substrate to be inspected by measuring and comparing with a normal value stored in advance have been widely put into practical use.
In this case, it is widely used to selectively use a large number of existing via holes without providing a dedicated check pad as a stylus copper foil pad.
In addition, via holes are each layer copper foil land of a two-layer or multi-layer electronic substrate, or a wiring pattern interlayer connection by through-hole plating, lead wires for component mounting are not inserted in this through-hole, This is simply a hole.
In the case of having such a hole through-hole plating, unexpected solder flows in and adheres in the soldering process of the electronic component, and the inflowing solder expands and contracts due to the increase or decrease of the environmental temperature in the practical stage, thereby destroying the plating layer and conducting. There are problems such as the occurrence of defects.
In addition, in order to prevent oxidation of the through-hole plating layer and the land brim portion that are in contact with the probe, there are those that have been subjected to leveler plating with eutectic solder containing lead.

As a technique for eliminating such leveler plating and protecting the hole surface of the through hole, a technique in which a solder resist film is generated in the through hole so that the solder does not flow is also known. For example, the substrate main body is provided with a substantially cylindrical conductive land portion forming a via hole on the inner side, and a solder resist is coated on the inner peripheral surface and the land portion of the cylindrical main body of the land portion to form a hole in the via hole. There has been disclosed a printed circuit board in which an exposed portion in which a part of a land portion is exposed without being covered with a solder resist is formed on an edge portion (see, for example, Patent Document 1).
According to this technology, the solder resist formed on the land portion can prevent the solder balls from rising to the component surface during soldering, and uses the exposed portion formed at the edge of the via hole in the land portion. Then, it is possible to determine whether or not the mounted component is appropriate by applying the check pin of the tester to the exposed portion.

However, when an oxide film is generated on the exposed copper foil portion, contact failure occurs. In particular, in the case of recent lead-free solder, high temperature soldering is performed, so that there is a problem that an oxide film tends to be generated on the copper foil portion.
In order to improve this, as a technique for generating a lead-free solder film on a copper foil portion, for example, in a soldering step of soldering a component onto an electronic circuit board using a solder material not containing lead, the electronic circuit board A technique is disclosed in which a soldering material similar to the soldering material of a component is applied to at least a part of the probe pin stylus part (see, for example, Patent Document 2).

  When soldering is applied to the check land that is the probe pin stylus location, if the solder center part rises, there is a problem that the tip slips at the time of stylus contact with the probe pin.To improve this, for example, By forming a check land on a part of the conductor pattern on the multilayer substrate and providing a wall of protrusions (ink layer) by silk printing around the solder-coated check land, the probe pin is displaced from the check land. The technique which prevented this is disclosed (for example, refer patent document 3).

Japanese Unexamined Patent Publication No. 09-237949 (FIG. 1 and abstract, paragraph “0017” and FIG. 3) Japanese Patent Laid-Open No. 2003-080364 (FIG. 2 and abstract, and paragraphs “0008” and “0009” and FIG. 2) JP 2001-308483 A (summary with FIG. 2)

  According to the printed circuit board disclosed in Patent Document 1 described above, solder can be prevented from flowing into the via hole, and in the case of flow solder using a low temperature jet bath, a solder resist is coated. When a solder film is generated on the lands that are not used and poor contact with the check pins due to oxidation of the copper foil is prevented, lead-free solder that is subjected to high-temperature soldering and reflow soldering of surface-mounted components For this, processing for generating a solder film is required.

Further, according to Patent Document 2, since a solder film is generated at the contact location of the probe pin, poor contact with the probe pin due to land oxidation is prevented. As a result, the probe pins may slip sideways, and it may be difficult to make uniform contact.
On the other hand, according to the printed wiring board of the above-mentioned patent document 3, the side slip of the probe pin can be prevented by the annular silk printing formed around the check land, but a problem that requires a silk printing process newly occurs. , Contrary to the recent trend to abolish silk printing.
In addition, there remains a problem that uniform contact of the probe pins cannot be performed due to variations in the thickness of the solder layer or unevenness.

This invention was made to solve the above problems,
The first purpose is to prevent the solder from flowing into the hole of the via hole in the stylus inspection using the via hole, and the conductive plating layer in the via hole is cut by expansion / contraction of the inflow solder. This is to inspect the electronic substrate that has been prevented as an object to be inspected.
A second object is to inspect as an inspection target an electronic board that prevents the occurrence of oxidation of the stylus part due to high-temperature soldering by lead-free solder and improves contact reliability.
A third object is to obtain an electronic board inspection apparatus and inspection method that prevents positional displacement of the stylus part and performs stable contact operation to improve contact reliability.

  An electronic substrate inspection apparatus according to the present invention is an electronic substrate inspection device that inspects a conduction state with a stylus using via holes provided in an electronic substrate. The electronic substrate as an object to be inspected includes a plurality of via holes. Each via hole is formed in a hole that penetrates between a plurality of lands provided in the front surface layer and back surface layer or intermediate layer of the electronic substrate, and a cylindrical shape that is formed in the inner wall of the hole and connects the lands. And at least a pair of extended copper foil portions formed continuously on the annular brim portions of the lands provided on the front surface layer or the back surface layer, and the extended copper foil portions covered with the solder layer with the holes interposed therebetween. Solder coating pads are provided, and all the copper foil portions of the front surface layer and the back surface layer excluding the solder coating layer pads and the soldered portions and the inner wall of the cylindrical conductive layer are coated with a solder resist film. The inspection device is equipped with an electronic board A fixing jig and a holding member to which a plurality of probes for stylus inspection are attached and to which a stylus inspection tool is connected are provided. One end of each probe is fixed or movable to the holding member, and the other end side A stylus bar having a shaft body portion that is freely fitted in a hole of a via hole in the electronic board, a contact electrode portion that is movably held or fixed to the shaft body portion, and a contact electrode portion And an elastic spring that press-contacts the solder covering pad with the contact electrode portion in contact with the solder covering pad in a state where the axial center portion of each probe is loosely fitted in the hole of the via hole of the electronic board. The state of conduction between a plurality of probes or between a probe and a ground terminal, or circuit resistance is measured by an inspection tool.

According to the inspection apparatus for an electronic substrate according to the present invention, the axial center portion of the probe is inserted into the hole of the via hole covered with the solder resist film, and the solder covering pad provided on the surface layer or the back surface layer of the electronic substrate is inserted. On the other hand, since the contact electrode portion of the probe is elastically pressed, the via hole of the electronic substrate to be inspected is covered with the solder resist film, so that the penetration of the solder is prevented, and the axial center portion of the probe is Reliability of inspection because it can be securely inserted into the hole, and the position of the probe is stable due to the positioning by the hole and the side slip is limited, so that the contact electrode part can be securely pressed against the solder coating pad. Will improve.
Further, since the contact electrode portion of the probe is coated with solder, it is possible to prevent contact failure due to oxidation of the copper foil.

It is a fragmentary figure which shows the electronic substrate test | inspected with the electronic substrate inspection apparatus by Embodiment 1 of this invention, (a) is a top view, (b) is side sectional drawing. It is the fragmentary figure which shows the other example of the electronic substrate test | inspected with the inspection apparatus of the electronic substrate by Embodiment 1 of this invention, (a) is a top view, (b) is side sectional drawing. 1 is a configuration diagram of an electronic substrate inspection apparatus according to Embodiment 1 of the present invention. It is a block diagram which shows the other example of the inspection apparatus of the electronic substrate by Embodiment 1 of this invention. It is a flowchart figure explaining the inspection method of an electronic substrate by Embodiment 1 of this invention. It is a block diagram of the inspection apparatus of the electronic substrate by Embodiment 2 of this invention. It is a block diagram which shows the other example of the inspection apparatus of the electronic board by Embodiment 2 of this invention.

Embodiment 1 FIG.
First, an electronic substrate that is an object to be inspected by the electronic substrate inspection apparatus according to Embodiment 1 of the present invention will be described.
1A and 1B are partial views showing an electronic substrate to be inspected by an electronic substrate inspection apparatus according to Embodiment 1 of the present invention, wherein FIG. 1A is a top view and FIG. 1B is a side sectional view. In both cases, only the vicinity of the via hole is shown, but it is the same as a normal electronic substrate except for the illustration.

In the figure, an electronic substrate 1 is a multilayer substrate in which a first laminated plate 1a and a second laminated plate 1b are laminated, and has three copper foil layers of a front surface layer, an intermediate layer, and a back surface layer. The layers are laminated and formed by etching to form a wiring pattern, an electrode land (not shown) for mounting the electrode portion of the surface mount component, a via hole land for interlayer connection, and the like. Yes.
A via hole 3 formed through the electronic substrate 1 includes a hole 3a into which a lead wire is not inserted, a cylindrical conductive layer 4 that is a through-hole plating formed on the inner peripheral surface of the hole 3a, and a cylindrical shape. The front surface 1c connected to the conductive layer 4 and a single land 5a which is an annular flange portion provided on the back surface 1d, and the cylindrical conductive layer 4 is also electrically connected to the wiring pattern 2 of the intermediate layer. .
In addition, the number of the laminated boards of an electronic substrate is not limited to a figure.
In the following description, the front and back surfaces refer to the front and back surfaces of the substrate, and when referring to the copper foil layer (including the insulating layer) formed on the front or back surface, It will be called a back layer.

Of the single land 5a, the single land 5a formed on the surface 1c side is formed with an extended copper foil portion 5c that is continuous with the annular brim portion and extends the periphery to increase the outer diameter.
In FIG. 1, a single land will be described, but a wiring land may be used. The single land here is an annular copper foil pattern without a wiring pattern, and a land to which a wiring pattern as described later in FIG. 2 is connected is called a wiring land.
A pair of substantially fan-shaped solder-covered pads 6a and 6b covered with a solder layer are provided at symmetrical positions around the hole 3a of the extended copper foil portion 5c. More specifically, the solder coating pads 6a and 6b are generated by applying a solder paste to a pair of fan-shaped regions formed symmetrically with respect to the center of the hole in the region of the extended copper foil portion 5c. Has been.
The solder paste is applied by squeegee printing from the opening of the metal mask, and is simultaneously applied to the electrode pad (not shown) portion for the surface mount component (not shown) mounted on the electronic substrate 1. The

Solder resist films 7a and 7b are deposited on the entire surface of the front and back layers of the electronic substrate 1 excluding the solder coating pads 6a and 6b and the portion to be soldered. The solder resist films 7a and 7b prevent solder adhesion, prevent oxidation of the copper foil, and prevent peeling of the copper foil.
Solder resist films 7c are also provided on the surfaces of the annular flanges of the individual lands 5a and 5b on the front and back sides and the surface of the cylindrical conductive layer 4 to prevent solder from flowing into and attaching to the holes 3a of the via holes 3. It is supposed to be.

Next, another example of the electronic substrate will be described.
FIG. 2 is a partial view showing another electronic substrate, in which (a) is a top view and (b) is a side sectional view. In both cases, only the vicinity of the via hole is shown, but it is the same as a normal electronic substrate except for the illustration. Parts equivalent to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. The main difference is the shape of the extended copper foil part and the solder coating pad.
In the electronic substrate 1 of FIG. 2, the wiring pattern 8 is connected to the annular flange portion of the surface layer among the lands at the end face position of the via hole 3 to constitute the wiring land 5 b. Hereinafter, although described as a wiring land, it may be a single land as described in FIG.

The extended copper foil portion 5d in FIG. 2 extends a part of the annular brim portion of the wiring land 5b on the surface 1c side in the two directions out of the wiring lands 5b made of the small-diameter copper foil, and the wiring is provided on one side thereof. Although the pattern 8 is provided, the wiring pattern 8 may be provided on both.
The solder covering pads 9a and 9b are formed in a pair of substantially rectangular regions in the extended copper foil portion 5d and symmetrically with respect to the center of the hole 3a. Similar to the case of FIG. 1, it is generated by applying a solder paste. The solder paste is applied by squeegee printing from the opening of the metal mask, and is applied simultaneously to the electrode pad portion for the surface mount component (not shown).

  As in FIG. 1, the solder resist films 7a and 7b are applied to the entire surface of the front and back layers, excluding the portion to be soldered, to prevent solder adhesion and to prevent oxidation of the copper foil. Or preventing peeling of the copper foil. A solder resist film 7c is also applied to the front and back annular flanges of the wiring land 5b and the surface of the cylindrical conductive layer 4 so as to prevent the solder from flowing into and attaching to the holes 3a of the via holes 3. It has become.

In addition, the shape of the solder coating pads 9a and 9b may be, for example, a circle other than the rectangle. In the figure, a pair of holes provided on the left and right sides of the hole 3a is shown. For example, in a plan view, a pair of holes may be provided vertically with the hole 3a interposed therebetween. It may be provided in both. The thickness of the solder coating pads 9a and 9b is set so as to protrude from the surface of the solder resist film 7a, so that contact with a contact electrode portion described later can be ensured.

Next, the electronic substrate inspection apparatus according to the first embodiment will be described.
FIG. 3 is a configuration diagram of an inspection apparatus that performs stylus inspection using the electronic substrate configured as shown in FIG. 1 or 2 as an object to be inspected. Hereinafter, the electronic substrate in FIG. 1 will be described as an inspection target.
In the figure, a fixing jig 10 positions and fixes an electronic substrate 1. The electronic substrate 1 to be inspected has a pair of solder coated pads 6a and 6b formed on the substrate surface as an upper surface, and is a surface-mounted component. 11 is mounted on the upper surface of the fixing jig 10 with the mounting surface as the lower surface, and is set at a predetermined plane position and height position.

On the main body side of the inspection apparatus, a plurality of probes 12 (only one is shown in the figure) are attached to the holding member 13 and a stylus inspection tool 28 described later is connected.
First, the probe 12 will be described.
Each probe 12 is provided on a stylus bar 16 composed of a shaft body portion 14 and a contact electrode portion 15, an elastic spring 17 that presses the contact electrode portion 15 against the solder coating pads 6 a and 6 b, and the stylus rod 16. A first stopper 18 and a second stopper 19 are provided.
The shaft body portion 14 of the stylus bar 16 has a fixed portion 14 a that is press-fitted and held by the holding member 13 at one end, and an axial center portion 14 b that is loosely fitted in the hole 3 a of the via hole of the electronic substrate 1 at the other end. Is formed.

The contact electrode portion 15 is a cylindrical block body having a circular shape in a plan view in which a through hole 15a that is loosely fitted to the large-diameter portion of the shaft body portion 14 is formed at the center, and engages with the elastic spring 17 on one surface side. A contact surface 15c that has an engagement surface 15b and contacts the solder coating pads 6a and 6b of the electronic substrate 1 is formed in the entire circumferential direction on the other surface side. The contact surface 15c is provided with irregularities such as a mountain shape, a wave shape, or a cone shape so that sufficient contact with the solder coating pads 6a and 6b can be secured.
The first stopper 18 is prevented from coming off at the end of the large-diameter portion of the shaft body portion 14 to prevent the contact electrode portion 15 from coming off to the tip side. The second stopper 19 made of a conductive member is provided on the side of the shaft body portion 14 fixed to the holding member 13 and is electrically connected to the contact electrode portion 15 via the elastic spring 17. It is a contact signal transmission path to the inspection tool.

Next, the holding member 13 side will be described. The holding member 13 is made of, for example, an insulating member such as a synthetic resin material, and the fixing portions 14a of the stylus bars 16 of the plurality of probes 12 are press-fitted. On the other hand, on the surface opposite to the probe mounting surface of the holding member 13, the auxiliary substrate 20 is mounted at the four corners by the fixing screws 21 (the figure shows a state before mounting).
The ends of the fixing portions 14a of the plurality of probes 12 press-fitted into the holding member 13 press the contact 23 through the auxiliary elastic spring 22, and are electrically connected to the wiring pattern 24 provided on the auxiliary substrate 20 through the contact 23. Is connected to the stylus inspection tool 28 via the connection cable 27 via the board-side connector 25 connected to the other end of the wiring pattern 24 and the counterpart connector 26 thereof.
Instead of using the auxiliary elastic spring 22, a flexible lead wire is soldered to the tip of the fixing portion 14a, a connector terminal is fixed by crimping to the other end of the lead wire, and the connector terminal is fixed to the board-side connector 25. Alternatively, it may be inserted into a collective connector housing instead.

  The stylus inspection tool 28 measures the electrical resistance between the plurality of probes 12 that stylus the plurality of via holes 3, and determines whether the connection state of the wiring pattern is good or not depending on whether or not this matches the previously stored resistance value. The quality of the connected resistance component is determined.

The fixing jig 10 or the holding member 13 on which the electronic substrate 1 is mounted is driven to contact and separate in the direction of the thick arrow in FIG. 2 by an actuator (not shown) or manual operation. For example, the electronic board 1 transferred by the conveyor is placed on the fixing jig 10 and lifted up, and the shaft center portion 14b at the tip position of the stylus bar 16 is loosely fitted into the hole 3a of the via hole. Subsequently, when the contact surface 15c of the contact electrode portion 15 comes into contact with the solder coating pads 6a and 6b and the elastic spring 17 is compressed within a predetermined dimension, the approach drive is stopped.
In the approaching operation, the fixing jig 10 side may be fixed and the holding member side 13 may be approached.

  In the above description, the stylus bar 16 is press-fitted and fixed to the holding member 13, the shaft center part 14 b is integrally formed on the distal end side of the shaft body part 14 of the stylus bar 16, and the contact electrode part 15 is the shaft body part. 14 was inserted so as to be movable in the axial direction. With this configuration, the tip of the stylus bar does not roll, and the shaft center portion can be loosely fitted to a small via hole hole with high accuracy.

Next, another example of the electronic substrate inspection apparatus will be described.
FIG. 4 is a configuration diagram illustrating another example of an inspection apparatus that performs stylus inspection using the electronic substrate configured as illustrated in FIG. 1 or 2 as an inspection target. The same parts as those in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted. The main difference is the shape of the contact electrode part of the stylus bar.
The electronic substrate to be inspected will be described with reference to the electronic substrate in FIG.

  In the electronic board inspection apparatus described with reference to FIG. 3, the shape of the contact electrode portion 15 is a cylindrical block body having a circular shape in plan view and having contact portions 15c formed in the entire circumferential direction. In the electronic substrate inspection apparatus, the contact electrode portion 33 of the stylus bar 32 of the probe 31 is a flat block body having a rectangular shape in plan view and a U shape in side view as shown in FIG. The center portion has a through hole 33a that is loosely fitted to the large diameter portion of the shaft body portion 14, and both sides of the shaft center of the through hole 33a project in the same direction as the tip end side of the shaft center portion 14b. The contact surface 33c is in contact with the solder coating pads 9a and 9b of the substrate 1. The contact surface 33c is provided with irregularities such as a mountain shape, a wave shape or a cone shape, and the distance between the contact surfaces 33c is substantially equal to the distance between the solder coating pads 9a and 9b. The opposite side of the contact surface 33 c is an engagement surface 33 b that engages with the elastic spring 17.

A positioning groove 34a is provided on the circumferential surface of the first stopper 34 in the axial direction (vertical direction in FIG. 4). The contact electrode portion 33 is provided with a positioning pin 35 that is press-fitted from the peripheral surface, and is loosely fitted in the positioning groove 34a.
Accordingly, the contact electrode portion 33 can be inclined in the left-right direction by the amount of loose insertion of the through hole 33a in the drawing, but cannot be rotated in the circumferential direction (around the axis).
A positioning protrusion 36 a is provided on the end surface of the second stopper 36, and the positioning protrusion 36 a is fitted in a positioning groove 13 a provided on the lower surface of the holding member 13. As a result, the relative angular relationship between the pair of contact surfaces 33c of the contact electrode portion 33 and the holding member 13 is determined and maintained at a predetermined angle. Further, the direction of the pair of contact surfaces 33c is matched with the arrangement direction of the solder coating pads 9a and 9b of the electronic substrate 1 to be inspected.

In the electronic board inspection apparatus configured as described above, the stylus bar 32 can be miniaturized. In particular, since the thickness of the contact electrode portion 33 is thin, when combined with the electronic substrate of FIG. 2, the extended copper foil portion 5 d connected to the annular flange portion of the via hole 3 is formed into an elongated shape, whereby the via hole 3 The distance between each other can be increased, and a stylus inspection between the close via holes 3 can be performed.
Further, by arranging the via holes 3 alternately in a staggered manner, more via holes 3 can be provided between dense wiring patterns. In this case as well, a further effect can be expected by combining the electronic substrate to be inspected with the electronic substrate as shown in FIG.

As an embodiment other than the configuration of FIG. 3 and FIG. 4, the attachment structure of the stylus bar 16 (or 32) to the holding member 13 can be as follows. In other words, the shaft body portion 14, the shaft center portion 14b, and the contact electrode portion 15 (or 33) are integrated, and the integrated stylus bar 16 (or 32) is fixed to the holding member 13 (see FIG. (Not shown) and is configured as a plunger that is expanded and contracted by a coil spring. The stylus bar 16 (or 32) is movably held by the holding member 13 so as to be movable in the axial direction, and the contact electrode portion 15 (or 33) is provided integrally with the shaft body portion 14 together with the shaft center portion 14b. The entire stylus bar 16 (or 32) is urged toward the electronic board by the coil spring.
In this case, if there is a step between the pair of solder coating pads 6a and 6b, the contact electrode portion 15 is inclined alone and cannot contact both the solder coating pads 6a and 6b. The rolling amount of the stylus bar 16 (or 32) as a whole is regulated by the shaft center part 14b loosely fitted to 3a, and an effect of preventing excessive bending of the stylus bar 16 (or 32) can be expected.

Next, an inspection method for inspecting the electronic substrate as shown in FIG. 1 or 2 using the electronic substrate inspection apparatus configured as shown in FIG. 3 or FIG. 4 will be described.
FIG. 5 is a flowchart showing an inspection method including processing steps before and after the manufacturing process of the electronic substrate 1. The combination of the electronic substrate of FIG. 1 and the inspection apparatus of FIG. 3 will be described.
In FIG. 5, Step 1 (hereinafter referred to as S <b> 1) is a start step of a series of operations in the electronic substrate manufacturing process including the stylus inspection process.
The subsequent steps S2 to S5 (S6) are steps executed in the printed circuit board factory for manufacturing the electronic substrate 1 described in FIG.

S2 is a step of generating a wiring pattern and various lands by applying copper foil or etching to the first laminated plate 1a of the electronic substrate 1 in FIG.
The subsequent S3 is a step of generating a wiring pattern and various lands by applying a copper foil or etching to the second laminated plate 1b.
In the subsequent S4, the first laminated plate 1a and the second laminated plate 1b, to which the copper foil is applied or etched by S2 and S3, are bonded, and the inner peripheral wall of the via hole 3 is plated by a through-hole plating tank to form a cylindrical shape. This is a step of generating the conductive layer 4.
The subsequent S5 is a step of generating a solder resist film on all surfaces of the electronic substrate 1 on which the soldering process is not performed.
In addition, the printed circuit board shipped from the printed circuit board factory is wrapped in a vacuum wrap and stored in a packaging container together with a desiccant to prevent rusting of exposed copper foil parts and through-hole plating parts. Yes.

In subsequent S7, it is determined whether or not the corresponding printed circuit board is a printed circuit board for double-sided mounting in an electronic circuit board factory that mounts electronic components on the printed circuit board shipped from the printed circuit board factory and performs soldering processing. It is a step. If it is for double-sided mounting (YES) in S7, it will transfer to S8a and will apply a solder paste with respect to the electrode land of the surface layer in which a surface mounting component is mounted. If it is for single-sided mounting (NO) in S7, the process proceeds to S8b, and the extended copper foil portion 5c for stylus inspection on the surface layer electrode land on which the surface mounting component is mounted and the back surface layer on which the surface mounting component is not mounted. This is a step of applying a solder paste to a part of the region.
The process block S8 constituted by S8a and S8b is a solder application process. In S8, the cream-like lead-free solder is squeegee printed on the front and back layers of the electronic substrate 1 through a metal mask (not shown). It is to be applied.

Next, in S9, the surface-mounted component 11 is first mounted on the surface layer of the electronic substrate 1, and the cream solder applied in S8a or S8b is melted by passing through a reflow solder bath heated to a predetermined temperature. In this step, the surface mount component 11 is soldered to the surface layer of the electronic substrate 1.
In subsequent S10, when the determination of S7 is double-sided mounting and only one side is mounted, NO is determined and the process returns to S8a, and the double-sided mounting is completed, or the determination of S7 is single-sided mounting. If yes, the determination step is YES, and the process proceeds to S11. When the determination in S10 is NO and the process returns to S8a, in S8a, solder paste is applied to the electrode land on the back layer on which the surface mount component 11 is mounted and a partial region of the extended copper foil portion 5c for stylus inspection. In the subsequent step S9, reflow soldering of the back surface layer is performed.

In S11, lead components such as connectors and large electrolytic capacitors are mounted on the surface layer of the electronic substrate 1, and the lead terminal portion on the back surface layer side penetrating the through-hole plating hole is brought into contact with the molten solder in the local jet solder bath. This is a step of performing flow soldering.
In place of the reflow soldering of the back surface layer in S9, for the surface mount component mounted on the back surface layer, the package portion of the surface mount component is temporarily bonded to the back surface layer of the electronic substrate 1 with an adhesive, and the surface mount component is mounted. It is also possible to perform flow soldering by passing the entire portion including the electrode portion through a jet solder bath.

Process block S14 constituted by the next S12 and S13 is a stylus inspection process performed using the inspection apparatus described in FIG. 3 or FIG.
S12 is a step of placing the electronic substrate 1 mounted on the fixing jig 10 on the probe lower surface position of the holding member 13 to which the stylus inspection tool 28 is connected, and the electronic substrate 1 transferred by a conveyor (not shown). Then, lift up to the probe side together with the fixing jig 10. As described above, the holding member 13 side may be lowered.

In subsequent S13, the fixing jig 10 is lifted up so that the solder coating pads 6a and 6b are brought into contact with the contact surface 15c of the contact electrode portion 15, and the electric resistance between the plurality of probes is measured by the stylus inspection tool 28. In this step, whether the electronic substrate 1 is good or bad is determined. By comparing the measured value with the value of the normal electrical resistance stored in advance, the quality of the connection state of the wiring pattern and the quality of the connected resistance component are determined. It comes to judge.
When the fixing jig 10 is lifted up, the shaft center portion 14b, which is the tip of the stylus bar 16, is loosely fitted into the hole 3a of the via hole 3, and the roll of the stylus bar 16 is restricted. ing. At this time, when the solder coating surfaces of the solder coating pads 6a and 6b are uneven and the left and right heights are uneven, the contact electrode portion 15 is inclined so as to contact the left and right solder coating surfaces. It has become.
When the pass / fail judgment of the electronic substrate 1 by the stylus inspection tool 28 is completed, the fixing jig 10 is lifted down, and the inspected electronic substrate 1 is transferred downstream by a conveyor (not shown).

In S15, a power supply and input / output devices are connected to the electronic substrate 1 determined to be non-defective in S13 via a connector (not shown), and performance inspections and initial setting / adjustment operations are performed. This is a step for performing an inspection.
The subsequent S16 is a series of work end processes.
The electronic substrate inspection method according to the present invention includes a stylus inspection in S14 using an inspection apparatus and a part of a series of preparation work steps from S2 to S11.

In the above description, the solder coating pads 6a and 6b, which are stylus parts where stylus inspection is performed, are the extended copper foil portions of the annular flange portions of the single lands provided in the via holes 3, but are replaced with single lands. In addition, the wiring land may be provided at the end or in the middle of the wiring pattern.
1 and the inspection apparatus of FIG. 3 have been described. As shown in FIGS. 1 and 4, FIGS. 2 and 3, and FIGS. 2 and 4, the electronic substrate of FIGS. On the other hand, any combination of the inspection apparatuses of FIG. 3 or FIG. 4 is possible.
In the above description, the solder resist film 4 is provided in the via hole 3 used for the stylus inspection. However, by providing the solder resist film also for the via hole not used for the stylus inspection. , Life reduction due to oxidative corrosion is suppressed.

As described above, according to the electronic substrate inspection apparatus of the first embodiment, in the electronic substrate inspection apparatus that inspects the conduction state with the stylus using the via hole 3 provided in the electronic substrate 1, A plurality of via holes 3 are formed in the electronic substrate 1 which is an object, and each via hole 3 is a hole 3a penetrating between a plurality of lands provided in a front surface layer and a back surface layer or an intermediate layer of the electronic substrate 1. And a cylindrical conductive layer 4 that is formed on the inner wall of the hole 3a and connects the land 5a (or 5b) to the annular flange portion of the land 5a (or 5b) provided on the front surface layer or the back surface layer. An extended copper foil portion 5c (or 5d) is continuously formed, and at least a pair of solder coating pads 6a, 6b (or 9a, 9b) and a solder coating layer pad 6a 6b (or 9a, 9b) and all the copper foil portions of the front surface layer and the back surface layer except the soldered portion and the inner wall of the cylindrical conductive layer 4 are coated with solder resist films 7a to 7c. ,
The inspection apparatus includes a fixing jig 10 on which the electronic substrate 1 is mounted, and a holding member 13 to which a plurality of probes 12 (or 31) for stylus inspection are attached and to which a stylus inspection tool 28 is connected. Each of the probes 12 (or 31) has one end fixed to the holding member 13 or movably held, and the other end is formed with an axis 14b that is loosely fitted into the hole 3a of the via hole 3 of the electronic substrate 1. The stylus bar 16 (or 32) having the body electrode 14 and the contact electrode portion 15 (or 33) movably held or fixed with respect to the shaft body portion 14 and the contact electrode portion 15 (or 33) are solder-coated pads 6a, 6b (or 9a, 9b) and an elastic spring 17 that presses against
In a state where the axial center portion 14b of each probe 12 (or 31) is loosely fitted into the hole 3a of the via hole 3 of the electronic substrate 1, the contact electrode portion 15 (the solder electrode pads 6a and 6b (or 9a and 9b) are contacted). Or 33) is contacted, and the stylus inspection tool 28 measures the electrical connection between the plural probes 12 (or 31) or between the probes 12 (or 31) and the ground terminal, or the circuit resistance. .
Therefore, the axial center of the probe is inserted into the hole of the via hole covered with the solder resist film, and the contact electrode portion of the probe is elastically pressed against the solder coating pad provided on the surface layer or the back surface layer of the electronic substrate. Because it is supposed to
The position of the probe tip is stable, and the contact electrode can be reliably pressed against the solder coating pad. The via hole is covered with a solder resist film, preventing solder penetration and penetration. The risk of damage to the cylindrical conductive layer of the via hole due to the expansion / contraction of the solder is reduced.
Further, since the contact surface of the contact electrode portion is coated with solder, there is an effect that the occurrence of contact failure due to oxidation of the copper foil is prevented.
Although the contact surface is uneven with solder coating, the position of the contact height with the contact electrode becomes unstable, but the side center slips because the axial center is positioned by the via hole. The amount is limited to prevent excessive bending stress from being generated, and the contact surface of the contact electrode section has a further error in the contact height position due to measures such as corrugated or mountain-shaped contact areas. Even so, the error of the height position of the contact surface is absorbed by the elastic spring.

  Moreover, since the shaft body part 14 of the stylus bar 16 (or 32) is fixed to the holding member 13 at one end side and the shaft center part 14b is formed integrally with the shaft body part 14, the stylus bar 16 No rolling occurs at the tip of (or 32), and the shaft center portion can be loosely fitted with high precision to the small via hole.

In addition, the contact electrode portion 15 (or 33) of the stylus bar 16 (or 32) is loosely fitted to the shaft body portion 14 by a through hole 15a (or 33a) provided in the center portion, and is moved to the distal end side by an elastic spring 17. Is being energized.
Accordingly, the contact area of the contact electrode portion is increased, the contact reliability is improved, and the tip of the contact electrode portion pressed by the elastic spring is stabilized, so that an excessive bending stress is not generated on the stylus bar. Therefore, it is possible to provide a highly reliable inspection apparatus without causing any trouble in insertion even for long-term use.

Further, the contact electrode portion 15 is a cylindrical block body in which a through hole 15a that is loosely fitted to the shaft body portion 14 of the stylus bar 16 is formed in the center portion, and is engaged with the elastic spring 17 on one surface side. The contact surface 15c which has the surface 15b and contacts the solder coating pads 6a and 6b (or 9a and 9b) of the electronic substrate 1 is formed on the outer peripheral portion on the other surface side.
Accordingly, the stylus bar constituting the probe and the contact electrode portion which is a cylindrical block body are configured by separate members, and the contact electrode portion is pressed against the solder-coated pad by an elastic spring. The diameter can be reduced, and a stylus between close via holes is possible.
In addition, the mounting angle in the horizontal direction of the electronic substrate, which is the object to be inspected, can be freely set with respect to the stylus bar of the probe, and the end face of the cylindrical block body with respect to the solder coating pads arranged symmetrically around the via hole Can be reliably brought into contact with each other.

Further, the contact electrode portion 33 is a flat block body having a rectangular shape in a plan view in which a through hole 33a that is loosely fitted to the shaft body portion 14 of the stylus bar 32 is formed in the center portion. A contact surface 33c that contacts the solder coating pads 9a and 9b of the electronic substrate 1 is formed on both sides of the other surface side with the axis of the through hole 33a interposed therebetween. The fitting angle in the direction around the axis with the shaft body part 14 is regulated to a predetermined angle, one end side of the shaft body part 14 is attached to the holding member 13 at a predetermined angle in the direction around the axis, and the contact electrode part 33 is The holding member 13 is maintained at a predetermined angle.
Therefore, the shaft center part constituting the probe and the contact electrode part which is a flat block body are configured by separate members, and the contact electrode part is pressed against the solder-coated pad by an elastic spring, so that the stylus bar has a small diameter. In addition, by making the extended copper foil portion connected to the annular flange portion of the via hole into an elongated shape, it becomes possible to inspect a stylus between close via holes.
The mounting angle of the stylus bar and the holding member around the axis can be simplified by unifying the mounting angles of the flat block bodies.
Further, by arranging the via holes alternately in a zigzag pattern, more via holes can be provided between dense wiring patterns.

The stylus bar 16 (or 32) includes a first stopper 18 (or 34) and a second stopper 19 (or 36), and the first stopper 18 (or 34) is biased by the elastic spring 17. Provided between the contact electrode portion 15 (or 33) and the tip end portion of the shaft body portion 14 to retain the contact electrode portion 15 (or 33), and to cover the solder coating pads 6a and 6b (or 9a and 9b). Depending on the height position variation or the relative distance between the holding member 13 and the electronic substrate 1, a slight gap is generated between the contact electrode portion 15 (or 33) and the contact electrode portion 15 (or 33) contacts. The second stopper 19 (or 36) is provided on the attachment side of the stylus bar 16 (or 32) to the holding member 13 and is connected to the shaft body portion 14 and via the elastic spring 17. Electrically connected to the contact electrode portion 15 (or 33) And is configured such that the transmission path of the contact signals leading to stylus inspection tool 28.
Accordingly, the contact pressure of the contact electrode part is regulated by the gap generated between the contact electrode part and the first stopper, and the stylus signal obtained from the contact electrode part is transmitted to the stylus inspection tool via the second stopper. Because it has come to be
The contact electrode part, which is a signal transmission path inside the probe, and the second stopper are always pressed against each other by an elastic spring, and the stylus signal obtained from the contact electrode part is surely transmitted to the stylus inspection tool via the second stopper. The contact reliability is improved.

  The auxiliary board 20 is mounted on the surface of the holding member 13 opposite to the probe mounting surface, and the end of the stylus bar 16 (or 32) held by the holding member 13 has an auxiliary elastic spring 22 and a contact 23. Are connected to one end of the wiring pattern 24 of the auxiliary substrate 20, and the other end of the wiring pattern 24 is connected to the stylus inspection tool 28 via the connectors 25 and 26 and the connection cable 27. The stylus inspection tool can be easily connected by the wiring pattern and the connector of the auxiliary board while reliably making contact between the rod and the auxiliary board.

Further, according to the stylus inspection method for an electronic substrate according to Embodiment 1 of the present invention, in the electronic substrate inspection method for inspecting the conduction state with the stylus using the via hole 3 provided in the electronic substrate 1, A plurality of via holes 3 are formed in the electronic substrate 1 which is an object to be inspected, and each via hole 3 is an empty space penetrating between a plurality of lands provided in the front surface layer and the back surface layer or intermediate layer of the electronic substrate 1. An annular flange of the land 5a (or 5b) provided on the front surface layer or the back surface layer, having a hole 3a and a cylindrical conductive layer 4 formed on the inner wall of the hole 3a and connecting the land 5a (or 5b). An extended copper foil portion 5c (or 5d) is formed continuously on the portion, and at least a pair of solder coated pads 6a, 6b (or 9a, 9b) and a solder coating layer package 6a, 6b (or 9a, 9b) and all copper foil portions of the front and back layers except the soldered portion and the inner wall of the cylindrical conductive layer 4 are coated with solder resist films 7a-7c. There,
The inspection apparatus includes a fixing jig 10 on which the electronic substrate 1 is mounted, and a holding member 13 to which a plurality of probes 12 (or 31) for stylus inspection are attached and to which a stylus inspection tool 28 is connected. Each of the probes 12 (or 31) has one end fixed to the holding member 13 or movably held, and the other end is formed with an axis 14b that is loosely fitted into the hole 3a of the via hole 3 of the electronic substrate 1. The stylus bar 16 (or 32) having the body electrode 14 and the contact electrode portion 15 (or 33) movably held or fixed with respect to the shaft body portion 14 and the contact electrode portion 15 (or 33) are solder-coated pads 6a, 6b (or 9a, 9b) and an elastic spring 17 that presses against
Solder coating layer pads 6a and 6b (or the state where the axial center portion 14b of each probe 12 (or 31) is loosely fitted in the hole 3a of the via hole 3 of the electronic substrate 1 with respect to the electronic substrate 1 to be inspected. 9a, 9b) is brought into contact with the contact electrode portion 15 (or 33), and the stylus inspection tool 28 is used to connect between the plurality of probes 12 (or 31) or between the probes 12 (or 31) and the ground terminal. Alternatively, the circuit resistance is measured.
Therefore, the axial center of the probe is inserted into the hole of the via hole covered with the solder resist film, and the contact electrode portion of the probe is elastically pressed against the solder coating pad provided on the surface layer or the back surface layer of the electronic substrate. To measure
The position of the probe tip is stable, and the contact electrode can be reliably pressed against the solder coating pad. The via hole is covered with a solder resist film, preventing solder penetration and penetration. The risk of damage to the cylindrical conductive layer of the via hole due to the expansion / contraction of the solder is reduced.
Further, since the contact surface of the contact electrode portion is coated with solder, there is an effect that the occurrence of contact failure due to oxidation of the copper foil is prevented.
Although the contact surface is uneven with solder coating, the position of the contact height with the contact electrode becomes unstable, but the side center slips because the axial center is positioned by the via hole. The amount is limited to prevent excessive bending stress from being generated, and the contact surface of the contact electrode section has a further error in the contact height position due to measures such as corrugated or mountain-shaped contact areas. Even so, the error of the height position of the contact surface is absorbed by the elastic spring.

In addition, the electronic substrate 1 is mounted with a surface mount component 11 mounted on a copper foil land provided on the wiring pattern with a solder paste interposed therebetween and heated and bonded by a reflow furnace. In addition to using cream-like lead-free solder applied from the opening of the metal mask in the solder application step, the solder coating pads 6a and 6b (or 9a and 9b) formed on the electronic substrate 1 are also used for the metal mask in the solder application step. The lead is coated with the same lead-free solder applied from the opening.
Therefore, the solder coating pad is generated by applying cream solder from the opening of the metal mask in the solder application process for reflow soldering the surface mount component.
Solder-coated pads can be easily generated without the need for an extra step, and the extended copper foil part to be solder-coated is an island-shaped part that is symmetrically arranged around the hole, so that the opening of the metal mask The thickness of the solder layer can be appropriately controlled by the thickness of the metal mask.
In addition, the use of lead-free solder with excellent environmental resistance causes a problem that the soldering temperature becomes high and the copper foil part is likely to be oxidized, but the contact part with the contact electrode part is a solder film. Since the other copper foil portions are rustproofed by the solder resist film, a highly reliable inspection method can be provided.

Further, the electronic substrate 1 is provided with solder coating pads 6a and 6b (or 9a and 9b) serving as stylus parts on either the front surface layer or the back surface layer of the electronic substrate 1, and the solder coating pads 6a and 6b ( Alternatively, all the copper foil patterns and all the via holes other than the portions 9a and 9b) and the portion to be the solder connection portion of the electronic component are covered with the solder resist film.
Therefore, the solder coating pad is provided on either the front surface layer or the back surface layer, and the via hole not subjected to the stylus inspection is also covered with the solder resist film.
The stylus inspection may be performed on either the front surface layer or the back surface layer, and the stylus inspection device is small and inexpensive.
In addition, since all the copper foil patterns and via holes that are not soldered are covered with the solder resist film, it is possible to prevent a short circuit accident between adjacent via holes due to adhesion of conductive foreign matter.

Embodiment 2. FIG.
FIG. 6 is a configuration diagram of an electronic substrate inspection apparatus according to Embodiment 2 of the present invention. Since it is basically similar to FIG. 3 of the first embodiment described above, the same parts are denoted by the same reference numerals, description thereof is omitted, and differences will mainly be described. The electronic substrate to be inspected is FIG. 1 or FIG. 2 described in the first embodiment, but will be described as FIG.

6 is different from FIG. 3 in the shape of the tip of the probe fixed to the holding member. That is, the shaft center part loosely fitted in the hole of the via hole is not provided on the tip side of the stylus bar. Other than that, it is equivalent to FIG.
In FIG. 6, the probe 41 of this inspection apparatus includes a stylus bar 42 having a contact electrode portion 15 on the tip end side of a shaft body portion 43, an elastic spring 17, a first stopper 18, and a second stopper 19. . The tip of the stylus bar 42 does not have a portion corresponding to the axial center portion 14b described in FIG. The contact electrode portion 15 is a cylindrical block body equivalent to that shown in FIG. 3, and is loosely fitted to the distal end side of the shaft body portion 43 of the stylus bar 42 through the through hole 15 a.

The electronic board inspection apparatus shown in FIG. 6 is suitable when the diameter of the via hole 3a of the electronic board 1 is small. When the hole diameter of the via hole 3a is very small, it is difficult to prevent rolling of the stylus bar because the shaft center is thin even if the shaft center as described in FIG. 3 is loosely fitted.
Therefore, the stylus bar 42 as shown in FIG. 6 is used. In the inspection method, the center of the probe 41 is brought close to the center of the via hole 3a so that the contact surface 15c of the contact electrode portion 15 contacts the solder coating pads 6a and 6b of the electronic substrate 1. Thereafter, the inspection is performed in the same manner as in FIG. 3 of the first embodiment.

Even when the solder coating surfaces of the solder coating pads 6a and 6b are uneven and the left and right heights are uneven, the contact electrode portion 15 is loosely fitted in the through hole 15a, so that it tilts and the left and right solders The coated surface can be contacted.
In addition, since the solder coating surface is uneven, the contact position with the contact electrode portion 15 becomes unstable, but the contact surface 15c of the contact electrode portion 15 pressed by the elastic spring 17 is inclined and stable. Therefore, an excessive bending stress is not generated on the stylus bar 42, and the stylus bar 42 is not curved even when used for a long period of time, thereby preventing the stylus position accuracy from being lowered.

Furthermore, another example of the electronic substrate inspection apparatus according to the second embodiment will be described.
FIG. 7 is a configuration diagram illustrating another example of the electronic substrate inspection apparatus according to the second embodiment. Since it is basically similar to FIG. 4 of the first embodiment described above, the same parts as those in FIG. 4 are denoted by the same reference numerals, description thereof will be omitted, and the description will mainly focus on the differences. The electronic substrate to be inspected is FIG. 1 or 2 described in the first embodiment, but FIG. 2 is more suitable and will be described as FIG.

7 is different from FIG. 4 in the shape of the tip of the probe fixed to the holding member. That is, the shaft center part loosely fitted in the hole of the via hole is not provided on the tip side of the stylus bar. Other than that, it is equivalent to FIG.
In FIG. 7, the probe 51 of this inspection apparatus includes a stylus bar 52 having a contact electrode portion 33 on the distal end side of the shaft body portion 43, an elastic spring 17, a first stopper 34, and a second stopper 36. . The tip of the stylus bar 52 does not have a portion corresponding to the axial center portion 14b described in FIG. The contact electrode portion 33 is a flat block body equivalent to that shown in FIG. 4, and is loosely fitted to the tip end side of the shaft body portion 43 (equivalent to FIG. 6) of the stylus bar 52 through a through hole 33 a.
Similarly to FIG. 4, the contact electrode portion 33 and the first stopper 34, and the second stopper 36 and the holding member 13 are each provided with a peripheral fastening in the direction around the axis.

The electronic board inspection apparatus shown in FIG. 7 is also suitable when the diameter of the hole 3a of the via hole of the electronic board is small, as in FIG. When the hole diameter of the via hole 3a is very small, it is difficult to prevent rolling of the stylus bar even if the shaft center portion as described in FIG.
According to the electronic substrate inspection apparatus of FIG. 7, even when the solder coating surfaces of the solder coating pads 9a and 9b are uneven and the left and right heights are uneven, the contact electrode portion 33 is inclined and the right and left 6 can be brought into contact with the solder-coated surface, and the same effect as in FIG. 6 can be obtained.
Further, as in the case of FIG. 4, since the thickness of the contact electrode portion 33 is thin, when combined with the electronic substrate of FIG. 2, the extended copper foil portion 5d connected to the annular flange portion of the via hole 3 is elongated. By doing so, the space | interval of the via holes 3 can be made close, and a stylus inspection between the close via holes 3 becomes possible.

In the stylus inspection apparatus for an electronic substrate according to FIG. 6 or FIG. 7, the stylus inspection method including the previous and subsequent processing steps is the same as that shown in the flowchart of FIG. 5 described in the first embodiment.
As an embodiment other than the configuration shown in FIGS. 6 and 7, the attachment structure of the stylus bar 42 (or 52) to the holding member 13 may be as follows. That is, a cylindrical sheath (not shown) in which the contact electrode portion 15 (or 33) is loosely fitted to the shaft body portion 43 so as to be swingable and the stylus bar 42 (or 52) is fixed to the holding member 13. ) And is configured as a plunger that is finely expanded and contracted by a coil spring. The stylus bar 42 (or 52) is movably held by the holding member 13 so as to be movable in the axial direction, and the contact electrode portion 15 (or 33) is swingably installed on the shaft body portion 43. It is urged | biased with the stick | rod 42 (or 52) to the electronic substrate side.
In this case, if there is a step between the pair of solder coating pads 6a and 6b, the contact electrode portion 15 (or 33) can be inclined independently to contact both the solder coating pads 6a and 6b. (Or 52) The amount of rolling of the whole is regulated, and an effect of preventing excessive bending of the stylus bar 42 (or 52) can be expected.

As described above, according to the electronic substrate inspection apparatus according to the second embodiment, in the electronic substrate inspection apparatus that inspects the conduction state with the stylus using the via hole 3 provided in the electronic substrate 1, A plurality of via holes 3 are formed in the electronic substrate 1 which is an object, and each via hole 3 is a hole 3a penetrating between a plurality of lands provided in a front surface layer and a back surface layer or an intermediate layer of the electronic substrate 1. And a cylindrical conductive layer 4 that is formed on the inner wall of the hole 3a and connects the land 5a (or 5b) to the annular flange portion of the land 5a (or 5b) provided on the front surface layer or the back surface layer. An extended copper foil portion 5c (or 5d) is continuously formed, and at least a pair of solder-coated pads 6a, 6b (or 9a, 9a) covered with a solder layer on the extended copper foil portion 5c (or 5d) with the holes 3a interposed therebetween. 9b) and a solder coating layer pad 6 , 6b (or 9a, 9b) and all the copper foil portions of the front surface layer and the back surface layer excluding the soldered portion and the inner wall of the cylindrical conductive layer 4 are coated with solder resist films 7a to 7c. And
The inspection apparatus includes a fixing jig 10 on which the electronic substrate 1 is mounted, and a holding member 13 to which a plurality of probes 41 (or 51) for stylus inspection are attached and to which a stylus inspection tool 28 is connected. Each of the probes 41 (or 51) is connected to the shaft body portion 43 by a through hole 15a (or 33a) formed in the center portion on the other end side of the shaft body portion 43 that is fixed or movably held on the holding member 13. The stylus bar 42 (or 52) having the loosely contacted contact electrode portion 15 (or 33) and the contact electrode portion 15 (or 33) or the shaft body portion 43 are solder-coated pads 6a, 6b (or 9a, 9b). The contact electrode portion 15 (or 33) when the solder coating surface of the solder coating pad pads 6a, 6b (or 9a, 9b) is uneven and the height is uneven. ) Can be tilted to contact the solder coated surface It has been made,
The center of the stylus bar 42 (or 52) of each probe 41 (or 51) is brought close to the center of the hole 3a of the plurality of via holes 3, and the solder covering pads 6a and 6b (or 9a and 9b) are approached. The contact electrode portion 15 (or 33) is brought into contact, and the stylus inspection tool 28 measures the conduction state between the plurality of probes 41 (or 51) or between the probes 41 (or 51) and the ground terminal, or the circuit resistance. It is like that.
Accordingly, the center of the stylus bar is brought close to the center of the hole of the via hole covered with the solder resist film, and the stylus bar fixed to the holding member or held between the stylus bar and the contact electrode part. The contact electrode portion of the probe with respect to a plurality of solder-coated pads provided on the front surface layer or the back surface layer of the electronic board by the elastic spring disposed on the surface or the elastic spring disposed between the holding member and the stylus bar Because the contact electrode portion that is elastically pressed and loosely fitted to the stylus bar comes into contact with the solder-coated pad so as to be tiltable,
Since the via hole is covered with the solder resist film, the penetration of the solder is prevented, and the risk that the cylindrical conductive layer of the via hole is damaged due to the expansion / contraction of the penetration solder is reduced, and the contact surface of the contact electrode portion is By being covered with solder, there is an effect of preventing the occurrence of contact failure due to oxidation of the copper foil.
In addition, the contact surface becomes an uneven surface coated with solder, so that the contact position with the contact electrode portion becomes unstable, but the tip of the contact electrode portion pressed by the elastic spring is inclined and stabilized. Thus, an excessive bending stress is not generated on the stylus bar, and the stylus bar is prevented from being bent even when used for a long period of time, thereby preventing the stylus position accuracy from being lowered.
Further, since the tip of the stylus bar is not loosely fitted in the hole of the via hole, there is an effect that can be applied to a small diameter via hole.

Further, according to the electronic substrate inspection method according to the second embodiment, the electronic substrate inspection method in which the continuity state is inspected by the stylus using the via hole 3 provided in the electronic substrate 1 is an object to be inspected. The electronic substrate 1 is an electronic substrate 1 equivalent to the above, and is configured in the same manner as described above, and a plurality of via holes 3 are formed around the center of the stylus bar 42 (or 52) of each probe 41 (or 51) by an inspection device. The contact electrode portion 15 (or 33) is brought into contact with the solder coating pads 6a, 6b (or 9a, 9b) and the plurality of probes 41 ( Or 51) The electrical connection between the probes 41 (or 51) and the ground terminal or the circuit resistance is measured.
Accordingly, the center of the stylus bar is brought close to the center of the hole of the via hole covered with the solder resist film, and the stylus bar fixed to the holding member or held between the stylus bar and the contact electrode part. The contact electrode portion of the probe with respect to a plurality of solder-coated pads provided on the front surface layer or the back surface layer of the electronic board by the elastic spring disposed on the surface or the elastic spring disposed between the holding member and the stylus bar Since the contact electrode part that is loosely fitted to the stylus bar can be contacted at an angle to the solder-coated pad, the stylus can be inspected.
Similar to the above, the via hole is covered with the solder resist film to prevent the solder from entering, and the risk of the via hole's cylindrical conductive layer being damaged due to the expansion / contraction of the intruding solder is reduced. Since the contact surface is coated with solder, there is an effect of preventing the occurrence of contact failure due to oxidation of the copper foil.
In addition, the contact surface becomes an uneven surface coated with solder, so that the contact position with the contact electrode portion becomes unstable, but the tip of the contact electrode portion pressed by the elastic spring is inclined and stabilized. Thus, an excessive bending stress is not generated on the stylus bar, and the stylus bar is prevented from being bent even when used for a long period of time, thereby preventing the stylus position accuracy from being lowered.
Further, since the tip of the stylus bar is not loosely fitted in the hole of the via hole, there is an effect that can be applied to a small diameter via hole.
In the electronic substrate inspection apparatus and electronic substrate inspection method according to the second embodiment, it is needless to say that the same effects can be obtained with respect to the same parts as those of the first embodiment.

DESCRIPTION OF SYMBOLS 1 Electronic substrate 1a 1st laminated board 1b 2nd laminated board 1c surface 1d back surface 2,8 wiring pattern 3 via hole 3a void | hole 4 cylindrical conductive layer 5a single land 5b wiring land 5c, 5d extension copper foil part 6a, 6b, 9a, 9b Solder coating pads 7a-7c Solder resist film 10 Fixing jig 11 Surface mount component 12, 31, 41, 51 Probe 13 Holding member 13a Positioning groove 14, 43 Shaft body portion 14a, 43a Fixing portion 14b Shaft center portion 15 , 33 Contact electrode portion 15a, 33a Through hole 15b, 33b Engagement surface 15c, 33c Contact surface 16, 32, 42, 52 Contact rod 17 Elastic spring 18, 34 First stopper 19, 36 Second stopper 20 Auxiliary substrate 21 Fixing screw 22 Auxiliary elastic spring 23 Contact 24 Wiring pattern 25 Board side connector 26 Mating side connector 27 Continued cable 28 stylus inspection tool 34a positioning groove 35 positioning pins 36a positioning protrusion.

Claims (12)

In an electronic substrate inspection apparatus that inspects the conduction state with a stylus using a via hole provided in the electronic substrate,
A plurality of via holes are formed on the electronic substrate that is the object to be inspected, and each via hole includes a hole penetrating between a plurality of lands provided in a front surface layer and a back surface layer or an intermediate layer of the electronic substrate. A cylindrical conductive layer that is formed on the inner wall of the hole and connects the land, and an extended copper foil portion is provided continuously with the annular flange portion of the land provided on the front surface layer or the back surface layer. And forming at least a pair of solder coating pads coated with a solder layer on the extended copper foil portion with the holes interposed therebetween, and the surface layer and the back surface layer excluding the solder coating layer pad and the soldered portion. All copper foil parts and the inner wall of the cylindrical conductive layer are coated with a solder resist film,
The inspection apparatus includes a fixing jig on which the electronic substrate is mounted, and a holding member to which a plurality of probes for stylus inspection are attached and a stylus inspection tool is connected.
Each probe has a shaft body portion in which one end side is fixed or movablely held on the holding member, and an axial center portion is formed on the other end side so as to loosely fit in the hole of the via hole, and the shaft A stylus bar having a contact electrode portion that is movably held or fixed with respect to the body portion, and an elastic spring that presses the contact electrode portion against the solder coating pad,
With the axial portion of each probe loosely fitted in the hole of the via hole of the electronic substrate, the contact electrode portion is brought into contact with the solder coating pad, and a plurality of stylus inspection tools are used to An electronic board inspection apparatus characterized by measuring a conduction state between the probes or between the probe and a ground terminal, or a circuit resistance. The electronic substrate inspection apparatus according to claim 1,
One end side of the shaft body portion of the stylus bar is fixed to the holding member, and the shaft center portion is formed integrally with the shaft body portion. The electronic substrate inspection apparatus according to claim 2,
The contact electrode portion of the stylus bar is loosely fitted to the shaft body portion through a through hole provided in a central portion, and is urged toward the distal end side of the probe by the elastic spring. Board inspection equipment. In an electronic substrate inspection apparatus that inspects the conduction state with a stylus using a via hole provided in the electronic substrate,
A plurality of via holes are formed on the electronic substrate that is the object to be inspected, and each via hole includes a hole penetrating between a plurality of lands provided in a front surface layer and a back surface layer or an intermediate layer of the electronic substrate. A cylindrical conductive layer that is formed on the inner wall of the hole and connects the land, and an extended copper foil portion is provided continuously with the annular flange portion of the land provided on the front surface layer or the back surface layer. And forming at least a pair of solder coating pads coated with a solder layer on the extended copper foil portion with the holes interposed therebetween, and the surface layer and the back surface layer excluding the solder coating layer pad and the soldered portion. All copper foil parts and the inner wall of the cylindrical conductive layer are coated with a solder resist film,
The inspection apparatus includes a fixing jig on which the electronic substrate is mounted, and a holding member to which a plurality of probes for stylus inspection are attached and a stylus inspection tool is connected.
Each probe has a contact electrode portion loosely fitted to the shaft body portion by a through hole formed in the center portion on the other end side of the shaft body portion whose one end side is fixed or movablely held by the holding member. A rod and an elastic spring that press-contacts the contact electrode portion or the shaft body portion to the solder coating pad, and the solder coating surface of the solder coating pad is uneven and the height is uneven. The contact electrode portion is inclined and configured to be able to contact the solder coating surface,
The center of the stylus bar of the probe is brought close to the center of the hole of the plurality of via holes, and the contact electrode portion is brought into contact with the solder coating pad. Conductivity between the probes or between the probe and the ground terminal,
Alternatively, an electronic board inspection apparatus characterized by measuring circuit resistance. In the electronic substrate inspection apparatus according to any one of claims 2 to 4,
The contact electrode portion is a cylindrical block body in which a through hole that is loosely fitted to the shaft body portion of the stylus bar is formed at a center portion, and has an engagement surface that engages with the elastic spring on one surface side. An inspection apparatus for an electronic board, wherein a contact surface that contacts the solder coating pad of the electronic board is formed on an outer peripheral portion of the other surface. In the electronic substrate inspection apparatus according to any one of claims 2 to 4,
The contact electrode portion is a flat block body having a rectangular shape in a plan view in which a through hole that is loosely fitted to the shaft body portion of the stylus bar is formed at a center portion, and is engaged with the elastic spring on one surface side. A contact surface that contacts the solder coating pad of the electronic substrate is formed on both sides of the other surface side with the axis of the through hole interposed therebetween,
The contact angle between the contact electrode portion and the shaft body portion in the direction around the axis is restricted to a predetermined angle, and the one end side of the shaft body portion is attached to the holding member at a predetermined angle in the direction around the axis. The contact electrode portion is maintained at a predetermined angle with respect to the holding member. In the electronic substrate inspection apparatus according to any one of claims 2 to 4,
The stylus bar includes a first stopper and a second stopper;
The first stopper is provided between the contact electrode portion urged by the elastic spring and a distal end portion of the shaft body portion to retain the contact electrode portion and to increase the height of the solder coating pad. Depending on the variation in position or the relative distance between the holding member and the electronic substrate, a slight gap is generated between the contact electrode portions to regulate the contact pressure of the contact electrode portions,
The second stopper is provided on the attachment side of the stylus bar to the holding member, is connected to the shaft body portion and is electrically connected to the contact electrode portion via the elastic spring, An electronic board inspection apparatus configured to be a contact signal transmission path to a stylus inspection tool. In the electronic substrate inspection apparatus according to any one of claims 2 to 4,
An auxiliary board is mounted on the opposite surface of the holding member to the probe mounting surface, and the end of the stylus bar held by the holding member is connected to the wiring pattern of the auxiliary board via an auxiliary elastic spring and a contact. An electronic board inspection apparatus, characterized in that one end is connected and the other end of the wiring pattern is connected to the stylus inspection tool via a connector and a connection cable. In the inspection method of the electronic substrate for inspecting the conduction state by the stylus using the via hole provided in the electronic substrate,
A plurality of via holes are formed on the electronic substrate that is the object to be inspected, and each via hole includes a hole penetrating between a plurality of lands provided in a front surface layer and a back surface layer or an intermediate layer of the electronic substrate. A cylindrical conductive layer that is formed on the inner wall of the hole and connects the land, and an extended copper foil portion is provided continuously with the annular flange portion of the land provided on the front surface layer or the back surface layer. And forming at least a pair of solder coating pads coated with a solder layer on the extended copper foil portion with the holes interposed therebetween, and the surface layer and the back surface layer excluding the solder coating layer pad and the soldered portion. All copper foil parts and the inner wall of the cylindrical conductive layer are coated with a solder resist film,
The inspection apparatus includes a fixing jig on which the electronic substrate is mounted, and a holding member to which a plurality of probes for stylus inspection are attached and a stylus inspection tool is connected.
Each probe has a shaft body portion in which one end side is fixed or movablely held on the holding member, and an axial center portion is formed on the other end side so as to loosely fit in the hole of the via hole, and the shaft A stylus bar having a contact electrode portion that is movably held or fixed with respect to the body portion, and an elastic spring that presses the contact electrode portion against the solder coating pad,
With the electronic substrate to be inspected in a state where the axial center portion of each probe is loosely fitted in the hole of the via hole of the electronic substrate, the contact electrode portion is brought into contact with the solder coating pad, A method for inspecting an electronic board, comprising: measuring a conduction state between a plurality of the probes or between the probe and a ground terminal or a circuit resistance by the stylus inspection tool. In the inspection method of the electronic substrate for inspecting the conduction state by the stylus using the via hole provided in the electronic substrate,
A plurality of via holes are formed on the electronic substrate that is the object to be inspected, and each via hole includes a hole penetrating between a plurality of lands provided in a front surface layer and a back surface layer or an intermediate layer of the electronic substrate. A cylindrical conductive layer that is formed on the inner wall of the hole and connects the land, and an extended copper foil portion is provided continuously with the annular flange portion of the land provided on the front surface layer or the back surface layer. And forming at least a pair of solder coating pads coated with a solder layer on the extended copper foil portion with the holes interposed therebetween, and the surface layer and the back surface layer excluding the solder coating layer pad and the soldered portion. All copper foil parts and the inner wall of the cylindrical conductive layer are coated with a solder resist film,
The inspection apparatus includes a fixing jig on which the electronic substrate is mounted, and a holding member to which a plurality of probes for stylus inspection are attached and a stylus inspection tool is connected.
Each probe has a contact electrode portion loosely fitted to the shaft body portion by a through hole formed in the center portion on the other end side of the shaft body portion whose one end side is fixed or movablely held by the holding member. A rod and an elastic spring that press-contacts the contact electrode portion or the shaft body portion to the solder coating pad, and the solder coating surface of the solder coating pad is uneven and the height is uneven. The contact electrode portion is inclined and configured to be able to contact the solder coating surface,
With respect to the electronic substrate to be inspected, the center of the stylus bar of the probe is brought close to the center of the hole of the plurality of via holes, and the contact electrode portion is brought into contact with the solder coating pad.
A method for inspecting an electronic board, comprising: measuring a conduction state between a plurality of the probes or between the probe and a ground terminal or a circuit resistance by the stylus inspection tool. In the inspection method of the electronic substrate of Claim 9 or Claim 10,
The electronic substrate is mounted on a copper foil land provided on a wiring pattern with a solder paste interposed therebetween, and surface-mounted components that are heated and bonded by a reflow furnace are mounted thereon,
The solder paste uses cream-like lead-free solder applied from an opening of a metal mask in a solder application process, and the solder coating pad formed on the electronic substrate also has an opening in the metal mask in the solder application process. A method for inspecting an electronic board, characterized in that it is coated with a homogeneous lead-free solder applied from a part. The inspection method for an electronic substrate according to claim 11,
The electronic substrate is provided with the solder coating pad serving as a stylus portion on either the front surface layer or the back surface layer of the electronic substrate, and serves as the solder coating pad portion and a solder connection portion of an electronic component. An inspection method of an electronic board, wherein all copper foil patterns and all via holes other than the portions are covered with the solder resist film.

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