JPH06303000A - Printed wiring board and mounted component inspecting method using it - Google Patents

Abstract

PURPOSE:To improve the productivity of a printed wiring board by constituting the printed wiring board so that the inspection of mounted components can be performed easily. CONSTITUTION:The connection electrodes of the board 4 for surface mounting is divided into circuit connecting electrodes 41 which are connected to a circuit on the board 4 through wiring conductors 41a and have inspection terminals 41b which are expanded in width in the middle of the wiring conductors on the outside of an electronic device mounting area and one or more electrodes 42 for discriminability of mounted components which are isolated and independent from the electrodes 41, have inspection terminals 42b expanded in blank areas between each wiring conductor on the outside of the electronic mounting area, and are connected to a wiring conductor 42a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a printed wiring board for mounting various electronic devices such as face-down bonding type IC chips as mounting components and a method of inspecting these various mounting components using the same, and particularly to mounting components. The present invention relates to a printed wiring board which facilitates the inspection of the printed circuit board to improve productivity and a mounting component inspection method using the same.

[0002]

2. Description of the Related Art FIG. 5 is a diagram for explaining a conventional printed wiring board configuration example together with a mounting component inspection method. (5-1) shows before mounting and (5-2) shows a mounting method after mounting. Shows.

In the figure, the case where the electronic device as a mounting component is an IC chip is taken as an example. Only the main part of the printed wiring board according to the present invention is extracted and enlarged ((5
-1), a plurality of bump electrodes 1a connected to a circuit pattern (not shown) of the chip 1 are formed in the vicinity of the periphery of one surface (lower surface in the figure) of the face-down bonding type IC chip 1 to be mounted. Has been done.

On the other hand, on one surface (upper surface in the figure) of the printed wiring board 2 on which the IC chip 1 is mounted, a plurality of the bump electrodes 1a are provided.
Wiring conductors connected to circuits (not shown) at positions corresponding to
The connection electrode 21 to 21a is patterned.

On the outside of the IC chip mounting area shown by the chain line A of each wiring conductor 21a, a widened inspection terminal 21b for contacting an inspection probe described later is formed.

Therefore, after the IC chip 1 as a mounting component is positioned and mounted as shown by an arrow B on the printed wiring board 2 on which each of the connection electrodes 21 is coated with solder paste, for example, by a normal reflow technique or the like. The IC chip 1 can be mounted on the printed wiring board 2 by soldering the two.

An example of the method of inspecting the mounted IC chip 1 is shown in (5-2), and 31a and 32b represent two probe pins connected to an inspecting device (not shown). Therefore, for example, while keeping the probe pin 31a on one side in contact with the inspection terminal 21b- ₁ of the wiring conductor connected to the connection electrode connected to the bump electrode on the input side of the IC chip 1, the other probe pin 31b is connected to the IC chip 1 of the IC chip 1. The output characteristics of the IC chip 1 can be inspected by bringing the connection electrode connected to the output bump electrode into contact with the inspection terminal 21b _-2 .

Further, while the probe pin 31a on one side is fixed, the probe pin 31b on the other side is moved to connect to another output-side bump electrode, the inspection terminals 21b- ₃ , 21b- ₃ , 2
All output characteristics related to the input side bump electrodes of the IC chip 1 can be efficiently inspected by sequentially making contact with 1b- ₄ and so on.

A measuring head composed of a plurality of probe pins having probe pins at respective positions corresponding to the respective inspection terminals of the printed wiring board 2 is positioned and lowered, and each probe pin and each of the printed wiring board 2 are placed. The characteristics of the IC chip 1 can also be inspected by bringing it into contact with the inspection terminal 21b.

[0010]

However, in the printed wiring board 2 and the IC chip inspection method using the printed wiring board 2 as described above, the measured value obtained includes the above-mentioned connection resistance between the bump electrode and the connection electrode.

This is because, for example, when a defect or variation is found in the measured characteristic value, it is caused by a defect as an IC chip. In other words, the above-mentioned defective solder connection between the bump electrode and the connection electrode is expressed. For example, it means that it is difficult to identify if it is due to mounting failure.

On the other hand, if the solder connection between the bump electrode and the connection electrode is incomplete, even an IC chip having a good measured value may become defective with time in the initial stage. In this case, the connection resistance value in the solder connection area at the time of mounting generally tends to be larger than the connection resistance value when completely connected, but the change in the connection resistance value is the above-mentioned printed wiring board. No. 2 and the IC chip inspection method using the same cannot detect.

Therefore, there has been a problem that analysis of a defect found at the time of inspection and a countermeasure against the defect are often delayed or wasteful man-hours are often spent, so that improvement in productivity cannot be expected as a result.

[0014]

The above problem is a printed wiring board for mounting a face-down bonding type electronic device, and the bump electrodes are provided at respective positions corresponding to the bump electrodes of the electronic device to be mounted. And a connection electrode formed to have a size substantially the same as that of the present invention, which is connected to a circuit on the printed wiring board by a wiring conductor and has a widened inspection terminal in the middle of the wiring conductor outside the electronic device mounting area. One connected to a wiring conductor formed by including a circuit connection electrode and an inspection terminal which is independent from the circuit connection electrode while maintaining insulation, and which is widened in the space area between the wiring conductors outside the electronic device mounting area, or This is solved by a printed wiring board that is divided into a plurality of mounting pass / fail determination electrodes.

A method of inspecting a face-down bonding type electronic device mounted on a printed wiring board, wherein the electronic device to be tested is positioned and mounted at a corresponding position on the printed wiring board by soldering and mounting. Then, the inspection terminal connected to the circuit connection electrode on the printed wiring board connected to the input side bump electrode of the mounted electronic device and the circuit connection electrode on the printed wiring board connected to the output side bump electrode of the electronic device When the characteristic value of the electronic device is inspected between the connected inspection terminals and the obtained characteristic value exceeds a predetermined value or is unstable, the bump electrodes on the input side and / or the output side of the electronic device and An inspection terminal connected to the circuit connection electrode on the printed wiring board to be connected and an inspection terminal connected to the mounting pass / fail judgment electrode corresponding to the circuit connection electrode. In electrical measurements between Terminal, it is solved by the inspection method of mounting components to inspect the quality of implementation for printed wiring board of the electronic device.

[0016]

If the quality of the connection between the bump electrode of the IC chip and the connection electrode of the printed wiring board can be detected separately from the characteristics of the IC chip, the quality of the IC chip and the quality of the mounting can be distinguished and tested.

Therefore, in the present invention, the conventional connection electrode area of the printed wiring board is divided into a circuit connection electrode connected to a circuit and a mounting pass / fail judgment electrode. This means that each bump electrode of the IC chip to be mounted is located in a state of straddling the circuit connecting electrode and the mounting / non-defining electrode, so that, for example, the bump electrode of the IC chip and the circuit connecting electrode of the printed wiring board are It is shown that when completely connected, the bump electrode and the electrode for determining the mounting quality are also completely connected.

Therefore, the circuit connection electrode and the mounting / non-defining electrode are connected via the bump electrode of the IC chip, and as a result, the connection between the bump electrode and each connection electrode (in other words, of the IC chip). If the mounting is complete, the electrical resistance between the circuit connecting electrodes and the mounting pass / fail judgment electrodes including these connection resistances can be made to be on the order of mΩ close to “0”.

On the other hand, if the above-mentioned mounting is incomplete, the connection between the bump electrode of the IC chip and the circuit connecting electrode or between the bump electrode and the mounting pass / fail judgment electrode becomes unstable, resulting in the circuit connecting electrode. And the electrical resistance between the mounting / non-defining electrodes becomes large or fluctuates, for example, to the order of Ω.

Therefore, by checking and comparing the electric resistance value between the bump electrode and the circuit connecting electrode and the electric resistance value between the circuit connecting electrode and the mounting / non-defining electrode, the characteristics as an IC chip and the printed wiring board can be obtained. It is possible to easily inspect whether or not the mounting is good.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining a configuration example of a printed wiring board according to the present invention, FIG. 2 is a diagram for explaining a mounting component inspection method, and FIG. 3 is another configuration example of a printed wiring board. 4 and 5 are diagrams showing a third configuration example of the printed wiring board.

In each of the figures, the case where the electronic device as the mounting component is the IC chip of FIG. 5 is taken as an example, and therefore the same target members and parts as those in FIG. The explanation is omitted.

In FIG. 1 in which only the main part of the printed wiring board according to the present invention is extracted and enlarged in the same manner as in FIG. 5, the IC chip 1 is mounted on one side (upper surface in the figure) of the printed wiring board 4 on which the IC chip 1 is mounted. At each position corresponding to the plurality of bump electrodes 1a, the circuit connecting electrode 41 whose outer shape is the same size as the connecting electrode 21 of FIG. Mounting pass / fail judgment electrode shaped to fit into the recess
Although 42 and 42 are patterned together as shown in the drawing (a) of the extraction circle, the conductor wiring 41a connected to the circuit connecting electrode 41 is shown in FIG.
An inspection terminal 41b which is the same as the inspection terminal 21b of FIG. 5 is provided in the same manner as in FIG. Are patterned.

In this case, each bump electrode 1a of the IC chip 1 described with reference to FIG. 5 includes the circuit connection electrode 41 and the mounting pass / fail judgment electrode 42 corresponding to the circuit connection electrode 41 as shown by the shaded area C in the circled figure (a). Can be made to correspond to the printed wiring board 4.

Therefore, for example, after solder paste is applied to each circuit connection electrode 41 and the mounting / non-defective electrode 42, the IC chip 1 is positioned and mounted as in FIG. 5, and the two are solder-connected by a normal reflow technique or the like. As a result, the IC chip 1 can be mounted on the printed wiring board 4 as in the case of FIG.

A method of inspecting the IC chip 1 will be described below with reference to FIG. In FIG. 2, (2-1) shows the mounting state of the IC chip, and (2-2) is an enlarged view of the vicinity of the connection electrode.

In (2-1) of the figure, the wiring conductor 41a of the circuit connection electrode 41 (not shown) of the printed wiring board 4 and the mounting pass / fail judgment electrode
The wiring conductors 42a of 42 are connected to each other via bump electrodes 1a (not shown) of the IC chip 1 and
The inspection terminals 41b and 42b connected to 41a and 42a are both exposed and located outside the IC chip mounting area.

Therefore, as described with reference to FIG. 5, for example, the probe pin 31a on one side is brought into contact with the inspection terminal 41b- ₁ connected to the circuit connecting electrode 41 of the printed wiring board 4 for connecting to the bump electrode on the input side of the IC chip 1. An inspection terminal 41 connected to the circuit connection electrode 41 of the printed wiring board 4 for connecting the other probe pin 31b to the bump electrode on the output side of the IC chip as it is.
The characteristics of the IC chip 1 can be inspected by bringing it into contact with b _-2 .

In this case, when a defect or instability occurs in the detected measurement value, for example, another probe pin 31c is attached to the inspection terminal 41b _-2 and the mounting pass / fail judgment electrode corresponding to the inspection terminal 41b- _2.
42 examined brought into contact with the terminal 42b _-2 inspection checks the electrical resistance between the terminals 41b _-2 ~ 42b _-2 or said other probe pin 31c for the determination mounting quality corresponding to the test terminals 41b _-1, By checking the electric resistance between the inspection terminals 41b _-1 to 42b _{-1 by} contacting the inspection terminal 42b _-1 of the electrode 42 with each other and checking the corresponding inspection terminals, the above-mentioned defects and instability are detected. It is possible to determine whether the cause is the chip itself or the connection at the time of mounting.

The electrical resistance Rs between the circuit connecting electrode 41 and the mounting / non-defining electrode 42 in this case is shown in an enlarged view (2-2) of the vicinity of the connecting electrode, between corresponding inspection terminals (for example, 4
1b _-2 to 42b _-2 ) can be easily obtained by measuring the electric resistance value.

In the case of FIG. 5, it is possible to determine by positioning and lowering the measuring head composed of a plurality of probe pins having probe pins at respective positions corresponding to the respective inspection terminals of the printed wiring board 4. Is the same as.

However, in the above-mentioned method for measuring the electric resistance Rs, the wiring conductor resistance of the printed wiring board and the electric resistance of the probe pin are included, and the normal contact resistance is several mΩ to several tens mΩ.
On the other hand, since the wiring conductor resistance is several tens Ω to several hundreds Ω, almost all of the measured values become the wiring conductor resistance. Therefore, it is difficult to obtain an accurate electric resistance Rs.

FIG. 3 shows another configuration example of a printed wiring board for solving such a weak point. That is, as shown in Fig. 2 (3-1) and its equivalent circuit diagram (3-2) in which the vicinity of the connection electrode is extracted and enlarged as in Fig. 2, the areas corresponding to the bump electrodes 1a on one side of the printed wiring board 5 are shown. Is a wiring conductor 51 having inspection terminals 51a to 53a, each of which is widened at one end thereof.
.About.53 are arranged in parallel while maintaining insulation, and only the wiring conductor 52 located in the middle is protruded from the electrode region to the outside in a U-shape, and three wiring conductors 51 are provided with inspection terminals 54a at their tips. The external connection electrodes consisting of ~ 53 are formed by patterning.

The alternate long and short dash line A shows the IC chip mounting area as in FIG. 1, and the hatched area C shows the bump electrode area as in FIG. Therefore, the conductor resistance from the inspection terminal 51a of the wiring conductor 51 to the bump electrode area C is R
h ₁ , the conductor resistance from the inspection terminal 52a of the wiring conductor 52 to the region C is Rh ₂ , the conductor resistance from the inspection terminal 53a of the wiring conductor 53 to the region C is Rh ₃ , and the inspection resistance 54a of the wiring conductor 52 to the region C Up to Rh ₄ and contact resistances between the wiring conductors 51 to 53 and the bump electrode 1a are Rs ₁ , Rs ₂ and Rs ₃ , respectively, and between the wiring conductors 51 to 52 and 52 to 53. The bump electrode resistances are R _IC1 , R _IC2 ,
Further, the constant current value flowing between the inspection terminals 51a to 52a is I,
Assuming that the potential difference generated between the Plurob pins that are brought into contact with the inspection terminals 53a and 54a is V, the potential difference V becomes equal to the potential difference applied to both ends of the contact resistance Rs ₂ , so that the required electrical resistance Rs ₂ is Rs ₂ . It can be easily calculated as ₂ = V / I.

Therefore, the required electric resistance can be accurately detected without being affected by the resistance value of the wiring conductor.
It is possible to reliably inspect the characteristics of the C chip and the quality of mounting on the printed wiring board.

Similarly to FIG. 3, a diagram (4-1) in which the vicinity of the connection electrodes is extracted and enlarged and its equivalent circuit diagram (4-2) are shown. Each electrode corresponding to each bump electrode 1a of the printed wiring board 6 is shown in FIG. In the area, the inspection terminals 61a _-1 , 61a _-2 widened at both ends
Connection electrodes are formed by patterning U-shaped wiring conductors 61, 62 having 62a _-1 , 62a _-2 in parallel while maintaining insulation so that two sides on one side face each other in the bump electrode region. .

An alternate long and short dash line A indicates an IC chip similar to that shown in FIG.
The mounting area and the shaded area C indicates the bump electrode area.
Is. Therefore, the inspection terminal 61a of the wiring conductor 61_-1Or
Conductor resistance from bump electrode area C to Rh₁, The wiring conductor 61
Inspection terminal 61a_-2To the area C to R
h₂, Wiring conductor 62 inspection terminal 62a_-1To area C
Conductor resistance at Rh₃, Inspection terminal 6 of the wiring conductor 62
2a_-2To the area C to Rh_FourAnd each wiring guide
The contact resistance between the bump electrodes 1a of the bodies 61 and 62 is measured respectively.
Rs₁, Rs₂, And bump electrode resistance between wiring conductors 61-62
R_{I c}, Further inspection terminal 61a_-1~ 62a _-2Constant
Current value is I, inspection terminal 61a_-1And 62a_-2Abut
Let V be the potential difference generated between the squeezing pins.
And the potential difference V is "the sum of the above contact resistance values and electrode resistances.
X current value "or" (Rs₁+ Rs₂+ R_{I c}) × I ”and so on
I'll get better.

Therefore, after measuring the R _IC in advance, the contact resistance values Rs ₁ and Rs ₂ are the required electric resistance values R _S.
Then, the required electric resistance value R _S can be easily obtained from R _S = {(V / I) −R _IC } / 2.

Therefore, the required electric resistance value can be accurately detected without being affected by the resistance value of the wiring conductor, and the characteristics of the IC chip and the quality of mounting on the printed wiring board can be surely inspected. be able to.

Note that such a printed wiring board has an advantage that the number of connections to the bump electrode area of the IC chip can be reduced as compared with the case of FIG.

[0041]

As described above, according to the present invention, it is possible to provide a printed wiring board which facilitates the inspection of mounted components and improves productivity, and a mounting component inspection method using the same.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration example of a printed wiring board according to the present invention.

FIG. 2 is a diagram illustrating a method for inspecting mounted components.

FIG. 3 is a diagram showing another configuration example of a printed wiring board.

FIG. 4 is a diagram showing a third configuration example of a printed wiring board.

FIG. 5 is a diagram illustrating a configuration example of a conventional printed wiring board together with a mounted component inspection method.

[Explanation of symbols]

1 IC chip (mounting component, electronic device) 4,5,6 Printed wiring board 31a, 31b, 31c Probe pin 41 Circuit connection electrode 41a, 42a, 51,52,53,61,62 Wiring conductor 41b, 41b _-1 , 41b _-2 , 41b _-3 , ~ Inspection terminal 42b, 42b _-1 , 42b _-2 , 42b _-3 , ~ Inspection terminal 42 Mounting pass / fail judgment electrode 51a, 52a, 53a, 54a, 61a _-1 , 61a _-2 , 62a _-1 ,, 61a _-2 Inspection terminal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Maruyama 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Hiroaki Kobayashi 1015, Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (2)

[Claims] 1. A printed wiring board for mounting a face-down bonding type electronic device, which is formed at substantially the same size as each bump electrode at each position corresponding to each bump electrode of the electronic device to be mounted. The connecting electrode connected to the circuit on the printed wiring board (4) by the wiring conductor (41a) and formed with the widened inspection terminal (41b) in the middle of the wiring conductor outside the electronic device mounting area. A circuit connection electrode (41) and an inspection terminal (42b) which is independent from the circuit connection electrode (41) while maintaining insulation and is widened in the margin area between the wiring conductors outside the electronic device mounting area. A printed wiring board, characterized in that it is divided into one or a plurality of mounting quality determination electrodes (42) connected to the formed wiring conductor (42a). 2. A method for inspecting a face-down bonding type electronic device mounted on a printed wiring board, wherein the electronic device to be tested (1) is placed at a corresponding position on the printed wiring board (4) according to claim 1. After mounting by positioning and soldering and mounting, the inspection terminal (41b _-1 ) connected to the circuit connection electrode (41) on the printed wiring board that is connected to the bump electrode on the input side of the mounted electronic device (1) and the The characteristics of the electronic device (1) were inspected between the inspection terminals (41b _-2 ) connected to the circuit connection electrodes (41) on the printed wiring board that are connected to the output side bump electrodes of the electronic device (1) and obtained. When the characteristic value exceeds a predetermined value or is unstable, the circuit connection electrodes (41) on the printed wiring board connected to the bump electrodes on the input side and / or the output side of the electronic device (1) are connected. Connected to the inspection terminal and the circuit connection electrode (41) The electronic device is electrically measured between the inspection terminals connected to the corresponding mounting / non-defining electrode (42).
A method for inspecting a mounted component, which comprises inspecting the quality of mounting on the printed wiring board (4) according to (1).