JP2000065892A - Jig for continuity inspection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To comply with fineness of a pitch between ball electrodes in an inspected object and to ensure contact and continuity by providing a conversion base board having lands formed on its surface and coil springs, in each of which a lower end part is directly surface-mounted to the land while an upper end part is brought into contact with the ball electrode in the inspected object. SOLUTION: In this jig A, a conversion base board 1 having predetermined wiring for inspection is fixed on a fixing base 2, while in the upper face center part of the conversion base board 1, lands 3 are formed, and a lower end part 4a in each of a forest of coil springs 4 is directly surface-mounted to each of the lands 3. A wiring pattern of the lands 3 on the conversion base board 1 is set to be the same pattern as that of ball electrodes 5a projected on the lower face of an inspected object 5, for example, positioned on the upper side of the jig A in inspection, and the coil springs 4 are also arranged in the same pattern. In this constitution, the inspected object 5 is pressed downward after it is positioned on the upper side of the jig A. The ball electrode 5a is brought into contact with the upper end part 4b of the coil spring 4 so as to be set in continuous condition, and a signal is taken out from each of the lands 3 for inspecting whether an obstacle point exists or not.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuity inspection jig, and more particularly, to an object to be inspected having ball electrodes formed in a grid array on a lower surface, such as an MCM substrate or a BGA semiconductor package. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for inspecting whether or not a test object is disconnected by contacting a ball electrode, and more particularly to a continuity inspection jig having a simple structure and high reliability of an inspection result.

[0002]

[Prior Art] Miniaturization and weight reduction of various electronic and electric devices
High-density mounting of semiconductor devices on a circuit board by a chip-on-board method has been promoted in order to realize multifunctionality. In that case, the semiconductor package mounted on the circuit board is made of, for example, Au or solder, and has a so-called BGA type in which a large number of ball electrodes having a substantially spherical shape are projected from the lower surface in a predetermined pattern. Things are used.

There are various shapes of the ball electrode at this time, but the ball electrode generally has a diameter of 0.3 to 0.5 mm and a height protruding from the lower surface of the semiconductor package of 0.15 to 0.5. It is customary for .3 mm. Prior to mounting, a continuity test is performed on the semiconductor package to check for any faults such as disconnection in the package.

Conventionally, the continuity test is usually performed by a pin probe method, and an inspection jig used in the pin probe method generally has a structure assembled as follows. I have. That is, by performing machining using a drill on the insulating material portion of the conversion board on which the predetermined inspection circuit pattern is wired, a predetermined pattern is formed on the conversion board in a pattern corresponding to the grid pattern of the ball electrodes of the inspection object. Drill a through hole with a hole diameter. Then, a spring probe having a spring at a lower portion and having a needle-shaped tip is manually inserted and fixed into the through hole. At this time, an effort is made to keep the tip of the probe flush. Next, a lead wire for signal extraction is manually soldered to the other end of each spring probe, and an inspection jig is assembled.

When conducting a continuity test using the inspection jig, the inspection object is positioned and arranged on the inspection jig, so that the tip of the forested spring probe and the inspection object are positioned. After the respective ball electrodes are brought into contact with each other, a signal is supplied from each probe by applying a current, and the presence or absence of a fault in the circuit in the inspection object is inspected.

[0006]

By the way, the above-mentioned pin probe type inspection jig has the following problems. First, the first problem is that a lead wire is attached to a spring probe arranged on a conversion board by a manual soldering operation.

That is, when the pitch between the hole electrodes arranged in the grid array on the object to be inspected becomes finer, the pitch between the spring probes of the inspection jig becomes finer correspondingly. However, when the pitch between the spring probes becomes finer, the lead wire must be reduced in diameter, and the soldering iron used for soldering must be reduced in size, which makes the soldering operation very difficult. At present, from the viewpoint of the diameter of the lead wire and the shape of the soldering iron, the pitch between the spring probes that can be soldered is limited to about 0.75 μm. Becomes virtually impossible.

The second problem is based on the fact that the shape of the ball electrode is substantially spherical and the tip of the spring probe is needle-shaped. That is, if the axis of the ball electrode and the tip of the spring probe form a coaxial line in the vertical direction, contact between the two will be realized, but if this relationship is not established, the spring probe May slip from the surface of the ball electrode, and the contact state between the two may become poor, so that a highly reliable inspection result may not be obtained.

In order to solve such a problem, the tip of the spring probe is formed into a shape such that the ball electrode can be securely contacted, or a through hole is formed in a pattern corresponding to the arrangement of the spring probes. A measure is taken such that a spring probe is inserted into the through hole of the provided insulating substrate to guide the positioning of the probe itself.

However, such measures tend to cause abrasion or the like on the surface of the ball electrode, which may cause inconvenience in a later step for incorporating the semiconductor package. In addition, as an inspection jig, a jig that uses anisotropic conductive rubber as a contact unit with a ball electrode is also known. However, in the case of this jig, if the ball electrode is made of solder, the jig cannot break the oxide film on the surface of the ball electrode, so that a stable conduction state with the ball electrode can be realized. Have difficulty. In addition, although the height of the ball electrode varies, there is also a problem that a margin value for the variation is small.

The present invention solves the above-described problems in the conventional spring probe type inspection jig, and can sufficiently cope with a fine pitch between ball electrodes of an object to be inspected. Contact and continuity with the ball electrode can be reliably achieved, and the structure is simple and assembly work can be performed easily. It can be manufactured at a lower cost than conventional spring probe type inspection jigs. An object of the present invention is to provide a continuity inspection jig having a new structure that can be used.

[0012]

In order to achieve the above object, according to the present invention, there is provided a conversion board having a land formed on a surface thereof; and a lower end portion is directly surface-mounted on the land, and an upper end portion is provided. There is provided a continuity inspection jig (hereinafter, referred to as a first jig), comprising: a coil spring that contacts a ball electrode of the inspection object.

In particular, a lower end of the coil spring is fixed to the land with a conductive adhesive, and a penetrating hole having a larger hole diameter than the outer diameter of the coil spring is provided on the conversion board. There is provided a continuity inspection jig in which an insulating substrate having a hole is vertically movably arranged with the coil spring inserted through the through hole. Also,
In the present invention, a conversion substrate having a land formed on a surface thereof; an insulating substrate fixedly disposed on the conversion substrate and having a through hole formed at a position facing the land; A spring terminal fixedly disposed therein, a lower end contacting the land, and an upper end fixedly disposed in a cylindrical socket with a coil spring in contact with a ball electrode of the object to be inspected. A continuity inspection jig (hereinafter, referred to as a second jig) is provided.

In particular, a second insulating substrate in which a through hole having a hole diameter larger than the outer diameter of the coil spring is formed on the insulating substrate has the coil spring inserted through the through hole. A continuity inspection jig arranged to be able to move up and down in a state, and furthermore, the spring terminal is provided in a cylindrical socket having a squeezing process at a substantially central portion in the longitudinal direction. There is provided a continuity inspection jig in which a coil spring whose substantially central portion is elongated and divided into a coil spring portion on an upper end portion and a coil spring portion on a lower end portion is fixedly arranged. As the coil spring incorporated in both the first jig and the second jig, the tip of the spring coil at the upper end of the coil spring projects obliquely upward toward the inside of the coil spring. To be preferred Conductivity test jig is provided.

Further, in the present invention, there is provided a conversion substrate having a land formed on a surface thereof; a step fixedly disposed on the conversion substrate, and a step formed of a small-diameter hole and a large-diameter hole at a position facing the land. An insulating substrate having a through hole with a hole;
And a coil spring disposed in the stepped through-hole, the lower end contacting the land, and the upper end protruding from the small-diameter hole. A tool (hereinafter, referred to as a third jig) is provided.

In particular, there is provided a continuity inspection jig in which the tip end of the spring coil at the upper end of the coil spring is extended in the longitudinal direction of the coil spring.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a jig of the present invention and its components will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a basic configuration of a first jig A according to the present invention. In FIG. 1, a conversion board 1 having a predetermined wiring for inspection is fixedly arranged on a fixed base 2, and a land 3 is formed at the center of the upper surface of the conversion board 1, and this land 3 will be described later. The jig A is configured by directly mounting the lower end portion 4a of the coil spring 4 on the surface to stand.

The arrangement pattern of the lands 3 on the conversion substrate is such that balls are arranged in a grid array and protrude from the lower surface of an object 5 to be inspected such as a semiconductor package positioned above the jig A at the time of inspection. It has the same pattern as the electrode 5a. Therefore, these lands 3
The arrangement pattern of the coil springs 4 which are surface-mounted on is also the same as the pattern of the ball electrodes 5a.

In order to conduct a continuity test of the inspection object with the jig A, as shown in FIG. 1, first, the inspection object 5 is positioned and arranged above the jig A, and then the inspection object is inspected. Press 5 down. The ball electrode 5a comes into contact with the upper end 4b of the coil spring 4, and a conduction state between them is realized.
Thereafter, power is supplied using a power supply circuit (not shown), signals from each land 3 are taken out, and the inspection object 5 is inspected for the presence or absence of a fault point.

During the continuity test, the upper end 4b of the coil spring 4
Contacts the ball electrode 5a as shown in FIG.
At this time, since the inner diameter is present at the upper end 4b of the coil spring, the spherical tip of the ball electrode 5a sinks slightly into the inner diameter, and its periphery is wrapped and gripped by the spring coil 4A. State. Thus, the contact state between the ball electrode 5a and the upper end 4b of the coil spring is ensured.

Therefore, the inner diameter of the coil spring 4 is set to be slightly smaller than the diameter of the ball electrode 5a. Considering that the diameter of the ball electrode 5a is usually about 0.3 mm, the inner diameter of the coil spring 4 is 0.2 to 0.25 mm.
It is preferred that it is about. The tip 4B of the spring coil 4A at the upper end 4b of the coil spring is shown in FIG.
As shown by, it is preferable that the projection protrudes obliquely upward toward the inside.

When the ball electrode 5a comes into contact with the upper end 4b and descends further, the tip 4B rubs the surface of the ball electrode 5a, breaking an oxide film on the surface of the ball electrode, for example. This is because a conduction state with the electrode 5a can be reliably achieved. In this case, if the tip 4B protrudes inward too much, the above-described sinking of the ball electrode 5a at the upper end 4b of the coil spring is impeded, and there is difficulty in securing a contact state between the two. For this reason, it is preferable that the tip 4B protrudes about 10% of the inside diameter of the coil spring 4 and protrudes about 50 μm in the longitudinal direction of the coil spring 4.

It is preferable that the axis of the coil spring 4 coincides with the axis of the ball electrode 5a during the conductivity test. However, even if the axis is slightly deviated, the jig A of the present invention may be used. In, the contact state between the coil spring 4 and the ball electrode 5a can be ensured. Even if the ball electrode 5a comes into contact with the upper end 4b of the coil spring 4 and moves down in a state where the axes of the two are shifted, the coil spring 4 retains the ball electrode 5a at its inner diameter.
This is because the ball electrode 5a is kept in contact with the front end of the spherical surface, and the ball electrode 5a is continuously corrected by correcting the deviation between the axes with its own spring resilient force.

The coil spring 4 having such a function can be designed in various shapes in consideration of the shape of the ball electrode 5a of the object to be inspected, inspection conditions, and the like. It is made of 04mm Au plated steel wire, 0.32mm in outer diameter, 0.24mm in inner diameter, and 3.2mm in free length.
Stroke length 1.3mm, spring constant 20-30g / mm
You can give something like

The coil spring 4 is provided on the surface 1 of the conversion board 1.
The lower end 4a is bonded and fixed to the land 3 wired to a using a conductive adhesive. FIG. 4 is a schematic view showing a modification A1 of the first jig A. In the jig A <b> 1, an insulating substrate 6 in which a through hole 6 a having a diameter larger than the outer diameter of the coil spring 4 is formed in the same pattern as the arrangement pattern of the coil spring 4 is disposed on the conversion substrate 1.
The coil spring 4 is inserted into each through-hole 6a, and the insulating substrate 6 is disposed on the conversion substrate 2 via another spring means 7a so as to be vertically movable.

In the case of the jig A1, the vicinity of the upper end of the coil spring 4 is held in the through hole 6a of the insulating substrate 6 so as to be movable up and down.
When the coil spring 4 comes down in contact with the upper end of the coil spring 4, the coil spring 4 is held in the through hole 6a while securing the ball electrode 5a, and reliably contracts in the vertical direction together with the insulating substrate 6. It is preferable because it can be performed.

In the case of this jig A1, as shown in FIG. 5, the coil spring 4 is inserted into the through hole 6a formed in the insulating substrate 6 and its lower end 4a is landed on the conversion substrate 1. The surface mounting of the coil spring 4 can be realized only by placing the coil spring 4 on the coil 3 without using the conductive adhesive. Even if the coil spring 4 is not fixed to the land 3 with a conductive adhesive, the vicinity of the upper end of the coil spring 4 is close to the through hole 6 a of the insulating substrate 6.
It is because it becomes the state held in. The jig A1 also has the advantage that when the coil spring 4 becomes fatigued, it can be replaced with a new coil spring.

FIG. 6 is a partial sectional view showing a second jig B of the present invention. In the case of this jig B, the insulating substrate 8 is fixedly arranged on the conversion substrate 1 by, for example, bolting. In the insulating substrate 8, a through hole 8a is formed at a position corresponding to the land 3 of the conversion substrate 1, and a through hole 8a is formed therein.
A spring terminal 9 described later is fixedly arranged.

A large through-hole 8b is formed at the end of the insulating substrate 8, and the second insulating substrate 10 is arranged here in a state capable of moving up and down with respect to the conversion substrate 1 via, for example, a spring means 7b. Have been. The second insulating substrate 10 includes
A through-hole 10a having a diameter larger than the diameter of the spring terminal is formed at a position corresponding to the spring terminal 9, and the upper portion of the spring terminal 9 is inserted there.

As shown in FIG. 7, the spring terminal 9 has a cylindrical socket 11 having a substantially central portion in the longitudinal direction and a spring formed by stretching the substantially central portion in the longitudinal direction. The coil spring 4 is separated into a coil spring portion 4C on the upper end side and a coil spring portion 4D on the lower end side via the coil 4A. The upper portion of the coil spring portion 4C projects upwardly from the cylindrical socket 11 by a desired length to be able to expand and contract and comes into contact with the ball electrode 5a, and the lower portion of the coil spring portion 4D also has a lower portion. Projecting downward by a desired length from the land 3 and is in surface contact with the land 3 in a stretchable state.

In this jig B, spring terminals 9 having a structure in which the coil spring 4 and the cylindrical socket 11 are integrated are fixed collectively in the through hole 8 a of the insulating substrate 8 in the same pattern as the pattern of the land 3. When the insulating substrate 8 is fixedly arranged on the conversion substrate 1, all the spring terminals 9 have the coil spring portions 4 </ b> D at the lower ends thereof surface-mounted on the lands 3, and the jigs A and This is preferable in that the operation of arranging and mounting the coil springs one by one on the land as in the case of the jig A1 can be omitted.

FIG. 8 is a partial sectional view showing a third jig C of the present invention. The jig C has a structure in which an insulating substrate 12 is fixedly arranged on the conversion substrate 1, and a coil spring 14 described later is disposed in a stepped through hole 13 described later formed in the insulating substrate 12. It has become. Insulating substrate 1
2 is fixed to the conversion board 1 at its peripheral end using, for example, bolts 14, and a portion excluding the peripheral end, in other words, a surface portion facing the land 3 is slightly recessed as a whole,
The following through holes 13 are formed at locations corresponding to the lands.

That is, a small-diameter hole 13a is formed on the inspection object side (the upper part in the figure), a large-diameter hole 13b is formed on the conversion substrate side (the lower part in the figure), and the boundary between the holes 13a and 13b is stepped. The stepped through hole 13 is a portion 13c. A coil spring having a shape shown in FIG. 9 and a coil spring having a shape shown in FIG. 10 are arranged in the stepped through-hole 13.

In each of these coil springs 4, the tip 4B of the coil spring at the upper end portion 4b is projected straight upward in the longitudinal direction of the coil spring. FIG. 9 shows a coil spring whose tip 4B is formed by bending and extending a spring coil as it is from its outer peripheral position. FIG. 10 shows that the spring coil is once bent to the axial center position of the coil spring, and then bent and extended therefrom. Indicates a coil spring having a tip 4B.

The small hole 13a of the stepped through hole 13
Is slightly larger than the tip 4B of the coil spring described above, and the hole diameter of the large hole 13b is slightly larger than the entire outer diameter of the coil spring 4. In addition, large hole 1
The depth of the 3b are shallower than the length L ₁ of the main body of the coil spring 4, further length of smaller-diameter 13a is shorter than the length L ₂ of the front end 4B of the coil spring 4.

Therefore, when the coil spring 4 is disposed in the stepped through-hole 13 and the insulating substrate 12 is fixedly disposed on the conversion substrate 1, the length L ₁ of the main body of the coil spring 4 is reduced by the concave length of the insulating substrate 12. By making the distance longer than the sum of the distance (D) between the submerged surface and the land surface of the conversion board 1 and the depth of the large hole 13b, the coil spring 4 is pressed against the land 3 by the difference in spring force and electrically connected. As shown in FIG. 8, the lower end 4a of the coil spring 4 is
3, the upper end 4b is in contact with the step 13c of the stepped through hole, and the tip 4B
Project upward from the small hole 13a and come into contact with the ball electrode 5a of the inspection object 5.

[0037] and this time, the length L ₁ of the main body of the coil spring 4, the length L ₂ of the front end 4B, the depth of the large hole 13b of the insulating substrate 12, and the insulating recessing surface and the land surface of the converter board substrate By appropriately selecting the interval D, the tip 4B of the coil spring can be pressed against the ball electrode 5a with an appropriate spring force. FIG. 11 is a partial sectional view showing a modification of the conversion board in the jig of the present invention.

The conversion board 1 of this jig includes an insulating substrate 1b having a small diameter through-hole 15 formed at a position corresponding to the above-mentioned land, an enamel signal line 1c inserted into these through-holes 15, and , These enamel signal lines 1c
Is connected to the connector 1d. The connector 1d is connected to a tester (not shown), and each enamel signal line 1c is connected to an insulating substrate 1b.
Is adhered and fixed by an adhesive 16 on the lower surface of the.

Here, the upper end face of each enamel signal line 1c inserted into the through hole 15 is flush with the surface of the insulating substrate 1b. Therefore, the stepped through hole 13
When the insulating substrate 12 is fixed to the insulating substrate 1b by bolting in a state where the coil spring 4 is
Is electrically connected to the exposed end surface of the enamel signal line 1c by spring force.

By using the jig shown in FIG. 11, it is possible to manufacture a jig in which the tip 4B of the coil spring 4 projects from the upper surface and the lower surface as shown in FIG. In the case of this jig, the upper coil spring 4 is
, And the lower coil spring 4 can be used, for example, mounted on the motherboard 17.

[0041]

As is apparent from the above description, the continuity inspection jig of the present invention does not require manual soldering as in the conventional spring probe method at the time of assembling. Can be fully adapted to fine pitch. Also, since the coil spring is the probe itself, it is inexpensive compared to the spring probe, and in the case of jig A or jig B, the contact state with the ball electrode at the inner diameter of the upper end of the coil spring is ensured. The contact state can be ensured by the self-correction function of the spring even if the shaft is held and there is some deviation of the shaft center, and the reliability of the inspection result is improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a basic configuration of a jig A of the present invention.

FIG. 2 is a perspective view showing a coil spring surface-mounted on a land.

FIG. 3 is a plan view showing an upper end portion of a coil spring.

FIG. 4 is a schematic view showing a modified jig A1 of the present invention.

FIG. 5 is a partial sectional view of a jig A1.

FIG. 6 is a partial sectional view showing a basic configuration of a jig B of the present invention.

FIG. 7 is a cross-sectional view for explaining a spring terminal of a jig B.

FIG. 8 is a partial sectional view showing a basic configuration of a jig C of the present invention.

FIG. 9 is a perspective view showing a coil spring used for a jig C.

FIG. 10 is a perspective view showing another coil spring used for the jig C.

FIG. 11 is a partial cross-sectional view showing a jig of the present invention using a modification of the conversion board.

FIG. 12 is a sectional view showing another jig using the jig of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conversion board 1a Surface of conversion board 1 1b Insulating board 1c Enamel signal line 1d Connector 2 Fixing base 3 Land 4 Coil spring 4a Lower end of coil spring 4b Upper end of coil spring 4A Spring coil 4B Tip of spring coil 4A 4C Upper end Side coil spring portion 4D lower end side coil spring portion 5 inspection object 5a ball electrode 6 insulating plate 6a through hole 7a, 7b spring means 8 insulating substrate 8a, 8b through hole of insulating substrate 8 9 spring terminal 10 insulating substrate 10a Through hole of insulating substrate 10 11 Cylindrical socket 12 Insulating substrate 13 Stepped through hole 13a Small diameter hole 13b Large diameter hole 13c Stepped portion 14 Bolt 15 Through hole 16 Adhesive 17 Motherboard

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Claims (9)

[Claims] 1. A conversion board having a land formed on a surface thereof; and a coil spring contacting a ball electrode of an object to be inspected at a lower end portion which is directly surface-mounted on the land and an upper end portion thereof. Characteristic jig for continuity inspection. 2. A continuity inspection jig according to claim 1, wherein a lower end portion of said coil spring is fixed to said land with a conductive adhesive. 3. An insulating substrate having a through hole having a hole diameter larger than the outer diameter of the coil spring is formed on the conversion substrate, and the insulating substrate is vertically moved with the coil spring inserted through the through hole. 2. The continuity inspection jig according to claim 1, which is movably arranged. 4. A conversion substrate having a land formed on a surface thereof; an insulating substrate fixedly disposed on the conversion substrate and having a through hole formed at a position facing the land; A spring terminal fixedly disposed therein, a lower end contacting the land, and an upper end fixedly disposed in a cylindrical socket with a coil spring in contact with a ball electrode of the object to be inspected. A continuity inspection jig characterized by the above-mentioned. 5. A second insulating substrate having a through hole having a hole diameter larger than an outer diameter of the coil spring formed on the insulating substrate, wherein the coil spring is inserted through the through hole. 5. The device is arranged so as to be able to move up and down in a state.
Jig for continuity inspection. 6. The coil terminal according to claim 6, wherein said spring terminal has a substantially central portion in the longitudinal direction extended in a cylindrical socket having a substantially central portion in the longitudinal direction and a coil spring portion on the upper end portion side. The continuity inspection jig according to claim 4, wherein a coil spring divided into a coil spring portion and a coil spring portion on a lower end portion side is fixedly arranged. 7. The continuity inspection jig according to claim 1, wherein a tip end of the spring coil at an upper end portion of the coil spring projects obliquely upward toward the inside of the coil spring. 8. A conversion substrate having a land formed on its surface; a stepped through-hole formed of a small-diameter hole and a large-diameter hole is fixedly disposed on the conversion substrate and opposed to the land. An insulating substrate that is provided; and is disposed in the stepped through hole, and a lower end portion contacts the land,
And a coil spring protruding from the small-diameter hole at an upper end portion. 9. The continuity inspection jig according to claim 8, wherein said coil spring has a tip of a spring coil at an upper end portion thereof elongated in a longitudinal direction of said coil spring.