System for testing photon counting detector package performance

Abstract

The application discloses a system for testing packaging effect of a photon counting detector. The photon counting detector comprises a photon detection element, an adapter plate and a photon counting integrated circuit board. A first connecting circuit is arranged on the photon detection element and connected with a pad on the photon detection element, and a second connecting circuit is arranged on the photon counting integrated circuit board and connected with a pad on the photon counting integrated circuit board. The first connecting circuit is connected with a pad on a first surface of the adapter plate, the second connecting circuit is connected with a pad on a second surface of the adapter plate, the pad on the first surface of the adapter plate is electrically connected with the pad on the second surface, and the first connecting circuit, the second connecting circuit and the pads of the adapter plate connecting the first connecting circuit and the second connecting circuit form an electrical connection path. A test unit is connected with the electrical connection path, used for detecting an electrical signal of the electrical connection path, judging a bonding state of the pads in the electrical connection path according to the electrical signal, and thus obtaining a process quality of the photon counting detector.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and in particular to a system for testing the packaging effect of a photon counting detector. Background Technology

[0002] A photon counting detector is a device for detecting extremely weak light pulses based on the direct detection quantum limit theory. It consists of a photon detection element and an integrated circuit board, with the photon detection element connected to the integrated circuit board via an adapter board. The photon detection elements mainly include silicon (Si), gallium arsenide (GaAs), cadmium telluride (CdTe), and cadmium zinc telluride (CdZnTe).

[0003] During packaging, photon counting detectors undergo a bonding process, where photon detection elements are soldered onto an integrated circuit board. Current technology lacks methods to assess the bonding effectiveness—specifically, whether the electrical connections between the photon detection elements (such as the CZT crystal), the adapter board, and the integrated circuit board are correct and the soldering is reliable. Only simple, visual observation methods are used for a cursory judgment, leading to subsequent processes proceeding with unknown bonding quality. For photon counting detectors with poor bonding, the issue can only be determined during finished product inspection, at which point the product must be completely scrapped, resulting in wasted components and increased manufacturing costs. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, a first aspect of this invention proposes a system for testing the packaging effect of a photon counting detector. This system employs a special link design, which allows for convenient testing of interconnection effects after the manufacturing process is completed, greatly reducing the cost of monitoring quality and minimizing device waste.

[0005] To achieve the above objectives, a system for testing the packaging effect of a photon counting detector according to a first aspect of the present invention is provided. The photon counting detector includes a photon detection element, an adapter board, and a photon counting integrated circuit board. The system includes: a first connection line disposed on the photon detection element and connected to pads on the photon detection element; a second connection line disposed on the photon counting integrated circuit board and connected to pads on the photon counting integrated circuit board; the first connection line is connected to pads on a first side of the adapter board, and the second connection line is connected to pads on a second side of the adapter board; the pads on the first side of the adapter board and the pads on the second side of the adapter board are electrically connected; the first connection line, the second connection line, and the pads on the adapter board connecting the first connection line and the second connection line form an electrical connection path; and a testing unit connected to the electrical connection path, used to detect electrical signals in the electrical connection path and determine the bonding state of the pads in the electrical connection path based on the electrical signals.

[0006] According to an embodiment of the present invention, a system for testing the packaging effect of a photon counting detector connects the pads of the first and second connecting lines via a first connecting line, a second connecting line, and an adapter board, thereby forming an electrical connection path between the photon detection element, the adapter board, and the photon counting integrated circuit board. The testing unit connects to the electrical connection path and detects the electrical signals in the electrical connection path to determine the bonding state of the pads in the electrical connection path, confirming whether the bonding effect meets the standard. As a result, products with substandard bonding effects are no longer subjected to subsequent processes, thereby reducing device waste and lowering product manufacturing costs.

[0007] In some embodiments, the photon detection element is provided with a first pad arranged in an M×N array, wherein M≥1 and N≥1; some or all of the first pads in the M×N array are connected according to a first connection rule to form the first connection line.

[0008] In some embodiments, in the M×N array, the first pads in odd-numbered columns are connected to the first pads in adjacent even-numbered columns to form the first connection lines.

[0009] In some embodiments, a second pad arranged in a P×Q array is provided on the first surface of the adapter board, wherein P≥1, Q≥1; the first pad in the first connection line is connected to the corresponding second pad on the adapter board.

[0010] In some embodiments, a third pad arranged in a P×Q array is provided on the second surface of the adapter board, and the third pad is electrically connected to the second pad through the adapter board.

[0011] In some embodiments, the photon counting integrated circuit board is provided with a fourth pad arranged in a J×K array, wherein J≥1, K≥1; some or all of the fourth pads in the J×K array are connected according to a second connection rule to form a second connection line, and the fourth pad in the second connection line is connected to the corresponding third pad on the adapter board, wherein the second connection rule matches the first connection rule so that the first connection line, the second connection line, and the pads of the adapter board connecting the first connection line and the second connection line form an electrical connection path.

[0012] In some embodiments, in the J×K array, the fourth pad in the k-th column is connected to the fourth pad in the (k+1)-th column, where k is an even number. <K。

[0013] In some embodiments, M = P = J, N = Q = K.

[0014] In some embodiments, the test unit includes: a first connection portion disposed on a first surface of the adapter board, the first connection portion being connected to a second pad on the adapter board that connects to the beginning end of the electrical connection path; a second connection portion disposed on the first surface of the adapter board, the second connection portion being connected to a second pad on the adapter board that connects to the end end of the electrical connection path; and a test piece connected to the first connection portion and the second connection portion, used to obtain the resistance value of the electrical connection path, and to determine that there is an abnormality in the pads of the electrical connection path when the resistance value is infinite.

[0015] In some embodiments, the first connection portion includes a plurality of first test pads, the plurality of first test pads being arranged in the column direction of the P×Q array, and the first test pads being connected to the second pads of the first column of the P×Q array; the second connection portion includes a plurality of second test pads, the plurality of second test pads being arranged in the column direction of the P×Q array, and the second test pads being connected to the second pads of the last column of the P×Q array.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a block diagram of a photon counting detector according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the pad connections of a photon detection element according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the pads on the first side of an adapter board according to an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the pads on the second side of an adapter board according to an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the pad connections on a photon counting integrated circuit board according to an embodiment of the present invention;

[0023] Figure 6 This is a block diagram of a test unit according to an embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the test pad distribution according to an embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram of a link for testing the bonding effect according to an embodiment of the present invention.

[0026] Figure label:

[0027] Photon counting detector 100;

[0028] 1. Photon detection element; 2. Adapter board; 3. Photon counting integrated circuit board; 4. Test unit; 5. Silver paste; 6. Through-hole copper; 7. Solder paste;

[0029] First pad 11; First connection line 12; Second pad 21; Third pad 22; Fourth pad 31; Second connection line 32;

[0030] First connecting part 41; Second connecting part 42; Test piece 43;

[0031] First test pad 411; second test pad 421. Detailed Implementation

[0032] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0033] The following is for reference. Figures 1-8 A system for testing the packaging effect of a photon counting detector according to an embodiment of the present invention is described.

[0034] Figure 1 This is a block diagram of a photon counting detector according to an embodiment of the present invention, as shown below. Figure 1As shown, the photon counting detector 100 includes a photon detection element 1, an adapter board 2, and a photon counting integrated circuit board 3.

[0035] In this embodiment of the invention, the photon detection element 1 can be a CZT (Cadmium Zinc Telluride) crystal. Cadmium Zinc Telluride crystals can detect infrared radiation, X-rays, gamma rays, other high-energy rays, and nuclear radiation. At room temperature, cadmium zinc telluride crystals can convert X-ray photons and gamma-ray photons into electrons, enabling the manufacture of room-temperature X-ray detectors and gamma-ray detectors. These can be used in the manufacture of medical imaging equipment, producing clearer images and significantly reducing radiation.

[0036] In this embodiment, the adapter board 2 can be a PCB (Printed Circuit Board), an FPC (Flexible Printed Circuit), or other types of circuit boards. This embodiment does not limit the material of the adapter board 2.

[0037] The photon detection element 1, the photon counting integrated circuit board 3, and the adapter board 2 have multiple densely distributed pads. The shape of the pads can be circular, triangular, quadrilateral, pentagonal, or any other polygon. During packaging, these pads can be used to connect the photon detection element 1 to the adapter board 2 and the photon counting integrated circuit board 3.

[0038] Current technology lacks testing measures for bonding effectiveness—specifically, whether the electrical connections between the CZT crystal, adapter board 2, and integrated circuit board are correct and whether the soldering is reliable. Only simple visual observation methods are used for preliminary judgment, leading to subsequent processes proceeding with unknown bonding performance. For photon counting detectors 100 with poor bonding, the issue can only be determined during finished product inspection, at which point the product must be completely scrapped, resulting in device waste and increased manufacturing costs. Therefore, reliable testing of the bonding effectiveness is necessary before packaging to reduce device waste and lower manufacturing costs.

[0039] To address the above issues, the system for testing the packaging effect of the photon counting detector 100 in this embodiment of the invention designs an electrical connection path based on the pads on the photon detection element 1, the adapter board 2, and the photon counting integrated circuit board 3. Before packaging, the bonding effect between the photon detection element 1, the adapter board 2, and the photon counting integrated circuit board 3 can be determined by testing the electrical signals in the electrical connection path.

[0040] Specifically, in the system for testing the packaging effect of the photon counting detector 100 according to an embodiment of the present invention, the first connection line 12 is disposed on the photon detection element 1 and connected to the pads on the photon detection element 1. The second connection line 32 is disposed on the photon counting integrated circuit board 3 and connected to the pads on the photon counting integrated circuit board 3. The first connection line 12 is connected to the pads on the first side of the adapter board 2, and the second connection line 32 is connected to the pads on the second side of the adapter board 2. The pads on the first side of the adapter board 2 and the pads on the second side of the adapter board 2 are electrically connected. The first connection line 12, the second connection line 32, and the pads on the adapter board 2 connecting the first connection line 12 and the second connection line 32 form an electrical connection path. The test unit 4 is connected to the electrical connection path and is used to detect the electrical signal of the electrical connection path and determine the bonding state of the pads in the electrical connection path based on the electrical signal. This means that by analyzing the impedance value, it is possible to determine whether the bonding effect meets the standard, and thus determine the interconnection effect of the electrical connection path. Therefore, the process quality of the photon counting detector 100 can be understood in advance before it is put into operation. Products with substandard bonding effects will not be processed further, thereby reducing device waste and lowering product manufacturing costs.

[0041] In some embodiments, such as Figure 2 As shown, the photon detection element 1 has first pads 11 arranged in an M×N array, where M≥1 and N≥1, for example, M=1 or 3 or 5 or 30 or 50, and N=1 or 3 or 5 or 30 or 50. Some or all of the first pads 11 in the M×N array are connected according to a first connection rule to form a first connection line 12, which can cover the photon detection element 1.

[0042] In some embodiments, the first pads 11 in the M×N array are connected in odd-numbered columns to adjacent even-numbered columns to form first connection lines 12. Specifically, the first pads 11 in odd-numbered columns are vertically connected into multiple columns by metal lines, and the first pads 11 in even-numbered columns are horizontally connected into multiple rows by metal lines; or the pads in even-numbered columns are vertically connected into multiple columns by metal lines, and the pads in odd-numbered columns are horizontally connected into multiple rows by metal lines.

[0043] In some embodiments, Figure 3 This is a schematic diagram of the pads on the first side of an adapter board according to an embodiment of the present invention, as shown below. Figure 3As shown, the first surface of the adapter board 2 is provided with second pads 21 arranged in a P×Q array, where P≥1 and Q≥1, for example, P=1, 3, 5, 30, or 50, and Q=1, 3, 5, 30, or 50, etc. The first pad 11 in the first connection line 12 is connected to the corresponding second pad 21 on the adapter board 2. Specifically, the first pad 11 and the second pad 21 are bonded together by bonding wires to electrically connect the first pad 11 and the second pad 21. The bonding can include, but is not limited to, thermo-press bonding, ultrasonic bonding, and thermo-ultrasonic ball bonding. The material of the bonding wires can include, but is not limited to, gold, silver, platinum, copper, aluminum, etc. Furthermore, the first pad 11 is fixed to the patterned metal layer of the photon detection element 1 by conductive materials such as solder paste 7 and silver paste 5, and the second pad 21 is fixed to the patterned metal layer of the adapter board 2 by conductive materials such as solder paste 7 and silver paste 5.

[0044] Figure 4 This is a schematic diagram of the pads on the second side of an adapter board according to an embodiment of the present invention, as shown below. Figure 4 As shown, a third pad 22 arranged in a P×Q array is provided on the second surface of the adapter board 2. The third pad 22 is electrically connected to the second pad 21 through the adapter board 2. The third pad 22 is fixed to the metal layer of the second surface of the adapter board 2 by conductive materials such as solder paste 7 and silver paste 5.

[0045] In some embodiments, Figure 5 This is a schematic diagram of the pad connections on a photon counting integrated circuit board according to an embodiment of the present invention, as shown below. Figure 5 As shown, the photon counting integrated circuit board 3 has a fourth pad 31 arranged in a J×K array, where J≥1 and K≥1. Some or all of the fourth pads 31 in the J×K array are connected according to a second connection rule to form a second connection line 32. The fourth pads 31 in the second connection line 32 are connected to the corresponding third pads 22 on the adapter board 2. The second connection rule matches the first connection rule so that the first connection line 12, the second connection line 32, and the pads of the adapter board 2 connecting the first connection line 12 and the second connection line 32 form an electrical connection path.

[0046] Furthermore, in the J×K array, the fourth pad 31 in the k-th column is connected to the fourth pad 31 in the (k+1)-th column, where k is an even number. <K。

[0047] In the system for testing the packaging effect of the photon counting detector 100 in this embodiment of the invention, for all pads, their row number and column number satisfy a matching correspondence, that is, M=P=J, N=Q=K.

[0048] Figure 6 This is a block diagram of a test unit according to an embodiment of the present invention, such as... Figure 6As shown, the test unit 4 includes a first connection part 41, a second connection part 42, and a test piece 43. The first connection part 41 is disposed on the first surface of the adapter board 2 and is connected to the second pad 21 on the adapter board 2 that connects to the beginning of the electrical connection path. The second connection part 42 is disposed on the first surface of the adapter board 2 and is connected to the second pad 21 on the adapter board 2 that connects to the end of the electrical connection path. The test piece 43 is connected to the first connection part 41 and the second connection part 42 and is used to obtain the resistance value of the electrical connection path. When the resistance value is infinite, it is determined that there is an anomaly in the pad of the electrical connection path, thereby evaluating the interconnection effect between the photon detection element 1, the adapter board 2, and the photon counting integrated circuit board 3.

[0049] Among them, such as Figure 7 As shown, the first connection portion 41 includes a plurality of first test pads 411, which are arranged in the column direction of the P×Q array. The first test pads 411 are connected to the second pads 21 of the first column of the P×Q array. The second connection portion 42 includes a plurality of second test pads 421, which are arranged in the column direction of the P×Q array. The second test pads 421 are connected to the second pads 21 of the last column of the P×Q array.

[0050] Figure 8 This is a schematic diagram of a link for testing bonding effectiveness according to an embodiment of the present invention. Figure 8 As shown, among the multiple first test pads 411 of the first connection part 41 of the adapter board 2, one first test pad 411 is selected as test point A. Among the multiple second test pads 421 of the second connection part 42 of the adapter board 2, one second test pad 421 is selected as test point B. The electrical signal starts from point A, passes through the photon detection element 1, silver paste 5, adapter board 2, copper via 6, solder paste 7, and photon counting integrated circuit board 3 along the line, and then returns to the photon detection element 1 along the next pad of the photon counting integrated circuit board 3. This process is repeated until it reaches the test point B of the second test pad 421 of the second connection part 42 of the adapter board 2. By testing the impedance from point A to point B, the interconnection effect of the link can be known. This allows the process quality of the photon counting detector 100 to be understood in advance before it is installed. Products with substandard bonding effects will not be processed further, thereby reducing device waste and lowering product manufacturing costs.

[0051] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0052] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A system for testing the packaging effect of a photon counting detector, characterized in that, The photon counting detector comprises a photon detection element, an adapter plate and a photon counting integrated circuit board, and the system comprises: a first connecting line arranged on the photon detection element and connected with a pad on the photon detection element; a second connecting line arranged on the photon counting integrated circuit board and connected with a pad on the photon counting integrated circuit board; the first connecting line is connected with a pad on the first surface of the adapter plate, the second connecting line is connected with a pad on the second surface of the adapter plate, the pad on the first surface of the adapter plate is electrically connected with the pad on the second surface of the adapter plate, the first connecting line, the second connecting line and the pad on the adapter plate connecting the first connecting line and the second connecting line form an electrical connection path; a test unit connected with the electrical connection path, used for detecting an electrical signal of the electrical connection path and judging a bonding state of a pad in the electrical connection path according to the electrical signal.

2. The system for testing the packaging effect of the photon counting detector according to claim 1, wherein the photon detection element is provided with first pads arranged in an M×N array, wherein M≥1 and N≥1; part or all of the first pads in the M×N array are connected according to a first connection rule to form the first connecting line.

3. The system for testing the packaging effect of the photon counting detector according to claim 2, wherein the first pads in the M×N array, the first pads in odd columns are connected with the first pads in adjacent even columns to form the first connecting line.

4. The system for testing the packaging effect of the photon counting detector according to claim 3, wherein the first surface of the adapter plate is provided with second pads arranged in a P×Q array, wherein P≥1 and Q≥1; the first pads in the first connecting line are connected with corresponding second pads on the adapter plate.

5. The system for testing the packaging effect of the photon counting detector according to claim 4, wherein the second surface of the adapter plate is provided with third pads arranged in a P×Q array, and the third pads are electrically connected with the second pads through the adapter plate.

6. The system for testing the packaging effect of the photon counting detector according to claim 5, wherein the photon counting integrated circuit board is provided with fourth pads arranged in a J×K array, wherein J≥1 and K≥1; part or all of the fourth pads in the J×K array are connected according to a second connection rule to form the second connecting line, the fourth pads in the second connecting line are connected with corresponding third pads on the adapter plate, and the second connection rule is matched with the first connection rule so that the first connecting line, the second connecting line and the pad on the adapter plate connecting the first connecting line and the second connecting line form an electrical connection path.

7. The system for testing the packaging effect of the photon counting detector according to claim 6, wherein The fourth pads in the J*K array, the fourth pad of the kth column is connected with the fourth pad of the (k+1)th column, wherein k is even, k<K.

8. The system for testing photon counting detector packages of claim 7, wherein, M=P=J, N=Q=K.

9. The system for testing a photon counting detector package effect according to any one of claims 4-8, characterized in that, The test unit comprises: A first connecting part is arranged on the first surface of the adapter plate, and the first connecting part is connected with the second pad of the adapter plate connected with the head end of the electric connection channel; A second connecting part is arranged on the first surface of the adapter plate, and the second connecting part is connected with the second pad of the adapter plate connected with the tail end of the electric connection channel; A test piece is connected with the first connecting part and the second connecting part, and is used for obtaining the resistance value of the electric connection channel, and determining that the pads in the electric connection channel are abnormal when the resistance value is infinite.

10. The system of claim 9, wherein The first connecting part comprises a plurality of first test pads, and the plurality of first test pads are arranged in the column direction of the P*Q array, and the first test pads are connected with the second pads of the first column of the P*Q array.

11. The system of claim 10, wherein The second connecting part comprises a plurality of second test pads, and the plurality of second test pads are arranged in the column direction of the P*Q array, and the second test pads are connected with the second pads of the last column of the P*Q array.

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